Vellakkal, Sukumar; Millett, Christopher; Basu, Sanjay; Khan, Zaky; Aitsi-Selmi, Amina; Stuckler, David; Ebrahim, Shah; (2014) Are estimates of socioeconomic inequalities in chronic disease artefactually narrowed by self-reported measures of prevalence in low-income and middle-income countries? Findings from the WHO-SAGE survey. Journal of epidemiology and community health, 69 (3). pp. 218-225. ISSN 0143-005X DOI: https://doi.org/10.1136/jech-2014-204621
Permanent Identifier
Use this Digital Object Identifier when citing or linking to this resource.
Abstract
BACKGROUND: The use of self-reported measures of chronic disease may substantially underestimate prevalence in low-income and middle-income country settings, especially in groups with lower socioeconomic status (SES). We sought to determine whether socioeconomic inequalities in the prevalence of non-communicable chronic diseases (NCDs) differ if estimated by using symptom-based or criterion-based measures compared with self-reported physician diagnoses. METHODS: Using population-representative data sets of the WHO Study of Global Ageing and Adult Health (SAGE), 2007-2010 (n=42 464), we calculated wealth-related and education-related concentration indices of self-reported diagnoses and symptom-based measures of angina, hypertension, asthma/chronic lung disease, visual impairment and depression in three 'low-income and lower middle-income countries'-China, Ghana and India-and three 'upper-middle-income countries'-Mexico, Russia and South Africa. RESULTS: SES gradients in NCD prevalence tended to be positive for self-reported diagnoses compared with symptom-based/criterion-based measures. In China, Ghana and India, SES gradients were positive for hypertension, angina, visual impairment and depression when using self-reported diagnoses, but were attenuated or became negative when using symptom-based/criterion-based measures. In Mexico, Russia and South Africa, this distinction was not observed consistently. For example, concentration index of self-reported versus symptom-based angina were: in China: 0.07 vs. -0.11, Ghana: 0.04 vs. -0.21, India: 0.02 vs. -0.16, Mexico: 0.19 vs. -0.22, Russia: -0.01 vs. -0.02 and South Africa: 0.37 vs. 0.02. CONCLUSIONS: Socioeconomic inequalities in NCD prevalence tend to be artefactually positive when using self-report compared with symptom-based or criterion-based diagnostic criteria, with greater bias occurring in low-income countries. Using standardised, symptom-based measures would provide more valid estimates of NCD inequalities.
Item Type | Article |
---|---|
Faculty and Department |
Faculty of Public Health and Policy > Dept of Health Services Research and Policy Faculty of Epidemiology and Population Health > Dept of Non-Communicable Disease Epidemiology |
PubMed ID | 25550454 |
ISI | 349542100005 |
Related URLs |
Download
Filename: jech-2014-204621-s1.pdf
Licence: Creative Commons: Attribution-Noncommercial-No Derivative Works 3.0
Download