Brazil: A cross-sectional study to evaluate the test accuracy of different screening strategies for identifying undiagnosed COPD in Brazil, amongst patients (≥40 years) with systemic arterial hypertension.
Research question:
What are the most cost effective screening strategies for identifying undiagnosed COPD in Brazil, amongst patients (≥40 years) with systemic arterial hypertension?
Study design:
Cross-sectional study (screening test accuracy)
Population:
Basic Health Unit patients with diagnosed systemic arterial hypertension (SAH), aged ≥40 years and living in São Bernardo do Campo, Brazil.
Recruitment:
Eligible patients will be invited to attend a study assessment session. Consented patients will undertake study measures including screening tests (questionnaires, peak flow and microspirometry) and diagnostic quality spirometry.
Sample size:
The study will aim to recruit approximately 1,100 patients.
Analysis:
Test performance (sensitivity, specificity, positive predictive value, negative predictive value, area under the curve) of all screening tests and strategies will be compared against quality diagnostic spirometry. Cases will be defined using a combination of clinical diagnosis and the lower limit of normal criteria for defining airflow obstruction, based on post-bronchodilator quality diagnostic spirometry data.