Primary Care COPD Screening Tool Shows Mixed Results

The five-question CAPTURE screening tool showed high specificity but low sensitivity in detecting undiagnosed chronic obstructive pulmonary disease (COPD) in primary care.

Of 110 patients with undiagnosed but clinically significant COPD, 53 had a positive result on CAPTURE with a specificity of 88.6% (95% CI 87.6%-89.6%) and a sensitivity of 48.2% (95% CI 38.6%-57.9%), reported Fernando J. Martinez, MD, MS, of Weill Cornell Medicine in New York City, and colleagues, in JAMA.

The area under the receiving operator curve (AUC) was 0.81 (95% CI 0.77-0.85) for various positive screening thresholds.

“The goal with trying to find COPD is to treat it earlier, which will help make patients feel better and hopefully prevent their disease from progressing,” Martinez said in a statement.

COPD is underdiagnosed in primary care and is the leading cause of death and morbidity, the researchers noted. “Undiagnosed patients experience impaired health status and greater risk of acute respiratory events, health care use, and all-cause mortality,” they wrote. “Although there is insufficient evidence to support COPD screening in asymptomatic individuals, identifying patients with respiratory symptoms has been suggested.”

Whether the CAPTURE (COPD Assessment in Primary Care To Identify Undiagnosed Respiratory Disease and Exacerbation Risk) screening tool is up to that task remains to be seen. “Sensitivity was influenced by the high proportion of individuals with airflow obstruction, but limited respiratory symptoms; specificity was influenced by high prevalence of respiratory symptoms among those with a normal spirometry result,” Martinez and co-authors noted. “Overall, this study demonstrates the challenge of identifying undiagnosed patients with COPD in primary care.”

For the cross-sectional study, 4,679 primary care patients (mean age 61.6; 63% female; predominantly white) without a prior COPD diagnosis were enrolled at seven U.S. primary care-based research networks from October 2018 to April 2022.

A total of 4,325 people had data adequate for analysis. Of these, 44.6% had ever smoked cigarettes, 18.3% had a prior asthma diagnosis or used inhaled respiratory medications, 13.2% currently smoked cigarettes, and 10% reported at least one cardiovascular comorbidity.

CAPTURE included questions on a patient’s ability to breathe during physical activity; exposure to forms of smoke, dust, or pollution; change in breathing as a result of seasons, air quality, or weather; ease of fatigue versus peers; and lapses in work, school, or other activities due to colds, bronchitis, or pneumonia. Questionnaire scores can range from 0-6 with larger scores indicating symptoms, acute respiratory illness, or greater respiratory exposure.

Positive results were defined as scores at ≥5, or scores 2, 3, or 4 that were accompanied by further spirometry and a peak expiratory flow rate (PEFR) below 350 L/min for males or below 250 L/min for females.

Clinically significant COPD was defined as spirometry-defined COPD combined with either forced expiratory volume in the first second of expiration (FEV₁), less than 60% of the predicted value, or a self-reported history of acute respiratory illness in the past year. Martinez’s group noted this definition “was based on older criteria that focused on the severity of airflow obstruction and prior respiratory illnesses,” whereas more up-to-date Global Initiative for Chronic Obstructive Lung Disease (GOLD) therapeutic strategies are dependent on symptoms and respiratory illness.

Overall, 12.3% of all patients received a positive result for clinically significant for COPD via CAPTURE; of those, 43.8% obtained a result based solely on the questionnaire, while 56.2% received a positive result from CAPTURE plus PEFR. Among patients with a positive screening result, 88.7% had either COPD, a preserved ratio impaired spirometry result, or were symptomatic but with a normal spirometry result compared with 43.4% of patients with a negative screening result.

One benefit of CAPTURE is that it can push physicians to escalate assessment of patients with respiratory symptoms, particularly if spirometry is too difficult to integrate into a brief primary care office visit, the researchers noted.

“CAPTURE was designed to be easy for physicians to use,” said Antonello Punturieri, MD, PhD, of the National Heart, Lung, and Blood Institute, which helped develop the tool. “The screening is simple, takes less than a minute, and helps identify adults with trouble breathing who should be evaluated further,” he said in a statement.

The sensitivity of CAPTURE needs improvement, Martinez and colleagues acknowledged. One possible strategy for boosting results “would be to consider using an alternate definition of clinically significant COPD that would be congruent with the current GOLD recommendations for treatment initiation,” they wrote. “Evaluation is ongoing to optimize the approach and composition of the CAPTURE screening tool’s questions.”