Bidirectional Association Between Sleep Quality and Low Back Pain in Older Adults: A Longitudinal Observational Study.

Objective: To investigate the bidirectional relationship by determining whether baseline sleep quality predicts pain intensity and whether baseline pain intensity predicts sleep quality in older individuals with chronic low back pain (LBP).

Design: A prospective longitudinal cohort study with a 6-month follow-up period.

Setting: Community.

Participants: Older adults with LBP aged 60 years or older (N=215).

Intervention: Not applicable.

Main Outcome Measures: Data collection occurred at baseline and at 6 months. Pain intensity and sleep quality were measured in both time points of assessment using the numeric pain rating scale (range, 0-10) and the Pittsburg Sleep Quality Index. At baseline, we also collected information on demographic anthropometric variables, cognitive status, depression, and comorbidities. Multivariable linear regression analyses adjusted for potential covariates were performed.

Results: A total of 215 individuals with LBP were recruited. Poor sleep quality at baseline predicted high pain intensity at 6 months (β coefficient, 0.18; 95% confidence interval [CI], 0.07-0.30). High pain intensity at baseline predicted poor sleep quality 6 months later (β coefficient, 0.14; 95% CI, 0.01-0.26).

Conclusion: Our findings give some support to the bidirectional relationship between pain and sleep quality in older individuals with LBP. This bidirectional relationship may be used as prognostic information by clinicians when managing patients with LBP.