Assessing latrine use in rural India: A cross-sectional study comparing reported use and passive latrine use monitors

Although large-scale programs, like India's Total Sanitation Campaign (TSC), have improved latrine coverage in rural settings, evidence suggests that actual use is suboptimal. However, the reliability of methods to assess latrine use is uncertain. We assessed the reliability of reported use, the standard method, by comparing survey-based responses against passive latrine use monitors (PLUMs) through a cross-sectional study among 292 households in 25 villages in rural Odisha, India, which recently received individual household latrines under the TSC. PLUMs were installed for 2 weeks and householders responded to surveys about their latrine use behavior. Reported use was compared with PLUM results using Bland-Altman (BA) plots and concordance statistics. Reported use was higher than corresponding PLUM-recorded events across the range of comparisons. The mean reported "usual" daily events per household (7.09, 95% confidence interval [CI] = 6.51, 7.68) was nearly twice that of the PLUM-recorded daily average (3.62, 95% CI = 3.29, 3.94). There was poor agreement between "usual" daily latrine use and the average daily PLUM-recorded events (ρ_c = 0.331, 95% CI = 0.242, 0.427). Moderate agreement (ρ_c = 0.598, 95% CI = 0.497, 0.683) was obtained when comparing daily reported use during the previous 48 hours with the average daily PLUM count. Reported latrine use, though already suggesting suboptimal adoption, likely exaggerates the actual level of uptake of latrines constructed under the program. Where reliance on self-reports is used, survey questions should focus on the 48 hours prior to the date of the survey rather than asking about "usual" latrine use behavior.