The Reproducibility and Responsiveness of a Patient-Specific Approach: A New Instrument in Evaluation of Treatment of Temporomandibular Disorders

Aims: To evaluate the choice of activities on the Patient Specific Approach (PSA) in a sample of temporomandibular disorder (TMD) patients and to determine the clinimetric properties of the visual analog scale (VAS) scores of the PSA, in terms of reproducibility and responsiveness. Methods: At treatment start, TMD patients reported the PSA activity which represents the most important activity that is impaired due to their TMD complaints. The amount of hindrance during this activity was rated on a VAS. During two follow-up measurements, patients used the VAS to rate the amount of hindrance and appraised their overall complaints in terms of "much worsened," "slightly worsened," "remained stable," "slightly improved," or "much improved." To determine the reproducibility and responsiveness, an intraclass correlation coefficient and receiver operating characteristics-curve were then calculated. Results: Of the 132 patients who fulfilled baseline measurements, 13% reported an activity that is not included in existing TMD-disability questionnaires. The reproducibility of the VAS scores of the 78 patients who reported that their complaints had "remained stable" at second measurement was good (intraclass correlation coefficient = 0.73). The responsiveness of the PSA was high, and the cutoff score for important improvement, where sensitivity (0.85) and specificity (0.84) were as much as possible the same, was 58%. Conclusion: The PSA for TMD patients is a new and easy-to-use tool in treatment evaluation. Moreover, the VAS score of the PSA has good reproducibility and responsiveness. Keywords: patient specific approach, reproducibility, responsiveness, TMD, treatment effect