Return to work: does cardiac rehabilitation make a difference? Danish nationwide register-based study

Aim: to assess whether participation in cardiac rehabilitation affects the probability of returning to work after ischaemic heart disease. Methods: the study population consisted of 24,509 patients (18–70 years of age) discharged from an inpatient admission at a Danish hospital during 2014–2018 and who were working before their admission. Only patients with a percutaneous coronary intervention or coronary artery bypass grafting surgery procedure and ICD-10 codes I20–I25 as their main diagnosis or ICD-10 codes I21, I240, I248 or I249 as secondary diagnosis during an emergency admission were included. Exposure was defined as participation in cardiac rehabilitation ( N = 15,742), and binary indicator of being at work in the last week of a given month were used as primary outcomes. Coarsened exact matching (CEM) of exposed and unexposed patients was used to reduce selection bias. Logistic regression models were applied on the matched population ( N = 15,762). Results: Less deprived and less comorbid patients were more likely to receive cardiac rehabilitation. CEM succeeded in arriving at a population where this selection was reduced and in this population we found that patients who received cardiac rehabilitation had a lower probability of returning to work after 3 months (OR 0.81, 95%CI: 0.77–0.84), a higher but insignificant probability after 6 (OR 1.02, 95%CI: 0.97–1.08), and a higher probability after 9 (OR 1.08, 95%CI: 1.02–1.15) and 12 months (OR 1.20, 95%CI: 1.13–1.28). Conclusions: Deprived and comorbid patients have lower use of cardiac rehabilitation. In a matched population where this bias is reduced, cardiac rehabilitation will increase the probability of returning to work.