Minimal clinically important differences of oral health-related quality of life after removable partial denture treatments

Abstract

ObjectivesThis study aimed to determine the minimal clinically important difference (MID) of the oral health-related quality of life (OHRQoL) in removable partial dentures (RPDs) wearers, using the oral health impact profile (OHIP). MethodsIn this study, RPD patients were asked to complete the OHIP and self-reported oral health (SROH) questionnaires before the treatment and 3 months after the RPD treatment. The Wilcoxon signed ranked test compared the pre- and post-treatment status and the Spearman correlation analysis evaluated the relationship between the pre- and post- treatment change scores of the OHIP and SROH. The median OHIP change score in a subgroup that showed minimum SROH improvement was determined as the MID. ResultsOf the 277 participants, 248 (89.5 %) completed the pre-and post- treatment evaluations. SROH and OHIP scores showed significant improvements after RPD treatment (P < 0.05). The OHIP change scores showed significant moderate correlations with the SROH change scores (P < 0.05). The MIDs for the summary scores of OHIP-49, 20, 14, and 5 versions were 14, 7, 3, and 2 points, respectively. An additional 2–3 points were assigned to the four dimensions (oral function, orofacial pain, orofacial appearance, and psychological impact). ConclusionsAn OHIP change of more than 14 points (OHIP-49), 7 points (OHIP-20), 3 points (OHIP-14), 2 points (OHIP-5) and 2–3 points (4 dimensions) was considered clinically meaningful in RPD treatments. Clinical SignificanceThe proposed MID scores could be used as a benchmark for clinical decision making, interpretation of RPD treatment effects on OHRQoL, and sample size calculations in clinical trials.