Hospitalization raises the risk that patients’ long-term medications for chronic diseases will be discontinued unintentionally, according to a report in the Aug. 24 issue of JAMA.
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 corresponding 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).
Although this study was not designed to assess how it is that necessary medications get "dropped" unintentionally, previous studies have suggested that miscommunication during transitions of care is not the only contributor. Many medications for chronic diseases are purposely discontinued during a critical illness, but then restarting them is forgotten or overlooked after the acute event resolves.
Previous research also found that unintentional discontinuation of medications is common, but they were primarily single-site, cross-sectional studies. In contrast, "our study examined potential errors of omission on a system-wide basis for an extended period in a diverse patient population with a focus on long-term medications for chronic diseases," the investigators wrote.
They added that "even though our study cohort only included elderly patients [aged 66 and older], the findings are likely generalizable to the general population."