Assessing Levels of Agreement between Two Commonly Used Oral Health‐Related Quality of Life Measures

OBJECTIVE: This study aimed to assess the level of agreement between two commonly used oral health-related quality of life (OHRQoL) measures, the short form of the Oral Health Impact Profile (OHIP14) and the Oral Impacts on Daily Performances (OIDP). METHODS: A sample of 1,675 15- to 16-year-old students attending all schools in Bauru (Sao Paulo, Brazil) was selected. The impact of oral conditions on quality of life in the last 6 months was reported using both OHIP14 and OIDP. To allow for comparison with the 100 percent OIDP score, OHIP14 scores were converted to percentages. Then, agreement between the two OHRQoL measures was analyzed using the Bland and Altman method. RESULTS: The mean difference between OHIP14 and OIDP was 6.48 percent [confidence interval 95% (6.08; 6.89)], with higher scores reported for OHIP14 than for OIDP. Besides, 95 percent of the differences between the two OHRQoL measures were between -10.59 and 23.56 percent. Finally, differences between OHIP14 and OIDP increased significantly as the magnitude of their average increased (P < 0.001). CONCLUSION: There was a moderate level of agreement between OHIP14 and OIDP, which may be partly due to the fact that both OHRQoL measures assess different levels of oral impacts on quality of life in addition to having different scoring systems.