An epidemiological profile of chronic obstructive pulmonary disease: A community-based study in Delhi

Abstract

Background: Different definitions used for chronic obstructive pulmonary disease (COPD) preclude getting reliable prevalence estimates. Study objective was to find the prevalence of COPD as per standard Global Initiative for Chronic Obstructive Lung Disease definition, risk factors associated, and treatment seeking in adults >30 years.

Methodology: Community-based cross-sectional study was conducted in Delhi, among 1200 adults, selected by systematic random sampling. Pretested questionnaire was used to interview all subjects and screen for symptoms of COPD. Postbronchodilator spirometry was done to confirm COPD.

Statistical analysis: Adjusted odds ratio (aOR) was calculated by multivariable analysis to examine the association of risk factors with COPD. Receiver operating characteristic (ROC) curve was developed to assess predictability.

Results: The prevalence of COPD was 10.1% (95% confidence interval [CI] 8.5, 11.9%). Tobacco smoking was the strongest risk factor associated (aOR 9.48; 95% CI 4.22, 14.13) followed by environmental tobacco smoke (ETS), occupational exposure, age, and biomass fuel. Each pack-year of smoking increased 15% risk of COPD. Ex-smokers had 63% lesser risk compared to current smokers. Clinical allergy seems to preclude COPD (aOR 0.06; 95% CI 0.02, 0.37). ROC analysis showed 94.38% of the COPD variability can be assessed by this model (sensitivity 57.4%; positive predictive value 93.3%). Only 48% patients were on treatment. Treatment continuation was impeded by its cost.

Conclusion: COPD prevalence in the region of Delhi, India, is high, and our case-finding population study identified a high rate of patients who were not on any treatment. Our study adds to creating awareness on the importance of smoking cessation, early diagnosis of COPD, and the need for regular treatment.

Figure 1

Methodology

Figure 2

Receiver operating characteristic curve of the multivariate model to predict chronic obstructive pulmonary disease (All factors significant in univariate analysis were used to create the model). Area under receiver operating characteristic curve 0.9438 (0.9260–0.9616), P < 0.001; model sensitivity: 57.38%, positive predictive value: 93.33%