Pre-employment functional capacity assessments predict musculoskeletal injury risk in healthy male coal mine workers

Abstract

Background: Musculoskeletal injuries in the workplace are a significant economic and social problem in industrial nations worldwide. Pre-employment screening endeavours to identify individuals who are at greater risk of sustaining an injury so that those risks may be managed. Traditional methods of screening, including back X-rays and medical screening are not valid predictors, nor meet current anti-discrimination legislation requirements. Short-form functional capacity evaluations are increasing in popularity despite limited evidence of their ability to predict future risk of injury in healthy workers. Purpose: The purpose of this study was to determine if job-specific pre-employment functional assessments predict musculoskeletal injury risk in healthymalemineworkers and to determine if the injury risk differs for different injury types or over time. Methods: This was a prospective observational study involving 600 healthy male coal mine workers who participated in a job-specificpre-employment functional assessment (PEFA) as part of the hiring process of an Australian coal mine. At baseline, participants were screened with a jobspecific JobFit System PEFA consisting of a musculoskeletal screen, aerobic fitness test and job specific postural tolerance and material handling activities. PEFA scores were dichotomized into PEFA 1 if they met the job demands and PEFA> 1 if they did not. Injury data was obtained from the company’s database and injuries were classified according to body location, severity and mechanism. Results: Of the 600 participants (median age 37 years, range 17.0 to 62.6 years), 427 (71%)met job demands (PEFA 1). The median follow-up time was 2 years (IQR 1.2 to 4.0). A total of 121 workers (20.2%) reported an injury and 29 workers (4.8%) reported a back injury associated with manual handling. Statistically significant differences were found between PEFA groups in time to injury over the longer term (>1.3 years) for all injury types: any injury (Hazard Ratio [HR] = 2.3, 95% confidence interval [CI] 1.4 to 3.9), manual handing injury (HR= 3.3, CI 1.6 to 7.2), any back injury (HR= 3.3, CI 1.6 to 6.6), back injuries from (HR= 5.8, CI 2.0 to 16.7). These relationships remained significant after adjustment for confounders. Conclusion(s): The JobFit System PEFA predicts musculoskeletal injury risk in healthy male mine workers over the longer term. Implications: Job-specific pre-employment assessments meet anti-discrimination legislation. The JobFit System PEFA predicts musculoskeletal injury risk over the longer term, but not the short term. More research is needed to identify why risk changes over time however, practitioners can maximize the opportunity of the period with physical conditioning and workplace modifications as part of a holistic workplace injury risk management program.