Clinical and economic factors associated with spirometry-diagnosed COPD in the Swedish ARCTIC study

Background: Though the GOLD recommendations state that chronic obstructive pulmonary disease (COPD) should be diagnosed using spirometry, this is not always done in practice. Objective: To assess differences in clinical and economic outcomes in COPD patients in whom the diagnoses included or did not include use of spirometry. Methods: Medical records data were collected from COPD patients in Swedish primary care and linked to primary and secondary care national registries data, including healthcare utilization (hospital visits/stays and medication use), exacerbations, mortality and COPD diagnosis method (with or without spirometry). Outcomes were compared based on diagnosis method. Results: Of 9,208 patients, 5,505 (60%) were diagnosed using spirometry. Patients diagnosed with spirometry were younger (66 vs 71 years) and more likely to be female (57 vs 50%) than those not. Total costs for patients without a spirometry-based diagnosis were higher than for spirometry-diagnosed patients (€12,790 vs €10,234; calculated during the 2 years post-diagnosis). These higher costs were driven by a larger number of COPD-related hospital visits (1.0 vs 0.3 visits) and non-COPD-related nights in hospital (5.4 vs 3.0) 2 years post-diagnosis. Costs of respiratory drugs were more than double for spirometry-diagnosed patients than those not (€617 vs €291). Mortality risk was higher for patients not diagnosed using spirometry compared with spirometry-diagnosed patients (HR 2.62 [95% CI 2.44, 2.81], p Conclusion: COPD patients diagnosed using spirometry were younger and had higher respiratory drug costs, but had lower total health care costs and lower mortality risk.