Investigation of sleep disturbance in chronic low back pain: an age- and gender-matched case-control study over a 7-night period.

Sleep disturbance is frequently reported by people with chronic low back pain (>12 weeks; CLBP), but few studies have comprehensively investigated sleep in this population. This study investigated differences in subjectively and objectively measured sleep patterns of people with CLBP, and compared this to age- and gender matched controls. Thirty-two consenting participants (n = 16 with CLBP, n = 16 matched controls), aged 24-65 years (43.8% male) underwent an interview regarding sleep influencing variables, completed the Pittsburgh Sleep Quality Index, Insomnia Severity Index, Pittsburgh Sleep Diary, SF36-v2, Hospital Anxiety and Depression Scale, Oswestry Disability Index, Numerical Pain Rating Scales, and underwent seven consecutive nights of actigraphic measurement in the home environment. Compared to controls, people with CLBP had, on self-report measures, significantly poorer sleep quality [Pittsburgh Sleep Quality Index (range 0-21) mean (SD) 10.9 (4.2)], clinical insomnia [Insomnia Severity Index mean (range 0-28) 13.7 (7.6)], lower sleep efficiency, longer sleep onset latency, more time awake after sleep onset, and more awakenings during sleep (p < 0.05). However, no significant differences between groups were found on objective actigraphy (p > 0.05). The findings provide some evidence to support self-reported sleep assessment as an outcome measure in CLBP research, while further research is needed to determine the validity of objective sleep measurement in this population.