Non-Occupational Risk Factors for Carpal Tunnel Syndrome: A Review

Context: Carpal tunnel syndrome (CTS) is a common neuropathy accounting for up to 90% of all entrapment neuropathies of the upper limb. Identifying potential risk factors might aid in the prevention of this injury. This systematic review aims to identify the current known non-occupational risk factors for CTS as published in three electronic databases.
Evidence Acquisition: Three electronic databases PubMed, Web of Knowledge, and SpringerLink were searched using the keywords “CARPAL TUNNEL SYNDROME RISK” for all published articles up to September 2015. Based on the inclusion and exclusion criteria, 2755 unique titles were independently analyzed and narrowed to a final list of 83 articles. Only articles with a level of evidence of I, II, or III were included, in accordance with robust study design and data analysis methods. The level of certainty for each risk factor was determined using previously defined criteria.
A total of 83 articles were included, which defined 29 individual, non-occupational risk factors. Only sex and previous musculoskeletal disorder/injury were found to have a moderate level of certainty to modify the risk of CTS. All other risk factors were evaluated as having a low level of certainty.
Considering the large number of studies reporting on non-occupational CTS risk factors as well as the differences in reporting between studies, a lack of consistency is observed in the current review. This review does, however, offer a broad outlook on the literature and the current evidence for risk factors commonly believed to be associated with altered CTS risk. Although several risk factors are commonly believed to be associated with altered risk of CTS, the current evidence to support these beliefs is limited. Prospective cohort studies, larger sample sizes, and consistent and robust measures of risk should be used in future research.