The accuracy of self-report versus objective assessment for estimating socioeconomic inequalities in disease prevalence in Indonesia

Objectives: To estimate socioeconomic inequalities in hypertension and asthma prevalence in Indonesia, to compare estimates based on self-report (SR) to those based on objective assessment (OA), and to assess the role of sensitivity and specificity of SR. Methods: We used data from the 2014 Indonesia Family Life Survey (n = 34,257). We measured inequalities in hypertension and asthma prevalence in relation to educational level and income, using standardised prevalence rate and the relative index of inequality (RII). Using OA as standard, we calculated the sensitivity and specificity of SR. Results: For hypertension, reversed inequalities were found when estimated by SR instead of OA (RII for education 0.86, 95% CI 0.74–0.99 vs. RII 1.29, 95% CI 1.16–1.44). For asthma, a similar but even larger reversal of inequalities was found. The sensitivity of SR was low overall, and especially for the lowest education or income group. Conclusions: Results imply that the use of SR may lead to underestimation of socioeconomic inequalities in disease prevalence in a low-income country such as Indonesia. The use of OA is recommended for monitoring inequalities in non-communicable disease prevalence.