Interpreting one oral health impact profile point
- Equal contributors
1 Department of Prosthetic Dentistry, Center for Dental and Oral Medicine, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, D-20246, Hamburg, Germany
2 Department of Diagnostic and Biological Sciences, University of Minnesota, 515 Delaware Street SE, Minneapolis 55455, MN, USA
3 Division of Epidemiology and Community Health, University of Minnesota, 1300 S Second Street, Minneapolis 55454, MN, USA
Health and Quality of Life Outcomes 2013, 11:12 doi:10.1186/1477-7525-11-12Published: 30 January 2013
Interpretation of scores from oral health-related quality of life (OHRQoL) instruments, such as the Oral Health Impact Profile (OHIP) is challenging. It was the aim of this study to determine how many oral impacts correspond to one point of the 49-item OHIP using a new approach which translates numeric problem counts into the traditionally used ordinal OHIP response categories.
A sample of 145 consecutively recruited prosthodontic patients seeking treatment or having a routine examination completed the German version of the 49-item OHIP with the original ordinal response format as a self-administered questionnaire. In addition, the numerical frequencies of impairment during the previous month were requested in personal interviews. Based on a multilevel mixed-effects linear regression, we estimated the mean difference with 95% confidence interval (CI) in numerical frequency between two adjacent ordinal responses.
A numerical frequency of 15.2 (CI: 14.8 – 15.7) impacts per month corresponded to one OHIP point. This translates to approximately one impact every other day in the past month.
The oral problem count per day that corresponds to one OHIP-49 point can be used to interpret this instrument’s scores in cross-sectional and longitudinal studies. This number can help to better understand OHRQoL burden for patients, clinicians, and researchers alike.