A stochastic model for the analysis of occupational injuries on jobs of varying physical stress

A stochastic model is used to analyze occupational injuries associated with heterogeneous job exposures, i.e., workers switch jobs with different physical stress. One problem encountered in modeling such cases is that the risk of injury while performing a low stress job may be affected by the length of previous exposure to a high stress job, and vice versa. A semi-Markov process is assumed for transition among heterogeneous jobs and subsequent injuries. The model is used to determine the significant factors related to major injury incidence for 1251 workers in a southwestern industrial plant. Gender is found to be highly significant in predicting major injuries among workers exposed to high stress jobs. A worker’s past minor injury experience also appears to be strongly associated with the likelihood of future major injury occurrence.