Objective
To evaluate the risk of falls and fractures in users of benzodiazepines, Z-drugs, or melatonin.

Methods
We followed 699,335 adults with a purchase of benzodiazepines, Z-drugs, or melatonin in the Danish National Prescription Registry between 2003 and 2016 for falls and fractures in the Danish National Patient Registry between 2000 and 2018. A self-controlled case-series analysis and conditional Poisson regression were used to derive incidence rate ratios (IRR) of falls and fractures during six predefined periods.

Results
In total 62,105 and 36,808 adults, respectively, experienced a fall or fracture. For older adults, the risk of falls was highest during the 3-month pre-treatment period (IRRmen+70, 4.22 (95% confidence interval, 3.53–5.05), IRRwomen + 70, 3.03 (2.59–3.55)) compared to the baseline (>1 year before initiation). The risk continued to be higher in the later treatment periods. Contrarily, in men and women aged 40–69 years, the risk was only higher in the 3-month pre-treatment period. The incidence of falls among young men and women was slightly lower after initiation of sedating medication (treatment period, IRRmen15–39, 0.66 (0.50–0.86), IRRwomen15–39, 0.65 (0.51–0.83)). Analyses with fractures as outcome yielded similar results.

Conclusions
Although falls and fractures occur more often in persons using sedative-hypnotic medication, the higher risk of falls and fractures in the pre-treatment period relative to the period directly after treatment, suggests that this association is better explained by other factors that elicited the prescription of this medication rather than the adverse effects of the sedative-hypnotic medication.