The validity and reliability of the Indonesian version of the Summated Xerostomia Inventory

OBJECTIVE: To validate and determine the reliability of the Indonesian version of the Summated Xerostomia Inventory (SXI‐ID) questionnaire. BACKGROUND: Xerostomia is a common problem in older people, and the SXI is increasingly being used to measure it. MATERIALS AND METHODS: The SXI questionnaire was cross‐culturally adapted to create an Indonesian version (SXI‐ID), which was assessed for validity and reliability in a cross‐sectional study of older adults living in nursing homes in Jakarta, Indonesia. Each participant signed an informed consent and was interviewed with the SXI‐ID. A subset of participants was interviewed again after two weeks. A standard question was used to check criterion‐related validity, by plotting the mean SXI‐ID scale scores against the ordinal response categories of the standard question. The reliability check included Cronbach's alpha, total and inter‐item correlation, and intraclass correlation for internal consistency, along with test‐retest reliability. RESULTS: A total of 110 older adults participated. Cronbach's alpha value for the SXI‐ID was .85, and the intraclass correlation coefficient value for test and retest in 15 participants was .9. The SXI‐ID total score showed a strong positive correlation (.87) with the global question. There was a consistent ascending gradient in mean SXI‐ID scores across the ordinal response categories of the global item. CONCLUSION: The SXI‐ID is psychometrically valid and reliable for measuring xerostomia in the Indonesian population.