Misreported diabetes: Estimating the 'real' burden of diabetes in Latin America and the Caribbean

Most studies in developing countries rely on self-reported measures as a way to assess the prevalence and incidence of chronic conditions. Self-reported measures are less expensive to be collected, but their validity is usually questioned. This paper proposes an innovative approach to estimate adjusted diabetes prevalence rates in Latin America and the Caribbean. This approach combines data on demographic, social and clinical diagnosis to predict new prevalence rates. Data from Salud, Bienestar y Envejecimiento en América Latina y el Caribe Proyecto (SABE), Mexican Health and Aging Study (MHAS), Encuesta Nacional de Salud (ENSA) and Estudio de Longevidad y Envejecimiento Saludable (CRELES) are used in the analysis. The results indicate that diabetes prevalence estimated by self-reports is underestimated for most part. For example, the self-reported diabetes prevalence among older adults in Buenos Aires is 12.4% (95% confidence interval [CI], 12.1-15.6), while the predicted prevalence can reach 30.2% (95% CI, 28.6-31.8). As a consequence, the average number of years expected to be lived with diabetes are considerably higher than one would expect using self-reported measures. Finally, using data from a nationally representative sample of Mexicans, this paper shows that estimates of total life expectancy and disability-free life expectancy of diabetics based on self-reports may be biased downwards. In any case, it is important to understand that diabetes reduces total life expectancy and the bulk of this reduction comes in the form of reductions in the number of years expected to be lived without disability. The new estimate shows that total life expectancy of diabetics at age 50 is about 4 years lower than among non-diabetics in Mexico. This estimate contrasts with the estimate obtained with self-reported measures, in which reduction in total life expectancy was about 8 years. The difference between these estimates can be explained by the fact that undiagnosed diabetics are relatively better off than those who self-report being diabetic – undiagnosed individuals are usually at earlier stages of the disease progression.