Sample size calculations
The Hooper and Bourke method for cluster randomization studies of parallel arms with repeated cross-sections was used to calculate the sample sizeThe second design effect (dThe second design effect (dThe required sample size was then calculated by multiplying the ‘sample size assuming individual randomization’ by both design effects (dc and dr). It was calculated as:In addition, the following parameters were considered: 95% CI 80% power, 1:1 allocation ratio of intervention to control, 10% potential loss to follow up, and tabulated sample size 