How often is diagnosis of COPD confirmed with spirometry?
Received 3 July 2009; accepted 28 October 2009. published online 20 November 2009.
Summary
Background
Chronic obstructive pulmonary disease (COPD) is an important cause of morbidity and mortality worldwide. Diagnosis is customarily confirmed with spirometry, but there are few studies on documented spirometry use in everyday clinical practice.
Methods
In a cross-sectional survey and study of the medical records of primary and secondary care COPD patients aged 18–75 in a Swedish region, patients with COPD were randomly selected from the registers of 56 primary care centres and 14 hospital outpatient clinics. Spirometry data at diagnosis ±6 months were analyzed.
Results
From 1114 patients with COPD, 533 with a new diagnosis of COPD during the four-year study period were identified. In 59% (n=316), spirometry data in connection with diagnosis were found in the medical records. Spirometry data with post-bronchodilator forced expiratory volume in 1s (FEV1)/ vital capacity (VC) ratios were available in 45% (n=241). FEV1/VC ratio <0.70 were found in 160 patients, which corresponds to 30% of the patients with a new diagnosis. Lower age, female gender, current smoking, higher body mass index (BMI) and shorter forced exhalation time were related to COPD diagnosis despite an FEV1/VC ratio of ≥0.70. The most common problem in the quality assessment was an insufficient exhalation time.
Conclusions
Only a third of Swedish patients with COPD had their diagnosis confirmed with spirometry. Our data indicate that female gender, current smoking, higher BMI and short exhalation time increase the risk of being diagnosed with COPD without fulfilling the spirometric criteria for the disease.
aPrimary Care Research Unit, County Council of Värmland, Universitetsgatan 3, SE-656 37, Karlstad, Sweden
bDepartment of Medical Sciences, Respiratory Medicine and Allergology, Uppsala University, Ing. 40, Akademiska sjukhuset, SE-751 85, Uppsala, Sweden
cDepartment of Public Health and Caring Sciences, Family Medicine and Clinical Epidemiology, Uppsala University, Uppsala Science Park, SE-751 85 Uppsala, Sweden
dDepartment of Medical Sciences, Clinical Physiology, Uppsala University, Ing. 40, Akademiska sjukhuset, SE-751 85, Uppsala, Sweden
eDepartment of Neuroscience, Physiotherapy, Uppsala University, Ing. 15, Akademiska sjukhuset, SE-751 85, Uppsala, Sweden
ABSTRACT