Factors affecting adverse event reporting during mass ivermectin treatment for onchocerciasis

This study examines the effect of age, sex, dosing round, time of day, and distance from the nurse monitor on adverse event reporting during mass ivermectin administration at Achi, south-east Nigeria. There was a significant increase in adverse event reporting with age but no significant difference between the sexes. Both compliance and the incidence of reported adverse events were less during the second dosing round than during the first. Only three (2%) out of 144 subjects interviewed gave adverse events as a reason for non-compliance. Significantly fewer adverse events were reported as starting at night (22:00–06:00 h) than by day. The effect of distance on adverse event reporting was not statistically significant for distances up to 1 km.