A 7-day recall period for a clinical application of the oral health impact profile questionnaire

Objectives: Aims were to investigate and compare the validity and reliability of Oral Health Impact Profile (OHIP) scores referencing 7-day and 1-month recall periods in international prosthodontic patients. Material and methods: A sample of 267 patients (mean age = 54.0 years, SD = 17.2 years, 58 % women) with stable oral health-related quality of life was recruited from prosthodontic treatment centers in Croatia, Germany, Hungary, Japan, Slovenia, and Sweden. These patients completed the OHIP on two occasions using a new 7-day recall period and the traditional 1-month recall period. OHIP score validity and reliability were investigated with structural equation models (SEMs) that included OHIP_{past 7 days} and OHIP_1 month latent factors and single indicator measures of global oral health status. The SEMs assessed measurement invariance and the relative validities of the two OHIP latent factors (representing the two recall periods). Results: The SEMs provided cogent evidence for recall period measurement invariance for the two OHIP forms and equal validities (r =.48) with external measures of global oral health status. Conclusion: When assessed in international prosthodontic patients, OHIP scores using the new 7-day recall period were as reliable and valid as the scores using the 1-month recall period. Clinical relevance: Conceptual advantages make a 7-day recall period a preferred frame of reference in clinical applications of the OHIP questionnaire.