Prevention in dangerous industries: does safety certification prevent tree-faller injuries?

Scand J Work Environ Health. 2015 Sep 1;41(5):478-85. doi: 10.5271/sjweh.3517. Epub 2015 Aug 6.


Objectives: The aim of this study was to evaluate if safety certification reduces the risk of work injury among experienced manual tree-fallers.

Methods: This study used a retrospective cohort study design. Experienced manual tree-fallers employed in the Canadian province of British Columbia (N=3251) between 2003-2008 were enumerated from a mandatory faller registry. Registry records with demographic and certification data were linked to workers' compensation claims for injury outcomes. Data were analyzed using discrete time survival analysis over a two-year period, centered on certification date with pre- and post-certification demarcated into four three-month periods. Models were adjusted for demographic, occupation/industry, previous injury, and seasonal/temporal effects.

Results: The relative risk (RR) of work injury during the post certification periods were elevated in comparison to the pre-certification reference period, but the 95% confidence intervals included "1" for all estimates by the end of follow-up, suggesting no statistically significant increased risk of injury. Results were consistent across different outcome measures of acute injury (ie, fracture or amputations) (N=186), musculoskeletal injury (ie, back strain) (N=137), and serious injury claims (ie, long duration, high cost and/or fatal) (N=155).

Conclusion: Certification did not reduce the risk of work injury among experienced tree-fallers in the province of British Columbia. Non-statistically significant increases in the observed risk of work injury in the months immediately following certification may be attributable to an intervention effect or a methodological limitation related to a lack of individual-level, time-at-risk exposure data.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • British Columbia / epidemiology
  • Canada
  • Certification / statistics & numerical data*
  • Female
  • Humans
  • Industry
  • Male
  • Middle Aged
  • Musculoskeletal Diseases / epidemiology*
  • Occupational Diseases / epidemiology*
  • Occupational Injuries / epidemiology*
  • Retrospective Studies
  • Risk Factors
  • Safety / standards*
  • Sick Leave
  • Socioeconomic Factors
  • Trees
  • Workers' Compensation / statistics & numerical data*
  • Young Adult