One-year mortality in patients with COPD across diagnostic settings – a registry study

<bold>Background:</bold> Chronic obstructive pulmonary disease (COPD) is often diagnosed late, such as at an acute exacerbation (AECOPD) requiring admission. <bold>Aim:</bold> To compare one-year mortality after first-ever admission for AECOPD between patients previously diagnosed in primary care and those diagnosed during first-ever AECOPD admission. <bold>Methods:</bold> Data were retrieved from the National Danish Patient- and Prescription Registries. We included patients with a first-ever AECOPD admission (primary diagnosis of COPD or either a primary diagnosis of acute respiratory failure or pneumonia with a secondary diagnosis of COPD) between 2010 and 2018. Patients with asthma or previous COPD-related hospital contacts were excluded. Diagnosis in primary care was based on redeemed prescriptions for inhalation medication before the first-ever admission. A multivariate logistic regression analysis, adjusted for age and gender, was conducted to compare one-year mortality among diagnostic settings. <bold>Results:</bold> A total of 29,992 patients were included. Of these, 2,007 out of 7,413 (27.1%) patients diagnosed during admission died within one year, compared to 659 out of 22,579 (2.9%) patients previously diagnosed in primary care. Diagnosis during AECOPD admission was associated with a significantly increased risk of one-year mortality (odds ratio (OR) 12.67, 95% confidence interval (CI) 11.53-13.93, p<0.001) compared to diagnosis in primary care. Increased mortality was seen across all ages and was highest in patients aged over 86 years (OR 14.41, CI 11.79-17.60, p<0.001). <bold>Conclusions:</bold> Diagnosis in primary care before the first-ever admission for AECOPD was associated with lower one-year mortality, emphasising the need for early diagnosis.