Socioeconomic status and COPD among low- and middle-income countries

Abstract

Matthew Grigsby,1,2 Trishul Siddharthan,1 Muhammad AH Chowdhury,3 Ali Siddiquee,3 Adolfo Rubinstein,4 Edgardo Sobrino,4 J Jaime Miranda,5,6 Antonio Bernabe-Ortiz,5 Dewan Alam,7 William Checkley1,2 1Division of Pulmonary and Critical Care, School of Medicine, 2Program in Global Disease Epidemiology and Control, Department of International Health, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA; 3Centre for Control of Chronic Diseases, icddr,b, Dhaka, Bangladesh; 4Institute for Clinical Effectiveness and Health Policy, Buenos Aires, Argentina; 5CRONICAS Centre of Excellence for Chronic Diseases, Universidad Peruana Cayetano Heredia, 6Department of Medicine, School of Medicine, Universidad Peruana Cayetano Heredia, Lima, Peru; 7Faculty of Health, School of Kinesiology and Health Science, York University, Toronto, ON, Canada Background: Socioeconomic status (SES) is a strong social determinant of health. There remains a limited understanding of the association between SES and COPD prevalence among low- and middle-income countries where the majority of COPD-related morbidity and mortality occurs. We examined the association between SES and COPD prevalence using data collected in Argentina, Bangladesh, Chile, Peru, and Uruguay.Methods: We compiled lung function, demographic, and SES data from three population-based studies for 11,042 participants aged 35–95 years. We used multivariable alternating logistic regressions to study the association between COPD prevalence and SES indicators adjusted for age, sex, self-reported daily smoking, and biomass fuel smoke exposure. Principal component analysis was performed on monthly household income, household size, and education to create a composite SES index.Results: Overall COPD prevalence was 9.2%, ranging from 1.7% to 15.4% across sites. The adjusted odds ratio of having COPD was lower for people who completed secondary school (odds ratio [OR] =0.73, 95% CI 0.55–0.98) and lower with higher monthly household income (OR =0.96 per category, 95% CI 0.93–0.99). When combining SES factors into a composite index, we found that the odds of having COPD was greater with lower SES (interquartile OR =1.23, 95% CI 1.05–1.43) even after controlling for subject-specific factors and environmental exposures.Conclusion: In this analysis of multiple population-based studies, lower education, lower household income, and lower composite SES index were associated with COPD. Since household income may be underestimated in population studies, adding household size and education into a composite index may provide a better surrogate for SES. Keywords: COPD, socioeconomic status, low- and middle-income country

Keywords

• COPD
• socioeconomic status
• low- and middle-income country