"New contraindications may have arisen that were not captured in the investigators' administrative database. Physicians may have used the admission as an opportunity to rethink the original medication indication," they wrote.
And, they said, the patients may have decided that the side effects of certain medications outweighed any benefit, in light of a new condition with which they had to grapple.
But Kahn and Angus said Bell and colleagues did everything they could to minimize this effect, using only medications with solid evidence and strong benefit-to-risk profiles "that are unlikely to be stopped without good clinical reason."
Another possibility, Kahn and Angus suggested, is the finding in the study that patients were prescribed "a median of 12 different medications in the year prior to the hospitalizations, and 75% were prescribed nine or more medications."
"As a consequence, hospital-based physicians increasingly not only must attend to the patient's acute medical problems, but also have to manage an ever-expanding array of complex and unfamiliar medications [which carry...] unknown adverse effects and put patients at risk for unexpected interactions between medications.
"Thus, for some patients, hospital care is now as much about organizing and reorganizing a litany of medications as it is managing acute disease...It is not so surprising that important medications become lost in the mix."