Characteristics | No. of trials, m | Fitted mean | 95% CI | F test | p value |
---|---|---|---|---|---|
Inclusion criteria | |||||
Gender | 1148 | 10.61 | <.0001 | ||
Both | 49.30 | (41.85–58.08) | |||
Female | 58.12 | (44.23–76.38) | |||
Male | 21.09 | (14.04–31.69) | |||
Age categories a | 1148 | 4.52 | 0.0004 | ||
Children only | 36.29 | (28.03–46.99) | |||
Adults only | 58.49 | (45.34–75.45) | |||
Elderly only | 89.17 | (58.86–135.08) | |||
Children and adults | 51.94 | (39.74–67.87) | |||
Children to elderly | 44.98 | (36.88–54.85) | |||
Adults to elderly | 50.93 | (42.66–60.80) | |||
Study designs | |||||
Has DMC? b | 963 | 9.94 | 0.0017 | ||
No | 42.95 | (35.92–51.36) | |||
Yes | 52.43 | (44.06–62.38) | |||
FDA regulated intervention? c | 1076 | 4.09 | 0.0433 | ||
No | 52.30 | (43.72–62.56) | |||
Yes | 46.20 | (38.77–55.06) | |||
Intervention model | 1114 | 56.55 | <.0001 | ||
Crossover assignment | 28.63 | (21.84–37.53) | |||
Factorial assignment | 139.83 | (56.36–346.91) | |||
Parallel assignment | 71.38 | (60.45–84.28) | |||
Single group assignment | 34.28 | (29.05–40.46) | |||
Interventions, facilities and authorities | |||||
Lead sponsor | 1148 | 1.53 | 0.2041 | ||
US Federal | 68.43 | (30.81–151.99) | |||
Industry | 46.20 | (38.50–55.43) | |||
NIH | 65.80 | (44.80–96.65) | |||
Other | 49.20 | (41.46–58.38) | |||
Trial location | 1148 | 7.68 | <.0001 | ||
US only | 42.50 | (35.57–50.79) | |||
EU only | 71.63 | (55.99–91.64) | |||
US and EU | 46.29 | (35.40–60.53) | |||
Single European country | 49.77 | (41.55–59.62) | |||
No. of countries involved in the trial | 1148 | 1.07 d | (1.04–1.11) | 16.07 | <.0001 |
Year that enrolment to the protocol begins | 1141 | 3.14 | 0.0081 | ||
<1990 | 131.48 | (34.06–507.57) | |||
1990–1999 | 57.83 | (41.44–80.69) | |||
2000–2004 | 63.10 | (50.12–79.44) | |||
2005–2009 | 44.61 | (37.31–53.34) | |||
2010–2014 | 48.72 | (40.92–58.01) | |||
2015 and after | 49.89 | (35.70–69.71) | |||
No. of arms | 1085 | 1.39 d | (1.30–1.49) | 83.75 | <.0001 |