Discussion
Potentially preventable medication-related ED visits and hospital
admissions are unfortunately common [1-4]. From prospective
observational studies, the median prevalence rate of hospital admissions
associated with medication nonadherence is around 4% with almost all
considered preventable [5].
In a prospective multicenter study involving twenty-one Dutch hospitals,
12,793 unplanned hospital admissions were screened with 714 (5.6%)
determined to be medication-related (either from harm due to adverse
effects or due to any error in the “process of [medication]
prescribing, dispensing, or administering”). For those admissions
categorized as preventable (332/714, 46.1%), a case-control design was
used to determine potential risk factors; and in the multivariate
analysis, nonadherence to medication regimen (odds ratio 2.3; 95%
confidence interval 1.4-3.8), dependent living situation (3.0; 1.4-6.5),
impaired cognition (11.9; 3.9-36.3), and polypharmacy (2.7; 1.6-4.4)
defined as greater than or equal the use of five chronic medications,
were among the statistically significant determinants of
medication-related preventable admissions [3].
Returning to our case, how might the omission of levothyroxine have been
prevented prior to admission ? It is possible that by decreasing
the number of home medications this patient was taking (and the daughter
was subsequently responsible for) and/or having a different reminder
packaging systems (e.g., pre-filled blister packs from a pharmacy), may
have prevented this episode of nonadherence leading to hospital
admission. However, due to a scarcity of high-quality evidence and the
need for more well-designed randomized controlled trials, optimal
interventions to improve medication adherence in older adults prescribed
multiple medications remains largely unknown [6].
How might the preadmission
omission of levothyroxine have been detected earlier in this
patient’s hospital encounter ? To decrease errors in the admission
medication history due to nonadherence (i.e., recording that a patient
is taking a particular medication preadmission, when in fact, they are
not) a review of medication fill data may be helpful. This data can be
obtained by directly contacting a patient’s pharmacy or pharmacies, or
by having one’s institution purchase medication insurance claims data
that can be viewed electronically. In our case, obtaining the fill
history in addition to the caregiver interview and review of
institutional medication records could have revealed this patient’s lack
of a recent levothyroxine refill. However, even when armed with fill
information, caution must still be exercised as even though a medication
has been filled, a patient may not be taking it or may be taking it
differently than prescribed.
Recently, a similar case of medication nonadherence masquerading as
treatment failure was reported. Jethwa et al describe a 58-year-old male
admitted to the hospital for deep vein thrombosis. Three weeks prior,
the patient had been hospitalized for pulmonary emboli and started on
apixaban, and although he described a 2-day period of nonadherence
immediately after discharge, he reported strict compliance since that
time. With his new deep vein thrombosis, treatment failure was the
leading diagnosis on the differential. However, the medical team later
consulted pharmacy to review the patient’s outpatient medication fill
history and only at that time did the patient’s persistent nonadherence
become clear. Adherence verification prevented mislabeling the patient
as failing apixaban and avoided warfarin therapy and bridging with a
parenteral anticoagulant [7].