P121 Feasibility of performing valid spirometry in rural India: preliminary results from a population study assessing the prevalence of COPD

The Mysuru stUdies of Determinants of Health in Rural Adults (MUDHRA), India

Between 2006 and 2010, in 16 randomly selected villages in rural areas of Mysore district, in south India, 8,457 subjects aged 30 and above were screened for symptoms of chronic respiratory disease. Of the 8,457 subjects, 1,692 were randomly invited for further evaluation of lung function and chronic obstructive pulmonary disease (COPD) by spirometry, and 1,085 of these subjects underwent lung function assessments for prevalent COPD and its risk factors. These 1,085 subjects, who were then aged between 35 and 80 years, constituted the Mysuru stUdies of Determinants of Health in Rural Adults (MUDHRA) cohort. Among other findings, threshold of biomass fuel smoke exposure suitable for use as a dichotomous risk factor for the diagnosis of chronic bronchitis was established, with a minimum biomass smoke exposure index of 60 found to be significantly associated with an elevated risk of developing chronic bronchitis. Five years later (between 2014 and 2016), 869 of the 1,085 participants were followed up with repeat lung function assessments for incident COPD and all-cause mortality. A subset of these participants (n=200) underwent blood tests for vitamin D levels, antioxidant activity, an assessment for anxiety and depression, and another subset (n=98) underwent a bioplex assay for 40 serum cytokines.

Prevalence of COPD in India: a systematic review

BACKGROUND

The increasing burden of chronic diseases is a particular risk to countries with developing health systems. Chronic obstructive pulmonary disease (COPD) is contributing to the burden of chronic diseases. Understanding the current prevalence of COPD in India is important for the production of sustainable management strategies.

AIMS

To provide a systematic review of studies assessing the prevalence of COPD in India.

METHODS

Database searches, journal hand searches, and scanning of reference lists were used to identify studies. Studies of general adult populations resident in India were included. Data extraction and quality assessment were carried out using pre-tested proformas. Owing to the heterogeneity of reviewed studies, meta-analysis was not appropriate. Thus, narrative methods were used.

RESULTS

We did not identify any studies from which we could draw a rigorous estimate of the prevalence of COPD by standard definition. Reliable standard estimates of chronic bronchitis were only available for rural populations. We identified four studies that gave estimated prevalences between 6.5% and 7.7%, and others suggestive that prevalences in some environmentally atypical regions may lie outside this range. Sex and smoking status were relatively important predictors of COPD prevalence. Residential environs, age, and domestic smoke exposure are also important, but investigation of their effect was limited by study heterogeneity.

CONCLUSIONS

Although limited by the number and heterogeneity of studies and their unsuitability for meta-analysis, we found the most rigorous existing estimates of the general prevalence of chronic bronchitis in rural areas to lie between 6.5% and 7.7%. These figures are unlikely to apply to all Indian subpopulations, so the general prevalence of chronic bronchitis in India remains unknown. Accurate estimates of the prevalence of chronic bronchitis/COPD from across the country are required to supplement existing data if optimal management strategies are to be devised.