METHODS: We conducted a nationally representative survey among 1925 adults aged 18-79 years of Chinese, Malay, Indian or other ethnicity. Participants reported socio-demographic characteristics and completed the PMH-I along with measures of health-related quality of life (HRQoL) and psychological distress. Construct validity of the PMH-I was assessed using confirmatory factor analysis and concurrent validity was tested through correlation with other psychological measures. Normative PMH values and differences in population subgroups were estimated.
RESULTS: The six-factor-higher-order structure of the PMH-I comprising six subscales of general coping, emotional support, spirituality, interpersonal skills, personal growth and autonomy and global affect was confirmed. Concurrent validity was shown through significant positive correlation of the total PMH score and its subscales with HRQoL and an inverse correlation with psychological distress. Weighted age, gender and ethnicity-specific norms were derived for the Singapore population. Total PMH was significantly higher in participants aged over 40 years as compared with 18-29 year olds and in non-Chinese ethnic groups as compared with Chinese. These differences were observed for all PMH-I subscales, with the exception of emotional support and interpersonal skills score differences by age. In contrast, gender, marital status, and education level were significantly associated with some of the subscales, but not with total PMH.
CONCLUSIONS: These results support the psychometric properties of the PMH-I in a multi-ethnic Asian population sample. The generalizable population-based norms support the application of the PMH-I for measuring mental health and assessing its determinants within the Singapore general population.
DESIGN AND METHODS: Four PPSs, including headache, chest pain, low back pain, and muscle pain, and subjective depressive symptoms were assessed using the Symptom Checklist-90-Revised.
FINDINGS: Out of 528 participants, 390 (73.9%) had at least one PPS. After adjusting for sex, depression severity, disability, fatigue, physical health status, and mental health status, PPSs were found to be associated with crying easily, blaming oneself, feeling lonely, feeling blue, and worrying too much.
PRACTICAL IMPLICATIONS: Almost three-quarters of Asian patients with MDD experience PPSs. PPSs are associated with some subjective feelings of depression.