ACCURACY OF COPD SCREENING STRATEGIES AMONG HYPERTENSIVE PATIENTS IN BRAZIL: A BREATHE WELL STUDY

Background:COPD and hypertension are often concomitant diseases, although undiagnosed COPD is common in Brazil and the optimal strategy to identify new cases is unclear. Aims: To evaluate the accuracy and cost-effectiveness of COPD screening strategies amongst hypertensive patients in Brazil. Methods: Test accuracy study conducted in 9 Basic Health Units. Participants completed 6 index tests (CDQ, CAPTURE, COPD-SQ, symptom based questionnaire [SBQ], microspirometry [COPD-6], peak flow [Mini Wright]) and the reference test (ndd Easy-On PC and clinical review). Cases were defined as below lower limit of normal (LLN-GLI) with clinically confirmed symptoms. Performance of all index tests and strategies was evaluated, with specificity being prioritised. Cost effectiveness analysis will be presented at the conference. Results: 1162 participants (mean age 62.3 [SD10.1] years, 32.5% [n=378] male) completed the study; 49.1% (n=570) were never smokers and 9.8% (n=114) had an existing COPD diagnosis. 79 participants (6.8%) were confirmed cases after clinical review. Airflow measurement devices (sensitivities 44.3% and 50.6%,specificity 95.5% and 87,2% for peak flow and microespirometry respectively) generally had better specificity than questionnaires, the most accurate of with was SBQ (sensitivity 75.9%, specificity 59,2%). For combinations requiring both tests to be positive, SBQ and peak flow maximised specificity(97.0%) with sensitivity of 39.2%. Conclusion: The peak flow was the best performing airflow measurement device, SBQ the best questionnaire, and the combination of SBQ and peak flow the most accurate strategy. Different cut-points need to be explored to optimise use in practice.