Major Finding: Rates of unintentional discontinuation of long-term medications for chronic diseases were significantly higher in hospitalized than in nonhospitalized patients, at 19.4% for antiplatelet/anticoagulants, 13.6% for statins, 12.9% for gastric acid suppressors, 12.3% for levothyroxine, and 4.5% respiratory inhalers.
Data Source: A population-based cohort study of 369,036 elderly patients in Ontario, including 160,568 who were hospitalized and 16,474 admitted to an ICU between 1997 and 2009.
Disclosures: Some researchers reported ties to Merck Frosst Canada, AstraZeneca, Sanofi-Aventis, Johnson & Johnson, and the Centre for Medical Technology Policy.
Hospitalization raises the risk that patients' long-term medications for chronic diseases will be discontinued unintentionally, a study has shown.
That risk is further heightened with ICU care, which suggests that the more patients are transitioned from site to site and from clinician to clinician, the greater the chance that their long-term medications (statins, antiplatelet or anticoagulant agents, levothyroxine, respiratory inhalers, and gastric acid-suppressing drugs) will get lost in the shuffle.
Discontinuing these necessary medications appears to raise patients' risk of death, further hospitalization, and ED visits for up to 1 year after discharge, said Dr. Chaim M. Bell of St. Michael's Hospital, Toronto, and his associates.
“These findings emphasize the importance of a systematic approach to transitions in health care to ensure medication continuity,” they noted.
The investigators conducted a population-based cohort study of all hospitalizations of patients aged 66 years and older in Ontario between 1997 and 2009 to examine medication continuity. They reviewed the records of 396,036 patients who had been taking any of the five types of medications for chronic disease listed above for at least 1 year.
In all, 160,568 of these study subjects were hospitalized during the study period, including 16,474 who were admitted to the ICU; the remaining 208,468 who were not hospitalized served as control subjects. The rate of patients who failed to refill prescriptions of the five categories of medication within 90 days of discharge was calculated.
The investigators excluded cases in which patients developed complications or contraindications to their medications, or otherwise had a clear reason for discontinuing a drug. They also controlled for confounding factors that could influence stopping a medication, such as comorbid disease burden and the number of physician contacts during the year preceding hospitalization.
Drugs in all five medication categories were significantly more likely to be discontinued after hospitalization than in the controls. Rates of unintentional discontinuation were highest for antiplatelet/anticoagulants (19.4%), followed by statins (13.6%), gastric acid suppressors (12.9%), levothyroxine (12.3%), and respiratory inhalers (4.5%). The rates for control subjects were 11.8%, 10.7%, 9.4%, 11%, and 3%, respectively.
Rates of unintentional discontinuation were even higher among ICU patients in four of the five medication categories (22.8% for antiplatelet/anticoagulants, 15.4% for gastric acid suppressors, 15% for levothyroxine, and 14.6% for statins).
In a secondary analysis, the unintentional discontinuation of antiplatelet/anticoagulants and of statins was associated with higher risk of the combined outcome of death, further hospitalization, or emergency admission for up to 1 year after hospital discharge. “This underscores the widespread prevalence of potential errors of omission and the risk for long-term harm following hospitalization,” Dr. Bell and his colleagues said (JAMA 2011;306:840-7).
Studies suggest that miscommunication during transitions of care is not the only contributor to unintentional dropping of medications, they said. Some medications are purposely discontinued during a critical illness, but restarting them is overlooked after the acute event resolves.
Dr. Bell and colleagues said the findings of their study “are likely generalizable to the general population.”
The study was funded by the Canadian Institutes of Health Research, the Institute for Clinical and Evaluative Sciences, and the Ontario Ministry of Health and Long-Term Care.
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Scope and Scale of Problem Is Concerning
The major limitation of this study is that it cannot measure whether discontinuation of long-term medications was really unintentional, said Dr. Jeremy M. Kahn and Dr. Derek C. Angus.
Dr. Bell and his colleagues minimized this problem by excluding patients who developed known contraindications or complications, and by adjusting for legitimate reasons to discontinue the drugs. They studied patients who had been taking the medications for at least 1 year, to rule out the chance that physicians were simply rethinking the use of the drug or that patients were choosing to stop because of side effects.
“Given the high incidence of medication discontinuation in this study, even if some of [it] was intentional, the remaining unintentional discontinuation is of concerning scope and scale,” they noted.