Document Detail

Efficient ways exist to obtain the optimal sample size in clinical trials in rare diseases.
MedLine Citation:
PMID:  18313556     Owner:  NLM     Status:  MEDLINE    
OBJECTIVE: Recruitment of pediatric patients in randomized clinical trials is hampered by the rarity of many conditions and by ethical constraints. The objective of this paper is to give an overview of design options to obtain a statistically valid result while including a minimum number of subjects. STUDY DESIGN AND SETTING: Overview and discussion of several approaches to conduct valid randomized clinical trials in rare diseases and vulnerable populations. RESULTS: Sequential designs have been developed as efficient ways to evaluate accumulating information from a clinical trial, thereby reducing the average size of trials. Different sequential procedures exist, including group sequential designs, boundaries designs, and adaptive designs. The sample size attained at the end of the trial is unknown at the start. The sample size for a given set of alpha, beta, and effect size may turn out to be larger than with a classical fixed sample size approach. Simulations have shown that on average, sample sizes are smaller. CONCLUSION: There are several possibilities to optimize the number of subjects in a clinical trial. The rarity of many disorders in children and the ethical requirements in this patient population should not obstruct the performance of well-designed research to support clinical decision making.
J H van der Lee; J Wesseling; M W T Tanck; M Offringa
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Publication Detail:
Type:  Journal Article; Review     Date:  2008-02-21
Journal Detail:
Title:  Journal of clinical epidemiology     Volume:  61     ISSN:  0895-4356     ISO Abbreviation:  J Clin Epidemiol     Publication Date:  2008 Apr 
Date Detail:
Created Date:  2008-03-03     Completed Date:  2008-09-15     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  8801383     Medline TA:  J Clin Epidemiol     Country:  England    
Other Details:
Languages:  eng     Pagination:  324-30     Citation Subset:  IM    
Department of Pediatric Clinical Epidemiology, Emma Children's Hospital, Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands.
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MeSH Terms
Epidemiologic Research Design*
Ethics, Clinical
Randomized Controlled Trials as Topic / ethics,  methods*
Rare Diseases*
Sample Size*

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