Association between anticholinergic drug prescription changes and rehabilitation outcome in post-acute hip fractured patients

The Prognostic Utility of Anticholinergic Burden Scales: An Integrative Review and Gap Analysis

BACKGROUND

Anticholinergic drugs are commonly prescribed, especially to older adults. Anticholinergic burden scales (ABS) have been used to evaluate the cumulative effects of multiple anticholinergics. However, studies have shown inconsistent results regarding the association between anticholinergic burden assessed with ABS and adverse clinical outcomes such as cognitive impairment, functional decline, and frailty. This review aims to identify gaps in research on the development, validation, and evaluation of ABS, and provide recommendations for future studies.

METHOD

A comprehensive search of five databases (MEDLINE, Embase, PsychInfo, CINAHL, CENTRAL) was conducted for relevant studies published from inception until 25 May 2023. Two reviewers screened for eligibility and assessed the quality of studies using different tools based on the study design and stage of the review framework. Research evidence was evaluated, and gaps were identified and grouped into evidence, knowledge, and methodological gaps, using evidence tables to summarize data.

RESULTS

Several evidence, knowledge, and methodological gaps in existing development, validation, and evaluation studies of ABS were identified. There is no universally accepted scale, and there is a need to define a clinically relevant threshold for measuring total anticholinergic burden. The current evidence has limitations, underrepresenting low- and middle-income countries, younger individuals, and populations with cognitive disabilities. The impact of anticholinergic burden on frailty is also understudied. Existing evaluation studies provide limited evidence on the benefit of reducing anticholinergic burden on clinical outcomes or the safety of anticholinergic deprescribing. There is also uncertainty regarding optimal reduction, clinically significant anticholinergic burden thresholds, and cost effectiveness.

CONCLUSIONS

Future research recommendations to bridge knowledge gaps include developing a risk assessment framework, refining ABS scales, establishing a standardized consensus scale, and creating a longitudinal measure of cumulative anticholinergic risk. Strategies to minimize bias, consider frailty, and promote multidisciplinary and multinational collaborations are also necessary to improve patient outcomes.

Pharmacotherapy and the Role of Pharmacists in Rehabilitation Medicine

Pharmacotherapy is important in older patients undergoing rehabilitation because such patients, especially those with frailty and physical disabilities, are susceptible to drug-related functional impairment. Drug-related problems include polypharmacy, potentially inappropriate medications (PIMs), and potential prescription omissions. These problems are associated with adverse drug events such as dysphagia, depression, drowsiness, falls and fractures, incontinence, decreased appetite, and Parkinson's syndrome, leading to impaired improvement in activities of daily living (ADL), quality of life (QOL), and nutritional status. Moreover, the anticholinergic burden is associated with impaired physical and cognitive functions. Therefore, pharmacist-centered multidisciplinary pharmacotherapy should be performed to maximize rehabilitation outcomes. Pharmacotherapy includes a review of all medications, the assessment of drug-related problems, goal setting, correction of polypharmacy and PIMs, monitoring of drug prescriptions, and reassessment of drug-related problems. The goal of pharmacotherapy in rehabilitation medicine is to optimize drug prescribing and to maximize the improvement of ADL and QOL as patient outcomes. The role of pharmacists during rehabilitation is to treat patients as part of multidisciplinary teams and as key members of nutritional support teams. In this review, we aim to highlight existing evidence regarding pharmacotherapy in older adults, including drug-related functional impairment and the association between pharmacotherapy and functional, cognitive, and nutritional outcomes among patients undergoing rehabilitation. In addition, we highlight the important role of pharmacists in maximizing improvements in rehabilitation outcomes and minimizing drug-related adverse effects.