Table 1 Covariates for constrained randomization

Socioeconomic status (SES), measured by dichotomizing INSE scores into two categories (> 3 vs ≤3)

SES may predict arboviral infection risk

Each arm within ±5% of overall proportion

Population density

Population density may predict arboviral infection risk

Each arm within ±5% of overall population density

Number of students in grades 1 and 2 combined

Proxy for age of participants to be enrolled in a given cluster. Age is predictive of individual arboviral infection risk.

Each arm 45–55% of total number