<p>A Novel Case-Finding Instrument for Chronic Obstructive Pulmonary Disease in Low- and Middle-Income Country Settings</p>

Abstract

Background Low- and middle-income countries (LMICs) account for >90% of deaths and illness episodes related to COPD; however, this condition is commonly underdiagnosed in these settings. Case-finding instruments for COPD may improve diagnosis and identify individuals that need treatment, but few have been validated in resource-limited settings. Methods We conducted a population-based cross-sectional study in Uganda to assess the diagnostic accuracy of a respiratory symptom, exposure and functional questionnaire in combination with peak expiratory flow for COPD diagnosis using post-bronchodilator FEV 1 /FVC z-score below the 5th percentile as the gold standard. We included locally relevant exposure questions and statistical learning techniques to identify the most important risk factors for COPD. We used 80% of the data to develop the case-finding instrument and validated it in the remaining 20%. We evaluated for calibration and discrimination using standard approaches. The final score, COLA (COPD in LMICs Assessment), included seven questions, age and pre-bronchodilator peak expiratory flow. Results We analyzed data from 1,173 participants (average age 47 years, 46.9% male, 4.5% with COPD) with acceptable and reproducible spirometry. The seven questions yielded a cross-validated area-under-the-curve [AUC] of 0.68 (95% CI 0.61–0.75) with higher scores conferring greater odds of COPD. The inclusion of peak expiratory flow and age improved prediction in a validation sample (AUC=0.83, 95% CI 0.78–0.88) with a positive predictive value of 50% and a negative predictive value of 96%. The final instrument (COLA) included seven questions, age and pre-bronchodilator peak expiratory flow. Conclusion COLA predicted COPD in urban and rural settings in Uganda has high calibration and discrimination, and could serve as a simple, low-cost screening tool in resource-limited settings.

Towards the elimination of chronic obstructive pulmonary disease: a Lancet Commission

“…Hence, interest is increasing in establishing new case-finding instruments for COPD that can be implemented in low-income settings (including use of symptoms and peak flow meters). 314 An example of a successful case-finding method implemented by WHO's acute lower respiratory infection programme was the use of respiratory rate and chest in-drawing for early diagnosis of pneumonia in children by primary health-care workers. 315 The simplification and broad deployment of this approach to early diagnosis and treatment of pneumonia have enabled substantial reductions in mortality in LMICs, where access to paediatricians is limited.…”

Feasibility of a pulmonary rehabilitation programme for patients with symptomatic chronic obstructive pulmonary disease in Georgia: a single-site, randomised controlled trial from the Breathe Well Group

“…8 This could be overcome by alternatives to spirometry such as peak flow and questionnaires to diagnose COPD. 45 Studies from other settings have also reported structural and healthcare practitioner factors affecting the quality of care delivered for COPD. 46–48…”

Challenges in the Implementation of Chronic Obstructive Pulmonary Disease Guidelines in Low- and Middle-Income Countries: An Official American Thoracic Society Workshop Report

“…In searching for a less costly and simpler alternative to spirometry, there is emerging evidence that a sequential approach using questionnaires and peak expiratory flow (PEF) testing enables identification of people with COPD ( 31 , 32 ). This pragmatic approach is best used to identify people who will go on to need spirometric confirmation.…”