The bidirectional relationship between sleep complaints and pain: Analysis of data from a randomized trial.

OBJECTIVE

The goal of this study was to examine the bidirectional relationship of sleep and pain to determine whether changes in sleep complaints over the course of a chronic pain treatment trial predict pain outcomes and vice versa, controlling for changes in depression and anxiety.

METHODS

Data were analyzed from a 12-month randomized, controlled trial that tested the effectiveness of a collaborative care intervention for veterans with chronic musculoskeletal pain. Participants were 250 veterans from 5 primary care clinics in a Veteran Affairs (VA) medical center. Measures of pain, sleep, and depression/anxiety symptoms were collected at baseline, 3 months, and 12 months. Factor analysis was used to clarify the boundaries of these domains, and structural equation modeling was used to examine whether changes in sleep complaints and depression/anxiety during the trial predicted pain at the end of the trial, controlling for covariates. An alternative model was also tested in which changes in pain predicted sleep complaints.

RESULTS

Changes in sleep complaints at 3 months significantly predicted changes in pain at 12 months (standardized path coefficient = .29, p < .001). To a lesser extent, changes in pain predicted changes in sleep (standardized path coefficient = .15, p < .05). Changes in depression/anxiety did not significantly predict changes in pain or sleep. There was also evidence of differential relations of specific sleep complaints with pain.

CONCLUSIONS

This work helps to further disentangle the complex relationship between pain and sleep. This bidirectional relationship may need to be considered to improve pain outcomes.