Table 1

Basic trial demographics of included SW-CRTs, values are numbers (percentages) unless stated otherwise

Total
N=60
Protocols
N=28
Full reports
N=32
Year of publication
 1987–201228 (46.7)12 (42.9)16 (50.0)
 2013–201432 (53.3)16 (57.1)16 (50.0)
Journal Impact Factor
 Median (IQR)2.6 (2.0–3.5)2.3 (2.1–4.8)3.3 (2.0–4.8)
Country of study
 Australia7 (11.7)6 (21.4)1 (3.1)
 Canada or USA15 (25.0)4 (14.3)11 (34.4)
 UK or Ireland11 (18.3)3 (10.7)8 (25.0)
 Other higher income country15 (25.0)9 (32.1)6 (18.8)
 Middle-income country9 (15.0)4 (14.3)5 (15.6)
 Low-income country3 (5.0)2 (7.1)1 (3.1)
Type of setting
 Healthcare50 (83.3)25 (89.3)25 (78.1)
 Non-healthcare10 (16.7)3 (10.7)7 (21.9)
Cluster
 General practice7 (11.7)6 (21.4)1 (3.1)
 Hospital/ward/specialties12 (20.0)5 (17.9)7 (21.9)
 Other health cluster20 (33.3)9 (32.1)11 (34.4)
 Geographical unit11 (18.3)5 (17.9)6 (18.8)
 Other/unclear10 (16.7)3 (10.7)7 (21.9)
Number of study arms
 Two56 (93.3)25 (89.3)31 (96.9)
 Three or more4 (6.7)3 (10.7)1 (3.1)
Randomisation type
 Simple35 (58.3)15 (53.6)20 (62.5)
 Paired4 (6.7)0 (0)4 (12.5)
 Stratified14 (23.3)10 (35.7)4 (12.5)
 Other/unclear7 (11.7)3 (10.7)4 (12.5)
Primary outcome type
 Continuous15 (25.0)10 (35.7)5 (15.6)
 Binary34 (55.7)13 (4.4)21 (65.6)
 Other5 (8.3)2 (7.1)3 (9.4)
 Unclear/not reported6 (10.0)3 (10.7)3 (9.4)
Published protocolNA5 (15.6)
  • NA, not available; SW-CRT, stepped-wedge cluster randomised trial.