Predictive relationship between psychological, social, physical activity, and sleep measures and somatosensory function in individuals with musculoskeletal pain: a systematic review and meta-analysis protocol

Background: Alteration in somatosensory function, assessed via responses to quantitative sensory testing (QST), has been associated with heightened pain severity and interference in individuals with musculoskeletal (MSK) pain. However, a range of factors may confound the relationship between QST and clinical outcomes of pain. Therefore, there is a need for a comprehensive systematic review establishing the relationships between a range of factors (psychological, social, sleep, and physical activity) and QST responses among individuals with MSK pain. Objective: To establish the level of evidence of associations between psychological, social, physical activity, and sleep measures and QST responses among patients with MSK pain. Method and analysis: A comprehensive literature search will be conducted in the following electronic database (CINAHL, Ovid-MEDLINE, Scopus, PsycINFO, PubMed, and Web of Science) from their inception to June 2018. Two reviewers will assess the methodological quality using a modified QUIPS tool, which is tailored for the need of this review and supplemented by recommendations from CHARMS checklist and QUADAS-2 tool. The level of evidence will be assessed using GRADE criteria. Data pertinent to statistical measures of relationships from the included studies will be pooled to evaluate the strength of the relationship for each factor with a somatosensory abnormality, through meta-analysis. Appropriate subgroup and sensitivity analyses will be conducted. Where statistical pooling of data not feasible, a narrative review of the findings will be conducted. Significance: This systematic review will provide evidence of modifiable factors associated with altered sensory processing in individuals with MSK pain. Such evidence may also direct to test interventions targeting those factors to influence somatosensory function, thereby improve pain outcomes.