Table 1 |
||||||||
| sample size calculations | ||||||||
| Detectable difference in SBP between both the groups | 80% power with an ICC of 0.02 | 90% power with an ICC of 0.02 | ||||||
| Sample size required for individual randomization per arm | Sample size required for cluster randomization per arm (DE = 2.98) | Sample size required for cluster randomization with CV = 0.25 (DE = 3.1) | Minimum no of clusters with a cluster size of 100 | Sample size required for individual randomization per arm | Sample size required for cluster randomization per arm (DE = 2.98) | Sample size required for cluster randomization with CV = 0.25 (DE = 3.1) | Minimum no of clusters with a cluster size of 100 | |
| 4 mm of Hg | 374 | 1115 | 1160 | 24 | 500 | 1490 | 1550 | 32 |
| 5 mm of Hg | 239 | 713 | 741 | 16 | 320 | 954 | 992 | 20 |
| 6 mm of Hg | 166 | 495 | 515 | 12 | 222 | 622 | 689 | 14 |
ICC = Intra Cluster correlation; DE = design effect; CV = coefficient of variation.
Anchala et al. BMC Public Health 2012 12:393 doi:10.1186/1471-2458-12-393
