Estimating Chronic Respiratory Disease (Asthma and COPD) burden in adults in Asian LMICs: a pilot study for 4CCORD [4 Country ChrOnic Respiratory Disease study]

Background: Chronic Respiratory Diseases (CRD) especially asthma and chronic obstructive pulmonary disease (COPD) are global public health problems. Although the majority of deaths and disability from CRD occur in low- and middle-income countries (LMICs), the true burden of CRD is unclear. Widely used questionnaire-based research tools have poor sensitivity and specificity, and the use of spirometry in the community is challenging.Methods: We undertook a pilot community-based survey at five sites in four countries [Bangladesh (1); India (2); Malaysia (1); Pakistan (1)] using random sampling strategies, a questionnaire (adapted from BOLD informed by our scoping review) and quality-assured spirometry. We made a provisional diagnosis of asthma, COPD or ‘other CRD’ based on the questionnaire/spirometry data (using a 70% fixed ratio for obstruction). Chest physicians at respective sites, examined participants with CRD symptoms and/ or abnormal spirometry to reach a clinical diagnosis.Results: 508 participants were surveyed from the five sites. 51.4% reported chronic respiratory symptoms. Based on the questionnaire and spirometry data, the provisional prevalence of asthma, COPD and ‘other CRD’ was 18.7%, 10.4%, and 21.2% respectively. Based on the clinicians’ diagnosis the prevalence of asthma, COPD and ‘other CRD’ was 18.8%, 13.3%, and 7.7% respectively. Analysis of concordance and discordance between provisional and clinical diagnosis is in progress. The prevalence of COPD ranged from 3.8% in [India] to 16.0% in [Bangladesh]; prevalence of asthma ranged from 11.9% in [Malaysia] to 32.0% in [Pakistan].Conclusion: This pilot study suggests a high prevalence of asthma, COPD and other CRD in the four LMICs. Our data will facilitate refinement of clinical algorithms to making a diagnosis of asthma, COPD and other CRD in readiness for a fully powered survey in these four countries. Evidence of the true prevalence of CRD will interest policymakers and developers of healthcare services. Implementation Science/Service Development Research Ideas on Respiratory Conditions and Tobacco Dependency Abstract Declaration of Interest Funding: NIHR Global Health Research Unit on Respiratory Health (RESPIRE) 16/136/109 References and Clinical Trial Registry Information Not applicable