The societal cost of modifiable risk factors in Singapore.

BACKGROUND: Singapore is one of the most rapidly ageing populations in the world. Nearly half of all disease burdens in Singapore are attributable to modifiable risk factors. This indicates that many illnesses are preventable by modifying behaviours such as increasing physical activity levels or maintaining a healthy diet. Prior cost-of-illness studies have estimated the cost of selected modifiable risk factors. However, no local study has compared costs between groups of modifiable risks. This study aims to estimate the societal cost attributable to a comprehensive list of modifiable risks in Singapore. METHODS: Our study builds on the comparative risk assessment framework from the Global Burden of Disease (GBD) 2019 study. A top-down prevalence-based cost-of-illness approach was undertaken to estimate the societal cost of modifiable risks in 2019. These include healthcare costs from inpatient hospitalisation and productivity losses from absenteeism and premature mortality. RESULTS: Metabolic risks had the highest total cost of US$1.62 billion (95% uncertainty interval [UI] US$1.51-1.84 billion), followed by lifestyle risks of US$1.40 billion (95% UI US$1.36-1.66 billion) and substance risks of US$1.15 billion (95% UI US$1.10-1.24 billion). Across the risk factors, the costs were driven by productivity losses, heavily skewed towards the older working-age group and among males. Most of the costs were driven by cardiovascular diseases. CONCLUSION: This study provides evidence of the high societal cost of modifiable risks and highlights the importance of developing holistic public health promotion programmes. As modifiable risks often do not occur in isolation, implementing effective population-based programmes targeting multiple modifiable risks has a strong potential to manage the cost of the rising disease burden in Singapore.

Effectiveness of Containment Measures Against COVID-19 in Singapore: Implications for Other National Containment Efforts.

BACKGROUND: We hypothesize that comprehensive surveillance of COVID-19 in Singapore has facilitated early case detection and prompt contact tracing and, with community-based measures, contained spread. We assessed the effectiveness of containment measures by estimating transmissibility (effective reproduction number, (Equation is included in full-text article.)) over the course of the outbreak. METHODS: We used a Bayesian data augmentation framework to allocate infectors to infectees with no known infectors and determine serial interval distribution parameters via Markov chain Monte Carlo sampling. We fitted a smoothing spline to the number of secondary cases generated by each infector by respective onset dates to estimate (Equation is included in full-text article.)and evaluated increase in mean number of secondary cases per individual for each day's delay in starting isolation or quarantine. RESULTS: As of April 1, 2020, 1000 COVID-19 cases were reported in Singapore. We estimated a mean serial interval of 4.6 days [95% credible interval (CI) = 4.2, 5.1] with a SD of 3.5 days (95% CI = 3.1, 4.0). The posterior mean (Equation is included in full-text article.)was below one for most of the time, peaking at 1.1 (95% CI = 1.0, 1.3) on week 9 of 2020 due to a spreading event in one of the clusters. Eight hundred twenty-seven (82.7%) of cases infected less than one person on average. Over an interval of 7 days, the incremental mean number of cases generated per individual for each day's delay in starting isolation or quarantine was 0.03 cases (95% CI = 0.02, 0.05). CONCLUSIONS: We estimate that robust surveillance, active case detection, prompt contact tracing, and quarantine of close contacts kept (Equation is included in full-text article.)below one.

Spatial-temporal potential exposure risk analytics and urban sustainability impacts related to COVID-19 mitigation: A perspective from car mobility behaviour.

Coronavirus disease-2019 (COVID-19) poses a significant threat to the population and urban sustainability worldwide. The surge mitigation is complicated and associates many factors, including the pandemic status, policy, socioeconomics and resident behaviours. Modelling and analytics with spatial-temporal big urban data are required to assist the mitigation of the pandemic. This study proposes a novel perspective to analyse the spatial-temporal potential exposure risk of residents by capturing human behaviours based on spatial-temporal car park availability data. Near real-time data from 1,904 residential car parks in Singapore, a classical megacity, are collected to analyse car mobility and its spatial-temporal heat map. The implementation of the circuit breaker, a COVID-19 measure, in Singapore has reduced the mobility and heat (daily frequency of mobility) significantly at about 30.0%. It contributes to a 44.3%-55.4% reduction in the transportation-related air emissions under two scenarios of travelling distance reductions. Urban sustainability impacts in both environment and economy are discussed. The spatial-temporal potential exposure risk mapping with space-time interactions is further investigated via an extended Bayesian spatial-temporal regression model. The maximal reduction rate of the defined potential exposure risk lowers to 37.6% by comparison with its peak value. The big data analytics of changes in car mobility behaviour and the resultant potential exposure risks can provide insights to assist in (a) designing a flexible circuit breaker exit strategy, (b) precise management via identifying and tracing hotspots on the mobility heat map, and (c) making timely decisions by fitting curves dynamically in different phases of COVID-19 mitigation. The proposed method has the potential to be used by decision-makers worldwide with available data to make flexible regulations and planning.

Decreased Influenza Incidence under COVID-19 Control Measures, Singapore.

We compared indicators of influenza activity in 2020 before and after public health measures were taken to reduce coronavirus disease (COVID-19) with the corresponding indicators from 3 preceding years. Influenza activity declined substantially, suggesting that the measures taken for COVID-19 were effective in reducing spread of other viral respiratory diseases.

Real-time monitoring the transmission potential of COVID-19 in Singapore, March 2020.

BACKGROUND: As of March 31, 2020, the ongoing COVID-19 epidemic that started in China in December 2019 is now generating local transmission around the world. The geographic heterogeneity and associated intervention strategies highlight the need to monitor in real time the transmission potential of COVID-19. Singapore provides a unique case example for monitoring transmission, as there have been multiple disease clusters, yet transmission remains relatively continued. METHODS: Here we estimate the effective reproduction number, Rt, of COVID-19 in Singapore from the publicly available daily case series of imported and autochthonous cases by date of symptoms onset, after adjusting the local cases for reporting delays as of March 17, 2020. We also derive the reproduction number from the distribution of cluster sizes using a branching process analysis that accounts for truncation of case counts. RESULTS: The local incidence curve displays sub-exponential growth dynamics, with the reproduction number following a declining trend and reaching an estimate at 0.7 (95% CI 0.3, 1.0) during the first transmission wave by February 14, 2020, while the overall R based on the cluster size distribution as of March 17, 2020, was estimated at 0.6 (95% CI 0.4, 1.02). The overall mean reporting delay was estimated at 6.4 days (95% CI 5.8, 6.9), but it was shorter among imported cases compared to local cases (mean 4.3 vs. 7.6 days, Wilcoxon test, p < 0.001). CONCLUSION: The trajectory of the reproduction number in Singapore underscores the significant effects of successful containment efforts in Singapore, but it also suggests the need to sustain social distancing and active case finding efforts to stomp out all active chains of transmission.

Early dengue outbreak detection modeling based on dengue incidences in Singapore during 2012 to 2017.

Dengue has been as an endemic with year-round presence in Singapore. In the recent years 2013, 2014, and 2016, there were several severe dengue outbreaks, posing serious threat to the public health. To proactively control and mitigate the disease spread, early warnings of dengue outbreaks, at which there are rapid and large-scale spread of dengue incidences, are extremely helpful. In this study, a two-step framework is proposed to predict dengue outbreaks and it is evaluated based on the dengue incidences in Singapore during 2012 to 2017. First, a generalized additive model (GAM) is trained based on the weekly dengue incidence data during 2006 to 2011. The proposed GAM is a one-week-ahead forecasting model, and it inherently accounts for the possible correlation among the historical incidence data, making the residuals approximately normally distributed. Then, an exponentially weighted moving average (EWMA) control chart is proposed to sequentially monitor the weekly residuals during 2012 to 2017. Our investigation shows that the proposed two-step framework is able to give persistent signals at the early stage of the outbreaks in 2013, 2014, and 2016, which provides early alerts of outbreaks and wins time for the early interventions and the preparation of necessary public health resources. In addition, extensive simulations show that the proposed method is comparable to other potential outbreak detection methods and it is robust to the underlying data-generating mechanisms.

Years of life with and without limitation in physical function and in activities of daily living by body mass index among older adults.

BACKGROUND: While older adults with pre-obesity and Class I obesity have similar or lower mortality risk versus those with normal weight, a heavier body mass index (BMI) may not translate into more healthy life years. Utilizing longitudinal data on 3452 older (≥60 years) Singaporeans, we assessed the association between BMI and years of remaining life overall with and without limitation in physical function and in activities of daily living (ADLs). METHODS: Difficulty in any of nine tasks involving upper or lower extremities was considered as limitation in physical function, and health-related difficulty in any basic ADL or instrumental ADL as limitation in ADLs. We utilized multistate life tables, including BMI as a time-varying covariate. RESULTS: At age 60, life expectancy (LE) was similar for those with normal weight, pre-obesity and obesity. However, those with obesity, versus normal weight, had 6.3 [95% confidence interval: 3.4-9.2] more years with limitation in physical function and 4.9 [3.4-6.5] less years without limitation in physical function. Those with pre-obesity, versus normal weight, also had 3.7 [1.9-5.3] more years with limitation in physical function. The same pattern across BMI categories was observed for years of life with and without limitation in ADLs. In stratified analyses, similar associations of BMI with years of life with and without limitation in physical function and in ADLs were observed across gender, ethnicity, and educational status. CONCLUSIONS: The increasing global prevalence of obesity may result in an increase in years of life with limitation in physical function and in ADLs at older ages. Older adults, their families and healthcare systems should be cognizant of this issue.

Particulate air pollution on cardiovascular mortality in the tropics: impact on the elderly.

BACKGROUND: Air pollution has a significant health impact. Most data originate from temperate regions. We aim to study the health impact of air pollution, particularly among the elderly, in a tropical region. METHODS: A daily time-series analysis was performed to estimate excess risk (ER) of various air pollutants on daily death counts amongst the general population in Singapore from 2001 to 2013. Air pollutants included particulate matters smaller than 10 µm, and 2.5 µm (PM10, PM2.5), carbon monoxide (CO), nitrogen dioxide (NO2), ozone (O3) and sulphur dioxide (SO2). The studied outcomes were non-accidental and cardiovascular mortality. Single-day lag and distributed lag models were studied and adjusted for confounders. RESULTS: In single-day lag models, a 10 µg/m3 increase in particulate matter was associated with significant increases in non-accidental (PM10 ER: 0.627%; 95% confidence interval (CI): 0.260-0.995% and PM2.5 ER: 0.660%; 95% CI: 0.204-1.118%) and cardiovascular mortality (PM10 ER: 0.897; 95% CI: 0.283-1.516 and PM2.5 ER: 0.883%; 95% CI: 0.121-1.621%). This was significant in the elderly ≥ 65 years but not in those < 65 years and were seen in the acute phase of lag 0-5 days. Effects by other pollutants were minimal. For cardiovascular mortality, the effects turned protective at a cumulative lag of 30 days in the elderly and could due to "harvesting". CONCLUSIONS: These first contemporary population-based data from an equatorial country with tropical climate show that exposure to particulate air pollution was significantly associated with non-accidental mortality and cardiovascular mortality, especially in the elderly.

Happy older people live longer.

Objective: research on the role of positive affect, such as happiness, on health outcomes is burgeoning. Within this context, evidence for an inverse effect of happiness on mortality is inconclusive. Furthermore, few studies link happiness with mortality among older people, and in Asian populations. We examine the association between happiness and all-cause mortality among older people in Singapore. Methods: data for 4,478 Singaporeans aged ≥60 years enrolled in a nationally-representative longitudinal survey (three waves: 2009; 2011; 2015) were utilised. Happiness, at baseline, in 2009, was measured using three positively-worded items from the Centre for Epidemiological Studies Depression Scale, and considered in two distinct ways in the analyses-continuous ('happiness score' [0-6]) and binary (happy [score = 6]/unhappy). All-cause mortality, until 31 December 2015, was assessed primarily using administrative databases, supplemented by data from survey waves 2 and 3. Multivariable Cox regression models assessed the association of 'happiness score' and the 'binary happiness variable' (separate models for each) with all-cause mortality. Results: the likelihood of all-cause mortality was lower by 9% (multivariable hazard ratio (HR) [95% confidence interval]: 0.91 [0.87-0.95]) for each unit increase in 'happiness score', and was 19% lower for happy, versus unhappy, older people (HR: 0.81 [0.68-0.97]). Conclusions: happiness is associated with reduced likelihood of all-cause mortality among older people in an Asian population, with the benefit observed even for incremental increases in happiness. Activities, policies and programs that maintain or improve happiness may be beneficial for a longer life among older people.

Influenza-Associated Hospitalizations for Cardiovascular Diseases in the Tropics.

Influenza is a major cause of mortality and morbidity. We aimed to examine the influenza-associated hospitalization rates and proportions for cardiovascular disease (CVD) in tropical Singapore. Hospital admissions for ischemic heart disease (IHD), congestive heart failure (CHF), and overall CVD were obtained from the national inpatient database for the period of 2010-2014. We used, as the key indicator of influenza virus activity, the overall proportion of specimens from outpatients with influenza-like illness in the community that tested positive for influenza as part of the national influenza surveillance program. The annual influenza-associated hospitalization rates per 100,000 person-years ranged from 9.5 to 12.2 for IHD, 7.7 to 9.1 for CHF, and 15.8 to 19.2 for overall CVD. The influenza-associated hospitalization rates increased with increasing age. Influenza was significantly associated with excess hospitalizations in elderly persons aged ≥80 years, with an excess hospitalization rate per 100,000 person-years of 242.7 for IHD (P = 0.02), 271.8 for CHF (P = 0.01), and 497.2 for overall CVD (P < 0.001). In the tropics, influenza accounts for excess cardiovascular-related hospitalizations, especially in the elderly.

Ambient Air Pollution Exposure Estimation for the Global Burden of Disease 2013.

Exposure to ambient air pollution is a major risk factor for global disease. Assessment of the impacts of air pollution on population health and evaluation of trends relative to other major risk factors requires regularly updated, accurate, spatially resolved exposure estimates. We combined satellite-based estimates, chemical transport model simulations, and ground measurements from 79 different countries to produce global estimates of annual average fine particle (PM2.5) and ozone concentrations at 0.1° × 0.1° spatial resolution for five-year intervals from 1990 to 2010 and the year 2013. These estimates were applied to assess population-weighted mean concentrations for 1990-2013 for each of 188 countries. In 2013, 87% of the world's population lived in areas exceeding the World Health Organization Air Quality Guideline of 10 µg/m(3) PM2.5 (annual average). Between 1990 and 2013, global population-weighted PM2.5 increased by 20.4% driven by trends in South Asia, Southeast Asia, and China. Decreases in population-weighted mean concentrations of PM2.5 were evident in most high income countries. Population-weighted mean concentrations of ozone increased globally by 8.9% from 1990-2013 with increases in most countries-except for modest decreases in North America, parts of Europe, and several countries in Southeast Asia.

Influenza-associated hospitalizations, Singapore, 2004-2008 and 2010-2012.

Studies of influenza-associated hospitalizations in tropical settings are lacking. To increase understanding of the effect of influenza in Singapore, we estimated the age-specific influenza-associated hospitalizations for pneumonia and influenza during 2004-2008 and 2010-2012. The rate of hospitalization was 28.3/100,000 person-years during 2004-2008 and 29.6/100,000 person-years during 2010-2012. The age-specific influenza-associated hospitalization rates followed a J-shaped pattern: rates in persons >75 years of age and in children <6 months of age were >47 times and >26 times higher, respectively, than those for persons 25-44 years of age. Across all ages during these 2 study periods, ≈12% of the hospitalizations for pneumonia and influenza were attributable to influenza. The rates and proportions of hospitalizations for influenza, particularly among the very young and the elderly, are considerable in Singapore and highlight the importance of vaccination in protecting populations at risk.

Problematic smartphone use and mental health outcomes among Singapore residents: The health and lifestyle survey.

BACKGROUND: The excessive use of smartphones and its association with adverse outcomes has been widely reported, with several studies showing an association between smartphone overuse, depression, anxiety, and sleep-related problems. METHODS: The study used data from the Health and Lifestyle Survey, a nationwide population survey. It examined the prevalence of Problematic Smartphone Use (PSU) and its association with mental health outcomes among Singapore residents aged 15-65 years. PARTICIPANTS: Participants were assessed for PSU using the Smartphone Addiction Scale-Short Version, psychological distress with the Patient Health Questionnaire-9, and Generalised Anxiety Disorder -7 questionnaire, sleep problems using the Insomnia Severity Index, and positive mental health with Rapid Positive Mental Health Instrument. RESULTS: In all, 6509 participants completed the survey, giving a survey response rate of 73.2 %. The prevalence of PSU was 30.2 % in the population. Individuals with PSU were more likely to have symptoms of moderate or severe depression (OR: 3.2, 95 % CI: 2.4-4.4), anxiety (OR: 3.4, 95 % CI: 2.4-4.8), insomnia (OR: 3.4, 95 % CI: 2.8-4.2), and poorer positive mental health (ß: -0.3, 95 % CI: -0.4 to -0.2). CONCLUSIONS: The study is the first to examine PSU in a national sample of Singaporeans across a wide age range. It provides valuable insights into mental health comorbidities among those with PSU, which is useful for practitioners.

Prevalence of consumption of illicit drugs and associated factors from a nationwide epidemiological survey: The Singapore Health and Lifestyle Survey.

Introduction: The primary aims of the current nationwide study were to establish the lifetime and 12-month prevalence of consumption of illicit drugs and its correlates in the general population of Singapore. Method: A representative sample of 6509 Singapore residents (Singapore citizens and permanent residents) aged between 15 and 65 years were randomly selected for participation. Questionnaires were administered to assess the consumption of illicit drugs and collect information on correlates. All analyses were weighted to produce prevalence estimates for the consumption of drugs and other measured outcomes. Rao-Scott chi-square test and logistic regression analyses were performed to determine the association of sociodemographic and clinical characteristics with lifetime consumption of illicit drugs. Results: The study was completed with a response rate of 73.2%. The lifetime prevalence of consuming illegal drugs was 2.3% (95% confidence interval [CI] 1.9-2.8) (n=180). Compared to individuals aged 15-34, those aged 50-65 (odds ratio [OR] 0.3, 95% CI 0.2-0.7) had lower odds of lifetime drug consumption. Current smokers (OR 4.7, 95% CI 2.7-8.3) and ex-smokers (OR 5.9, 95% CI 3.2-11.1) had significantly higher odds of lifetime drug consumption than non-smokers. Individuals with hazardous alcohol use (OR 3.3, 95% CI 1.7-6.5) had higher odds of lifetime drug consumption than those without hazardous alcohol use. Conclusion: This is the first nationwide study to examine the prevalence of illicit drug consumption in the general population of Singapore. The results highlight the need to increase awareness of drug consumption in Singapore, especially among parents, teachers, healthcare workers and others who work with young people.

Reliability and validity of the English (Singapore) and Chinese (Singapore) versions of the Short-Form 36 version 2 in a multi-ethnic urban Asian population in Singapore.

PURPOSE: We aimed to evaluate the measurement properties of the Singapore English and Chinese versions of the Short-Form 36 version 2 (SF-36v2) Questionnaire, an improved version of the widely used SF-36, for assessing health-related quality of life (HRQoL) in a multi-ethnic urban Asian population in Singapore. METHODS: SF-36v2 scores and data on medical history, demographic and lifestyle factors from the Singapore Prospective Study Programme were analyzed. Convergent and divergent validity, internal consistency, floor and ceiling effects, known group validity and factor structure of the SF-36v2 were assessed for the English and Chinese versions, respectively. RESULTS: Complete data for 4,917 participants (45.8 %) out of 10,747 eligible individuals were analyzed (survey language: 4,115 English and 802 Chinese). Item-scale correlations exceeded 0.4 for all items of the English SF-36v2 and for all except one item of the Chinese SF-36v2 (bathe and dress: item-scale correlation: 0.36). In the English SF-36v2, Cronbach's alpha exceeded 0.70 for all scales. In the Chinese SF-36v2, Cronbach's alpha exceeded 0.7 on all scales except social functioning (Cronbach's alpha: 0.68). For known groups validity, respondents with chronic medical conditions expectedly reported lower SF-36v2 score on most English and Chinese SF-36v2 scales. In confirmatory factor analysis, the Singapore three-component model was favored over the United States two-component and Japan three-component models. CONCLUSIONS: The English and Chinese SF-36v2 are valid and reliable for assessing HRQoL among English and Chinese-speaking Singaporeans. Test-retest reliability and responsiveness of the English and Chinese SF-36v2 in Singapore remain to be evaluated.

Association of anthropometric measures with SF-36v2 PCS and MCS in a multi-ethnic Asian population.

PURPOSE: Obesity adversely affects health-related quality of life (HRQoL). Most studies have used body mass index (BMI) to measure obesity. Other measures of obesity, such as waist circumference (WC) or waist-to-hip ratio (WHR), may be better predictors of cardiovascular disease and mortality. We, therefore, examined the associations between other anthropometric measures and HRQoL in a multi-ethnic Asian population. METHODS: In this follow-up study from four previous cross-sectional surveys, HRQoL was measured, at follow-up, using the Short-Form 36 version 2 (SF-36v2) questionnaire. Linear regression was used to assess the relationship between anthropometric measures [BMI, WC, waist residuals (WR) (generated by regressing WC on BMI), WHR, waist-to-height ratio (WHtR) and height (Ht)] and HRQoL. We compared the models' R2, Akaike's information criteria (AIC), and Schwarz Bayesian information criteria (BIC) from the different models. RESULTS: Among 4,981 subjects, 47.6% were men aged 50.6 ± 12.2 and women aged 49.3 ± 11.6 years. All gender-specific anthropometric measures were significantly correlated with BMI, except WR. After adjusting for known determinants of HRQoL, we found significant associations between BMI, WC and WHtR with SF-36v2 Physical Component Summary (PCS) scores in women but not men. In contrast, after adjusting for known determinants of HRQoL, WR and WHR were significantly associated with SF-36v2 Mental component summary (MCS) scores in men, but not women. R², AIC and BIC were similar for all anthropometric measures in the final model. CONCLUSIONS: The associations between measures of central obesity and HRQoL differed between men and women. In women, associations were seen with SF-36v2 PCS, but measures of central obesity did not have significant associations with HRQoL after controlling for BMI. In men, an association between WC and SF-36v2 MCS was statistically significant independent of BMI. These gender differences require further investigation.

Risk prediction models for type 2 diabetes using either fasting plasma glucose or HbA1c in Chinese, Malay, and Indians: Results from three multi-ethnic Singapore cohorts.

AIMS: To assess three well-established type 2 diabetes (T2D) risk prediction models based on fasting plasma glucose (FPG) in Chinese, Malays, and Indians, and to develop simplified risk models based on either FPG or HbA1c. METHODS: We used a prospective multiethnic Singapore cohort to evaluate the established models and develop simplified models. 6,217 participants without T2D at baseline were included, with an average follow-up duration of 8.3 years. The simplified risk models were validated in two independent multiethnic Singapore cohorts (N = 12,720). RESULTS: The established risk models had moderate-to-good discrimination (area under the receiver operating characteristic curves, AUCs 0.762 - 0.828) but a lack of fit (P-values < 0.05). Simplified risk models that included fewer predictors (age, BMI, systolic blood pressure, triglycerides, and HbA1c or FPG) showed good discrimination in all cohorts (AUCs ≥ 0.810), and sufficiently captured differences between the ethnic groups. While recalibration improved fit the simplified models in validation cohorts, there remained evidence of miscalibration in Chinese (p ≤ 0.012). CONCLUSIONS: Simplified risk models including HbA1c or FPG had good discrimination in predicting incidence of T2D in three major Asian ethnic groups. Risk functions with HbA1c performed as well as those with FPG.

The ARIC predictive model reliably predicted risk of type II diabetes in Asian populations.

BACKGROUND: Identification of high-risk individuals is crucial for effective implementation of type 2 diabetes mellitus prevention programs. Several studies have shown that multivariable predictive functions perform as well as the 2-hour post-challenge glucose in identifying these high-risk individuals. The performance of these functions in Asian populations, where the rise in prevalence of type 2 diabetes mellitus is expected to be the greatest in the next several decades, is relatively unknown. METHODS: Using data from three Asian populations in Singapore, we compared the performance of three multivariate predictive models in terms of their discriminatory power and calibration quality: the San Antonio Health Study model, Atherosclerosis Risk in Communities model and the Framingham model. RESULTS: The San Antonio Health Study and Atherosclerosis Risk in Communities models had better discriminative powers than using only fasting plasma glucose or the 2-hour post-challenge glucose. However, the Framingham model did not perform significantly better than fasting glucose or the 2-hour post-challenge glucose. All published models suffered from poor calibration. After recalibration, the Atherosclerosis Risk in Communities model achieved good calibration, the San Antonio Health Study model showed a significant lack of fit in females and the Framingham model showed a significant lack of fit in both females and males. CONCLUSIONS: We conclude that adoption of the ARIC model for Asian populations is feasible and highly recommended when local prospective data is unavailable.

Transitions between social network profiles and their relation with all-cause mortality among older adults.

BACKGROUND: The importance of social network in mortality among older adults has been acknowledged. However, existing studies typically overlook the interplay among social network indicators, and seldom consider the change in social network over time. We take a person-centered approach to identify transitions between social network profiles, and examine the linkage of such transitions with subsequent mortality risk. METHODS: Data came from 2738 older Singaporeans enrolled in a longitudinal study. Latent transition analysis examined nine social network indicators assessed at two time points, two years apart to reveal the corresponding transitions between social network profiles. Adjusted Cox regression then associated the identified transitions with all-cause mortality risk in the subsequent four years. RESULTS: We observed three diverse social network profiles (that featured diversified social interaction and involved both household and non-household members) and three relatively restricted social network profiles (that focused on household or non-household members). Compared to sustained diverse profiles over time, sustained restricted profiles or a transition from diverse to restricted profiles entailed increased mortality risk. The mortality risk following a restricted-to-diverse profile transition could be as low as that associated with sustained diverse profiles. CONCLUSIONS: Dynamics of social network profiles have implications for mortality risk in later life. To promote longevity, initiatives are needed to help older people to maintain or shift to diverse social network profiles.