Carpal tunnel syndrome among Manitoba workers: Results from the Manitoba Occupational Disease Surveillance System

Abstract

Background

Carpal tunnel syndrome (CTS) is associated with occupational high-force repetitive tasks and vibration. This project examines the relationship between CTS and work to: (1) identify jobs and industries with increased CTS risk; (2) explore whether there is a sex difference in the risk of CTS after controlling for occupation; and (3) determine whether any observed relationships persist after excluding Workers Compensation Board (WCB) accepted time-loss CTS claims.

Methods

We linked 95.5% of time-loss WCB claims from 2006 to 2019 to provincial administrative health data. The cohort included 143,001 unique person-occupation combinations. CTS cases were defined as at least two medical claims for (ICD-9 354) within a 12-month period or a surgical claim for CTS from 2 years before the WCB claim to 3 years after. WCB accepted CTS time-loss claims not identified by the medical claims were also included.

Results

A total of 4302 individuals (3.0%) met the CTS definition. Analysis revealed that the hazard ratios (HRs) of CTS vary considerably with occupation. Sex-based differences in CTS risks were observed, both in low- and high-risk occupations. In many occupations with increased HR, the HR remained elevated after excluding accepted time-loss WCB cases.

Conclusions

The risk of developing CTS varied with occupation. Job titles with ergonomic risk factors had higher risks than those with lower exposures. This finding remained after eliminating time-loss compensated WCB cases, suggesting that all cases of CTS in high risk jobs are not identified in WCB statistics. Female workers in some job titles had excess CTS cases compared to male workers within the same job title.