Intensive care unit (ICU) admission may connote an elevated risk of unintentional chronic medication discontinuation because of its focus on acute illnesses and the multiple care transitions.  The objective of this study was to determine the proportion of patients discharged from the ICU whose previously prescribed chronic medications were unintentionally discontinued during their hospitalization.

Hospital records of consecutive ICU discharges at one academic and two community hospitals in Toronto, Canada, throughout 2002 were reviewed.  Eligible patients were prescribed at least one of six medication groups before hospitalization: (1) HMG co-A reductase inhibitors (statins); (2) antiplatelets/anticoagulants (aspirin, clopidogrel, ticlopidine, warfarin); (3) l-thyroxine; (4) non-prn inhalers (anticholinergic, beta-agonist, or steroid); (5) acid-suppressing drugs (H2 antagonists and proton pump inhibitors); and, (6) allopurinol.  Investigators assessed the proportion of patients whose previously prescribed chronic medications were unintentionally discontinued at hospital discharge.

A total of 1,402 charts were eligible for the study and 834 had prescriptions for at least one of the medication groups.  Thirty-three percent (251/834) of patients had one or more of their chronic medications omitted at hospital discharge.  Multivariable logistic regression analysis found that patients from the academic hospital (adjusted odds ratio [OR] = 0.70, 95% confidence interval [CI] 0.49 to 1.0) and those with medical diagnoses (adjusted OR=0.48, 95% CI 0.31 to 0.75) had a decreased risk for chronic medication discontinuation.

Patients discharged from the ICU often leave the hospital without note of their previously prescribed chronic medications.  Careful review of medication lists at ICU discharge could avoid potential adverse outcomes related to unintentional discontinuation of chronic medications at hospital discharge.