Background data: The Dictionary of Occupational Titles (DOT) is a U.S. government publication that defines each job in the United States according to 20 job factors. Fishbain et al. (Spine 1994;19:872-80) developed a DOT residual functional capacity (RFC) battery whose predictive validity for employment/unemployment had not been tested previously.
Objectives: The purposes of this study were as follows: (a) to determine whether results of a DOT-RFC battery performed at completion of pain facility treatment predicted employment status at 30 months' follow-up and (b) to determine whether the DOT-RFC battery predicted employment capacity as determined by the DOT employment levels of the chronic pain patients' (CPPs) jobs.
Study design: This is a prospective low back pain CPP pain facility treatment study using employment status and the DOT occupational levels as outcome measures.
Methods: One hundred eighty-five consecutive CPPs who fitted the selection criteria completed a DOT-RFC battery at the completion of pain facility treatment and were contacted at 1, 3, 6, 12, 18, 24, and 30 months for determination of their employment status and DOT employment level. Eight DOT job factors plus pain and worker compensation status were found to be significantly different between employed and unemployed CPPs and between those employed in different DOT employment levels. For the 10 variables, stepwise discriminant analysis was used to select final predictor variables. Sensitivity and specificity were calculated along with pain level cutpoints that separated the groups.
Results: The eight DOT job factors found to be statistically significant between groups were the following: stooping, climbing, balancing, crouching, feeling shapes, handling left and right, lifting, carrying, and pain and worker compensation status. In the discriminant analysis, these variables could discriminate between the employed and unemployed categories, with a sensitivity and specificity of approximately 75%. The pain level cutpoint between employed and unemployed was 5.4 on a 10-point scale.
Conclusions: We cannot as yet predict DOT-RFC employment levels. However, if a CPP can pass the above eight DOT job factors and has a pain level less than the 5.4 cutpoint, that CPP will have a 75% chance of being employed at 30 months after treatment at the pain facility. Therefore, some DOT-RFC battery job factors demonstrate a predictive validity in the "real work world."