The Utility of Actigraphy to Measure Sleep in Chronic Pain Patients and Its Concordance with Other Sleep Measures: A Systematic Review and Meta-Analysis

There may be a bidirectional relationship between sleep and pain in patients with chronic pain. Actigraphy is increasingly being used as a non-invasive and objective method to assess sleep in chronic pain patients. This systematic review aimed to evaluate the utility of actigraphy in chronic pain patients. Additionally, meta-analyses were conducted to compare sleep parameters measured by actigraphy with those measured by sleep diary and polysomnography. Medline (1946-2019), Medline In-Process (May 2019), Embase (1947-2019), Cochrane Central Register of Controlled Trials (1991-2019), Cochrane Database of Systematic Reviews (2005-2019), and PubMed-NOTMedline (1946-2019) were searched for studies using actigraphy to measure sleep in chronic pain patients. Using the random effects model, meta-analyses were conducted to examine the concordance of actigraphy versus sleep diary and actigraphy versus polysomnography for commonly measured sleep parameters. Thirty-four studies with 3,590 patients were included. As an adjunct to sleep diary, actigraphy detected improvements in various sleep parameters after interventions in 10 studies and provided a useful objective sleep metric when comparing pain patients with healthy subjects in four studies; however, diary measurements were more “sensitive”. Comparing sleep diary versus actigraphy, sleep onset latency was significantly lower with actigraphy (mean difference of 22.7 minutes lower; 95% confidence interval: 13.2 to 32.2 minutes lower; p<0.01). No sleep parameters were significantly different between polysomnography and actigraphy; however, the confidence intervals were large. Actigraphy is an objective assessment tool that is being increasingly utilized to measure sleep in chronic pain patients. Based on studies that have measured sleep with both sleep diary and actigraphy, there are intrinsic differences between the two assessment methods as actigraphy lacks the cognitive component of subjective measures. Even though no differences in sleep parameters were detected between actigraphy and polysomnography, it cannot be established that the two are equivalent objective measures because of the limited number of studies and large variability.