Chinese version of the Pain Assessment in Advanced Dementia Scale: Initial psychometric evaluation

Aim: This paper is a report of the validity and reliability testing of the Chinese version of the Pain Assessment in Advanced Dementia Scale (PAINAD-C). Background: Pain is under-reported and under-treated for people with dementia, largely due to impairment of communication. An adequate instrument for assessment of pain in this population is essential to improving their quality of life and decreasing disability and behavioural disturbances, but none were found that were appropriate for these purposes. Method: The PAINAD-C was developed in three phases in 2006. First, back-translation was used to create the Chinese version, where five medical and nursing experts assessed content validity. Inter-rater reliability, internal consistency reliability and test-retest reliability were then examined. Finally, principal component analysis and known-group comparisons were used to test construct validity. Participants with dementia were selected from five licensed long-term care facilities in Taiwan. Direct observation was used to collect data. Results: Inter-rater reliability showed an intra-class correlation coefficient of 0·80-0·86, and a test-retest reliability intra-class correlation coefficient of 0·71. The internal consistency reliability was 0·55-0·66. Factor analysis of the PAINAD-C showed two factors that explained 62·48% of variance. The PAINAD-C scores showed statistically significant differences between the non-dementia group and the advanced dementia group as well as significant differences between activities and rest groups. Conclusion: The PAINAD-C is useful in a clinical setting for people with advanced dementia for both research and practice. It is easy to use and is a comprehensive instrument.