Validation of the Hong Kong Cantonese Version of World Health Organization Five Well-Being Index for People with Severe Mental Illness.

ABSTRACT

OBJECTIVE: The World Health Organization Five Well-Being Index (WHO-5) has been developed to measure psychological wellbeing. Translation and linguistic validation of the WHO-5 into a Cantonese version has been accomplished for local use but it is not yet validated in people with severe mental illness in Hong Kong. This study aimed to examine the applicability of WHO-5 in measuring the psychological wellbeing dimension of people with severe mental illness. A brief and easily administrated tool to measure psychological wellbeing of people with severe mental illness can be used to provide an outcome measure in research studies and clinical trials. METHODS: Subjects were randomly recruited from the Extended-Care Patient Intensive Treatment, Early Diversion and Rehabilitation Stepping-Stone Project (EXITERS) and the Rehabilitation Activity Centre (RAC) of Kwai Chung Hospital in Hong Kong. They were invited to complete the abbreviated version of Hong Kong Chinese World Health Organization Quality of Life (WHOQOL-BREF [HK]) and WHO-5 (Cantonese version) separately and concurrent validity was examined. RESULTS: A total of 84 subjects were recruited, 42 each from EXITERS and RAC. In all, 49 (58%) were male and 35 (42%) were female. The mean ± standard deviation age was 43.2 ± 9.7 years. Their mean duration of mental illness was 16.4 ± 10.5 years and the mean years of education was 10.17 ± 2.5 years, i.e. about junior secondary school level in Hong Kong. The internal consistency of the WHO-5 was satisfactory (0.86) and was comparable with previous reports. Regarding validity, 1-factor structure with an eigenvalue of 3.24 explained 64.8% of total variance of WHO-5 for people with severe mental illness. Concurrent validity was established with moderate correlation (0.41-0.51) between WHO-5 and 4 domains of the WHOQOL-BREF (HK). CONCLUSION: The WHO-5 (Cantonese version) is a reliable and valid tool to assess the psychological wellbeing of people with severe mental illness in Hong Kong. It can be used to monitor the effectiveness of psychological intervention aimed at improving the wellbeing of such patients.