Table 1 Some reviews of published cluster randomised trials
From: Cluster randomised trials in the medical literature: two bibliometric surveys
Authors | Source of trials | Years | Clustering allowed for in sample size | Clustering allowed for in analysis |
|---|---|---|---|---|
Donner et al. [8] | 16 non-therapeutic intervention trials | 1979 – 1989 | <20% | <50% |
Simpson et al. [9] | 21 trials from American Journal of Public Health and Preventive Medicine | 1990 – 1993 | 19% | 57% |
Isaakidis and Ioannidis [11] | 51 trials in Sub-Saharan Africa | 1973 – 2001 (half post 1995) | 20% | 37% |
Puffer et al. [10] | 36 trials in British Medical Journal, Lancet, and New England Journal of Medicine | 1997 – 2002 | 56% | 92% a |
Eldridge et al. [12] | 152 trials in primary health care | 1997 – 2000 | 9% | 59% |
Varnell et al. [13] | 60 trials in American Journal of Public Health and Preventive Medicine | 1998 – 2002 | 20% | 54% (all analyses) + 25% (some analyses only) |