LOS ANGELES – Spirometry is the standard for diagnosing chronic obstructive pulmonary disease, but it’s underused and misused in primary care, according to investigators from the Corpus Christi (Tex.) Medical Center.
The conclusion is based on a review of just 65 patients from internal medicine and family practice clinics near the medical center, but “I do think this [pattern] is representative of what we are seeing in every primary care office. This has been a problem [documented] in the literature for a decade, and it remains a problem,” said lead investigator Stephen Eikermann, DO, an internal medicine resident at the center.
Only 29% of patients diagnosed with chronic obstructive pulmonary disease (COPD) at the two clinics had spirometry. Patients “are being diagnosed based on symptoms,” and those with atypical symptoms are probably being missed, he said.Meanwhile, of those diagnosed by spirometry, 32% didn’t meet the gold-standard Global Initiative for Chronic Obstructive Lung Disease (GOLD) diagnostic criteria by having a postbronchodilator forced expiratory volume in 1 second/forced vital capacity (FEV1/FVC) of less than 70%. Clinicians might not have known that postbronchodilator values are the ones that matter. “People who have asthma are being tagged as having COPD,” and once that diagnosis is in the chart, it’s hard to remove, even when patients improve. “With the COPD readmission penalty in place, an erroneous diagnosis of COPD [has] significant financial risks,” Dr. Eikermann said.
“Misdiagnosis leads to significant financial consequences and puts patients at risk for osteoporotic fractures and malignant arrhythmias. It’s a problem of education.” Busy practitioners might not have had time to catch the latest 2015 GOLD standards, he said.
The guidelines state that COPD should be considered in any patient who has dyspnea, chronic cough, or sputum production, plus smoking or other risks. “Spirometry is required to make the diagnosis.”
To help, Dr. Eikermann and his colleagues plan lectures and a quick reference handout, and maybe a smartphone app. They also plan to remind practitioners that Medicare pays at a reasonable rate for spirometry.
The 65 patients in the study were about evenly split between men and women, and were 70 years old, on average. They had about 34 pack-years of smoking, and some were still smoking despite being on home oxygen.
Men were less likely to have spirometry than women; older subjects and current smokers – as opposed to former smokers – were, too. The risk of COPD increases with age and smoking, so the finding was puzzling. For unknown reasons, “there appears to be a bias against ordering spirometry” for some patients, Dr. Eikermann said.
There was no outside funding for the work, and the investigators had no disclosures.