Validation of the Oral Health Impact on Daily Life Questionnaire (OHIDL) among Hong Kong older adults.

BACKGROUND: The Oral Health Impact on Daily Life Questionnaire (OHIDL) was developed through a qualitative study to measure oral health-related quality of life, including intensity and bother measurements, among older adults in Hong Kong. The instrument comprises 20 items divided into eight domains. OBJECTIVES: This study describes the psychometric properties of the OHIDL and refines the instrument through validity and reliability testing. MATERIALS AND METHODS: The OHIDL was administered to older adults who attended dental clinics for general dental treatments. Items with low discriminant ability were to be eliminated. Construct validity was assessed through convergent, divergent and factorial validity. Criterion validity was investigated by assessing the correlation between the measurements and the global questions. Reliability was assessed with Cronbach's alpha. RESULTS: In total, 306 participants (mean age: 69.6 years) completed the interviews. Two items for which over 90% of the participants reported no impact and two items with poor discriminant validity were eliminated. Both intensity and bother measurements demonstrated good construct and criterion validity, with the intensity measurement showing better performance being selected for the OHIDL to reduce the respondents' burden. The intensity measurement also showed satisfactory internal consistency. CONCLUSIONS: The refined OHIDL with 16 items in seven domains is valid and reliable in measuring the oral health impacts on daily life among Hong Kong older adults.