Table 2.

Recruitment and sample size characteristics of the trials included in the review

Characteristic (n=388)		n (%)	Mean (SD)	Median (IQR)	Range
No of centres	1	25 (6)	29 (34)	17 (7–37)	1–274
	2–5	61 (16)
	6–10	48 (12)
	11–20	69 (18)
	21–50	112 (29)
	51–100	48 (12)
	>100	16 (4)
	Missing	9 (2)
Original target recruitment	≤200	49 (13)	1097 (3080)	500 (300–900)	50–46 000
	201–400	101 (26)
	401–600	86 (22)
	601–800	41 (11)
	>800	109 (28)
	Missing	2 (1)
Final target recruitment	≤200	53 (14)	1041 (3074)	480 (270–802)	44–46 000
	201–400	112 (29)
	401–600	84 (22)
	601–800	42 (11)
	>800	97 (25)
Final total recruitment	≤200	72 (19)	991 (3025)	452 (236–800)	2–47 062
	201–400	99 (26)
	401–600	82 (21)
	601–800	39 (10)
	>800	96 (25)
Final recruitment target achieved	Yes	245 (63)
	No, but with ≥80% of target	86 (22)
	No, <80% of target	57 (15)
Timing of primary outcome follow-up (months postrandomisation)	≤1 month	42 (11)	12 (13)	10 (3–12)	0–120
	1< months ≤6	129 (33)
	6< months ≤18	131 (34)
	>18 months	63 (16)
	Missing	23 (6)
Timing of final follow-up (months postrandomisation)	≤1 month	20 (5)	16 (19)	12 (6–18)	0.066–144
	1< months ≤6	87 (22)
	6< months ≤18	181 (47)
	>18 months	88 (23)
	Missing	12 (3)