For stepped-wedge cluster randomized trial (India)
syphilis
SYPHILIS
For estimating the sample size for the stepped-wedge cluster randomized design, we utilized one of the primary indicators: proportion of pregnant women who were screened for syphilis during their pregnancy. The current estimates for this indicator are approximately 20% in both Tamil Nadu and Assam. Considering 20% as the baseline, and our study having 80% power to detect a minimum change of 15%, alpha error of 5%, cluster size of 100 per period, intracluster correlation coefficient (ICC) of 0.1 and cluster autocorrelation coefficient (CAC) of 0.8, the total sample size computed is 4800 women, or 800 per period. To account for issues around data loss (incomplete entries, errors in entries, etc.), we have further inflated this computed sample size by 20%. This results in a total sample of 5760 women, or 960 per period.