Researchers have developed a simple and convenient method to identify patients with chronic obstructive pulmonary disease (COPD) who would benefit from currently available therapies.
CAPTURE is a five-item questionnaire that when used in conjunction with peak expiratory flow measurements had a high rate of sensitivity and specificity for identifying these patients, according to a study published in the American Journal of Respiratory and Critical Care Medicine.
The study by Fernando J. Martinez, MD, MS, of Weill Cornell Medical College, and colleagues was a multi-site, case-control study of 346 men and women. They sought to identify patients with undiagnosed severe asymptomatic COPD.
“There are estimates that state that COPD is undiagnosed in between 60% and 98% of cases depending on what part of the world you are in, and patients with undiagnosed COPD tend to have worse quality of life, higher utilization of health care resources and high mortality compared with people without COPD,” Martinez, told Medical Economics. “We targeted patients with severe COPD in this study because that group of patients has a series of therapeutic alternatives which clearly work to improve health status, symptoms, exacerbation rates and maybe even mortality.”
The study compared patients with COPD and a history of one or more exacerbation in the last 12 months or those with COPD with moderate to severe airflow obstruction who were exacerbation free for 12 months with controls with no known diagnosis or treatment of COPD or those with mild COPD.
At participating primary care sites, participants completed the five-team questionnaire and received a score from 0 to 6. Patients whose answers put them in the middle range for risk performed a simple peak flow test during their visit. Fifty-two percent of participants required peak flow testing. Men who exhaled less than 350 L/minute and women who exhaled less than 250 L/minute were referred for definitive testing.
The combined questionnaire and peak flow testing resulted in a sensitivity of 89.7% and specificity of 78.1% for cases versus controls, including those patients with mild COPD; this specificity improved to 93.1% when comparing cases versus all controls without COPD.
One of the keys to the study, according to Martinez, was the involvement of patients in the development of the questionnaire.
“A lot of work was done to get a sense from patients who were recently diagnosed with COPD of what they thought were the most important questions and the best way to ask those questions,” Martinez explained. For example, if a patient was asked, “Are you breathless?” they might reply, “No.” However, if the question read, “Are you breathless doing activities that you used to do?” they might reply, “Yes.”
CAPTURE’s five questions
Using this patient feedback, the researchers were able to narrow their questionnaire down to five questions that addressed activity limitation, fatigue, seasonal change in symptoms, previous exacerbation events and exposure to inhaled substances.
The final five questions were:
1. Have your ever lived or worked in a place with dirty or polluted air, smoke, second-hand smoke or dust?
2. Does your breathing change with seasons, weather or air quality?
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. Compared to others your age, do you tire easily?
5. In the past 12 months, how many times did you miss work, school, or other activities due to a cold, bronchitis or pneumonia?
“One advantages to asking broader questions is that it can identify a group of patients with COPD globally and in the U.S.,” Martinez said.
Martinez also noted that this instrument is not yet ready for widespread use in primary care practices. He and colleagues have submitted a grant application to the National Institutes of Health for funding to expand this study to 5,000 patients across 75 U.S. primary care sites.
“The grant study will give us a sense of whether this really works across a broad range of primary care practices and whether the practices will actually do it,” Martinez said.
Finally, current United States Preventive Services Task Force recommendations state that healthy adults who do not recognize or report respiratory symptoms to a clinician should not be screened for COPD using spirometry. Martinez emphasized that the CAPTURE tool was designed to illicit symptoms that are likely to be related to significant COPD.
“We took the approach of trying to generate something simple in the least intrusive fashion possible for the practitioner and the patient,” Martinez said. “It is designed to identify symptoms that are significant enough to justify further evaluation.”