Patient Explanatory Model as a Predictor of Delivered Treatment

A large body of research evidence demonstrates that temporomandibular disorder (TMD) symptoms are caused and/or maintained by a combination of both physical and psychological factors. The Explanatory Model Scale (EMS; Massoth, 1992) is a self-report questionnaire that measures the perceived influence of physical, behavioral, and stress factors on the cause, aggravation of, and importance in treatment for TMD pain. OBJECTIVES: The purpose of the present study was to determine the utility of the EMS as a predictor for treatment needed and treatment delivered. METHODS: Following exploratory cluster analysis, subjects (n=124) previously treated for TMD were assigned to one of four groups based on EMS responses pertaining to perceived aggravating factors and to perceived treatment needs: (1) all factors very important; (2) physical factors very important and behavioral/stress factors somewhat important; (3) physical factors somewhat important; (4) some missing data. Analyses were based on ANOVA and chi squared. RESULTS: The EMS aggravating factor groups did not differ on age, gender, pain chronicity, pain intensity, or perceived control of pain; pain-related disability was marginally higher in EMS group 1 (p=0.06). 60-81% of subjects remained in same perceived treatment need group as in the aggravating factor group, with reassignment balanced across remaining groups. Usual treatment recommendations were fulfilled 100% of the time while recommendations for adding biobehavioral treatment was successful in 65% of cases (chi squared, p=0.000); successful biobehavioral treatment addition was even lower for treatment need group 1. Depression, anxiety, and somatization (SCL-90) did not predict EMS group assignments. CONCLUSIONS: Easy assessment of patient explanatory model about TMD pain remains elusive; such beliefs do not appear to be related to expected predictors. Patient indication that biobehavioral factors should be involved in treatment is not always accompanied by delivery of such treatment. Research supported by NIH DE-13221 and T-35 DE-07106.