Poverty and chronic airflow obstruction in the multinational Burden of Obstructive Lung Disease (BOLD) study: An update

Abstract

Background: Poverty has been associated with COPD mortality and prevalence. Yet, little information is available on the relationship between poverty and chronic airflow obstruction.

Aims: To examine the association between poverty and chronic airflow obstruction in 28 sites (mainly from low- and middle-income countries: LMICs) from the BOLD study.

Methods: We used data from 19,721 adults (≥40 years) participating in the BOLD study. Poverty at an individual level was evaluated using a wealth score, which was based on household assets, ranging from 0 (poorest) to 10 (richest). Using a wealth score from 14,595 participants, we imputed wealth scores for 5,126 participants whose information on wealth score was missing. Using a Bayesian linear regression model, we assessed the association between wealth score and forced expiratory volume in 1 second (FEV1) to forced vital capacity (FVC) ratio (%)adjusted for potential confounders. We also used a Bayesian logistic regression model to examine the association between wealth score and prevalence of FEV1/FVC<lower limit of normal.

Results: The FEV1/FVC(%) was associated with wealth score, increasing on average by 0.21% for each unit increase in the score (β-coef.=0.21, 95%CI: 0.12-0.31). The prevalence of chronic airflow obstruction was inversely associated with wealth score (OR=0.94, 95%C:I 0.91-0.97).

Conclusions: Our findings provide further evidence for the association of chronic airflow obstruction with poverty. One possible explanation being the limited access to healthcare services for poorer people, particularly in LMICs.