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Adult oral health-related quality of life instruments: A systematic review.

OBJECTIVES
To identify the existing OHRQoL instruments for adults, describe their scope (generic or specific), theoretical background, validation type and cross-cultural adaptation.


METHODS
A systematic search was conducted, and articles presenting validation of OHRQoL instruments in adults were included. Data were collected about the validation type: external validation (correlations/associations); or internal validation (factor analysis/principal components analysis, item response theory); and cross-cultural adaptation.


RESULTS
Of 3730 references identified, 326 were included reporting 392 studies. Forty-two original instruments were found among 74 different versions, 40 generic and 34 condition-specific. Locker's theoretical framework was the predominant model. The oral health impact profile (OHIP) presented 20 versions, with OHIP-14 being the most frequent (26.8%), followed by geriatric oral assessment index (GOHAI) (14.0%), OHIP-49 (11.7%) and oral impacts on daily performances (OIDP) (9.7%). Most studies focused on external validation (65.3%), while internal validation was reported in 24.8% (n = 26) of OHIP-14 studies, 50.9% (n = 28) of GOHAI and 21.1% (n = 8) of OIDP studies. Most internal validation studies were conducted in English-speaking countries (n = 33), and cross-cultural adaptation was mostly in non-English-speaking European countries (n = 40).


CONCLUSIONS
Many generic and condition-specific instruments were found, but few have gone through a rigorous internal validation process or have undergone cross-cultural adaptation. This, in turn, makes it difficult for researchers to choose an appropriate measure based on known psychometric properties. OHIP-14, OIDP and GOHAI seem to be the most widely validated instruments. Equalizing measurement properties for comparability are challenging due to theoretical heterogeneity. Future studies should assess psychometric properties, explore the factorial structure and work towards a consensus on critical issues.