Widespread inappropriate prescribing for older people with reduced kidney function: what are the harms and how do we tackle them? A scoping review for primary care

Background Increasing age is associated with reductions in kidney function and increasing polypharmacy. Most medicines are eliminated through the kidney, meaning older patients are at risk of medication accumulation and toxicity. This scoping review synthesised: (1) the prevalence at which older patients with reduced kidney function in primary care are exposed to inappropriate prescribing; (2) its associated harms; (3) the reasons for this occurring; and (4) the interventions used to improve prescribing practices. Methods This scoping review searched ‘Medline’, ‘Embase’, ‘PsycINFO’, ‘CINAHL’ and ‘Web of Science’ for publications before October 2024. References were managed on EndNote V.X5 and thematic data analysis was undertaken on Microsoft Excel. Common themes were identified, summary statistics were calculated and insights were summarised through a narrative technique. Results 43 relevant studies explored the scale of inappropriate prescribing, estimating prevalences of patient exposure ranging from 0.6% to 49.1% (median 24.9%). Five studies explored the associated harm from inappropriate prescribing, but only one study assessed harm as a primary outcome. Eight studies that assessed difficulties in following prescribing guidelines in reduced kidney function suggested that a lack of awareness and trusted guidelines are fundamental problems. While 13 studies evaluated interventions for improving prescribing in reduced kidney function, only two demonstrated evidence of effectiveness and only one intervention was theoretically informed. Conclusions Despite significant heterogeneity in study characteristics, it is clear that the prevalence of inappropriate prescribing for older people is uncomfortably high. There is a lack of evidence linking this to associated adverse outcomes, as well as identifying the causative issues driving this behaviour and the preventative interventions that could prevent harm.