Comparison of randomized controlled trials discontinued or revised for poor recruitment and completed trials with the same research question: a matched qualitative study

Table 1 Recruitment characteristics of included randomized controlled trials with and without poor recruitment across research questions

	RCTs with poor recruitment, n = 29	RCTs without poor recruitment, n = 48
Originally planned number of patients (median; IQR)	395 (72–600)	272 (22–500)
Number of patients randomized (median; IQR)	150 (41–329)	306 (23–559)
Duration of recruitment period in months (median; IQR)	39 (10–47)	24 (7–45)
Number of patients recruited per year and center^a (median; IQR)	3 (1–5)	7 (1–25)
Trial sponsor (industry n (%) / investigator n (%))	12 (41%) / 17 (59%)	20 (42%) / 27 (56%) / NR 1 (2%)

IQR interquartile range (25th and 75th percentile), NR not reported, RCT randomized controlled trial
^aRough estimate for recruitment speed based on own calculations (number of patients recruited divided by recruitment duration and number of study centers); not adjusted to the time a site was actually open for recruitment, because this was not reported in the publications of included trials)

ISSN: 1745-6215