Influence of Ethnicity, Age, and Time on Sex Disparities in Long-Term Cause-Specific Mortality After Acute Myocardial Infarction.

BACKGROUND: We examined the influence of sex, ethnicity, and time on competing cardiovascular and noncardiovascular causes of death following acute myocardial infarction in a multiethnic Asian cohort. METHODS AND RESULTS: For 12 years, we followed a prospective nationwide cohort of 15 151 patients (aged 22-101 years, median age 63 years; 72.3% male; 66.7% Chinese, 19.8% Malay, 13.5% Indian) who were hospitalized for acute myocardial infarction between 2000 and 2005. There were 6463 deaths (4534 cardiovascular, 1929 noncardiovascular). Compared with men, women had a higher risk of cardiovascular death (age-adjusted hazard ratio [HR] 1.3, 95% CI 1.2-1.4) but a similar risk of noncardiovascular death (HR 0.9, 95% CI 0.8-1.0). Sex differences in cardiovascular death varied by ethnicity, age, and time. Compared with Chinese women, Malay women had the greatest increased hazard of cardiovascular death (HR 1.4, 95% CI 1.2-1.6) and a marked imbalance in death due to heart failure or cardiomyopathy (HR 3.4 [95% CI 1.9-6.0] versus HR 1.5 [95% CI 0.6-3.6] for Indian women). Compared with same-age Malay men, Malay women aged 22 to 49 years had a 2.5-fold (95% CI 1.6-3.8) increased hazard of cardiovascular death. Sex disparities in cardiovascular death tapered over time, least among Chinese patients and most among Indian patients; the HR comparing cardiovascular death of Indian women and men decreased from 1.9 (95% CI 1.5-2.4) at 30 days to 0.9 (95% CI 0.5-1.6) at 10 years. CONCLUSION: Age, ethnicity, and time strongly influence the association between sex and specific cardiovascular causes of mortality, suggesting that health care policy to reduce sex disparities in acute myocardial infarction outcomes must consider the complex interplay of these 3 major modifying factors.

The association of body mass index with health-related quality of life: an exploratory study in a multiethnic Asian population.

OBJECTIVES: To evaluate the association between body mass index (BMI) and health-related quality of life (HRQoL) in a multiethnic Asian population in Singapore, and to explore if the World Health Organization (WHO) recommendation of alternative BMI cutoffs for Asians could be further strengthened by evidence of higher risk of impaired HRQoL using these criteria. METHODS: Consenting English, Chinese, Malay and Tamil-speaking primary care patients (age >or= 21 years) were interviewed using English/their respective mother tongue versions of the EQ-5D/EQ-VAS, Health Utilities Index (HUI2 & HUI3) and the SF-6D. We first evaluated the relationship between BMI and HRQoL (overall and individual attributes for each instrument) using multiple linear/logistic regression (where appropriate) to adjust for factors known to affect HRQoL. We next reorganized BMI into five categories (reflecting the differences in cutoffs between International/Asian classifications) and evaluated if median HRQoL scores were significantly different across these categories. RESULTS: Among 411 participants [response rate: 87%; median age: 51 years; obese: 19% (International); 33% (Asian)], after adjusting for sociodemographic and other factors, a tendency for underweight and obese subjects to report lower overall HRQoL scores was observed for most instruments. At the individual attribute level, obese subjects reported significantly lower HUI2 pain scores (regression coefficient: -0.035, P = 0.029) and greater odds of reporting problems for SF-6D role-limitations (odds ratio: 2.9, P = 0.005). Median overall HRQoL scores were not significantly different across the five BMI categories. CONCLUSION: Consistent with available studies, obese subjects reported worse HRQoL than normal-weight subjects. That underweight subjects also reported worse HRQoL is interesting and requires confirmation. HRQoL was similar in Asians using either WHO criteria.

Validity, feasibility and acceptability of time trade-off and standard gamble assessments in health valuation studies: a study in a multiethnic Asian population in Singapore.

OBJECTIVES: To assess the validity, feasibility and acceptability of standard gamble (SG) and time trade-off (TTO) assessments in a multiethnic Asian population. METHODS: Through in-depth interviews performed among Chinese, Malay, and Indian Singaporeans (education >or= 6 years), we assessed validity of SG/TTO methods for eliciting health preferences by hypothesizing that 1) SG/TTO scores for three hypothetical health states (HS) would exhibit ranked order (decreasing scores with worse HS); and 2) more subjects would rate the most severe HS as worse than dead. Subjects also evaluated feasibility and acceptability of SG/TTO using a 10-point visual analog scale (VAS) and open-ended questions. Ratings were compared using Kruskal-Wallis, Wilcoxon signed-rank tests or tests of proportions. VALIDITY: In 62 subjects (90% response rate), as hypothesized, SG and TTO scores exhibited ranked order with increasing HS severity (SG: 0.85, 0.08, -19.00; TTO: 0.85, 0.00, -0.18). More subjects rated the most severe HS as worse than dead (SG: 8%, 39%, 59%; TTO: 8%, 45% and 62%). FEASIBILITY: Subjects felt SG and TTO were easy to understand (median VAS scores: 8.0 vs. 8.0, P = 0.87) and to complete (8.0 vs. 8.0, P = 0.84). Acceptability: SG and TTO were well accepted, with TTO less so than SG (median [interquartile range] offensiveness: 2.0 [0, 4.0] vs. 2.0 [0, 3.0], P = 0.045). Overall, subjects did not have a clear preference for SG/TTO (50% vs. 45%, P = 0.70). CONCLUSIONS: This study suggests the validity, feasibility and acceptability of SG and TTO for population-based HS valuation studies in a multiethnic Asian population.

Assessing differences in utility scores: a comparison of four widely used preference-based instruments.

OBJECTIVES: To characterize the differences in utility scores (dUTY) among four commonly used preference-based Health-Related Quality of Life instruments, to evaluate the potential impact of these differences on cost-utility analyses (CUA), and to determine if sociodemographic/clinical factors influenced the magnitude of these differences. METHODS: Consenting adult Chinese, Malay and Indian subjects in Singapore were interviewed using Singapore English, Chinese, Malay or Tamil versions of the EQ-5D, Health Utilities Index Mark 2 (HUI2) and Mark 3 (HUI3), and SF-6D. Agreement between instruments was assessed using Bland-Altman (BA) plots. Changes in incremental cost-utility ratio (ICUR) from dUTY were investigated using eight hypothetical decision trees. The influence of sociodemographic/clinical factors on dUTY between instrument pairs was studied using multiple linear regression (MLR) models for English-speaking subjects (circumventing structural zero issues). RESULTS: In 667 subjects (median age 48 years, 59% female), median utility scores ranged from 0.80 (95% confidence interval [CI] 0.80, 0.85) for the EQ-5D to 0.89 (95% CI 0.88, 0.89) for the SF-6D. BA plots: Mean differences (95% CI) exceeded the clinically important difference (CID) of 0.04 for four of six pairwise comparisons, with the exception of the HUI2/EQ-5D (0.03, CI: 0.02, 0.04) and SF-6D/HUI2 (0.02, CI: 0.006, 0.02). Decision trees: The ICER ranged from $94,661/QALY (quality-adjusted life-year; 6.3% difference from base case) to 100,693 dollars/QALY (0.3% difference from base case). MLR: Chronic medical conditions, marital status, and Family Functioning Measures scores significantly (P-value < 0.05) influenced dUTY for several instrument pairs. CONCLUSION: Although CIDs in utility measurements were present for different preference-based instruments, the impact of these differences on CUA appeared relatively minor. Chronic medical conditions, marital status, and family functioning influenced the magnitude of these differences.

Are Asians comfortable with discussing death in health valuation studies? A study in multi-ethnic Singapore.

BACKGROUND: To characterize ease in discussing death (EID) and its influence on health valuation in a multi-ethnic Asian population and to determine the acceptability of various descriptors of death and "pits"/"all-worst" in health valuation. METHODS: In-depth interviews (English or mother-tongue) among adult Chinese, Malay and Indian Singaporeans selected to represent both genders and a wide range of ages/educational levels. Subjects rated using 0-10 visual analogue scales (VAS): (1) EID, (2) acceptability of 8 descriptors for death, and (3) appropriateness of "pits" and "all-worst" as descriptors for the worst possible health state. Subjects also valued 3 health states using VAS followed by time trade-off (TTO). The influence of sociocultural variables on EID and these descriptors was studied using univariable analyses and multiple linear regression (MLR). The influence of EID on VAS/TTO utilities with adjustment for sociocultural variables was assessed using MLR. RESULTS: Subjects (n = 63, 35% Chinese, 32% Malay, median age 44 years) were generally comfortable with discussing death (median EID: 8.0). Only education significantly influenced EID (p = 0.045). EID correlated weakly with VAS/TTO scores (range: VAS: -0.23 to 0.07; TTO: -0.14 to 0.11). All subjects felt "passed away", "departed" and "deceased" were most acceptable (median acceptability: 8.0) while "sudden death" and "immediate death" were least acceptable (median acceptability: 5.0). Subjects clearly preferred "all-worst" to "pits" (63% vs. 19%, p < 0.001). CONCLUSION: Singaporeans were generally comfortable with discussing death and had clear preferences for several descriptors of death and for "all-worst". EID is unlikely to influence health preference measurement in health valuation studies.

Development of a Smiling Touchscreen multimedia program for HRQoL assessment in subjects with varying levels of literacy.

OBJECTIVE: As low literacy affects the assessment of health-related quality of life (HRQoL) in several ways (e.g., subject eligibility and cost of administration), better approaches to HRQoL assessment in subjects with varying literacy levels are needed. METHODS: We developed a multimedia touchscreen program (the Smiling Touchscreen, ST) to administer HRQoL instruments to subjects with varying levels of Chinese language and computer literacy, using an iterative process where patients' input on design, clarity of instructions, and user-friendliness were repeatedly gathered and incorporated in development. The ST thus has several user-friendly features for low-literacy subjects (e.g., presentation of individual items using visual and auditory stimuli, voice-text synchronization, and visual analog scale with a touch and drag function), which we evaluated using qualitative and quantitative methods. RESULTS: The ST was well accepted by subjects (n = 66, 76% female, median [interquartile] age: 49.0 [40.0, 56.0]) with high (n = 43) or low (n = 23) literacy, 98% of whom found it easy or very easy to use, and 85% found the voice-text synchronization feature useful. In low-literacy subjects without computer experience (30%), none reported any difficulties using the ST. The median (interquartile) time spent to complete the ST (four Instruction and Practice screens, 24 questions, one visual analog scale) for high- and low-literacy groups was 13.9 (9.6, 23.9) and 23.2 (15.8, 26.5) minutes, respectively. Among subjects expressing a preference (n = 47), 21 (47%) favored the ST over interviewer- or self-administration. CONCLUSION: The ST is well accepted by subjects with varying literacy levels, including those without computer experience. It is thus a promising new approach for HRQoL assessment among subjects with varying literacy levels.

Quality of life in an urban Asian population: the impact of ethnicity and socio-economic status.

The relationships between ethnicity, socio-economic status (SES) and health-related quality of life (HRQoL) have not been well characterised in most Asian populations. We therefore studied the influence of ethnicity and SES on HRQoL in a multi-ethnic urban Asian population, adjusting for the influence of other known determinants of HRQoL. In a disproportionately stratified, cross-sectional, population-based survey, Chinese, Malay and Indian subjects in Singapore completed the Short Form 36 Health Survey (SF-36) HRQoL measure and were assessed to determine demographic, socio-economic, psychosocial and other characteristics. Multiple linear regression models were used to study the influence of ethnicity and SES on SF-36 scores while adjusting for the influence of other determinants of HRQoL. The survey participation rate was 92.8%. Ethnic differences in HRQoL were present for all 8 SF-36 scales (p<0.001 for all scales except General Health) among the 4122 Chinese, Malays and Indians surveyed. These ethnic groups also differed in several known determinants of HRQoL (e.g., Chinese had more years of education and Indians had more chronic medical conditions). After adjusting for the influence of these factors, ethnicity and SES independently influenced HRQoL, with mean differences in SF-36 scores due to ethnicity ranging from 1.4 to 13.1 points. Educational level and housing type (markers of SES) were also associated with SF-36 scores (0.5-0.6 point increase per year of education and 3.5-4.0 point increase with better housing type, respectively). Better HRQoL was also associated with better family support, and poorer HRQoL with acute and chronic medical conditions and sick days. The study concludes that ethnicity and SES are associated with clinically important differences in HRQoL in a multi-ethnic, urban Asian population.