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Definitions and methods of measuring and reporting on injurious falls in randomised controlled fall prevention trials: a systematic review.
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PMID:  22510239     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
BACKGROUND: The standardisation of the assessment methodology and case definition represents a major precondition for the comparison of study results and the conduction of meta-analyses. International guidelines provide recommendations for the standardisation of falls methodology; however, injurious falls have not been targeted. The aim of the present article was to review systematically the range of case definitions and methods used to measure and report on injurious falls in randomised controlled trials (RCTs) on fall prevention.
METHODS: An electronic literature search of selected comprehensive databases was performed to identify injurious falls definitions in published trials. Inclusion criteria were: RCTs on falls prevention published in English, study population ≥ 65 years, definition of injurious falls as a study endpoint by using the terms "injuries" and "falls".
RESULTS: The search yielded 2089 articles, 2048 were excluded according to defined inclusion criteria. Forty-one articles were included. The systematic analysis of the methodology applied in RCTs disclosed substantial variations in the definition and methods used to measure and document injurious falls. The limited standardisation hampered comparability of study results. Our results also highlight that studies which used a similar, standardised definition of injurious falls showed comparable outcomes.
CONCLUSIONS: No standard for defining, measuring, and documenting injurious falls could be identified among published RCTs. A standardised injurious falls definition enhances the comparability of study results as demonstrated by a subgroup of RCTs used a similar definition. Recommendations for standardising the methodology are given in the present review.
Authors:
Michael Schwenk; Andreas Lauenroth; Christian Stock; Raquel Rodriguez Moreno; Peter Oster; Gretl McHugh; Chris Todd; Klaus Hauer
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Publication Detail:
Type:  Comparative Study; Journal Article; Research Support, Non-U.S. Gov't; Review     Date:  2012-04-17
Journal Detail:
Title:  BMC medical research methodology     Volume:  12     ISSN:  1471-2288     ISO Abbreviation:  BMC Med Res Methodol     Publication Date:  2012  
Date Detail:
Created Date:  2012-07-04     Completed Date:  2012-10-18     Revised Date:  2013-06-26    
Medline Journal Info:
Nlm Unique ID:  100968545     Medline TA:  BMC Med Res Methodol     Country:  England    
Other Details:
Languages:  eng     Pagination:  50     Citation Subset:  IM    
Affiliation:
Department of Geriatric Research, AGAPLESION Bethanien-Hospital/Geriatric Center at the University of Heidelberg, Rohrbacherstr.149, Heidelberg 69126, Germany. mschwenk@bethanien-heidelberg.de
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MeSH Terms
Descriptor/Qualifier:
Accidental Falls*
Aged
Data Collection / standards*
Documentation / standards*
Endpoint Determination
Europe
Humans
Injury Severity Score
Outcome Assessment (Health Care) / methods*
Randomized Controlled Trials as Topic* / statistics & numerical data
Sample Size
Terminology as Topic
Wounds and Injuries*
Comments/Corrections

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

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Journal ID (nlm-ta): BMC Med Res Methodol
Journal ID (iso-abbrev): BMC Med Res Methodol
ISSN: 1471-2288
Publisher: BioMed Central
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Copyright ©2012 Schwenk et al; licensee BioMed Central Ltd.
open-access:
Received Day: 22 Month: 9 Year: 2011
Accepted Day: 17 Month: 4 Year: 2012
collection publication date: Year: 2012
Electronic publication date: Day: 17 Month: 4 Year: 2012
Volume: 12First Page: 50 Last Page: 50
ID: 3388463
Publisher Id: 1471-2288-12-50
PubMed Id: 22510239
DOI: 10.1186/1471-2288-12-50

Definitions and methods of measuring and reporting on injurious falls in randomised controlled fall prevention trials: a systematic review
Michael Schwenk1 Email: mschwenk@bethanien-heidelberg.de
Andreas Lauenroth2 Email: lauenroth@nar.uni-heidelberg.de
Christian Stock23 Email: c.stock@Dkfz-Heidelberg.de
Raquel Rodriguez Moreno1 Email: raquerm@gmx.de
Peter Oster1 Email: profoster@web.de
Gretl McHugh4 Email: gretl.mchugh@manchester.ac.uk
Chris Todd4 Email: chris.todd@manchester.ac.uk
Klaus Hauer1 Email: khauer@bethanien-heidelberg.de
1Department of Geriatric Research, AGAPLESION Bethanien-Hospital/Geriatric Center at the University of Heidelberg, Rohrbacherstr.149, Heidelberg 69126, Germany
2Network Aging Research, University of Heidelberg, Heidelberg, Germany
3Division of Clinical Epidemiology and Aging Research, German Cancer Research Center Heidelberg, Heidelberg, Germany
4School of Nursing, Midwifery and Social Work and Manchester Academic Health Sciences Centre, University of Manchester, Manchester, UK

Background

At least 30% of persons aged over 65 years experience one or more falls each year [1,2] and this proportion increases to 40% after age of 75 [3]. Both the incidence of falls and the severity of complications stemming from a fall increase with age, level of disability, and extent of functional impairment [4,5]. Falls are a major health problem in older adults, causing fall-related sequelae such as fractures, head injuries, and post-fall anxiety [6-11]. Older adults are hospitalised for fall-related injuries five times more often than they are for injuries from other causes [6]. The costs of injurious falls substantially burden health care systems [12].

The prevention of falls in older people is an important health target in many countries [13,14] and numerous studies have been published to identify appropriate intervention strategies [7,15-18]. Systematic reviews of RCTs of fall prevention interventions demonstrate that the risk of falling can effectively be reduced [7,15-18]. However, sound evidence for the reduction of injurious falls remains limited [13,16,19-23]. Evidence for the prevention of fall-related injuries has been shown in controlled trials [21,23,24] but so far no randomised controlled trial (RCT) evidence of effectiveness is available [14]. Most RCTs are underpowered to detect a significant reduction in injurious fall rates owing to the relative infrequency of injurious fall events [19,22,25] and the extremely large sample sizes required to achieve adequate statistical power.

However, severe falls and their resultant injuries have a high impact on medical sequelae [26], quality of life [27] and cost to health services [12,28]. Reducing injurious falls should therefore represent a major goal of fall prevention policy [13] and necessarily be benchmarked by a high level of evidence [29].

Because of the high cost of performing RCTs to evaluate the effects of specific fall prevention strategies on injurious falls, the combination of trial data in a meta-analysis is an attractive option but is dependent on the comparability of interventions and outcome measures. A substantial precondition for high-quality meta-analysis is a standardised methodology [30] characterised by consistency in defining injurious falls and methods of collecting and documenting falls data. However, existing international guidelines for the conduct of fall prevention trials [13] do not provide sufficient recommendations for the standardisation of injurious falls methodology. A systematic literature review on definitions and methods of measuring falls in randomised controlled fall prevention trials [31] provided a methodological consensus for defining and collecting falls, but not injurious falls, data.

Limited standardisation in defining injuries has repeatedly been reported as a serious methodological pitfall when comparing study outcomes [13,31] and has been identified as a substantial methodological challenge for future studies [32]. Standardised methodology has therefore been repeatedly requested [13,33]. However, to our knowledge, there is no systematic review focusing on injurious falls methodology in fall prevention trials aiming to develop a methodological consensus for future studies.

We therefore conducted a systematic review of definitions and methods of measuring and reporting on injurious falls in randomised controlled fall prevention trials. The aim of this study was to collect and compare definitions of injurious falls and associated assessment methods and develop an outcome data set for use in future fall prevention trials including injurious falls as a study endpoint.


Methods

This review is part of a series of reviews on behalf of the Prevention of Falls Network Europe (ProFaNE) which evaluate methodology in RCTs of fall prevention interventions in older adults. Inclusion criteria were (1) RCTs of fall prevention interventions published in English, (2) target population ≥ 65 years, (3) definition of injurious falls as a study endpoint by using the terms "injury" and "falls".

Search strategy

An electronic literature search was performed through Ovid MEDLINE, Ovid EMBASE, CINAHL, PsycINFO, the Cochrane library and GeroLit (all from inception until 16th of July 2011). The following search strategy was applied: ("Accidental Falls/" OR "fall.mp." (mp)) AND ("Accident Prevention/" OR "prevent$.mp." OR "prophyl$.mp.") AND ("clinical trials/" OR "clinical trial.mp" OR "randomised.mp" OR "randomized.mp" OR "randomly.mp"). Reference lists of included studies and of related reviews were searched for potentially eligible studies. Moreover researchers in the field were contacted and asked for additional trial reports.

Study selection and data extraction

Study selection was performed by three independent reviewers (AL, CS, GM) and disagreements were resolved by a fourth party (KH) [34]. Titles and abstracts of retrieved references were screened for inclusion and full texts of potential articles were analysed for meeting the inclusion criteria.

Data extraction was performed by three independent reviewers using a standardised form (AL, MS, GM). Definitions of injurious falls and methods used to record injurious falls were extracted from papers and classified according to subcategories. Frequencies of the definitions and methods used were documented as absolute (number of articles = n) and relative (number of articles using a specific definition or method/number of articles included in the review * 100) values. Where possible, the number of falls and injurious falls was extracted from the papers and the proportion of injurious falls to all falls (number of injurious falls/number of all falls * 100) was calculated. Relationship between the type of injurious fall definition used in studies and the proportion of injurious falls reported was evaluated by descriptive analysis. To measure the variability of the proportion of injurious falls between studies, the coefficient of variation [35] [(CV = (standard deviation/mean) × 100)] was calculated. The CV expresses the percentage variation between articles, thereby providing an indicator of agreement with respect to the proportion of injurious falls. Higher CVs indicate less agreement between studies.


Results
Selection of articles

The search yielded 2089 articles, 1778 were excluded on initial screening as not fulfilling entry criteria, thus 311 were potentially appropriate for inclusion in the review (Figure 1). Of these 311 papers, 270 were excluded, because on closer inspection they did not provide a definition of injurious falls or did not report on injurious falls or did not meet other inclusion criteria. Forty-one articles were finally included in the review.

Injurious fall definition

Definitions of injurious falls used in the articles included in this review are shown in Table 1. There was considerable heterogeneity in defining injurious falls and no definition stood out as the gold standard. Three main categories of definitions were found: (1) definitions based on symptoms (n = 16, 39%); (2) combined definitions based on symptoms and healthcare use (n = 19, 46%); (3) definitions based on healthcare use (n = 6, 15%). The most frequent type of definition that has been used similarly in different articles (n = 6, 15%) originates from a study by Campbell et al. [36]. This definition sub-classifies falls according to severity (serious, moderate) by using both symptomatic features (fractures, bruising, sprains, cuts, abrasions, reduction in physical function) and healthcare use (hospital, any wounds needed stitches, medical help). Referencing for this definition was inconsistent as some papers gave other primary sources [37] and some no reference at all [36,38,39].

Four articles (10%) used the definition of the Frailty and Injuries Cooperative Studies of Intervention Techniques (FICSIT) collaboration, with two studies [56,57] using the original definition and two using a modified version ("head injuries with altered consciousness" instead of "head injuries requiring hospitalisation" [58]; "severe sprains" instead of "sprains" [59]). Three articles (7%) defined injurious falls according to the Abbreviated Injury Scale (AIS) [77] using a severity score based on medical symptoms (ranging from low-level injuries that did not require medical attention to high-level injuries which necessitated medical care). One paper [48] used a modified version of the AIS.

Six included papers (14%) defined injurious falls only by fractures whereupon one study [40] defined hip fractures and non-hip fractures and five did not specify the type of fracture [41-45]. Seven articles (14%) defined injurious falls only by healthcare use by either using unspecific terms such as "medical treatment" [70,71] or "medical care" [73] or specific definitions such as "hospital visits or admission for the treatment of a fracture or suspected fracture" [72].

A considerable number of articles (n = 15, 37%) used heterogeneous definitions by either defining symptoms (n = 7, 17%) or by combining symptoms and healthcare use (n = 8, 20%). These types of definitions ranged from single sentences including a variety of symptoms (e.g. bruises, strains, cuts and abrasions, back pain and fractures [49,50]) regardless of severity to multiple-level definitions categorising injurious falls according to five levels of severity (from no injury [level 0] to broken bone [level 4] [67]). The majority of studies (n = 30; 73%; [36,38-45,49-55,58,61-64,67-70,72-76]) did not provide a reference for the definition of an injurious fall.

Methods of collecting injurious falls data

Table 2 details the methods of collecting injurious falls data used in RCTs. There was considerable heterogeneity in reporting systems and the time period over which information was collected. Three main methods of collecting falls data were found in the articles: (i) prospective reporting systems using calendars, postcards or diaries (n = 33, 80%); (ii) retrospective reporting systems using telephone interview or postal questionnaire (n = 30, 73%); (iii) medical records (n = 18, 44%). Prospective registration systems requested immediate return of the data, or return at specified time points ranging from one week to three months. Studies used prospective reporting systems often followed up with data collection by secondary data capture mechanisms where by telephone calls (82%), hospital records (24%), records from nursing homes, physicians or emergency departments (15%) or radiological records (12%) were used.

Studies using the Campbell et al. definition [36-39,60,61] consistently collected data by prospective daily recording with calendars, monthly reporting, and telephone interview follow up. In contrast there was little consistency in methods of data collection among studies that used other types of definitions (FICSIT, fracture, AIS, health care use, other).

Three studies (7%) [47,52,58] collected data on injurious falls only by the use of medical records whereupon information was gathered from hospitals [47,52,58], nursing homes [47,52,58], radiology departments [52,58], emergency departments [52,58], or physicians' records [52,58].

Proportion of injurious falls to all falls

For 27 (65.9%) studies the proportion of injurious falls to all falls was computed (Table 3). For 13 (31.7%) studies [44,45,50-53,57,58,65,69,71-73] calculation of the proportion of injurious falls is not possible as data on the number of falls and/or number of injurious falls are not available. Two papers [36,39] use the same data, one paper [39] is therefore not included in Table 3.

Calculation of the proportion of falls which are injurious allows a comparison of injurious falls outcomes across studies. A considerable range (3.6%-63.5%) in the proportion of injurious falls is apparent. The proportion appears to be related to the type of definition used: lowest proportions are found in studies that defined injurious falls as fractures only (0.4%-11.3%), studies using multi-level definitions such as the AIS report higher proportions (23.4%-56.2%) and the highest proportion (63.5%) is found if a single definition had been used which included a range of symptoms (e.g. back pain, bruises, strains, cuts and abrasions, and fractures [49]).

For the proportion of total injurious falls reported across studies, variation is high (CV = 50.1%). Considerable variation between studies is also apparent for subcategories of injurious falls in terms of fractures (CV = 51.5%), serious (CV = 68.0%) and moderate (CV = 35.4%) falls. However, variation is related to the standardisation of definition and outcomes: for the group of studies using versions of the Campbell et al definition, variation in the proportion of all injurious falls is considerably lower (CV = 12.0%) compared to variation of other studies included in the analysis (CV = 66.3%). The same result is obtained for the subcategories: across studies which applied the Campbell et al. definition a lower variation is apparent for proportion of serious (CV: Campbell et al.: 38.3% vs. other studies: 75.2%) and moderate (CV: Campbell et al.: 20.1% vs. other studies: 35.5%) injurious falls compared to all studies included.

In those studies using healthcare definitions (n = 10, 24.4%) the proportion of injurious falls varies substantially (2.9-30.4%) leading to a high CV of 46.8%. Lowest proportion is apparent for injurious falls defined as "hospitalisation" (2.9% [64]), whereas high proportions of injurious falls are apparent if unspecific "medical care" definitions are used (14.6-23.6% [38,59,61,64]) (Table 3).

Methods of summarising injurious fall outcomes

Table 4 details the methods used to summarise data on injurious falls in identified articles. The way data are summarised differs across papers. The most frequently reported summary statistic is the number of participants sustaining an injurious fall (n = 17, 41%) and the number of injurious falls (n = 17, 41%).

Some papers report on injurious falls by specifying the number of participants sustaining medical care falls (n = 5, 12%) and/or the number of medical care falls (n = 11, 27%). A few articles (n = 3, 7%) report on the number of falls requiring hospital admission. Fracture falls are specified in some papers as number of events (n = 11, 27%) and in some as number of participants (n = 11, 27%). Categories of injurious falls partly overlap as some studies report on both less specific types of injurious falls (e.g. medical care falls) and more specific types of injurious falls (e.g. fracture falls) whereas other studies only report one category.

Beside absolute values, several articles report rates of injurious falls or fall-related injuries. Calculation of rates was inconsistent. Some studies calculated the mean number of injurious falls per participant (n = 5, 12%). A number of studies calculated a particular relationship between a numerator and a denominator, where the denominator included time measurement. Different types of numerators (severity of injury, type of injury such as fracture or soft tissue) and denominators (resident year, 10 resident years, 100 person years, 1000 person years) had been used for calculation (Table 4).


Discussion

The results of this review highlight that existing fall prevention RCTs substantially vary in their methods of defining, collecting, and reporting injurious falls. No method has to date been implemented as a designated standard. Instead, a variety of approaches to defining and categorising injurious falls are identified. The use of different approaches leads to substantial differences in study results and thus limits the comparability of findings, and makes interpretation difficult.

Injurious fall definition

A large variety of definitions, in a number of cases not referenced, are identified in the present review. Some studies defined only specific injuries, such as fractures, while others collapsed multiple symptoms related to injurious falls into a single definition. The proportion of injurious falls to all falls reported substantially increases if several symptoms of different grades of severity are included into a single definition. For example, Lord [49] defined bruises, strains, cuts and abrasions, back pain and fractures and reported 63.5% of all falls were injurious. In contrast, Becker included only radiologically confirmed fractures resulting in 4.5% being reported as injurious falls. Although some of the differences between studies might be explained by the different populations and settings, the high proportion of injurious falls in the Lord study is most likely due to the inclusion of falls that caused minor injuries [49].

Inconsistent definitions with respect to healthcare use limit the comparability of RCTs, e.g. studies which used the FICSIT definition [56,59] included injurious falls predominantly requiring medical care and thus reported lower proportions of injurious falls (24-35.7%) compared to a study [49] which uses definitions based on multiple symptoms (63.5%) not all necessitating medical care use (e.g. abrasion, back pain).

Various definition of healthcare use can be identified ranging from specific interventions such as "suturing" to unspecific terms such as "medical treatment" or "urgent physician visits"and this exacerbates problems in comparing comparability of study outcomes. Methodological problems in injury research with respect to healthcare use have been discussed elsewhere [32]. If medical care services are used as a measure of injury, then the definition of injury becomes entangled with service configuration and policy issues, the type and availability of care and factors that influence care-seeking behaviour, including personality, pain tolerance, and anxiety [32].

Grouping injuries by severity, as found in several studies included in this review, is important; however, the use of different schemes can lead to confusion and makes it difficult to compare findings [32]. Authors who used differentiated scales for severity classification such as the AIS (seven categories) [48] summarised single categories into one (e.g. 4-7) either in order to facilitate statistical analysis or to compare results with other studies that used only one or two categories. However, the way severity categories were collapsed differ between studies and hamper the comparability of outcomes. A small change in the definition of injury severity can substantially influence the reported proportion of injurious falls as indicated by the following example: use of the expression "severe sprains" in the FICSIT definition resulted in 12% of falls being serious injurious falls [59]. In contrast 24% of falls were serious injurious falls were reported if "sprains" (without the word "severe") were defined [56].

Overall, the adverse impact of the variability in definitions and categorisation systems is reflected by the substantial variation of the proportion of injurious falls across studies. High CVs were found for the proportion of all injurious falls as well as for subgroups or fracture, serious, moderate and healthcare falls. However, one of the major findings of the present review is that a strict standardisation of the definition could substantially enhance comparability of studies. This is reflected by the group of RCTs which defined injurious falls according to Campbell et al. [36-39,60,61]. Whereas high variation had been obtained between outcomes of all RCTs included in this review, variation was considerably lower across those studies which applied the standardised Campbell et al. definition. This highlights the importance of using a standardised definition in future.

Methods of collecting injurious falls data

The high variation in proportion of injurious falls found in the present study may not only be due to the varying definitions, but also to different assessment methods. Several studies did not record injurious falls prospectively [47,50,52,58,65,71,74] or did not follow up prospective data collection to verify information on injurious falls, e.g. by phone call [40,41,46,47,53,63,66,68]. In addition, periods of recording data by the study centre substantially varied (from three weeks to three months) between studies. Long delay between event and data recording might limit the verification of injurious falls information. Thus, in particular due to short recovery periods of soft-tissue injuries [13] and memory deficits in the elderly [79] prospective daily recording in combination with short latency periods for reporting information to the study centre is essential to gather valid information about injurious falls [13].

Interestingly, we found that those RCTs which had higher consistency in the proportion of injurious falls (RCTs using the Campbell et al. definition) used similar methods for data collection suggesting that a standardised assessment enhances the comparability of results.

Some variation in proportion of injurious falls might be related to the limited standardisation of medical records. Medical reports have been recommended for confirming prospective injurious falls data and verifying severity of injury [78]. Radiological confirmation of fractures has been requested as a gold standard [13]. However, only 44% of the authors used medical reports as a data source and radiological confirmation of fractures was reported in only 15% of the RCTs included in the review. Accuracy of self-report of fracture is questionable since its agreement with radiologic diagnosis is limited [80].

Studies differed considerably with respect to the type of patient reports used. Some studies included nursing home reports [41,52,58] whereas others only included reports of physicians [38,46,57,60,63] or emergency departments [46,57,63]. As records can differ in validity [13] this might explain some of the variability, particularly in those studies [47,52,58] which used medical reports as a primary data source.

Injurious falls documentation

The way data are summarised differs among articles. Several studies reported on the number of injurious falls or on injurious fallers, whereas others specified fractures or reported on medical care falls. Selection of outcomes depends on the predefinition of specific endpoints such as serious injuries or fractures. For a number of studies the calculation of the proportion of injurious falls was not possible as data on the number of falls and/or injurious falls were not given and only fallers, injurious fall rates or fall rate ratios were reported. Varying numerators (fracture, serious, moderate, healthcare use) and different time denominators (1-1000 years) additionally exacerbate the comparability of outcomes as recently highlighted standardised documentation of injuries is a crucial issue for injury epidemiology and should be implemented in future studies [81].

Development of a standardised methodology for future RCTs

To date no standardised methodology exists for defining, assessing, and reporting injurious falls in RCTs, and thus needs to be developed for future research.

The most robust measure of injurious falls is considered to be peripheral fracture rate, verified by radiological evidence [13,29,78]. However, definition of fractures as primary endpoint requires large sample sizes [29,82]. By way of example, we determined sample sizes in order to detect statistically significant differences in outcomes related to falls and injurious falls (Table 5). The calculations demonstrate that, for instance, in a study population with a hip fracture incidence of 3% (medium risk) [83] a sample close to 42.000 study participants would be needed to observe a significant effect of an intervention if it reduced the hip fracture incidence by 15% (significance level 5%, power 80%). Based on this assumption no study in the present review met the requisite sample size calculation disallowing any statement on effectiveness of interventions with respect to falls resulting in hip fracture.

Including a range of fall-related injuries into one definition substantially increases the incidence of injurious falls and thus requires smaller sample sizes to achieve adequate statistical power. However, if several symptoms are included then a proper definition with respect to severity and the use of medical care is essential for comparability of results. Established scales such as the AIS provide a differentiated severity scoring (7 categories); however, its utility for population-based research is limited due to the time-consuming assignment of scores [84]. In contrast, categorising serious and moderate injurious falls according to the definition of Campbell et al. is feasible, even in large scale studies. It is the most frequent type of definition that has been used consistently in different articles (n = 6, 15%) included in the review. A meta-analysis, including RCTs and controlled trials, has been successfully conducted on the basis of the Campbell et al. definition [24].

According to our findings, a comprehensive, standardized system for categorising and defining serious, moderate and minor fall-related injuries by both symptoms and medical care use is recommendable for future RCTs of fall prevention (Table 6, Figure 2). Categories can be chosen for defining specific types on injurious falls depending on the research question and sample size calculation requirements. Each of the categories can be used independently as it is characterised by a standardised definition. Ideally, the injuries in each category should be reported even if a specific study is not powered to detect effects. Reporting all injuries will prevent an outcome bias and the data will be available for future meta-analysis. Data of medical care can be used for focus on cost calculation. A fall-related injury should be classified by an independent person, blind to group allocation.

Accuracy of moderate and minor injurious falls data is lower as the definition of injury becomes entangled with the type and availability of care and factors that influence care-seeking behaviour, including personality, pain tolerance, and anxiety [32] (Figure 2). However, research on falls causing minor injuries has been highlighted as an important issue as they have also serious consequences such as depression, fear of falling and activity restriction [14].

Injurious falls data should be collected by prospective daily recording, a minimum of monthly reporting, and telephone or face-to-face interview as recommended in a consensus paper on fall prevention studies [13]. We recommend standardised documentation of injurious falls data as number of injurious falls, number of people sustaining injurious falls, injurious falls rate per person-year of follow-up, and number of people sustaining multiple events [13]. Along with a standardised statistical analysis indicating the absolute risk difference between groups a common data set will improve comparability of future RCTs.

Limitations

Only RCTs in fall prevention were included in the present review and therefore it reflects the methodological status in this specific research area. We are aware that by this pre-selection relevant data, including epidemiological sources may not have been considered. We also note that our inclusion only of papers that defined their terms may have resulted in exclusion of papers where the outcome might be considered self-evident, for example we may have underreported the number of papers reporting fracture if fracture was not defined as an injury.


Conclusion

To date, no method has been defined as an international standard for RCTs in the field of fall prevention. Defining serious and moderate injurious falls according to Campbell et al. is the most frequently used methodology in RCTs to date and allow a comparison of study results. On the basis of this methodology we developed a standardised system for defining different categories of injuries which is feasible also in large scale studies. We recommend use of this system in future studies to reach a consensus on injurious falls methodology.

What is already known on this subject

• The combination of single randomised controlled trials in meta-analyses may help to generate evidence based data on specific prevention strategies to reduce injurious falls.

• The standardisation of the assessment methodology and case definition represents a major precondition for the conduction of meta-analyses.

• International guidelines provide recommendations for the standardisation of falls methodology; however, injurious falls have not been targeted.

What this study adds

• The definitions and methods used to measure and document injurious falls substantially vary in existing randomised controlled trials on fall prevention and thus hampering the comparability of study results and the conduction of meta-analyses.

• Our results highlight that the use of a standardised definition of injurious falls leads to a higher concurrence in study outcomes.

• Based on our results we recommend use of a standardised methodology in future randomised controlled trials including a comprehensive system for categorising and defining injurious falls and standardised methods of collecting and reporting on injurious falls data.


Competing interests

The authors declare that they have no competing interests.


Authors' contributions

MS: development of study concept and design, preparation of manuscript, interpretation of data, statistical analysis; AL: literature search, study selection, interpretation of data, preparation of manuscript, development of study design; CS: literature search, study selection, critical revision of manuscript; RRM: literature search; GM: literature search, study selection, critical revision of manuscript; CT: critical revision of manuscript; KH: study selection, development of study concept and design, critical revision of manuscript. All authors including PO contributed to the interpretation of data, drafting the article and final approval of published version. All authors read and approved the final manuscript.


Pre-publication history

The pre-publication history for this paper can be accessed here:

http://www.biomedcentral.com/1471-2288/12/50/prepub


Funding

This study was supported by the Dietmar Hopp Stiftung, the Klaus Tschira Stiftung, the Robert Bosch Stiftung and the Landesgraduiertenförderung Baden-Württemberg.


References
Hausdorff JM,Rios DA,Edelberg HK,Gait variability and fall risk in community-living older adults: a 1-year prospective studyArch Phys Med RehabilYear: 20018281050105610.1053/apmr.2001.2489311494184
Tinetti ME,Speechley M,Ginter SF,Risk factors for falls among elderly persons living in the communityN Engl J MedYear: 1988319261701170710.1056/NEJM1988122931926043205267
Tinetti ME,Williams CS,The effect of falls and fall injuries on functioning in community-dwelling older personsJ Gerontol A Biol Sci Med SciYear: 1998532M112M1199520917
Oakley A,Dawson MF,Holland J,Arnold S,Cryer C,Doyle Y,Rice J,Hodgson CR,Sowden A,Sheldon T,et al. Preventing falls and subsequent injury in older peopleQual Health CareYear: 19965424324910.1136/qshc.5.4.24310164150
van Weel C,Vermeulen H,van den Bosch W,Falls, a community care perspectiveLancetYear: 199534589641549155110.1016/S0140-6736(95)91091-37791442
Alexander BH,Rivara FP,Wolf ME,The cost and frequency of hospitalization for fall-related injuries in older adultsAm J Public HealthYear: 19928271020102310.2105/AJPH.82.7.10201609903
Gillespie LD,Robertson MC,Gillespie WJ,Lamb SE,Gates S,Cumming RG,Rowe BH,Interventions for preventing falls in older people living in the communityCochrane Database Syst RevYear: 20092CD00714619370674
Kannus P,Sievanen H,Palvanen M,Jarvinen T,Parkkari J,Prevention of falls and consequent injuries in elderly peopleLancetYear: 200536695001885189310.1016/S0140-6736(05)67604-016310556
Rubenstein LZ,Falls in older people: epidemiology, risk factors and strategies for preventionAge AgeingYear: 200635Suppl 2ii37ii4116926202
Sattin RW,Lambert Huber DA,DeVito CA,Rodriguez JG,Ros A,Bacchelli S,Stevens JA,Waxweiler RJ,The incidence of fall injury events among the elderly in a defined populationAm J EpidemiolYear: 19901316102810372343855
Tinetti ME,Doucette J,Claus E,Marottoli R,Risk factors for serious injury during falls by older persons in the communityJ Am Geriatr SocYear: 19954311121412217594154
Davis JC,Robertson MC,Ashe MC,Liu-Ambrose T,Khan KM,Marra CA,International comparison of cost of falls in older adults living in the community: a systematic reviewOsteoporos IntYear: 20102181295130610.1007/s00198-009-1162-020195846
Lamb SE,Jorstad-Stein EC,Hauer K,Becker C,Development of a common outcome data set for fall injury prevention trials: the Prevention of Falls Network Europe consensusJ Am Geriatr SocYear: 20055391618162210.1111/j.1532-5415.2005.53455.x16137297
Todd C,Skelton D,What are the main risk factors for falls among older people and what are the most effective interventions to prevent these falls?Year: 2004Copenhagen: WHO Regional Office for Europe (Health Evidence Network report)
Chang JT,Morton SC,Rubenstein LZ,Mojica WA,Maglione M,Suttorp MJ,Roth EA,Shekelle PG,Interventions for the prevention of falls in older adults: systematic review and meta-analysis of randomised clinical trialsBMJYear: 2004328744168010.1136/bmj.328.7441.68015031239
Costello E,Edelstein JE,Update on falls prevention for community-dwelling older adults: review of single and multifactorial intervention programsJ Rehabil Res DevYear: 20084581135115210.1682/JRRD.2007.10.016919235116
Cusimano MD,Kwok J,Spadafora K,Effectiveness of multifaceted fall-prevention programs for the elderly in residential careInj PrevYear: 200814211312210.1136/ip.2007.01753318388232
Sherrington C,Whitney JC,Lord SR,Herbert RD,Cumming RG,Close JC,Effective exercise for the prevention of falls: a systematic review and meta-analysisJ Am Geriatr SocYear: 200856122234224310.1111/j.1532-5415.2008.02014.x19093923
Gardner MM,Robertson MC,Campbell AJ,Exercise in preventing falls and fall related injuries in older people: a review of randomised controlled trialsBr J Sports MedYear: 200034171710.1136/bjsm.34.1.710690444
Lin MR,Hwang HF,Wang YW,Chang SH,Wolf SL,Community-based tai chi and its effect on injurious falls, balance, gait, and fear of falling in older peoplePhys TherYear: 20068691189120110.2522/ptj.2004040816959668
McClure R,Turner C,Peel N,Spinks A,Eakin E,Hughes K,Population-based interventions for the prevention of fall-related injuries in older peopleCochrane Database Syst RevYear: 20051CD00444115674948
Province MA,Hadley EC,Hornbrook MC,Lipsitz LA,Miller JP,Mulrow CD,Ory MG,Sattin RW,Tinetti ME,Wolf SL,The effects of exercise on falls in elderly patients. A preplanned meta-analysis of the FICSIT Trials. Frailty and Injuries: Cooperative Studies of Intervention TechniquesJAMAYear: 1995273171341134710.1001/jama.1995.035204100350237715058
Sydenham E,Systematic reviews on preventing fall-related injuries in older peopleInj PrevYear: 200814427410.1136/ip.2008.01961218676789
Robertson MC,Campbell AJ,Gardner MM,Devlin N,Preventing injuries in older people by preventing falls: a meta-analysis of individual-level dataJ Am Geriatr SocYear: 200250590591110.1046/j.1532-5415.2002.50218.x12028179
Lyons RA,John A,Brophy S,Jones SJ,Johansen A,Kemp A,Lannon S,Patterson J,Rolfe B,Sander LV,et al. Modification of the home environment for the reduction of injuriesCochrane Database Syst RevYear: 20064CD00360017054179
Rapp K,Lamb SE,Erhardt-Beer L,Lindemann U,Rissmann U,Klenk J,Becker C,Effect of a statewide fall prevention program on incidence of femoral fractures in residents of long-term care facilitiesJ Am Geriatr SocYear: 2010581707510.1111/j.1532-5415.2009.02630.x20002505
Rubenstein LZ,Josephson KR,Robbins AS,Falls in the nursing homeAnn Intern MedYear: 199412164424518053619
Stevens JA,Corso PS,Finkelstein EA,Miller TR,The costs of fatal and non-fatal falls among older adultsInj PrevYear: 200612529029510.1136/ip.2005.01101517018668
Karlsson M,Does exercise reduce the burden of fractures? A reviewActa Orthop ScandYear: 200273669170512553521
Crowther M,Lim W,Crowther MA,Systematic review and meta-analysis methodologyBloodYear: 2010116173140314610.1182/blood-2010-05-28088320656933
Hauer K,Lamb SE,Jorstad EC,Todd C,Becker C,Systematic review of definitions and methods of measuring falls in randomised controlled fall prevention trialsAge AgeingYear: 200635151010.1093/ageing/afi21816364930
Cummings P,Koepsell TD,Mueller BA,Methodological challenges in injury epidemiology and injury prevention researchAnnu Rev Public HealthYear: 19951638140010.1146/annurev.pu.16.050195.0021217639878
Butler M,Kerse N,Todd M,Circumstances and consequences of falls in residential care: the New Zealand storyN Z Med JYear: 20041171202U107615477905
Haywood KL,Hargreaves J,White R,Lamb SE,Reviewing measures of outcome: reliability of data extractionJ Eval Clin PractYear: 200410232933710.1111/j.1365-2753.2003.00411.x15189399
Bland JM,An Introduction to Medical StatisticsYear: 19953Oxford: Oxford University Press
Campbell AJ,Robertson MC,Gardner MM,Norton RN,Tilyard MW,Buchner DM,Randomised controlled trial of a general practice programme of home based exercise to prevent falls in elderly womenBMJYear: 199731571151065106910.1136/bmj.315.7115.10659366737
Elley CR,Robertson MC,Garrett S,Kerse NM,McKinlay E,Lawton B,Moriarty H,Moyes SA,Campbell AJ,Effectiveness of a falls-and-fracture nurse coordinator to reduce falls: a randomized, controlled trial of at-risk older adultsJ Am Geriatr SocYear: 20085681383138910.1111/j.1532-5415.2008.01802.x18808597
Campbell AJ,Robertson MC,La Grow SJ,Kerse NM,Sanderson GF,Jacobs RJ,Sharp DM,Hale LA,Randomised controlled trial of prevention of falls in people aged > or = 75 with severe visual impairment: the VIP trialBMJYear: 2005331752081710.1136/bmj.38601.447731.5516183652
Robertson MC,Devlin N,Scuffham P,Gardner MM,Buchner DM,Campbell AJ,Economic evaluation of a community based exercise programme to prevent fallsJ Epidemiol Community HealthYear: 200155860060610.1136/jech.55.8.60011449021
Becker C,Kron M,Lindemann U,Sturm E,Eichner B,Walter-Jung B,Nikolaus T,Effectiveness of a multifaceted intervention on falls in nursing home residentsJ Am Geriatr SocYear: 200351330631310.1046/j.1532-5415.2003.51103.x12588573
Dyer CA,Taylor GJ,Reed M,Robertson DR,Harrington R,Falls prevention in residential care homes: a randomised controlled trialAge AgeingYear: 200433659660210.1093/ageing/afh20415381507
Pfeifer M,Begerow B,Minne HW,Suppan K,Fahrleitner-Pammer A,Dobnig H,Effects of a long-term vitamin D and calcium supplementation on falls and parameters of muscle function in community-dwelling older individualsOsteoporos IntYear: 200920231532210.1007/s00198-008-0662-718629569
Sanders KM,Stuart AL,Williamson EJ,Simpson JA,Kotowicz MA,Young D,Nicholson GC,Annual high-dose oral vitamin D and falls and fractures in older women: a randomized controlled trialJAMAYear: 2010303181815182210.1001/jama.2010.59420460620
De Vries OJ,Peeters GMEE,Elders PJM,Muller M,Knol DL,Danner SA,Bouter LM,Lips P,Multifactorial intervention to reduce falls in older people at high risk of recurrent falls: A randomized controlled trialArch Intern MedYear: 2010170131110111710.1001/archinternmed.2010.16920625015
Kemmler W,Von Stengel S,Engelke K,Haberle L,Kalender WA,Exercise effects on bone mineral density, falls, coronary risk factors, and health care costs in older women: The randomized controlled senior fitness and prevention (SEFIP) studyArch Intern MedYear: 2010170217918510.1001/archinternmed.2009.49920101013
Jensen J,Lundin-Olsson L,Nyberg L,Gustafson Y,Fall and injury prevention in older people living in residential care facilities. A cluster randomized trialAnn Intern MedYear: 20021361073374112020141
Stenvall M,Olofsson B,Lundstrom M,Englund U,Borssen B,Svensson O,Nyberg L,Gustafson Y,A multidisciplinary, multifactorial intervention program reduces postoperative falls and injuries after femoral neck fractureOsteoporos IntYear: 200718216717510.1007/s00198-006-0226-717061151
Reinsch S,MacRae P,Lachenbruch PA,Tobis JS,Attempts to prevent falls and injury: a prospective community studyGerontologistYear: 199232445045610.1093/geront/32.4.4501427246
Lord SR,Tiedemann A,Chapman K,Munro B,Murray SM,Gerontology M,Ther GR,Sherrington C,The effect of an individualized fall prevention program on fall risk and falls in older people: a randomized, controlled trialJ Am Geriatr SocYear: 20055381296130410.1111/j.1532-5415.2005.53425.x16078954
Barnett A,Smith B,Lord SR,Williams M,Baumand A,Community-based group exercise improves balance and reduces falls in at-risk older people: a randomised controlled trialAge AgeingYear: 200332440741410.1093/ageing/32.4.40712851185
Means KM,Rodell DE,O'Sullivan PS,Balance, mobility, and falls among community-dwelling elderly persons: effects of a rehabilitation exercise programAm J Phys Med RehabilYear: 200584423825010.1097/01.PHM.0000151944.22116.5A15785256
Ray WA,Taylor JA,Brown AK,Gideon P,Hall K,Arbogast P,Meredith S,Prevention of fall-related injuries in long-term care: a randomized controlled trial of staff educationArch Intern MedYear: 2005165192293229810.1001/archinte.165.19.229316246997
Ashburn A,Fazakarley L,Ballinger C,Pickering R,McLellan LD,Fitton C,A randomised controlled trial of a home based exercise programme to reduce the risk of falling among people with Parkinson's diseaseJ Neurol Neurosurg PsychiatryYear: 200778767868417119004
Blalock SJ,Casteel C,Roth MT,Ferreri S,Demby KB,Shankar V,Impact of enhanced pharmacologic care on the prevention of falls: A randomized controlled trialAm J Geriatr PharmacotherYear: 20108542844010.1016/j.amjopharm.2010.09.00221335296
Haran MJ,Cameron ID,Ivers RQ,Simpson JM,Lee BB,Tanzer M,Porwal M,Kwan MM,Severino C,Lord SR,Effect on falls of providing single lens distance vision glasses to multifocal glasses wearers: VISIBLE randomised controlled trialBMJ (Clin Res Ed)Year: 2010340c226510.1136/bmj.c2265
Rizzo JA,Baker DI,McAvay G,Tinetti ME,The cost-effectiveness of a multifactorial targeted prevention program for falls among community elderly personsMed CareYear: 199634995496910.1097/00005650-199609000-000078792783
Wolf SL,Barnhart HX,Kutner NG,McNeely E,Coogler C,Xu T,Reducing frailty and falls in older persons: an investigation of Tai Chi and computerized balance training. Atlanta FICSIT Group. Frailty and Injuries: Cooperative Studies of Intervention TechniquesJ Am Geriatr SocYear: 19964454894978617895
Ray WA,Taylor JA,Meador KG,Thapa PB,Brown AK,Kajihara HK,Davis C,Gideon P,Griffin MR,A randomized trial of a consultation service to reduce falls in nursing homesJAMAYear: 1997278755756210.1001/jama.1997.035500700490379268276
Tinetti ME,Baker DI,McAvay G,Claus EB,Garrett P,Gottschalk M,Koch ML,Trainor K,Horwitz RI,A multifactorial intervention to reduce the risk of falling among elderly people living in the communityN Engl J MedYear: 19943311382182710.1056/NEJM1994092933113018078528
Campbell AJ,Robertson MC,Gardner MM,Norton RN,Buchner DM,Falls prevention over 2 years: a randomized controlled trial in women 80 years and olderAge AgeingYear: 199928651351810.1093/ageing/28.6.51310604501
Robertson MC,Devlin N,Gardner MM,Campbell AJ,Effectiveness and economic evaluation of a nurse delivered home exercise programme to prevent falls. 1: Randomised controlled trialBMJYear: 2001322728869770110.1136/bmj.322.7288.69711264206
Nikolaus T,Bach M,Preventing falls in community-dwelling frail older people using a home intervention team (HIT): results from the randomized Falls-HIT trialJ Am Geriatr SocYear: 200351330030510.1046/j.1532-5415.2003.51102.x12588572
Kerse N,Butler M,Robinson E,Todd M,Fall prevention in residential care: a cluster, randomized, controlled trialJ Am Geriatr SocYear: 200452452453110.1111/j.1532-5415.2004.52157.x15066066
Hornbrook MC,Stevens VJ,Wingfield DJ,Hollis JF,Greenlick MR,Ory MG,Preventing falls among community-dwelling older persons: results from a randomized trialGerontologistYear: 1994341162310.1093/geront/34.1.168150304
Luukinen H,Lehtola S,Jokelainen J,Vaananen-Sainio R,Lotvonen S,Koistinen P,Pragmatic exercise-oriented prevention of falls among the elderly: a population-based, randomized, controlled trialPrev MedYear: 200744326527110.1016/j.ypmed.2006.09.01117174387
Li F,Harmer P,Fisher KJ,McAuley E,Chaumeton N,Eckstrom E,Wilson NL,Tai Chi and fall reductions in older adults: a randomized controlled trialJ Gerontol A Biol Sci Med SciYear: 200560218719410.1093/gerona/60.2.18715814861
Skelton D,Dinan S,Campbell M,Rutherford O,Tailored group exercise (Falls Management Exercise - FaME) reduces falls in community-dwelling older frequent fallers (an RCT)Age AgeingYear: 200534663663910.1093/ageing/afi17416267192
Fitzharris MP,Day L,Lord SR,Gordon I,Fildes B,The Whitehorse NoFalls trial: Effects on fall rates and injurious fall ratesAge and AgeingYear: 2010396pp 728pp 733.afq109
Spice CL,Morotti W,George S,Dent THS,Rose J,Harris S,Gordon CJ,The Winchester falls project: A randomised controlled trial of secondary prevention of falls in older peopleAge and AgeingYear: 2009381334018829689
Sihvonen S,Sipila S,Taskinen S,Era P,Fall incidence in frail older women after individualized visual feedback-based balance trainingGerontologyYear: 200450641141610.1159/00008018015477703
Salminen M,Vahlberg T,Kivela SL,The long-term effect of a multifactorial fall prevention programme on the incidence of falls requiring medical treatmentPubl HealthYear: 20091231280981310.1016/j.puhe.2009.10.018
Wolf SL,Sattin RW,Kutner M,O'Grady M,Greenspan AI,Gregor RJ,Intense tai chi exercise training and fall occurrences in older, transitionally frail adults: a randomized, controlled trialJ Am Geriatr SocYear: 200351121693170110.1046/j.1532-5415.2003.51552.x14687346
Hendriks MR,Bleijlevens MH,van Haastregt JC,Crebolder HF,Diederiks JP,Evers SM,Mulder WJ,Kempen GI,van Rossum E,Ruijgrok JM,et al. Lack of effectiveness of a multidisciplinary fall-prevention program in elderly people at risk: a randomized, controlled trialJ Am Geriatr SocYear: 20085681390139710.1111/j.1532-5415.2008.01803.x18662214
Karkkainen MK,Tuppurainen M,Salovaara K,Sandini L,Rikkonen T,Sirola J,Honkanen R,Arokoski J,Alhava E,Kroger H,Does daily vitamin D 800 IU and calcium 1000 mg supplementation decrease the risk of falling in ambulatory women aged 65-71 years? A 3-year randomized population-based trial (OSTPRE-FPS)MaturitasYear: 201065435936510.1016/j.maturitas.2009.12.01820060665
Suman S,Myint PK,Clark A,Das P,Ring L,Trepte NJB,Community-based fall assessment compared with hospital-based assessment in community-dwelling older people over 65 at high risk of falling: A randomized studyAging - Clin Exp ResYear: 2011231354121499018
Vind AB,Andersen HE,Pedersen KD,Jorgensen T,Schwarz P,An outpatient multifactorial falls prevention intervention does not reduce falls in High-risk elderly danesJ Am Geriatr SocYear: 200957697197710.1111/j.1532-5415.2009.02270.x19507291
Association for the Advancement of Automotive Medicine, Committee on Injury ScalingThe Abbreviated Injury Scale-1990 Revision (AIS-90)Year: 1990Des Plains, IL: Association for the Advancement of Automotive Medicine
Buchner DM,Hornbrook MC,Kutner NG,Tinetti ME,Ory MG,Mulrow CD,Schechtman KB,Gerety MB,Fiatarone MA,Wolf SL,et al. Development of the common data base for the FICSIT trialsJ Am Geriatr SocYear: 19934132973088440854
Cummings SR,Nevitt MC,Kidd S,Forgetting falls. The limited accuracy of recall of falls in the elderlyJ Am Geriatr SocYear: 19883676136163385114
Nevitt MC,Cummings SR,Browner WS,Seeley DG,Cauley JA,Vogt TM,Black DM,The accuracy of self-report of fractures in elderly women: evidence from a prospective studyAm J EpidemiolYear: 199213554904991570815
Alexandrescu R,O'Brien SJ,Lecky FE,A review of injury epidemiology in the UK and Europe: some methodological considerations in constructing ratesBMC Publ HealthYear: 2009922610.1186/1471-2458-9-226
Gregg EW,Cauley JA,Seeley DG,Ensrud KE,Bauer DC,Physical activity and osteoporotic fracture risk in older women. Study of Osteoporotic Fractures Research GroupAnn Intern MedYear: 1998129281889669990
Cumming RG,Nevitt MC,Cummings SR,Epidemiology of hip fracturesEpidemiol RevYear: 199719224425710.1093/oxfordjournals.epirev.a0179569494786
MacKenzie EJ,Shapiro S,Eastham JN,The Abbreviated Injury Scale and Injury Severity Score. Levels of inter- and intrarater reliabilityMed CareYear: 198523682383510.1097/00005650-198506000-000083925257

Figures

[Figure ID: F1]
Figure 1 

Flowchart of the process of literature search and extraction of RCTs meeting the inclusion criteria.



[Figure ID: F2]
Figure 2 

Injury categories of the newly developed system are defined by both symptoms and medical care use. Definition of serious injuries represents the endpoint with highest accuracy but requires largest sample size due to low incidence of these falls. Definition of moderate and/or minor injuries requires smaller sample sizes but reduces accuracy of data (illustrated by left and right arrow).



Tables
[TableWrap ID: T1] Table 1 

Types of definitions used to describe injurious falls in RCTs


Type of definition, n (%) Description of definition
Based only on symptoms, 16 (39%)

Fractures only,
6 (14%)
• Hip fractures and non-hip fractures [40]
• All fractures [41-45]

AIS definition,
3 (7%)
• AIS scores: 1 = minor injury, 2 = moderate injury, 3 = severe, non-life-threatening injury, 4 = severe, life-threatening injury, 5 = critical injury [46,47]
• Adapted AIS Scale ranging from "no injury, no pain" (level 1) to "fractures of hip, leg, or skull" (level 7) [48]

Other definitions,
7 (17%)
• Bruises, strains, cuts and abrasions, back pain and fractures [49,50]
• Any detectable residual adverse physical change persisting beyond 1 hr after the fall [51]
• Fractures or soft tissue injuries [52]
• Cuts and bruises, fractures or other trauma [53]
• If participants indicated that they were injured by the fall, irrespective of the severity of the injuries [54]
• Fracture, dislocations, and organ and soft tissue trauma [55]

Based on symptoms and healthcare use, 18 (44%)

FICSIT definition,
4 (10%)
• Original FICSIT definition: Fractures, head injuries requiring hospitalisation, joint dislocations, sprains and lacerations requiring suturing [56,57]
• Modified FICSIT definition: fractures, other head injuries with altered consciousness, joint dislocations or sprains, or sutured lacerations [58]; Fractures, head injuries requiring hospitalisation, joint dislocations, severe sprains and lacerations requiring suturing [59]

Definition according to Campbell et al. [36],
6 (15%)
• Serious: fracture or admission to hospital or if any wounds needed stitches (sutures); moderate: bruising, sprains, cuts, abrasions, or a reduction in physical function for at least three days, or if the participant sought medical help [36-39,60,61]

Other definitions,
8 (20%)
• dislocations, injuries of chest, abdomen, or pelvis; open wounds requiring suturing; injuries to blood vessels; crushing injuries; and injuries to nerves and spinal cord [62]
• Injury: any sequelae relating from a fall; serious injury: sprains, joint dislocation, hip fracture, other fracture, transfer to acute hospital, urgent physician visit, radiological examination [63]
• Injury falls: any fracture, strain, sprain, laceration, or persistent pain (more than seven days); Medical care falls: any fall for which medical care was sought; Fracture falls and hospitalised falls [64]
• Fractures, dislocations and soft tissue injuries needing suturing and even more severe injuries [65]
• Fractures, head injuries, sprains, bruises, scrapes, or other serious joint injuries, or if the participant sought medical care [66]
• Medical attention falls were coded ranging from no injury (0) to broken bone (4) [67]
• Cut, scrape, gash, bruise or fracture; a head injury resulted or where the fall resulted in hospitalisation [68]
• Fractures and hospital admission [69]

Based only on healthcare use, 7 (17%)

Healthcare use definition,
7 (17%)
• Medical treatment [70,71]
• Hospital visits or admission for the treatment of a fracture or suspected fracture [72]
• Medical care [73]
• Falls requiring medical attention [74]
• Doctor's or hospital attendance [75]
• General practitioner or emergency department or admission to the hospital [76]

n = number of articles used a specific definition; AIS = Abbreviated Injury Scale [77]; FICSIT = Frailty and Injuries: Cooperative Studies of Intervention Techniques [78]


[TableWrap ID: T2] Table 2 

Methods of collecting injurious falls data


Ref. Prospective Retrospective Medical record
Method Recording Reporting
Fracture definition
[40] Calendar daily not specified - Radiological
[44] Calendar weekly not specified Postal Questionnaire -
[41] Diary after fall every three weeks - Hospital, Other4
[45] Calendar daily monthly Phone1,2 -
[42] Diary daily Every two month Phone3 Radiological
[43] Calendar daily monthly Phone1,2 Radiological
AIS definition
[46] not specified daily after fall - Hospital
[47] - - - - Hospital
[48] Diary daily monthly Phone3 -
FICSIT definition
[56] Calendar daily monthly Phone1,2 -
[57] Calendar daily monthly Phone3 Hospital, Other4
[58] - - - - Hospital, Radiological, Other4
[59] Calendar daily monthly Phone1,2 -
Campbell et al. Definition
[36] Calendar daily monthly Phone1,2 Hospital
[60] Calendar daily monthly Phone1,2 Hospital
[38] Calendar daily monthly Phone2 Other4
[37] Calendar daily monthly Phone1,2 -
[61] Calendar daily monthly Phone2 Hospital, Other4
[39] Calendar daily monthly Phone1,2 -
Health care use definition
[71] - - - - Hospital, Other
[70] Diary daily monthly Phone1,2 -
[72] Calendar weekly monthly Phone1,2 -
[73] Calendar daily monthly Phone3 -
[74] - - - Phone3 -
[75] Diary daily After 3,6 and twelve month Phone3 -
[76] Diary daily monthly Phone3 Hospital
Other definitions
[50] - - - Phone1, Postal Questionnaire -
[49] Calendar daily monthly Phone1,2 -
[51] Postcard weekly monthly Phone1 -
[52] - - - - Hospital, Radiological, Other4
[53] Diary daily monthly - -
[54] Calendar daily monthly Phone1,2 -
[55] Calendar daily monthly Phone3 -
[62] Diary daily monthly Phone2,3 -
[63] Calendar daily monthly - Radiological
[64] Calendar, Postcard daily every three month, after fall Phone2, 3 -
[65] - - - Phone3 Hospital, Other4
[66] Calendar daily every three month - Hospital, Other4
[67] Diary daily every two weeks Phone1 -
[68] Calendar daily monthly - -
[69] Postcard - monthly Phone1 -
Method applied in n (%5)of studies: Calendar:
n = 22 (54%)
Postcard:
n = 3 (7%)
Diary:
n = 9 (22%)
not specified:
n = 1 (2%)
not applied (-):
n = 7 (17%)
daily:
n = 29 (71%)
weekly:
n = 3 (7%)
after fall:
n = 1 (2%)
not applied (-): n = 8 (20%)
weekly:
n = 2 (5%)
monthly:
n = 29 (71%)
after fall:
n = 2 (5%)
not specified:
n = 2 (5%)
not applied (-): n = 7 (17%)
Phone: n = 29 (71%)
Postal Questionnaire: n = 2 (5%)
not applied(-): n = 11 (27%)
Radiological:
n = 6 (15%)
Hospital:
n = 13 (32%)
Other:
n = 9 (22%)
not applied (-):
n = 23(56%)

Given are the methods of collecting injurious falls data in the articles included in the review. n = number of studies; AIS = Abbreviated Injury Scale; FICSIT = Frailty and Injuries: Cooperative Studies of Intervention Techniques

1if calendar, diary, or postcard not returned; 2following occurrence of a fall; 3regular phone call; 4records from nursing homes, physicians or emergency departments; 5calculation of percentages: number of articles used a specific method/total number of articles * 100, percentages may sum up to more than 100 percent as some studies used multiple methods


[TableWrap ID: T3] Table 3 

Falls and proportion of injurious falls as reported in the RCTs


Ref. Sample size, n All falls, n Proportion of injurious falls to all falls, % (n)
Total Fracture Serious Moderate Healthcare use
Definitions based only on symptoms
Fracture definition
[40] 981 1527 4.5% (68) 2.1%(32)1
2.4%(36)2
- - -
[41] 196 460 3.6% (7) 3.6%(7)3 - - -
[42] 242 275 11.3% (31) 11.3%(31)3 - - -
[43] 2.256 5.404 4.6% (246) 4.6%(246)3 - [59.2% (3.198)]8 -
AIS definition
[46] 384 619 23.4% (145) 2.4% (15)4
2.9%(18)5
- 18.1%(112)9 -
[47] 199 78 28.2% (22) 2.6%(2)1
2.6%(2)2
- 23.1%(18)7 -
[48] 230 89 56.2% (50) 1.1%(1)1
4.5%(4)2
14.6%(13)6 36%(32)10 -
Other definition
[49] 597 510 63.5% (324) - - - -
[54] 186 322 39,4% (127) - - - -
[55] 597 957 48,0% (459) - - - -
[62] 360 367 8.2% (30) 1.9%(7)3 6.3% (23) - -
Definitions based on symptoms and health care use
FICSIT definition
[56] 288 238 24.0% (57) - 24.0% (57) - -
[59] 291 258 35.7% (92) - 12.0% (31) - 23.6%(61)11
Campbell et al. definition
[36] 233 240 45.8% (110) - 10.4% (25) 35.4% (85) -
[60] 152 358 40.5% (145) - 9.5% (34) 31.0% (111) -
[38] 391 443 51.5% (228) - 6.8% (30) 44.7% (198) 25.5%(113)11
[37] 312 584 55.8% (326) - 3.6% (21) 52.2% (305) -
[61] 240 189 48.1% (91) - 5.8% (11) 42.3% (80) 23.3% (44)11
Other definition
[63] 547 1299 40.3% (523) - 4.2% (54) - -
[64] 3.182 3.814 30.5% (1.163) 5.1%(193)3 - - 14.6% (558)11
2.9%(111)12
[66] 188 111 21.6% (24) - 2.7% (3) 18.9% (21) 17.1%(19)12
[67] 70 546 14.6% (80) 0.4%(2)1
3.3%(18)2
- - -
[68] 1.090 1.448 55.5% (804) - - - 8.6% (124)13
Definitions based only on health care use
[70] 27 23 30.4% (7) - - - 30.4% (7)14
[74] 3.139 3.776 21.7% (821) - - - 21.7% (821)15
[75] 349 224 13.5% (47) - - - 9.2%(32)16
4.3%(15)17
[76] 392 820 12.2% (100) - - - 12.2%(100)12,16,17
Range: 3.6-63.5% 0.4-11.3% 2.7-24.0% 18.1-52.2% 2.9-30.4%
CV: 50.1% 51.518 68.0% 35.4% 46.8%

Displayed are falls (number) and injurious falls (proportion = injurious falls/falls * 100; number) as reported in the RCTs. Injurious falls data are given for the following categories: total, fracture, serious, moderate, healthcare use

n = number; AIS = Abbreviated Injury Scale; FICSIT = Frailty and Injuries: Cooperative Studies of Intervention Techniques. CV = Coefficient of variation [(SD/mean) × 100]) as a measure of the variability (%) of injurious falls outcomes between studies. 1Hip fracture; 2other fracture (except hip); 3fracture type not specified; 4hip or other femoral fractures; 5vertebral or wrist fracture; 6pain, injury, medical help required; 7Injuries; no fracture; 8bruise, abrasion or muscle injury without fracture, results are not included in analysis as only fractures were defined; 9superficial wounds and bruises; 10pain, minor injury, friends help needed, Bruises and no help needed; 11medical care; 12hospitalised falls; 13medical treatment; 14hospitalisation, emergency department visits or physician visits; 15medical attention; 16general practitioner surgery; 17accident and emergency department; 18total fracture incidence per study

For the following reference calculation of the proportion of injurious falls is not possible as data on the number of falls and/or number of injurious falls are not available: [44,45,50-53,57,58,65,69,71-73]. Reference [39] uses the same data as [36] and is therefore not included in the table


[TableWrap ID: T4] Table 4 

Methods of summarising injurious fall outcomes


Data reported Articles n (%) Reference
Number of participants sustaining injurious falls 17 (41%) [36,38,40,41,47,51,53,55,59,63,65-67,70,72,73,76]
 Sustaining medical care falls 5 (12%) [53,59,69,74,75]
 Sustaining fracture falls 11 (27%) [40-44,46,47,53,55,69,75]
Number of injurious falls 17 (41%) [43,46,48,49,52,54,55,58,59,61,63,64,67,68,71,73,76]
 Medical care falls 11 (27%) [38,39,56,59,61,64,66,68,74-76]
 Fracture falls 11 (27%) [40,42,43,45,52,58,62,64,67,71,76]
 Falls requiring hospital admission 3 (7%) [58,59,64]
Injury rate 4 (10%) [40,52,54,65]
Injurious fall rates 8 (20%) [37-39,56,58,61-63]
 Mean number of injurious falls per participants 5 (12%) [37,40,49,63,67]
 Injurious falls/person time 11 (27%) [40]1 ,[54]1, [62]5, [38]4,[61]2,[63]4,[68]4,[58]4,[52]4,[2]2,[39]4
Serious injury/person time 3 (7%) [37,38,63]2
 Moderate injury/person time 2 (5%) [37,38]2
 Medical care falls/person time 1 (2%) [56,68]4
 Soft tissue/person time 1 (2%) [52]1
 Hip fracture/person time 2 (5%) [40,52]1
 Other fracture/person time 2 (5%) [40,52]1
Time to injurious fall event 4 (10%) [43,48,57,76]

Methods of fall documentation used in the articles. n = number of studies; calculation of percentages: number of articles used a specific method/total number of articles * 100; 1number/1000 persons year; 2number/persons year; 3number/10 persons year; 4number/100 persons year


[TableWrap ID: T5] Table 5 

Hypothetical examples of sample size requirements for RCTs of injurious falls prevention by risk group


Outcome Incidence in study population Required sample size
Low risk (25% lower than intermediate risk)
Fallers1 37.50% 2246
≥ 1 injurious falls 15.00% 7408
≥ 1 fractures 3.75% 33222
≥ 1 hip fractures 2.25% 56168
Intermediate risk
Fallers1 50.00% 1386
≥ 1 injurious falls 20.00% 5258
≥ 1 fractures 5.00% 24618
≥ 1 hip fractures 3.00% 41828
High risk (25% higher than intermediate risk)
Fallers1 62.50% 868
≥ 1 injurious falls 25.00% 3966
≥ 1 fractures 6.25% 19456
≥ 1 hip fractures 3.75% 33222

Assumptions for sample size calculation: effect size -15% with respect to all outcomes, statistical power 80%, significance-level 5%, two-sided tests, not adjusted for multiple testing.

1Fallers reflect those study participants who experience any fall (injurious or not injurious) during the study period


[TableWrap ID: T6] Table 6 

Standardized system for categorizing and defining fall-related injuries


Category Definition
a - serious injury medically recorded fracture, head or internal injury requiring accident and emergency or inpatient treatment
b - moderate injury wounds, bruises, sprains, cuts requiring a medical/health professional examination such as physical examination, x-ray, suture
c - minor injury minor bruises or abrasions not requiring health professional assistance; reduction in physical function (e.g. due to pain, fear of falling) for at least three days.
d - no injury no physical injury detected


Article Categories:
  • Research Article

Keywords: Systematic review, Injurious falls, Elderly, Fall-related outcomes, Fall prevention trials.

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