Accuracy of self-reported private health insurance coverage

Abstract

Studies on health insurance coverage often rely on measures self-reported by respondents, but the accuracy of such measures has not been thoroughly validated. This paper is the first to use linked Australian National Health Survey and administrative population tax data to explore the accuracy of self-reported private health insurance (PHI) coverage in survey data. We find that 11.86% of individuals misreport their PHI coverage status, with 11.57% of true PHI holders reporting that they are uninsured and 12.37% of true non-insured persons self-identifying as insured. Our results show reporting errors are systematically correlated with individual and household characteristics. Our evidence on the determinants of errors is supportive of common reasons for misreporting. We directly investigate biases in the determinants of PHI enrollment using survey data. We find that, as compared to administrative data, survey data depict a quantitatively different picture of PHI enrollment determinants, especially those capturing age, gender, language proficiency, labor force status, disability status, number of children in the household, or household income. We also show that PHI coverage misreporting is subsequently associated with misreporting of reasons for purchasing PHI, type of cover and length of cover.

Keywords: Australia; administrative data; health insurance; linked data; measurement error; survey misreporting.