The dentine hypersensitivity experience questionnaire (DHEQ): A longitudinal validation study

Aim: To validate the Dentine Hypersensitivity Experience Questionnaire (DHEQ) in terms of responsiveness to change and to determine the minimally important difference (MID).Materials and methods: The study was a secondary analysis of data from three randomized controlled trials with 311 participants. Three aspects of responsiveness were examined: change within individuals; differences between people who improved, stayed the same, or worsened using an external referent; and change attributable to treatment. Responsiveness to treatments of differing efficacy was assessed in trials with negative and active controls.Results: The measure showed excellent internal reliability, test-retest reliability, and criterion validity. The measure was highly responsive to change within individuals (Cohen's effect sizes (ES): 0.28, 0.56, 0.86), showing decreases in the total score (i.e., improvement in oral health-related quality of life) across all trials. The ES for participants whose self-reported quality of life was "improved" were large (0.73-1.31). DHEQ detected a treatment effect in one of two negative control trials (ES: 0.47). DHEQ scores were similar in the test and control groups in the active control trial. The MID range was between 22 and 39 points.Conclusions: The measure is longitudinally stable, valid, and responsive, and it can discriminate between treatments of different efficacy.