Table 2.
Characteristics of the included trials
| Trials (n = 100) | |
|---|---|
| Number of clustersa – median (IQR) | 25 (15 to 44) |
| Number of clustersa – number (%) | |
| 4–9 | 14 (14) |
| 10–19 | 23 (23) |
| 20–29 | 18 (18) |
| 30–39 | 13 (13) |
| 40–49 | 11 (11) |
| 50–79 | 7 (7) |
| 80–99 | 4 (4) |
| 100 or more | 9 (9) |
| Patients per clustera – median (IQR) | 31 (14 to 94) |
| Primary outcome – number (%) | |
| Continuous | 40 (40) |
| Binary | 53 (53) |
| Count | 7 (7) |
| Accounted for clustering in analysis – number (%) | |
| Yes | 86 (86) |
| No | 10 (10) |
| Unclear | 4 (4) |
aIncludes data from 99 trial reports, as one trial report did not state the number of clusters involved
IQR interquartile range