One-Year Evolution of Sleep Quality in Older Users of Benzodiazepines: A Longitudinal Cohort Study in Belgian Nursing Home Residents

Abstract

Objectives: Chronic use of benzodiazepines and z-drugs (BZD/Zs), the most commonly used symptomatic treatment for sleep problems, is discouraged because of the unproven long-term effectiveness. In this study, we evaluated 1-year evolution of subjective sleep quality of chronic BZD/Z users compared with nonusers. Methods: All cognitively competent residents from ten Belgian nursing homes were screened and compiled in a group of chronic BZD/Z users or nonusers, based on the medication chart. We collected demographic, functional and psychometric characteristics (depressive symptoms with the 8-item Geriatric Depression Scale), sleep parameters (with the Pittsburgh Sleep Quality Index—PSQI) and medication use. We analysed evolution of sleep quality with nonparametric statistics. Associations with worsening of sleep quality were analysed with linear regression. Results: We collected data of 131 BZD/Z users and 95 nonusers. The mean age in both groups was 85 years and 77 % was female. Over a period of 1 year, the PSQI score evolved from 5.2 to 5.8 (p = 0.035) in the BZD/Z users, and from 4.3 to 4.7 (p = 0.078) in the nonusers. Though the mean deterioration in 1 year did not differ significantly between both groups, the BZD/Z users had a significantly worse sleep quality compared with nonusers at both time points. Depressive symptoms were significantly associated with worsening sleep quality (β = −0.243, p < 0.001). Conclusion: Sleep quality in chronic BZD/Z users significantly decreased over 1 year and was significantly worse than in nonusers at the end of this period. This study suggests that using BZD/Zs chronically does not maintain or improve sleep quality. Depressive symptoms are an important factor in the deterioration of sleep quality.