Single and combined use of fall-risk-increasing drugs and fracture risk: a population-based case-control study.

Background: while many drug groups are associated with falls in older people, less is known about absolute increases in risk and how these risks vary across different groups of drugs or individuals.

Method And Design: we conducted a population based nested case-control study among people aged ≥65 years in the Scottish regions of Tayside and Fife. Cases were individuals hospitalised with a fracture between 2010 and 2020, to whom we matched up to 10 controls. We examined relative and absolute risks of drug groups known as 'Fall-Risk-Increasing Drugs' (FRIDs), alone and in combination, and among younger and older (≥75 years) adults. Adjusting for previous hospitalisations, drug use and laboratory data, we used conditional logistic regression to quantify associations between drug exposures and outcomes. We conducted four sensitivity analyses to test the robustness of our findings.

Results: the cohort comprised 246,535 people aged ≥65 years, of whom 18,456 suffered an incident fracture. Fracture risks were significantly increased for most FRIDs examined. Absolute risks were much larger among older vs younger people and both relative and absolute risks increased with the number of FRIDs combined. Overall, the highest absolute increase in risk were found in people aged ≥75 years for selective serotonin reuptake inhibitors (number needed to harm 53), tricyclic antidepressants (NNH 81), antipsychotics (NNH 75) and use of three or more FRIDs (NNH ≤66).

Conclusion: patients aged ≥75 years prescribed antidepressants or antipsychotics or taking three or more drugs that increase risk of falls may benefit most from deprescribing interventions.