Combining case-finding methods for COPD in primary care: a large, two-stage design study

Area of Science:

• Pulmonary Medicine
• Diagnostic Strategies
• Primary Care Research

Background:

• Chronic Obstructive Pulmonary Disease (COPD) is frequently underdiagnosed in primary care settings.
• Effective case-finding strategies are crucial for timely COPD diagnosis and management.

Purpose of the Study:

• To evaluate the effectiveness of the Chronic Obstructive Pulmonary Disease-Population Screener (COPD-PS) questionnaire combined with pre-bronchodilator peak expiratory flow (PEF) measurements for identifying potential COPD cases in primary care.
• To assess the impact of this combined screening strategy on the number of spirometry tests required.

Main Methods:

• A two-stage, cross-sectional study involving a primary care population aged 35 years and older without prior COPD diagnosis.
• Screening involved the COPD-PS questionnaire and pre-bronchodilator PEF measurements, with positive results validated by spirometry (post-bronchodilator FEV1/FVC <0.70).
• A case-control sub-study assessed the predictive capacity of the combined screening strategy.

Main Results:

• Out of 10,071 individuals surveyed, 6,969 were included. COPD was confirmed in 130 participants (1.9% of total, 16.2% of those with positive screening).
• The combined COPD-PS and PEF strategy demonstrated a sensitivity of 67.5%, specificity of 71.3%, and diagnostic accuracy of 69.6%.
• The combined screening approach resulted in a 90% reduction in the number of spirometry tests needed.

Conclusions:

• The combination of COPD-PS questionnaire and pre-bronchodilator PEF serves as an effective case-finding strategy for COPD in primary care.
• This integrated approach significantly enhances diagnostic efficiency by reducing the need for extensive spirometry testing.