Association between critical care admission and chronic medication discontinuation post-hospital discharge: A retrospective cohort study

Background: Discontinuation of important chronic medication after hospitalisation is common. This study aimed to investigate the association between critical care (vs non-critical care) admission and discontinuation of chronic medications post-hospital discharge, along with factors associated with discontinuation among critical care survivors. Methods: This was a retrospective cohort study in Lothian, Scotland of adults who were admitted to hospital between 01/01/2012 and 31/12/2019 and survived to hospital discharge. Medication classes investigated were statins, angiotensin converting enzyme inhibitors/angiotensin receptor blockers (ACEi/ARBs), beta-blockers, oral anticoagulants, and thyroid hormones. The risk of medication discontinuation for each class was estimated by odds ratios (OR), with 95% confidence intervals (95%CI), using multivariable logistic regression adjusted for patient demographics, main clinical condition, and index comorbidity. A secondary analysis assessed factors associated with discontinuation in critical care survivors. Results: There were 22,340 critical care and 367,185 non-critical care survivors included. Critical care admission had the highest association with ACEi/ARBs discontinuation (adjusted OR 2.41, 95%CI: 2.26-2.58), followed by oral anticoagulants (adjusted OR 1.33, 95%CI: 1.15-1.53), and beta blockers (adjusted OR 1.18, 95%CI: 1.07-1.29). There was no significant association with thyroid hormones or statin discontinuation. Among critical care survivors, hospital length of stay of 14 days or more was associated with increased discontinuation across all medication classes. Conclusion: Critical care admission was associated with discontinuation of three out of five medication classes studied (ACEi/ARBs, beta-blockers, and oral anticoagulants). Further research is needed to understand the reason for increased medication discontinuation in critical care survivors and how these risks can be mitigated to improve patient outcomes.