Survey of Inter- and Intra- Observer Reliability of Three Ergonomic Risk Assessment Methods of Strain Index, Assessment of Repetitive Tasks and Occupational Repetitive Actions

There are many tools for assessing of semi-quantitative and observational risk to be used by researchers and ergonomists. This study aim was to examine the reliability of intra-tester and inter- observer reliability of three risk assessment methods of Strain Index (SI), Assessment of Repetitive Tasks (ART) and Occupational Repetitive Actions (OCRA) in the repetitive tasks and exposure to upper limb risk factors.
A total of 30 tasks among workers exposed to upper limb musculoskeletal disorder risk factors were evaluated by 9 testers using SI, OCRA Checklist and ART methods. The results of the assessments were analyzed using Kappa and ICC weighted tests in SPSS and R soft wares.
The results of reliability of inter-tester with Kappa's coefficient for risk level classification were obtained for OCRA Checklist and ART (κ=0.68) VS (κ=0.72), respectively and for SI (κ=0.52). The reliability of intra-tester for the final score of OCRA Checklist, ART and SI methods were (p=0.76), (p=0.81) and (p=0.82), respectively.
In general, the reliability of inter-tester was obtained for three studied methods ranged moderate to good status. However, the general results showed the higher reliability of ART method than two other methods. According to the findings, SI, OCRA Checklist and ART are appropriate to use in the work environment, but in order to use these methods the items such as the purpose of assessment, experience of tester, and the required time for each task should be considered.