Exacerbations in COPD patients with comorbid depression and anxiety

Research question: How are comorbid depression and/or anxiety related to exacerbation rates in patients with Chronic Obstructive Pulmonary Disease (COPD) in Sweden? Background: Depression and/or anxiety are associated with an increased risk of exacerbations and hospitalization in COPD patients. However, real-world studies about the impact of mental health issues on exacerbation rates in patients with COPD are scarce. Possible methodology: We use data from two patient cohorts recruited in eight regions in Sweden (2005; n=1089 and 2014; n=2245), and a joint follow-up of these cohorts (2022), and a new cohort (2024). The cohorts consist of patients with a doctor-diagnosed COPD, randomly selected from primary healthcare centres and hospitals. Data is collected via self-completion patient questionnaires, medical records, questionnaires about the organization of healthcare, and national registers. Information about symptoms, treatments, healthcare contacts and hospital admissions due to exacerbations will be collected from patient questionnaires. Comorbid depression and/or anxiety can be identified through self-reported symptoms in the questionnaire, and/or through ICD-10 diagnosis and pharmacological treatment of depression and/or anxiety. Questions to discuss: As the cohorts are large and include COPD patients of different severity, we will adjust for lung function. In our data set, several methods for defining patients with depression and/or anxiety are possible, and strengths and limitations of these methods need to be discussed. Another point of discussion is the preferable, or most interesting, study design as our data enable us to conduct both cross-sectional and longitudinal, observational studies.