Authors | Year | Data Source | Findings |
---|---|---|---|
Charlson et al. | 1984 | 41 RCTs (≥ 250 patients) identified by an inventory of the National Institute of Health in 1979; investigator survey was principal data source | A third of RCTs recruited fewer than 75% of their planned sample size |
Easterbrook et al. | 1992 | 720 research protocols (N = 137 RCTs) approved by REC (UK); investigator survey was principal data source | Main reason (28%) for terminating the study was slow recruitment of patients |
Wilson et al. | 2000 | RCT that investigated two management strategies for dyspepsia in primary care (UK) | 90 primary care physicians were contacted; 43 agreed to participate, 31 recruited at least one patient, only 23 recruited more than 5 patients. |
Foy et al | 2003 | 7 primary care trials of dyspepsia management in the UK | One study reached its recruitment target; five recruited less than 50% of target and three of those closed prematurely |
McDonald et al. | 2006 | 114 RCTs funded by the Medical Research Council and Health Technology Assessment (UK); full scientific applications and subsequent trial reports were principal data source | Less than a third of the trials achieved their original recruitment target |
Toerien et al. | 2009 | 133 publications of RCTs identified by a systematic literature review (restricted to six major journals) | Of those trials reporting sample size calculation, 21% failed to achieve planned numbers at randomisation and 48% at outcome assessment. |