Table 4 Illustrative example to determine the cluster size (m) for a fixed number of clusters (k) and set maximum likely error (10%) across a range of intra-cluster correlation coefficients (ICCs)
Cluster size (m) needed by number of clusters (k) and ICC | ||||||
|---|---|---|---|---|---|---|
k = 6 | k = 8 | k = 10 | k = 14 | k = 20 | ||
ICC | 0.30 | NA | NA | NA | NA | NA |
0.15 | NA | NA | NA | NA | 28 | |
0.10 | NA | NA | NA | 51 | 12 | |
0.05 | NA | 276 | 38 | 14 | 8 | |