ArticleContemporary clinical trials communications2018
Sample size estimation practices in research protocols submitted to Danish scientific ethics committees.
Article in Contemporary clinical trials communications, 2018. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 1 paper.
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Authors and funding
2 authors.
Funding
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Abstract
backgroundSample size in research projects is estimated before initiation of the study to minimise type 1 and type 2 error, while keeping the study's financial cost and subject enrolment to a minimum. This study investigates project-specific factors potentially associated with correct estimation of sample size in study protocols.
methodsExamination of 189 non-commercially sponsored study protocols (84 randomised controlled trials (RCTs) and 105 non-RCT studies) submitted to the Scientific Ethics Committees of The Capitol Region of Denmark from 2013 to 2015.
results119 (63%) study protocols contained a sample size calculation, with a significantly higher rate of sample size calculations in RCT vs non-RCT study protocols (76% vs. 52%, p < 0.001). Significantly more intervention studies than non-intervention studies (69% vs 52%, p = 0.020), studies including blood samples compared to those without (69% vs. 55%, p = 0.045), studies funded by a foundation donation compared to those with no funding (68% vs. 49%, p = 0.040) performed sample size calculations. Further, increasing number of sick patients enrolled (p = 0.048) and newer studies (p = 0.032) were more likely to include a sample size calculation in the protocol.
conclusionsEstimation of sample size is more often reported in RCT than non-RCT study protocols. Also, intervention studies, studies funded by a foundation donation, studies including blood samples, studies with a greater amount of sick participants and chronologically newer study protocols more often reported a sample size calculation.
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