Medication safety in older inpatients: Measurement and intervention strategies

Older patients (65 years and older) experience far more adverse drug events (ADEs) compared with younger adults. Appropriate prescribing and recognition of ADEs in older inpatients is challenging endeavor because of often present polypharmacy, multimorbidity, and impaired cognitive and physical functions. The main objectives of this thesis were to determine medication safety in older inpatients by measuring ADEs, to develop and implement a multifaceted intervention strategy (MFIS), and to investigate the effect of this strategy on preventable ADEs and ADE recognition in older inpatients.
In total 118 ADEs were identified in 250 included older inpatients (65 years and older and taking ≥ 5 medications on admission). Of the 118 ADEs, 71% was preventable and 43% caused serious preventable patient harm. Most preventable ADEs (86%) were ADEs caused by prescribing errors. Furthermore, of the ADEs already present upon hospital admission 20% was not recognized by the medical teams, and 20% of ADEs occurring during the hospital stay was also missed.
The implementation of MFIS in three Dutch hospitals resulted in 51% reduction in the rate of preventable ADEs (pADEs) occurring during the hospital stay (P < 0.001), 63% reduction in the rate of serious pADEs (P < 0.001), and 52% reduction in the rate of unrecognized ADEs (P < 0.001). All rates were calculated per 100 hospitalizations. The MFIS consisted of a comprehensive medication review followed by face-to-face feedback on prescribing by hospital pharmacists, geriatric pharmacotherapy education, and a pocket-sized checklist of drug-related problems for internal medicine residents.