Introduction
Hospital admissions and emergency department (ED) visits due to problems
related to pharmacotherapy remain a major healthcare concern, despite
efforts to improve medication prescribing and use in the last decades
[1,2]. Two recent systematic reviews on drug-related readmissions to
hospital report an average prevalence of 15% and 21%, of which at
least a third seem preventable [3,4]. There is large variation
between studies due to heterogeneity in definitions and methods
[3,4]. In this study, a drug-related readmission or drug-related ED
visit is defined as an unplanned hospital visit where a drug-related
problem (DRP) is either the main cause or a significantly contributing
cause (i.e., without the DRP, the visit would not have taken place).
DRPs are defined as ‘undesirable patient experiences that involve drug
therapy and that actually or potentially interfere with desired patient
outcomes’ [5]. These can involve not only adverse drug reactions to
prescribed medication, but also problems such as inappropriate
prescribing and non-compliance.
The literature on risk factors
associated with drug-related visits is extensive, but also characterised
by heterogeneity. Common positively associated factors are age,
functional disability or dependent living situation, previous hospital
visits, length of previous hospital stay, number of medications in use
and multimorbidity (e.g., high Charlson Comorbidity Index score [6])
[1,3,7–9]. There is little
agreement between studies regarding specific diseases related to
drug-related visits. Commonly associated drug classes are cardiovascular
drugs, antibiotics, corticosteroids, opioids and psychotropic drugs
[1,3,9]. Studies often fail
to report the degree of preventability and the causes of visits.
A better understanding of
preventable drug-related visits is essential for developing targeted
interventions to minimise drug-related harm.
One of the interventions proposed to prevent hospital visits in older
patients is conducting a medication review [10]. In a recent
multicentre randomised controlled trial (MedBridge) in Sweden, aiming to
study the effects of comprehensive medication reviews with or without
post-discharge follow-up, a total of 2,637 hospitalised patients aged ≥
65 years was included [11]. Patients were excluded
if they were admitted for less
than 24 hours, had undergone a
medication review by a clinical pharmacist within the preceding month,
did not reside in the hospital county or were receiving palliative
treatment. The trial interventions did not affect drug-related
readmissions or all-cause readmissions within 12 months after discharge.
Drug-related ED visits were not a study outcome, but all-cause ED visits
were increased in one of the intervention groups compared with in usual
care [11]. It is unclear whether drug-related revisits could have
been prevented or whether these visits were caused by the trial
interventions. There was a large variation in the trial population, with
2,055 (78%) patients experiencing no drug-related readmission.
It is important to target
patients at risk of drug-related readmission and to understand the
underlying preventability and causes of drug-related revisits. In this
study, we therefore aimed to: 1) identify older patients’ risk factors
for drug-related readmissions and 2) assess the preventability of older
patients’ drug-related revisits (admissions and ED visits).