Cost effectiveness of a participatory ergonomics education intervention among office workers; A randomized controlled trial

Introduction
Aim: To study whether an intervention that uses participatory ergonomics education method is cost-effective compared to doing no intervention in office workers

Methods
Methods: The study is a prospective randomized trial including cost-effectiveness analysis; with a one year of follow-up (November 2008-November 2009). Study was conducted at Municipality of Balcova, in Izmir/Turkey with 110 office workers. Intervention consisted of participatory office ergonomics including self risk assessment method. Screening process started 3 months before the intervention and continued for 10 months after the intervention. Effectiveness was measured with Quick Disabilities of Arm, Shoulder and Hand- Turkish Language Version (DASH) and Northwich Park Neck Pain Scale.

Costs included intervention cost, productivity costs and cost of health care. Costs were presented in Turkish liras (TL). Probabilistic sensitivity analysis was conducted to explore the effect of uncertainty on results.

Results
Results: Effectiveness scores slightly improved over time. After one year 75% of participants were free of complaints at the intervention group while it was only 50% at the non-intervention group. After one year intervention group had lower mean total costs and better outcomes in scores. At twelve months after baseline there is a probability of 84 to 86% that the ICER is acceptable at a ceiling of zero. When the willingness to pay for an additional unit of effect on one of these outcome parameters is 1400 TL, the probability of being cost effective increased to 100%.

Discussion
Conclusion: We found significant differences in DASH and PARK scores at one-year compared to baseline and our analysis suggest that participatory ergonomics education has a higher probability of being cost-effective compared to doing no intervention.