[Reference values in oral health-related quality of life for the abbreviated version of the Oral Health Impact Profile].

Questionnaires measuring oral health-related quality of life (OHRQoL) need reference values for their interpretation. Population-based norms for a questionnaire allow a comparison of the level of OHRQoL observed for an individual or a group of subjects with the level of that construct in the general population. The aims of this study were to establish normative values for abbreviated instruments of the German version of the Oral Health Impact Profile (OHIP-G). Data of the long OHIP-G (53 items) were collected in a national survey (N=2050, age: 16-79 years). Three short instruments with 5 (OHIP-G5), 14 (OHIP-G14) and 21 items (OHIP-G21) were derived from the long OHIP. Norms were computed for the OHIP-G summary score (simple sum of all item responses). The OHIP-G summary score distribution was described by empirical cumulative distribution functions. Because denture usage was strongly associated with OHIP-G summary scores, percentile-based norms were stratified by this variable. Among subjects without dentures, 50% of the population had OHIP-G5 or OHIP-G14 scores 0 and OHIP-G21 scores < or = 2. Summary scores for the three abbreviated OHIPs were < or = 2, < or = 4, and < or = 7 for subjects with removable dentures and < or = 3, < or = 6, and < or = 8 for subjects with complete dentures. Among subjects without dentures, 90% of the population had < or = 4 OHIP-G5, < or = 11 OHIP-G14, and < or = 16 OHIP-G21 points. For subjects with removable dentures, the figures were < or = 7, < or = 17, and < or = 26 points for OHIP-G5, OHIP-G14 and OHIP-G21, respectively; and for subjects with complete dentures, < or = 10, < or = 25, and < or = 38 points, respectively. The presented norms will provide a frame of reference in future cross-sectional studies in the general population or samples with specific oral conditions when OHRQoL is measured by OHIP-G5, OHIP-G14 or OHIP-G21.