Unintentional Discontinuation of Medications for Chronic Diseases

Patients admitted to hospitals are particularly vulnerable during periods of transition in care; incomplete or inaccurate communication as responsibility moves from one physician to another can result in medical errors. Likewise, at hospital discharge, patients encounter prescription errors of omission; medications needed to manage chronic conditions may be unintentionally discontinued upon discharge. Patients in the intensive care unit (ICU) may be at increased risk for errors of omission, according to researchers, due to focus on acute care, transitions of additional care, and the practice of temporarily discontinuing medications for chronic conditions during a critical illness. Once the acute event is resolved or the patient leaves the ICU, prescription errors of omission may occur, putting the patient at risk of continued omission of the medications during the balance of the hospital stay or upon discharge. The researchers recently conducted a study to assess whether the potentially unintended discontinuation of common, evidence-based medications for chronic conditions occurs following hospital admission for acute care and whether admission to an ICU is poses a greater risk. Study results were reported in the Journal of the American Medical Association [2011;306(8):840-847]. The population-based cohort study utilized linked administrative records between 1997 and 2009 of all hospitalizations in Ontario, Canada, for residents ≥60 years of age who had at least 1 year of continuous medication use in at least 1 of 5 medication groups: (1) statins, (2) antiplatelet or anticoagulant agents, (3) levothyroxine, (4) respiratory inhalers, and (5) gastric acid–suppressing drugs. The primary outcome measure was the failure to renew a prescription for the study medication within 90 days following discharge from the hospital. The secondary composite outcome was death, emergency department visit, or emergent hospitalization from day 91 through day 365 after the index date. The study included 3 cohorts: (1) patients who were discharged after a hospitalization that included an ICU admission, (2) patients who were discharged after a hospitalization that did not include an ICU admission, and (3) patients who were not hospitalized (control group). The index dates for patients in the 2 groups with hospitalizations were assigned by discharge date; for those in the control group, the index dates were randomly assigned from within the study period. The study comprised 171,438 individuals hospitalized without an ICU admission, 16,474 hospitalized with an ICU admission, and 208,468 in the control group. The majority of those with a hospitalization were women (53.3%) and 25.5% had low-income status; 348,814 of all patients fell into 1 of 3 medication groups (statins, levothyroxine, and gastric acid suppressors). In the separate medication categories, there was a range in the proportion of patients who experienced the primary outcome: 19.4% (n=5564) in the antiplatelet or anticoagulant agent group to 11.8% (n=2535) in the control group. The lowest rate of medication discontinuation occurred in the respiratory inhaler group (4.5%, n=231); of those who experienced medication discontinuation, 5.4% (n=20) were in the ICU admission group compared with 3% (n=79) in the control group. Compared with nonhospitalized patients, patients admitted to an ICU had an increased risk of medication discontinuation. The lowest adjusted odds ratio (AOR) was 1.18 for discontinuing levothyroxine and the highest AOR was 1.86 for discontinuing antiplatelet or anticoagulant agents. Compared with hospitalized patients not admitted to an ICU, there was a statistically significant increased risk of medication discontinuation in patients admitted to an ICU in 4 of the 5 medication groups (antiplatelet or anticoagulant agents, gastric acid suppressors, statins, and levothyroxine). The lowest AOR was for discontinuing statins (1.11) and the highest was for discontinuing levothyroxine (1.29). For the secondary composite outcome, there was an elevated AOR in the statins group (1.07) and in the antiplatelet/anticoagulant agents group (1.10). In summary, the researchers stated, “Patients prescribed medications for chronic diseases were at risk for potentially unintentional discontinuation after hospital admission. Admission to the ICU was generally associated with an even higher risk of medication discontinuation.”