working and living in northern vs southern ontario is associated with the duration of compensated time off work: a retrospective cohort study

background: northern ontario, canada has a larger elder population, more resource-based employment, and limited access to physicians and specialists compared to southern ontario. given these important differences, it is possible that work disability rates will vary between the two ontario jurisdictions. objective: to determine the association between time lost due to workplace injuries and illnesses occurring in northern vs southern ontario and work disability duration from 2006– 2011. methods: the study base included all lost-time claims approved by the workplace safety and insurance board in ontario, canada for workplace injury or illness compensation occurring between january 1, 2006 and december 31, 2011. all eligible participants had to be 18 years of age or older at the time of making the claim and participants were excluded if one of the three variables used to determine location (claimant home postal code, workplace geographical code, and wsib firm location) were missing. multivariable proportional hazards regression models were used to estimate hazard ratios and 95% confidence intervals adjusted for sex, age, occupation, part of body, and nature of injury relating ontario geographical location to compensated time off work. results: a total of 156 453 lost-time claims were approved over the study period. injured and ill workers from northern ontario were 16% less likely to return to work than those from southern ontario. adjustment for potential confounding factors had no effect. conclusion: the disability duration in northern ontario is longer than that in southern ontario. future research should focus on assessing the relevant factors associated with this observation to identify opportunities for intervention.