Background: Spirometry is recommended for diagnosis and management of obstructive lung disease. While many patients with asthma and COPD are cared for by primary care practices, limited data are available on the use and results associated with spirometry in primary care.
Object: To assess the technical adequacy, accuracy of interpretation, and impact of office spirometry.
Design: A before-and-after quasiexperimental design.
Setting: Three hundred eighty-two patients from 12 family medicine practices across the United States.
Participants: Patients with asthma and COPD, and staff from the 12 practices.
Measurements: Technical adequacy of spirometry results, concordance between family physician and pulmonary expert interpretations of spirometry test results, and changes in asthma and COPD management following spirometry testing.
Results: Of the 368 tests completed over the 6 months, 71% were technically adequate for interpretation. Family physician and pulmonary expert interpretations were concordant in 76% of completed tests. Spirometry was followed by changes in management in 48% of subjects with completed tests, including 107 medication changes (>85% concordant with guideline recommendations) and 102 nonpharmacologic changes. Concordance between family physician and expert interpretations of spirometry results was higher in those patients with asthma compared to those with COPD.
Discussion and conclusions: US family physicians can perform and interpret spirometry for asthma and COPD patients at rates comparable to those published in the literature for international primary care studies, and the spirometry results modify care.