Related Experiment Video
Updated: May 6, 2026

A Contusive Model of Unilateral Cervical Spinal Cord Injury Using the Infinite Horizon Impactor
Published on: July 24, 2012
Examination of the relationship between theory-driven policies and allowed lost-time back claims in workers'
Jessica J Wong1, Marion McGregor2, Silvano A Mior3
1Research Associate, UOIT-CMCC Centre for the Study of Disability Prevention and Rehabilitation, University of Ontario Institute of Technology (UOIT) and the Canadian Memorial Chiropractic College (CMCC), Toronto, Ontario, Canada.
Objective:
The purpose of this study was to develop a model that evaluates the impact of policy changes on the number of workers' compensation lost-time back claims in Ontario, Canada, over a 30-year timeframe. The model was used to test the hypothesis that a theory- and policy-driven model would be sufficient in reproducing historical claims data in a robust manner and that policy changes would have a major impact on modeled data.
Methods:
The model was developed using system dynamics methods in the Vensim simulation program. The theoretical effects of policies for compensation benefit levels and experience rating fees were modeled. The model was built and validated using historical claims data from 1980 to 2009. Sensitivity analysis was used to evaluate the modeled data at extreme end points of variable input and timeframes. The degree of predictive value of the modeled data was measured by the coefficient of determination, root mean square error, and Theil's inequality coefficients.
Results:
Correlation between modeled data and actual data was found to be meaningful (R(2) = 0.934), and the modeled data were stable at extreme end points. Among the effects explored, policy changes were found to be relatively minor drivers of back claims data, accounting for a 13% improvement in error. Simulation results suggested that unemployment, number of no-lost-time claims, number of injuries per worker, and recovery rate from back injuries outside of claims management to be sensitive drivers of back claims data.
Conclusion:
A robust systems-based model was developed and tested for use in future policy research in Ontario's workers' compensation. The study findings suggest that certain areas within and outside the workers' compensation system need to be considered when evaluating and changing policies around back claims.
Related Concept Videos
Pharmacodynamic Models: Link Model and Systems Pharmacodynamic Model
Pharmacodynamic Models: Direct Effect Model and Indirect Response Model
Pharmacodynamic Models: Overview
Modeling with Differential Equations
Methods of Documentation VI: Case Management Model
For example, a patient with a chronic...
Pharmacokinetic–Pharmacodynamic Relationship: Model Components

