Development of a simple screening tool for opportunistic COPD case finding in primary care in Latin America: The PUMA study

BACKGROUND AND OBJECTIVE: Opportunistic chronic obstructive pulmonary disease (COPD) case finding approaches for high-risk individuals with or without symptoms is a feasible option for disease identification. PUMA is an opportunistic case finding study conducted in primary care setting of Argentina, Colombia, Venezuela and Uruguay. The objectives were to measure COPD prevalence in an at-risk population visiting primary care for any reason, to assess the yield of this opportunistic approach and the accuracy of a score developed to detect COPD. METHODS: Subjects attending routine primary care visits, ≥40 years of age, current or former smokers or exposed to biomass smoke, completed a questionnaire and performed spirometry. COPD was defined as post-bronchodilator (post-BD) forced expiratory volume in 1 s (FEV1 )/forced vital capacity (FVC) < 0.70 and the lower limit of normal of FEV1 /FVC. RESULTS: A total of 1743 subjects completed the interview; 1540 performed acceptable spirometry. COPD prevalence was 20.1% (n = 309; ranging from 11.0% in Venezuela to 29.6% in Argentina) when defined using post-BD FEV1 /FVC < 0.70, and 14.7% (n = 226; ranging from 8.3% in Venezuela to 21.8% in Colombia) using the lower limit of normal. Logistic regression analysis for both definitions showed that the risk of COPD was significantly higher for persons >50 years, heavy smokers (>30 pack-years), with dyspnoea, and having prior spirometry. A simple score and a weighted score constructed using the following predictive factors: gender, age, pack-years smoking, dyspnoea, sputum, cough and spirometry, had a mean accuracy for detecting COPD (post-BD FEV1 /FVC < 0.70) of 76% and 79% for the simple and weighted scores, respectively. CONCLUSION: This simple seven-item score is an accurate screening tool to select subjects for spirometry in primary care.