MATERIALS AND METHODS: The Singapore Cardiovascular Cohort Study is a longitudinal follow-up study on a general population cohort of 5920 persons drawn from 3 previous cross-sectional surveys. Morbidity and mortality from IHD and stroke were ascertained by record linkage using a unique identification number with the death registry, Singapore Myocardial Infarct Registry and in-patient discharge databases.

RESULTS: There were 193 first IHD events and 97 first strokes during 52,806 person-years of observation. The overall incidence of IHD was 3.8/1000 person-years and that of stroke was 1.8/1000 person-years. In both males and females, Indians had the highest IHD incidence, followed by Malays and then Chinese. For males after adjusting for age, Indians were 2.78 times (95% CI 1.86, 4.17; P < 0.0001) and 2.28 times (95% CI 1.34, 3.88; P = 0.002) more likely to get IHD than Chinese and Malays respectively. For females after adjusting for age, Indians were 1.97 times (95% CI 1.07, 3.63; P = 0.03) and 1.37 times (95% CI 0.67, 2.80; P = 0.39) more likely to get IHD than Chinese and Malays respectively. For stroke, male Chinese and Indians had higher incidence than Malays (though not statistically significant). However, in females, Malays had the highest incidence of stroke, being 2.57 times (95% CI 1.31, 5.05; P = 0.008) more likely to get stroke than Chinese after adjustment for age.

DESIGN AND SETTING: A cross-sectional survey was carried out in rural and urban areas in a state in Malaysia. Secondary schools were randomly selected and used as sampling units.

PARTICIPANTS: Adults aged ≥18 years old were invited to answer a self-administered questionnaire on pain experienced over the previous 6 months. Out of 9300 questionnaires distributed, 5206 were returned and 150 participants who did not fall into the 3 ethnic groups were excluded, yielding a total of 5056 questionnaires for analysis. 58.2% (n=2926) were women. 50% (n=2512) were Malays, 41.4% (n=2079) were Chinese and 8.6% (n=434) were Indians.

RESULTS: 21.1% (n=1069) had knee pain during the previous 6 months. More Indians (31.8%) experienced knee pain compared with Malays (24.3%) and Chinese (15%) (p<0.001). The odds of Indian women reporting knee pain was twofold higher compared with Malay women. There was a rising trend in the prevalence of knee pain with increasing age (p<0.001). The association between age and knee pain appeared to be stronger in women than men. 68.1% of Indians used analgesia for knee pain while 75.4% of Malays and 52.1% of Chinese did so (p<0.001). The most common analgesic used for knee pain across all groups was topical medicated oil (43.7%).

METHODS: Two separate studies were conducted among adult community-dwelling Singapore residents of Chinese, Malay or Indian ethnicity where participants completed self-administered questionnaires. In the first study, secondary data analysis was conducted using confirmatory factor analysis (CFA) to shorten the PMH instrument. In the second study, the newly developed short PMH instrument and other scales were administered to 201 residents to establish its factor structure, validity and reliability.

RESULTS: A 20-item short PMH instrument fulfilling a higher-order six-factor structure was developed following secondary analysis. The mean age of the participants in the second study was 41 years and about 53% were women. One item with poor factor loading was further removed to generate a 19-item version of the PMH instrument. CFA demonstrated a first-order six-factor model of the short PMH instrument. The PMH-19 instrument and its subscales fulfilled criterion validity hypotheses. Internal consistency and test-retest reliability of the PMH-19 instrument were high (Cronbach's α coefficient = 0.87; intraclass correlation coefficient = 0.93, respectively).