A general population study of the Chinese Whiteley-7 index in Hong Kong

To examine the psychometric properties of the Chinese seven-item Whiteley Index (WI-7) in the general population of Hong Kong.

A random community-based telephone survey of 3014 respondents aged 15-65 was conducted using a fully structured questionnaire that included the WI-7, 15-item Patient Health Questionnaire (PHQ-15), Sheehan Disability Scale (SDS), and items about the frequency of health service use, perceived helpfulness of doctors, level of satisfaction with doctors, and sociodemographic variables. A sub-sample of 199 respondents was re-interviewed to assess test-retest reliability.

The WI-7 exhibited satisfactory internal consistency (Cronbach's α=0.73) and stable one-month test-retest reliability. The most commonly endorsed item was "worrying a lot about one's health" (55.7%), followed by "worrying about getting the disease oneself if it is brought to his/her attention" (48.7%) and "bothered by many different pains and aches" (33.9%). Age, gender, and monthly family income significantly predicted WI-7 score. Confirmatory factor analysis revealed that a 2-factor structure was superior to a 1-factor structure in fitting the data. WI-7 total score was positively associated with PHQ-15 somatic distress, SDS impairment, number of healthcare visits, lower levels of perceived helpfulness of doctors and of satisfaction with doctors.

The Chinese WI-7 exhibits satisfactory reliability and internal validity in a general population. It is a promising tool for the empirical examination of health anxiety which is a common experience with a mostly typical epidemiological profile among Chinese people in Hong Kong.