Improving drug use in older adults during hospital stay

Within the community as well as in hospitals, older adults constitute an important group that is furthermore expected to increase the coming decades. They are susceptible to drug-related problems (DRP) and more so than younger adults. Partially owing to these DRP, older adults are admitted in higher numbers to hospitals. DRP might be avoided however by applying certain strategies in primary care, but also during hospital stay, during which patients can be monitored closely in a multidisciplinary setting.

Despite several previous investigations, that regularly involved clinical pharmacists and screening tools for potentially inappropriate medications (PIMs), the prevalence of aforementioned DRP remains high. It was therefore the general aim of this PhD dissertation to research the impact of several novel strategies to improve drug use and subsequently lower PIMs in older adults.

Due to the breadth of the issue at hand, the PhD research focused the impact of clinical pharmacy (CP) services on drug use in geriatric inpatients. The investigations targeted several unmet clinical needs and the PhD thesis was categorized in three parts, covering a total of six studies.

In a first part, an improved screening tool for PIMs in older adults was developed, the RASP list, bearing in mind local experiences and taking into account newly published evidence. The RASP list was based on the Screening Tool of Older Persons' Prescriptions criteria (STOPP) criteria. The final version of the RASP list was considered reliable and valid. It contained 76 items of which only 26 (34%) were directly based on the STOPP criteria.

In a second part of the PhD thesis, four clinical investigations involving ward-based CP were performed to ascertain whether drug use could be improved during hospital stay in several patient settings. These investigations also included the use of the RASP list. Furthermore, all studies, except for one, took place in UZ Leuven, Leuven, Belgium.

In a first controlled study, the impact of a structured pharmacist-led medication review was evaluated in older inpatients (n=172) admitted to geriatric wards in a large academic hospital. More drugs were discontinued or reduced in dose in the intervention group. More RASP PIMs were discontinued in the intervention group and not reinitiated during hospital stay, leading to less PIMs at discharge. No signal of harm was seen. A significant improvement of quality of life and fewer emergency department (ED) visits without hospitalization were observed.

In a follow-up investigation, a comparable controlled study (n=61) was performed on geriatric wards in a non-academic hospital (Jessa Hospital, Hasselt, Belgium). The aim was to externally validate previous findings on the CP intervention. Preadmission drugs were discontinued likewise in control and intervention patients. Drug use declined during hospital stay, without differences between control and intervention. Furthermore, data on RASP PIM reduction were compared post hoc across three interventional cohorts, including the Jessa data. PIM reduction was comparable across these investigations, showing an overall reduction of 2.7 (95% confidence interval: 2.3-3.2) RASP PIMs during hospital stay.

In the first controlled study, it was observed that an important portion of geriatric inpatients suffered from heart failure (HF), mostly with preserved ejection fraction on a background of atrial fibrillation. A prospective interventional study was performed in geriatric inpatients (n=29) to discern the impact of a CP intervention on drug therapies. A majority of the CP recommendations were accepted and implemented by the treating physicians. A comprehensive algorithm was developed to provide a structured approach for the pharmacotherapeutic evaluation of older HF patients.

Many geriatric inpatients are managed by a medical specialist other than a geriatrician. For these patients, admitted to non-geriatric wards, the interdisciplinary geriatric consultation team (IGCT) can be consulted to comprehensively assess patient status and to provide recommendations in order to improve geriatric care. A structured medication review is however not provided systematically. Hence, a pre/post study (n=59) was done to evaluate the impact of a CP intervention on the number of IGCT-provided drug-related recommendations. The CP intervention increased the number of drug-related recommendations and patients were discharged with fewer drugs and RASP PIMs compared to admission in the post cohort.

Finally, a third part of the PhD thesis was directed toward evaluating the performance of an implemented CP care program on acute geriatric wards. Here, we sought to identify those geriatric inpatients who were most likely to benefit from the care program in terms of the number of CP recommendations. A retrospective chart study was performed (n=524). At discharge, three CP recommendations were provided per patient, a majority of which targeted drug discontinuation. A multivariable Poisson regression model was derived, containing five determinants: number of drugs on admission, number of previous contacts with the geriatric department, presence of left-ventricular dysfunction, the number of new drugs and the use of colecalciferol. Using a threshold of at least 5 CP recommendations, a high positive likelihood ratio of 9.32 was found for the number of recommendations at discharge.

In conclusion, this PhD thesis has described a journey to optimize drug use in geriatric inpatients, which we embarked on with the development of a screening tool, the RASP list. This tool was then used as basis for further defining a CP intervention, which was investigated in several subsequent studies, all involving geriatric inpatients. Our results show that PIM reduction is readily feasible among diverging subpopulations, even when provided under a minimized iteration such as was the case in the IGCT study or the Jessa study. The CP intervention was furthermore correlated with lower rates of ED visits and improved quality of life. Our experiences finally led to the uptake of the CP approach into clinical practice, resulting in an implemented CP care program at the geriatric wards of UZ Leuven.