BACKGROUND: 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.
OBJECTIVE: To determine the proportion of patients discharged from the ICU whose 
previously prescribed chronic medications were unintentionally discontinued 
during their hospitalization.
DESIGN AND PARTICIPANTS: Hospital records of consecutive ICU discharges at 1 
academic and 2 community hospitals in Toronto, Canada, throughout 2002 were 
reviewed. Eligible patients were prescribed at least 1 of 6 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.
MEASUREMENTS: Use of explicit criteria to assess the proportion of patients 
whose previously prescribed chronic medications were unintentionally 
discontinued at hospital discharge.
RESULTS: A total of 1,402 charts were eligible for the study and 834 had 
prescriptions for at least 1 of the medication groups. Thirty-three percent 
(251/834) of patients had 1 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.
CONCLUSIONS: 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.