Research opportunities using administrative databases and existing surveys for new knowledge in occupational health and safety in Canada, Quebec, Ontario and British Columbia

Adult Asthma among Workers in Ontario. Results from the Occupational Disease Surveillance System

Rationale: Given that approximately 15% of new-onset adult asthma cases originate because of exposures in the workplace, there is a need for systematic and ongoing monitoring of risk among workers. Objectives: To characterize the risk of new-onset adult asthma among workers in Ontario. Methods: We used 575,379 provincial accepted time-loss workers' compensation claimants data linked to physician billing data. Workers aged 15 to 65 years with a nonasthma compensation claim between January 1, 2002, and December 31, 2013, were eligible for inclusion. Cohort entry corresponded to the date of the claim. The case definition required two or more records for asthma within a 12-month period, within a 3-year time window after cohort entry. A 3-year washout period preceding cohort entry was used to exclude prevalent cases. Workers at risk of new-onset adult asthma were followed from cohort entry date to date of diagnosis, emigration, age 65 years, death, or end of study period. Cox regression models were used to generate birth year- and sex-adjusted hazard ratios (HRs) by occupation, industry, and exposures identified using a job exposure matrix. Sex-stratified risk estimates were also generated. Results: Increased risks were detected among well-recognized groups, including bakers (HR, 1.60; 95% confidence interval [CI], 1.22-2.09) and painters and decorators (HR, 1.67; 95% CI, 1.23-2.28). In the job exposure matrix analysis, flour and isocyanates were associated with increased risk of asthma. Concrete finishers (HR, 1.93; 95% CI, 1.12-3.32) and shipping and receiving clerks (HR, 1.21; 95% CI, 1.03-1.43) also showed elevated risk, whereas results varied across woodworker groups. Decreased risks were detected for nursing and farming groups. Conclusions: This practical data linkage approach was successful for examining associations across hundreds of jobs. Unexpected and previously unrecognized findings deserve further investigation and emphasize the importance of an ongoing system to guide research as well as prevention.

The utility of medico-legal databases for public health research: a systematic review of peer-reviewed publications using the National Coronial Information System

BACKGROUND

Medico-legal death investigations are a recognised data source for public health endeavours and its accessibility has increased following the development of electronic data systems. Despite time and cost savings, the strengths and limitations of this method and impact on research findings remain untested. This study examines this issue using the National Coronial Information System (NCIS).

METHODS

PubMed, ProQuest and Informit were searched to identify publications where the NCIS was used as a data source for research published during the period 2000-2014. A descriptive analysis was performed to describe the frequency and characteristics of the publications identified. A content analysis was performed to identify the nature and impact of strengths and limitations of the NCIS as reported by researchers.

RESULTS

Of the 106 publications included, 30 reported strengths and limitations, 37 reported limitations only, seven reported strengths only and 32 reported neither. The impact of the reported strengths of the NCIS was described in 14 publications, whilst 46 publications discussed the impacts of limitations. The NCIS was reported to be a reliable source of quality, detailed information with comprehensive coverage of deaths of interest, making it a powerful injury surveillance tool. Despite these strengths, researchers reported that open cases and missing information created the potential for selection and reporting biases and may preclude the identification and control of confounders.

CONCLUSIONS

To ensure research results are valid and inform health policy, it is essential to consider and seek to overcome the limitations of data sources that may have an impact on results.

The relationship between worker, occupational and workplace characteristics and whether an injury requires time off work: a matched case-control analysis in Ontario, Canada

BACKGROUND

The objective of this study was to examine individual, occupational, and workplace level factors associated with time loss following a similar injury.

METHODS

Seven thousand three hundred and forty-eight workers' compensation claims that did not require time off work were matched with up to four claims that required time off work on the event, nature, and part of body injured as well as injury year. Conditional logistic regression models examined individual, occupational, and workplace level factors that were associated with the likelihood of not requiring time off work.

RESULTS

Employees from firms with higher premium rates were more likely to report no time loss from work and workers in more physically demanding occupations were less likely to report no time loss from work. We observed no association between age or gender and the probability of a time loss claim submission.

CONCLUSIONS

Our results suggest that insurance costs are an incentive for workplaces to adopt policies and practices that minimize time loss following a work injury.

Are the predictors of work absence following a work-related injury similar for musculoskeletal and mental health claims?

OBJECTIVE

To examine if the factors associated with days of absence following a work-related injury are similar for mental health versus musculoskeletal (MSK) conditions.

METHODS

A secondary analysis of wage replacement workers' compensation claims in the state of Victoria, Australia. We examined the relationship between individual, injury, occupational and workplace variables with days of wage replacement over the 2-year period following first day of absence from work separately for mental health claims and MSK claims using negative binomial regression models.

RESULTS

Mental health conditions were associated with a greater number of days of absence over the 2 years following first incapacity compared to MSK conditions. Differences were observed in employment, injury and industry variables on absence from work for mental claims compared to MSK claims. Working in the agriculture, forestry, fishing and mining industries and employment with a small organisation were more strongly associated with the number of days of wage-replacement among MSK compared to mental health claims, and working in the public administration and safety, or education and training industries or being employed in a position with high time pressure were associated with greater days of wage-replacement among mental health compared to MSK claims.

CONCLUSIONS

Predictors of days away from work in the 2 years following an injury differ for mental health versus MSK claims. Given the increasing number of mental health claims in Australia more research is required to understand differences in return-to-work for this group of claimants compared to those with physical injuries.

Comparing the risk factors associated with serious versus and less serious work-related injuries in Ontario between 1991 and 2006

BACKGROUND

The objective of this study was to examine and compare the demographic and labor market risks for more serious and less serious work-related injuries and illnesses.

METHODS

Secondary analysis of accepted workers' compensation claims in Ontario, combined with labor force estimates for the period 1991 to 2006. Serious injuries and illnesses were claims resulting in wage replacement. Less serious injuries and illnesses were claims only requiring health care. Regression models examined the relationship between demographic and labor market characteristics (age, gender, industry, job tenure, and unemployment) and claim type.

RESULTS

Relative risk estimates for serious and less serious claims were not concordant across age, gender and industry employment groups. For example, while the mining and utilities and the construction industry had an increased probability of reporting NLTCs, they had a decreased probability of reporting LTCs.

CONCLUSIONS

The risk for serious and less serious work-related injury and illness claims differ by demographic and labor market groups. The use of composite measures that combine wage-replacement and health care only claims should be considered when using compensation data for surveillance and primary prevention targeting strategies.