Validity of an abbreviated Individual Water Insecurity Experiences (IWISE-4) Scale for measuring the prevalence of water insecurity in low- and middle-income countries

Abstract

Abstract The 12-item Water Insecurity Experiences Scales provide high resolution, cross-context equivalent data on household and individual water insecurity. A 4-item, 1-minute version of the Household Water Insecurity Experiences (HWISE-4) Scale has proven useful for understanding the prevalence of household water insecurity experiences when limited resources preclude the use of the HWISE-12 Scale. Herein, we tested the validity of an analogous four-item version of the Individual Water Insecurity Experiences Scale (IWISE-4) for measuring the prevalence of individual water insecurity when limited resources prevent implementation of the IWISE-12 Scale. We used data from adults in 31 low- and middle-income countries (n=43,970) to assess internal consistency, cross-country equivalence, predictive accuracy, and construct validity of the IWISE-4. Receiver operating characteristic curves showed that the IWISE-4 (range 0–12) predicted individual water insecurity with ≥95% accuracy in every country. An IWISE-4 cut-point of ≥4 provided the closest approximation of water insecurity prevalence as predicted by the IWISE-12 scale (cut-point ≥12), correctly classifying 87.1–98.5% of adults across countries, and was similarly associated with water quality dissatisfaction, a measure of construct validity. Although the IWISE-4 Scale cannot measure the severity of water insecurity, the IWISE-4 provides suitable and cross-country equivalent estimates of the prevalence of individual water insecurity.