1 Montreal University Hospital Centre Research Centre, 900 Rue Saint-Denis, Montreal, Quebec, H2X 0A9, Canada; Quebec Network for Research on Aging, 4565 Queen-Mary Road, Montreal, Quebec, H3W 1W5, Canada. Electronic address: patrick.nguyen@umontreal.ca.
2 Centre de recherche de l'institut universitaire de gériatrie de Montréal (CRIUGM), CIUSSS Centre-Sud-de-l'île-de-Montréal, 4565 Chem. Queen Mary, Montréal, QC H3W 1W5, Canada; Concordia University, 1455 De Maisonneuve Blvd. W, Montreal, Quebec, H3G 1M8, Canada.
3 Montreal University, 2900, boul. Édouard-Montpetit, Montréal, Quebec, H3T 1J4, Canada.
4 Montreal University Hospital Centre Library, 1000, rue Saint-Denis, Montréal, Québec, H2X 0C1, Canada.
5 Montreal University Hospital Centre Research Centre, 900 Rue Saint-Denis, Montreal, Quebec, H2X 0A9, Canada.

Objective: This systematic review and meta-analysis evaluates the efficacy in improving sleep quality and safety of hypnotics in individuals aged 65 years or older compared to those under 65 years.

Methods: MEDLINE, EMBASE, Web of Science, and EBM Reviews were searched for randomized clinical trials comparing hypnotics to the placebo in adults with chronic insomnia between Jan 2000 and Dec 2022. The efficacy outcome included all participant self-assessments sleep quality questionnaires. The safety outcome included acceptability and tolerance. Standardized mean differences (SMD) was estimated using a random effect model.

Results: We included 17 and 53 clinical trials with 3688 and 14,720 participants in the =65 years and <65 years group respectively. The SMD for the sleep quality outcome was -0.36 [Confidence interval (CI) 95 %: 0.45; -0.26] in the =65 years group compared to -0.51 [95%CI: 0.61; -0.41] in the <65 years group (p = 0.02). Differences in efficacy were observed between pharmacological classes. The overall SMD for the tolerance outcome was - 0.25 [95%CI: 0.34; -0.16] favoring the placebo group (p < 0.001). In the =65 years group the SMD was -0.07 [95%CI: 0.21; 0.08] compared to -0.31 [95%CI: 0.41; -0.21] in the <65 years group (p = 0.01). There were no differences for acceptability.

Conclusion: We found that some hypnotics classes could be less effective in older individuals. We encourage authors to include details on multimorbidity and polypharmacy in their publications.