New questionnaire appears to successfully identify COPD in primary care settings

When used with selective peak expiratory flow (PEF), a new questionnaire may help identify patients with undiagnosed, clinically significant chronic obstructive pulmonary disease (COPD), according to a recent case-control study.

Researchers derived the questionnaire from a pool of 44 candidate questionnaires. The final survey, named CAPTURE (COPD Assessment in Primary Care To Identify Undiagnosed Respiratory Disease and Exacerbation Risk), includes 5 items:

1. 1. Have you ever lived or worked in a place with dirty or polluted air, smoke, secondhand smoke, or dust?
2. 2. Does your breathing change with seasons, weather, or air quality?
3. 3. Does your breathing make it difficult to do things such as carry heavy loads, shovel dirt or snow, jog, play tennis, or swim?
4. 4. Compared to others your age, do you tire easily?
5. 5. In the past 12 months, how many times did you miss work, school, or other activities due to a cold, bronchitis, or pneumonia?

Researchers analyzed a sample of 346 participants (186 cases in 2 groups, those with COPD and exacerbation risk or COPD and severity risk, and 160 controls in 2 groups, those with no COPD and those with mild COPD). Results were published online on Oct. 26 by the American Journal of Respiratory and Critical Care Medicine.

CAPTURE scores and PEF were both significantly related to spirometric values (P<0.0001 for both), but the best method for predicting case/control or group membership was a combination of CAPTURE scores and PEF. In the study sample, 52% of patients required PEF to determine if further diagnostic evaluation was needed, whereas the other 48% required only the questionnaire.

PEF would be indicated only for mid-range CAPTURE scores (2 to 4), the study authors said. These patients would be considered to have clinically significant COPD at thresholds of less than 350 L/min for men and less than 250 L/min for women. Patients with scores of 0 or 1 would not be considered to be at risk and would not require further evaluation, and those with scores of 5 or 6 (yes to all items) would be referred for further evaluation, including spirometry.

The study authors wrote that although these results suggest the method is sensitive and specific and “may offer an efficient case-finding approach for primary care,” further study in primary care settings is warranted. They noted limitations to their work, such as how sites included pulmonary clinics in addition to primary care settings and how the study included a limited number of patients with mild airflow obstruction and exacerbation risk.