Results of univariate linear regression of force of infection estimated using model 4 on demographic, socioeconomic, and climatic characteristics of provinces.

School attendance, percent of homes constructed with permanent materials, percent of provincial population in urban areas, gross provincial product (Baht per capita), and average temperature were not statistically significantly associated with the mean force of infection. Covariates significant in multiple linear regression: median age ?3.2e?3 (95% CI ?5.9e?3 to ?5.1e?4), latitude ?1.1e?8 (95% CI ?2.0e?8 to ?1.4e?9), and birth rate ?1.4e?3 (95% CI ?2.3e?3 to ?4.1e?4).