Impact of COPD diagnosis timing on clinical and economic outcomes: the ARCTIC observational cohort study

Abstract

Purpose: Assess the clinical and economic consequences associated with an early versus late diagnosis in patients with COPD. Patients and methods: In a retrospective, observational cohort study, electronic medical record data (2000-2014) were collected from Swedish primary care patients with COPD. COPD indicators (pneumonia, other respiratory diseases, oral corticosteroids, antibiotics for respiratory infections, prescribed drugs for respiratory symptoms, lung function measurement) registered prior to diagnosis were applied to categorize patients into those receiving early (2 or less indicators) or late diagnosis (3 or more indicators registered >90 days preceding a COPD diagnosis). Outcome measures included annual rate of and time to first exacerbation, mortality risk, prevalence of comorbidities and health care utilization. Results: More patients with late diagnosis (n=8827) than with early diagnosis (n=3870) had a recent comorbid diagnosis of asthma (22.0% vs 3.9%; P<0.0001). Compared with early diagnosis, patients with late diagnosis had a higher exacerbation rate (hazard ratio [HR] 1.89, 95% confidence interval [CI]: 1.83-1.96; P<0.0001) and shorter time to first exacerbation (HR 1.61, 95% CI: 1.54-1.69; P<0.0001). Mortality was not different between groups overall but higher for late versus early diagnosis, after excluding patients with past asthma diagnosis (HR 1.10, 95% CI: 1.02-1.18; P=0.0095). Late diagnosis was also associated with higher direct costs than early diagnosis. Conclusion: Late COPD diagnosis is associated with higher exacerbation rate and increased comorbidities and costs compared with early diagnosis. The study highlights the need for accurate diagnosis of COPD in primary care in order to reduce exacerbations and the economic burden of COPD.

Keywords: Sweden; chronic obstructive pulmonary disease; diagnosis; exacerbations; mortality.

Figure 1

Study cohorts and criteria for early versus late COPD diagnosis. ^aIndicator diagnosis codes; Pneumonia J10–J18; respiratory diseases J00–J99, excluding pneumonia; oral steroids H02AB; antibiotics for respiratory disease J01AA, J01CA; prescription for respiratory disease R01–R03, R05–R07; lung function measurements from spirometry database and laboratory module in EMR. Disposition of patients by COPD and concomitant asthma versus COPD only is based on diagnosis at any time during the patient’s disease history. Abbreviation: EMR, electronic medical records.

Figure 2

Risk of exacerbations and mortality by stage of diagnosis (early vs late). Risk of exacerbations (A) and mortality (B) in the total population and risk of exacerbations (C) and mortality (D) in patients excluding those with concomitant asthma, in the year following diagnosis.

Figure 3

Time trend in direct costs (Euro/year) according to the stage of diagnosis (early vs late). In the year 2007, 2010, 2012 and 2013, total yearly costs were significantly higher for late diagnosis versus early diagnosis.

Figure 4

Direct costs during the 2 years after COPD diagnosis by early vs late diagnosis. Costs were calculated from Swedish Krona based on exchange rates in 2013. Abbreviations: hospital nights, number of nights where the patient has been at the hospital; hospital visit, outpatient care where the patient did not stay overnight at the hospital.