Sample size
The sample size for the study was calculated considering 80% power, 5% level of significance, an attrition rate of 20%, a design effect of 1.5, an improvement of cognitive status in the standard of care of 30%, and 50% improvement in researcher intervention. Considering these, the required sample size was 230 for the intervention and control groups (115 in each group). Thus, 253 samples were included in the study from the selected clusters (127 + 126).