External validation of the PUMA COPD diagnostic questionnaire in a general practice sample and the PLATINO study population

Abstract

Background

A seven-item prescreening questionnaire (gender, age, pack-years smoking, dyspnea, sputum, cough, previous spirometry data) was developed for COPD detection in the primary care setting (PUMA Study) of four Latin America countries.

Objectives

To validate the PUMA prescreening COPD questionnaire externally in two different populations (primary care and general).

Methods

The PUMA prescreening COPD questionnaire score was applied to subjects from the Hospital Maciel, Montevideo (primary care), case-finding program and the PLATINO population (general) using PUMA study inclusion criteria. Post-bronchodilator FEV₁/FVC <0.70 and lower limit of normal (LLN) criteria were used to define COPD. Area under the received operator curve (ROC_AUC), sensitivity, specificity, predictive positive and negative values (PNV), number needed to treat (NNT), and best cut-points of the score were calculated.

Results

974 individuals from Hospital Maciel and 2512 from the PLATINO population were eligible, using post-bronchodilator FEV₁/FVC <0.70, 45.1% and 18.7% had COPD, respectively, and using LLN 38.4% and 15.4% had COPD, respectively. From Hospital Maciel (post-bronchodilator FEV₁/FVC <0.70), the best cut-point of ≥6 had moderate discriminatory power (ROC_AUC 0.70), sensitivity 69.9%, specificity 62.1%, PNV 70.9%, and NNT of 3. The discriminatory power was 0.73 (ROC_AUC) in the PLATINO population with three potential cut-points (Youden’s index): ≥3 (sensitivity 85.4%, specificity 46.9%), ≥4 (sensitivity 66.7%, specificity 66.5%), and ≥5 (sensitivity 51.5%, specificity 81.6%); the PNV at each cut-point was 93.3%, 89.9%, and 88.0%, respectively. The NNT was 5 for scores ≥3 and ≥4, and 4 for ≥5. The mean accuracy using the LLN for Hospital Maciel and PLATINO was 0.67 and 0.70, respectively.

Conclusion

External validation of the PUMA prescreening questionnaire in two Latin American populations (general and primary care) suggests moderate accuracy, similar to the original study in which the questionnaire was developed.

Keywords:

• COPD
• diagnostic questionnaire
• primary care
• validation
• Latin America

Supplementary material

Table S1 Points applied for each variable in the PUMA questionnaire

Acknowledgments

We are grateful to the other investigators of the PLATINO team, namely, Rogelio Perez-Padilla, Adriana Muiño, Gonzalo Valdivia, and Jose Roberto B. Jardim. This observational study was funded by AstraZeneca Latin America. AstraZeneca had no input into the study design, analysis and interpretation of the result.

Data sharing statement

All relevant data are within the paper.

Author contributions

Conceived and designed the experiments: MVLV, MMO, AMM; performed the experiments: MVLV, MMO, CR, LR, AMM; analyzed the data: FCW, AMM; contributed reagents/materials/analysis tools: MVLV, MMO, CR, LR, AMM. MVLV, MMO, and AMM led the writing of the article but all authors provided input into revising the article and gave final approval of the version to be published, and agree to be accountable for all aspects of the work.

Disclosure

Larissa Ramirez is a full-time employee of AstraZeneca Latin America. Ana Menezes has been paid for her work as a statistician for the study.

The Hospital Maciel, Montevideo, data of this paper were presented at the European Respiratory Society 2017 Congress as a poster presentation with interim findings. The poster’s abstract was published in the European Respiratory Journal 2017; 50 (Suppl 61): PA1198. DOI: 10.1183/1393003. The authors report no other conflicts of interest in this work.