Table 4 Percentages accounting for clustering in sample size calculations and analysis in previous reviews
Authors | Source of trials | Years | Clustering accounted for | |
|---|---|---|---|---|
In sample size | In analysis | |||
Donner et al. [5] | 16 non-therapeutic Intervention trials | 1979-1989 | 19% | 50% |
Simpson et al. [6] | 21 trials from Amer J Pub Health Prev Med | 1990-1993 | 19% | 57% |
Chuang et al. [7] | 24 trials of computer based decision support | 1975-1998 | 0% | 58% |
Isaakidis et al. [8] | 51 trials in Sub-Saharan Africa | 1973-2001 | 20% | 37% |
Puffer et al. [3] | 36 trials in BMJ, Lancet and NEJM | 1997-2002 | 56% | 92% |
Eldridge et al. [10] | 152 trials in primary health care | 1997-2000 | 9% | 59% |
Varnell et al. [39] | 60 trials in Amer J PubHealth Prev Med | 1998-2002 | 15% | 54% |
Bland [9] | 18 articles in BMJ | 1983-2003 | n/a | 72% |
Eldridge et al. [4] | 34 articles in primary health care | 2004-2005 | 62% | 88% |
Murray et al. [38] | 75 trials in oncology | 2002-2006 | 24% | 45% |
Bowater et al. [11] | 35 trials in tropical parasitic diseases | 1998-2007 | 29% | 43% |
Handlos et al. [24] | 35 trials in maternal and child health | 1998-2008 | 71% | 80% |
Froud et al. [27] | 23 trials in oral health | 2005-2009 | 65% | 78% |
Ivers et al. [12] | 300 trials of cluster design randomly selected | 2000-2008 | 33%h | 70% |
This review | 73 trials in residential facilities for older people | 1993-2010 | 27% i | 74% |