Table 1

Some reviews of published cluster randomised trials

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)


a My review of trials identified by Puffer et al. [10]

Bland BMC Medical Research Methodology 2004 4:21   doi:10.1186/1471-2288-4-21

Open Data