Background: The Oral Health Impact Profile-14 (OHIP-14) and the Geriatric/General Oral Health Assessment Index (GOHAI) have never been compared for a group of the same subjects in the Polish population. The aim of the study was to compare the OHIP-14 and GOHAI measures.
Methods: 178 independently living people over the age of 55 were included in the study. The GOHAI and OHIP-14 measures were used. Other variables included age, gender, self-ratings of oral general health, education, number of missing teeth, chewing problems and dry mouth.
Results: The mean age of respondents was 70.8 years. The internal reliability (Cronbach's alpha) showed a high internal consistency for both measures. Spearman's rank correlation coefficient between the GOHAI and OHIP-14 scores was 0.81. Using the additive method of creating scores, 1.1% of respondents had the GOHAI score of zero, indicating no impact from oral conditions, while 13.5% of them had an OHIP-14 score of zero. Dental status, partial dentures, chewing problems, dry mouth and self-rated oral health were significantly associated with the results of the GOHAI and the OHIP-14 (Kruskal-Wallis test, Mann-Whitney U test). The numbers of preserved and missing teeth significantly correlated with the GOHAI and the OHIP-14, while DMF was significantly associated with the GOHAI only. 6 individuals with discrepant results were revealed. After the exclusion of the abovementioned patients, the internal reliability (Cronbach's alpha) still showed a high internal consistency, and the correlation between the GOHAI and OHIP-14 scores using Spearman's rank-correlation coefficient increased to 0.87. This phenomenon was identified as a "fatigue effect".
Conclusions: There was a strong correlation between the GOHAI and the OHIP-14. Both instruments demonstrated good discriminant properties and helped capture the respondents' oral health problems. The questionnaires should be randomly distributed to avoid the influence of "fatigue effect" on the results of a comparison of different measures.