Test is not enough to diagnose COPD

DEAR DR. ROACH>>

I am a healthy 70-year-old woman. The only prescription medication I take is for dry eyes. I recently visited my new primary physician for the first time, and she had me do a breathing test, where I exhaled into a tube to measure airflow. I was told to breathe deeply and exhale completely into the tube three times in succession. It took less than a minute to complete. It is apparently a routine test.

She then told me I have COPD, on the basis of that test alone. She asked if I had ever smoked or been exposed to secondhand smoke. That was her only question — coughing or shortness of breath was never mentioned. I have never smoked. I actually do have a slightly productive cough most mornings. I probably walk about 10 miles a week, and I do notice some shortness of breath on long uphill sections, though I can walk briskly in level areas for miles with no problem.

She said it is not advanced enough to require an inhaler at this time. I am bothered by this very easy “diagnosis” on the basis of one simple test. I wonder if I should ask to be referred to a pulmonologist for a more thorough evaluation.

— O.P.

ANSWER>> The test your doctor performed is called office spirometry, and it is useful for monitoring known pulmonary diseases, especially COPD and asthma. However, by itself, it is inadequate to make the diagnosis of COPD, which I am not sure you have.

The diagnosis of COPD is made in people with persistent respiratory symptoms, usually shortness of breath or coughing. Spirometry will usually show obstruction to airflow. Formal pulmonary function testing, which is an extensive process taking an hour or so with a skilled and experienced technician, is ideal for determining severity.

The problem with getting a breathing test in someone who has no significant symptoms is that you can find someone whose test results are at or just below the lower limit of normal, and the diagnosis is unclear. The prognosis for people with mild airway obstruction but with no symptoms of COPD is much better than for people with COPD and who continue to smoke. For this reason, using spirometry as a screening test for everyone is not recommended.

Contact Dr. Roach at ToYourGoodHealth@med. cornell.edu.