The German version of the Oral Health Impact Profile – translation and psychometric properties Mike T. John 1 , Donald L. Patrick 2 , Gary D. Slade 3 1 Department of Prosthodontics, School of Dentistry, Martin Luther University Halle- Wittenberg, Halle (Saale), Germany; 2 Department of Health Services, University of Washington, Seattle, WA, USA; 3 Department of Dental Ecology, UNC School of Dentistry, Chapel Hill, NC, USA The impact of oral disorders and interventions on patients’ perceived oral health state and oral health- related quality of life (OHRQoL) is increasingly recog- nized as an important component of health (1). Subjective indicators used to measure OHRQoL can be of benefit in evaluating oral health for political, theor- etical and practical purposes (2). Such measures of patients’ perceived oral health are increasingly in demand for epidemiological and clinical studies in Germany (3) because they add a complementary out- come dimension to the traditional use of clinical oral disease indicators. Although well-tested and standar- dized assessment instruments for measuring OHRQoL are available in the Anglo-American literature, such instruments do not exist in Germany. The English-language Oral Health Impact Profile (OHIP) (4), originally developed in Australia, is an intensively used instrument. It consists of 49 items which are grouped into seven domains based on a conceptual model of oral health that uses the framework of the World Health Organization (WHO) International Clas- sification of Impairments, Disabilities and Handicaps (5). A short version of the instrument has also been developed (6). The OHIP questionnaire has well-docu- mented psychometric properties (4). In cross-sectional studies, it has been used in the general population (7) as well as in patients with specific oral disorders such as temporomandibular disorders and orofacial pain (8). In addition, the OHIP has been used in longitudinal studies (9) and its sensitivity to change has been demonstrated in clinical trials (10). These characteristics suggest that a German-language version of the OHIP questionnaire would be valuable. However, a thorough translation of the OHIP into German would not necessarily ensure applicability across nations because of cultural diversity. Guidelines for cross-cultural validation of health-related quality of life measures have been developed (11). In addition, psychometric testing of the translated instru- ment in the new cultural context (cross-cultural adapta- tion) is recommended (12). This article presents the translation and the psycho- metric testing of the German version of the Oral Health Impact Profile (OHIP-G). Material and Methods The German version of the OHIP was developed in two steps using 516 subjects from six independent samples (Table 1). First, the instrument was translated into German using state-of-the-art cultural adaptation techniques (11). The second step involved the assessment of validity, reli- ability, responsiveness, preference weights, and appropriate recall periods for the OHIP-G. John MT, Patrick DL, Slade GD. The German version of the Oral Health Impact Profile – translation and psychometric properties. Eur J Oral Sci 2002; 110: 425–433 Ó Eur J Oral Sci, 2002 The need for cross-culturally adapted oral-health specific health outcome measures is increasingly recognized in Germany. Following accepted cultural adaptation tech- nique guidelines, we report the development of the German version of the Oral Health Impact Profile (OHIP). The original 49 items were translated using a forward–back- ward method. A de novo development of German items established content validity. A priori hypothesized associations between the OHIP summary score and self-reported oral health and five oral disorders were confirmed in a random sample of the general population (n ¼ 163, age 20–60 yr). These associations were interpreted as support for construct validity. The instrument’s responsiveness, as indicated by a mean OHIP summary score change from 45.0 to 28.3, was established in 67 consecutive patients treated for temporomandibular disorder pain (age 19–85 yr; 72% women). Test-retest reliability was demonstrated by intraclass correlation coefficients of 0.63–0.92 for dimensions and summary scores (convenience sample, n ¼ 30, age 18–85 yr; 53% women). Internal consistency was high (Cronbach’s a > 0.74). Sufficient discrimina- tive and evaluative psychometric properties of the Oral Health Impact Profile German version (OHIP-G) make the instrument suitable for assessment of oral health-related quality of life in cross-sectional as well as longitudinal studies. Mike T. John, Department of Prosthodontics, Martin Luther University Halle-Wittenberg, Große Steinstrasse 19, D)06097 Halle/Saale, Germany Telefax: +49–345–5573779 E-mail: mike.john@medizin.uni-halle.de Key words: quality of life; oral health; behavioral sciences; reliability; validity Accepted for publication September 2002 Eur J Oral Sci 2002; 110: 425–433 Printed in UK. All rights reserved Copyright Ó Eur J Oral Sci 2002 European Journal of Oral Sciences ISSN 0909-8836