The effect of malaria on work time: analysis of data from two Nepali districts.

Malaria patients' loss of effective work time can account for an important proportion of the disease's economic cost. Here the extent, incidence and determinants of this loss are investigated. Data from 695 matched patient-control pairs from Nawal Parasi and Dhanusa districts in Nepal are analysed. Pairwise differences in work time are attributed to malaria, and the individual influences of the differences' determinants identified by regression. The mean pairwise differences in the number of days wholly and partially disabled by illness in the month preceding interview were respectively 5.31 (95% confidence interval 4.82-5.79) and 1.21 days (95% CI 0.95-1.47). The interval between fever onset and presumptive treatment, parasite species, the density of peripheral parasitaemia and district of residence each exerted significant influences over the difference in complete disability. The mean pairwise difference in the number of minutes worked on the day before the interview was 108 (95% CI 97-120). Socioeconomic variables, the interval between interview and perceived complete recovery, the pairwise difference in the number of days' complete disability in the month preceding interview and district of residence were significant to this difference. Poorer patients lose more time. The results corroborate past assumptions of debility, demonstrate that malaria's effect on effective work time may vary between socioeconomic groups, and underline the economic importance of speedy case detection and presumptive treatment.