Health and disability - a multi-group latent class analysis of the World Health Organization Disability Assessment Schedule 2.0 among those with mental and physical health conditions.

BACKGROUND: This study aims to identify disability classes among people with schizophrenia spectrum disorder, depression, anxiety or diabetes via the WHODAS 2.0; investigate the invariance of disability patterns among the four diagnostic groups; and examine associations between disability classes and sociodemographic variables. METHODS: Patients seeking treatment for schizophrenia spectrum disorder, depression, anxiety or diabetes (n=1076) were recruited. Latent class analysis was used to identify disability classes based on WHODAS 2.0 responses. Measurement invariance was tested using multi-group latent class analysis. Associations between classes and sociodemographic variables were tested via multinomial logistic regression. RESULTS: A five-class solution was identified; examination of model invariance showed that the partially constrained five-class model was most appropriate, suggesting that class structure was consistent while class membership differed across diagnostic groups. Finally, significant associations were found between class membership and ethnicity, education level, and employment status. CONCLUSIONS: The results show the feasibility of using the WHODAS 2.0 to identify and compare different disability classes among people with mental or physical conditions and their sociodemographic correlates. Establishing a typology of different disability profiles will help guide research and treatment plans that tackle not just clinical but also functional aspects of living with either a chronic psychiatric or physical condition.

Association between sleep quality and quality of life in Singapore.

PURPOSE: Several studies have examined the relationship between sleep quality and health-related quality of life (HRQOL). However, there are a lack of generalizable data on this association in Singapore. Our study aimed to (1) investigate the association between sleep quality and HRQOL and (2) examine whether age moderated these associations. METHODS: Data were obtained from nationwide Singapore Mental Health Study 2016 (n = 6126, response rate = 69.5%). Sleep quality was assessed using Pittsburgh Sleep Quality Index (PSQI) where higher scores indicate poorer sleep quality. HRQOL [Physical component summary (PCS) and Mental component summary (MCS)] were measured using 12-item Short-Form Survey. Associations were investigated using multivariable linear regression models, adjusted for sociodemographic, physical, and mental comorbidities. Interactions between age and sleep quality were examined by including interaction terms individually. RESULTS: Poorer PSQI score was significantly associated with lower PCS (ß = - 0.44) and lower MCS (ß = - 0.73). Among PSQI components, lower PCS was significantly associated with subjective sleep quality (ß = - 1.06), sleep duration (ß = - 0.30), sleep disturbance (ß = - 0.33), and daytime dysfunction (ß = - 0.75). Lower MCS was significantly associated with subjective sleep quality (ß = - 1.36), sleep latency (ß = - 0.24), sleep disturbance (ß = - 0.16), using of sleeping medication (ß = - 1.12), and daytime dysfunction (ß = - 2.08). Age moderated the association between PSQI score with PCS and MCS. Stronger association between PSQI score and MCS was observed in younger individuals (ß = - 0.90) than older adults (ß = - 0.45). CONCLUSION: Our study found that poor sleep quality was associated with HRQOL of certain age groups more than others. Future studies may identify potential mediators to help people with chronic sleep problems.

Treatment delays for mental disorders in Singapore: results from the Singapore Mental Health Study 2016.

PURPOSE: Although the trajectory of mental disorders can be improved with timely treatment, many people defer treatment-seeking. This study aimed to examine the prevalence and correlates of treatment delays for mental disorders in Singapore, as well as perceived effectiveness of treatment received. METHODS: A total of 6126 respondents, aged 18 and above, participated in the Singapore Mental Health Study 2016-a cross-sectional, nationwide study conducted in Singapore from 2016 to 2018. Lifetime treatment contact for mood, anxiety, and alcohol use disorders (AUD) was assessed using the World Mental Health-Composite International Diagnostic Interview (Version 3.0). Multivariable logistic regression was conducted to examine correlates of delayed treatment. RESULTS: A total of 137 participants had made lifetime treatment contact for a mental disorder. The proportion of respondents who received delayed treatment (i.e., at least one year after onset of disorder) was 60.8% for any disorder, 59.5% for mood disorders, 56.3% for anxiety disorders, and 92.7% for AUD. The median delay was 5 years for mood disorders, one year for anxiety disorders, and 4 years for AUD. Treatment delay was significantly associated with older age, higher educational qualification, lifetime AUD, and earlier age of onset of disorder. 58.4% of respondents with lifetime treatment contact had received treatment that they considered effective. CONCLUSION: The high prevalence and long durations of treatment delay underscore the need to encourage help-seeking for mental disorders, especially since treatment is generally perceived to be helpful. Our findings also highlight several population groups more susceptible to receiving delayed treatment.

Public awareness of war on diabetes campaign and its association with behavioural outcomes.

The War on Diabetes campaign was launched in 2016, encouraging Singapore residents to engage in regular exercise, adopt healthy dietary habits and screen for early detection of diabetes. This study aims to examine campaign awareness and its associations with sedentary behaviour, dietary habits and identifying diabetes. Data were obtained from the nationwide Knowledge, Attitudes and Practices study on diabetes in Singapore. A total of 2895 participants responded to a single question assessing campaign awareness. The Dietary Approaches to Stop Hypertension (DASH) diet screener assessed dietary habits, and the Global Physical Activity Questionnaire (GPAQ) measured sedentary behaviour. Recognition of diabetes was established using a vignette depicting a person with diabetes mellitus. Logistic and linear regression models were used to measure the associations. Most participants were 18- to 34-years old (29.9%) and females (51.6%). About 57.4% identified the campaign. Campaign awareness exhibited positive associations with identifying diabetes based on the vignette [odds ratio (OR): 1.5; 95% confidence interval (CI): 1.1-2.2; P = 0.022], lower odds of sedentary behaviour ≥7 h/day (OR: 0.7; CI: 0.5-0.9; P = 0.018) and higher DASH scores (ß = 1.3; P < 0.001). The study recognized early significant associations between the behavioural outcomes and the campaign, emphasizing the need for ongoing campaign sustainability and evaluation of its long-term impact on population health.

Food insufficiency, adverse childhood experiences and mental health: results of the Singapore Mental Health Study 2016.

OBJECTIVE: This study aimed to investigate the prevalence and correlates of food insufficiency and its association with mental disorders and adverse childhood experiences (ACE) in Singapore. DESIGN: This analysis utilised data from the Singapore Mental Health Study (SMHS 2016). SETTING: SMHS 2016 was a population-based, psychiatric epidemiological study conducted among Singapore residents. PARTICIPANTS: Interviews were conducted with 6126 respondents. Respondents were included if they were aged 18 years and above, Singapore citizens or permanent residents and able to speak in English, Chinese or Malay. RESULTS: The prevalence of food insufficiency was 2·0 % (95 % CI (1·6, 2·5)) among adult Singapore residents. Relative to respondents who did not endorse any ACE, those with ACE (OR: 2·9, 95 % CI (1·2, 6·6)) had higher odds of food insufficiency. In addition, there were significant associations between lifetime mental disorders and food insufficiency. Bipolar disorder (OR: 2·7, 95 % CI (1·2, 6·0)), generalised anxiety disorder (OR: 4·5, 95 % CI (1·5, 13·5)) and suicidal behaviour (OR: 2·37, 95 % CI (1·04, 5·41)) were shown to be significantly associated with higher odds of food insufficiency. CONCLUSIONS: The prevalence of food insufficiency is low in Singapore. However, this study identifies a vulnerable group of food-insufficient adults that is significantly associated with mental disorders, including suicidality. Government-funded food assistance programmes and multi-agency efforts to deal with the social determinants of food insufficiency, such as income sufficiency and early detection and intervention of mental distress, are key to ensuring a sustainable and equitable food system.

Measuring social desirability bias in a multi-ethnic cohort sample: its relationship with self-reported physical activity, dietary habits, and factor structure.

BACKGROUND: Social desirability bias is one of the oldest forms of response bias studied in social sciences. While individuals may feel the need to fake good or bad answers in response to sensitive or intrusive questions, it remains unclear how rampant such a bias is in epidemiological research pertaining to self-reported lifestyle indicators in a multicultural Asian context. The main purpose of the current study is, therefore, to examine the sociodemographic correlates and impact of social desirability responding on self-reported physical activity and dietary habits at an epidemiological scale in a non-western multi-cultural Asian setting. METHODS: Prior to the main analyses, confirmatory and exploratory factor analyses were conducted to determine the factorial validity of a western derived concept of social desirability. Multiple regression analyses were conducted on cross-sectional data (n = 2995) extracted from a nationwide survey conducted between 2019 and 2020. RESULTS: A unique factor structure of social desirability was found and was therefore used for subsequent analyses. Multiple regression analyses revealed older age groups, the Indian ethnic group, those with past or present marriages, and having no income, had a significantly greater tendency to act on the bias. CONCLUSION: The construct of social desirability bias was fundamentally different in a multicultural context than previously understood. Only a small proportion of variance of self-report lifestyle scores was explained by social desirability, thus providing support for data integrity.

The economic burden of mental disorders among adults in Singapore: evidence from the 2016 Singapore Mental Health Study.

BACKGROUND: Little is known about the economic burden of mental disorders in multiethnic Asian populations. AIMS: The study aimed to estimate the economic cost of mental disorders in Singapore using data from the second Singapore Mental Health Study (SMHS 2016). METHOD: The SMHS 2016 is a nationally representative survey of the Singapore Resident population aged 18 years and above. Data on mental disorders and healthcare resource utilization were obtained from the World Mental Health Composite International Diagnostic Interview and the adapted version of the Client Service Receipt Inventory. RESULTS: The costs of visits to a restructured hospital doctor, other private health workers, accident and emergency, and intermediate and long-term care services and productivity losses tend to be much higher in those with mental disorders than those without mental disorders. The average annual excess cost associated with mental disorders per person was estimated to be S$3938.9 (95% CI, S$-100.8-S$7978.7). Extrapolation of these excess costs to the population suggests that the incremental costs of mental disorders in Singapore is about S$1.7 billion per year. CONCLUSION: This study provides evidence of the substantial burden of mental disorders on Singaporean society - both in terms of direct medical costs and loss of productivity costs.

A prospective observational study exploring the association of comorbid chronic health conditions with total healthcare expenditure in people with mental health conditions in an Asian setting.

BACKGROUND: It is pertinent to focus on chronic medical condition (CMC) comorbidity with mental health conditions (MHC) as their co-occurrence has significant cost and health implications. However, current evidence on co-occurrence of MHC with CMC is mixed and mostly from Western settings. Therefore, our study aimed to (i) describe the association between MHC and total healthcare expenditure, (ii) examine the association between CMC and total healthcare expenditure and (iii) examine determinants of total and different types of healthcare expenditure in respondents with and without MHC in an Asian setting. METHODS: The data from Singapore Mental Health Study (SMHS) 2016, a nationwide epidemiological survey, were linked with the National claims record (from 2017 to 2019). Multivariable Generalized Linear Models (GLM) were used to examine the association between MHC and total and different types of healthcare expenditure. RESULTS: A total of 3077 survey respondents were included in current analysis. Respondents with MHC had a lower mean age of 38.6 years as compared to those without MHC (47.1 years). MHC was associated with increased total healthcare expenditure after adjusting for covariates (b = 0.508, p < 0.05). In respondents with MHC, presence of CMC increased the total healthcare expenditure by 35% as compared to 40% increase in those without MHC. Interestingly, 35-49 years age group with MHC had almost 3 times higher total healthcare expenditure and 7.5 times higher inpatient expenditure as compared to the 18-34 years age group. CONCLUSION: Our study highlights variations in association of CMC and age with total healthcare expenditure in those with versus without MHC in an Asian setting. Practical recommendations include appropriate planning and resource allocation for early diagnosis and management of MHC, proactive screening for CMC in those with MHC and addressing the dual issues of treatment gap and stigma to facilitate early help seeking and prevent episodic, costly healthcare utilization.

Factors influencing uptake of diabetes health screening: a mixed methods study in Asian population.

BACKGROUND: Health screens are the cornerstones for health promotion and preventive interventions at a community level. This study investigated the barriers and facilitators to the uptake of diabetes health screening in the general population of Singapore. METHODS: In this mixed methods study, participants without diabetes were recruited from the general population. The quantitative phase (n = 2459) included face to face survey of participants selected through disproportionate stratified random sampling. Those who participated in the quantitative survey were then randomly chosen for a one-to-one semi-structured interview (n = 30). RESULTS: Among the survey respondents, 73.09% (n = 1777) had attended a diabetes health screening in their lifetime whilst 42.36% (n = 1090) and 57.64% (n = 1328, p < 0.0001) attended the health screens regularly (every 12 months) and irregularly, respectively. A significantly higher proportion of older adults (≥ 40 years) attended regular diabetes health screening compared to younger adults (less than 40 years; 55.59% vs 24.90%, p < 0.001). The top 3 reasons for attending regular health screens were to detect diabetes early, to make lifestyle changes in case of a diagnosis and being health conscious. Qualitative interviews identified similar issues and complex nuances that influenced the uptake of regular diabetes health screening. Several personal factors (laziness, self-reliance, psychological factors, etc.), competing priorities, fatalistic beliefs, affordability, misconceptions about the screens, and appointment related factors (inconvenient location, time, etc.) were identified as barriers, while affordable screens, sense of personal responsibility, perception of susceptibility /risk, role of healthcare team (e.g. reminders and prescheduled appointments) and personal factors (e.g. age, family, etc.) were facilitators. Age, household income, ethnicity and educational level were associated with the uptake of regular diabetes health screening. CONCLUSION: The uptake of regular diabetes health screening can be improved. Several barriers and enablers to the uptake of diabetes health screening were identified which should be addressed by the policy makers to alleviate misconceptions and create greater awareness of the importance of the programme that will improve participation.

Occupational groups and its physical and mental health correlates: results from the Singapore Mental Health Study 2016.

PURPOSE: The physical and mental wellbeing of an individual is impacted by the type occupation one does. This study aims to establish the prevalence of mental and physical disorders, the association of occupational groups and health-related quality of life, and the extent of work-loss and work-cut back in past 30 days among the employed in the Singapore resident population. METHODS: Data from a population-based, epidemiological survey of a representative sample of Singapore citizens and permanent residents aged 18 years and above were used. Lifetime diagnosis of select mental disorders was established using the World Health Organization's Composite International Diagnostic Interview version 3.0 (WHO-CIDI 3.0). Data on nicotine dependence, work productivity, quality of life and socio-demographics were obtained via self-report. Ten major occupational groups based on the Singapore Standard Occupational Classification were included in the analysis. RESULTS: The sample comprised 4021 employed individuals who were predominantly males (54.7%) and aged 35-49 years (35.4%). 'Service and sales workers' (22.6%), 'Professionals' (17.3%) and 'Legislators, senior officials and managers' (16.4%) were the three largest occupational groups. Socio-demographic characteristics differed significantly (p < 0.001) across all occupational groups. Lifetime prevalence of mood disorders among the employed was 8.4% and the most prevalent physical disorder was chronic pain (18.9%). No significant differences were observed in work productivity loss across the occupational groups. CONCLUSIONS: The disparities in the socio-demographic characteristics and prevalence of mental and physical disorders across occupational categories provide policymakers with vital information to pilot effective interventions that can improve the psychosocial and physical conditions at work.

A cross-sectional study on the perceived barriers to physical activity and their associations with domain-specific physical activity and sedentary behaviour.

BACKGROUND: Physical inactivity and sedentary behaviour have detrimental consequences to the individual and the economy. Our study examined the prevalence of perceived barriers to physical activity in Singapore's adult population and their associations with physical activity and sedentary behaviour. METHODS: This cross-sectional analysis utilised data from a nationwide survey in Singapore. Participants (n = 2867) were recruited from February 2019 to March 2020. The independent variables were internal (e.g. fatigue, age) and external (e.g. weather, cost) perceived barriers to physical activity. The outcomes were domain-specific physical activity (work, transport and leisure) and sedentary behaviour, all of which were assessed using the Global Physical Activity Questionnaire. The associations were examined using zero-inflated negative binomial regressions for physical activity and linear regression for sedentary behaviour. RESULTS: The median (Interquartile range) for work-related, transport-related and leisure-related physical activity were 0 (0 - 1440), 600 (160 - 1120) and 360 (0 - 1080) MET (metabolic equivalent)-minutes per week. The median sedentary behaviour (IQR) was 360 (240 - 540) minutes per day. The top three barriers were lack of time (65.3%), fatigue (64.7%) and pollution (56.1%). After adjustment, the level of transport-related physical activity was lower for respondents who cited lacking pavement or parks as a barrier, but higher for those who indicated cost and safety concerns. Respondents who reported pollution as a barrier were more likely to engage in transport-related physical activity. The level of leisure-related physical activity was lower for respondents indicating weather, lack of time and age as barriers, but higher for those reporting safety concerns. The odds of engaging in leisure-related physical activity was lower for those citing age, cost and fatigue as barriers, but higher for those indicating the weather. Sedentary behaviour was positively associated with work and limited accessibility to exercise facilities, but negatively with safety concerns. CONCLUSION: Individuals can be motivated to overcome internal barriers (fatigue, lack of time, cost and age) through social support and emphasis on exercise benefits. External barriers (weather and lack of pavements or parks) can be reduced by raising awareness of existing infrastructure. Sedentary behaviour can be improved by implementing workplace measures, such as reducing the time spent sitting.

Acceptance of healthy lifestyle nudges in the general population of Singapore.

BACKGROUND: In recent years, behaviourally driven policies such as nudges have been increasingly implemented to steer desired outcomes in public health. This study examines the different nudges and the socio-demographic characteristics and lifestyle behaviours that are associated with public acceptance of lifestyle nudges. METHODS: The study used data from the nationwide Knowledge, Attitudes and Practices study (KAP) on diabetes in Singapore. Three types of nudges arranged in increasing order of intrusiveness were examined: (1) information government campaigns, (2) government mandated information and (3) default rules and choice architecture. Acceptance was assessed based upon how much respondents 'agreed' with related statements describing heathy lifestyle nudges. Multivariable linear regressions were performed with socio-demographics and lifestyle behaviours using scores calculated for each nudge. RESULTS: The percentage of respondents who agreed to all statements related to each nudge were: 75.9% (information government campaigns), 73.0% (government mandated information), and 33.4% (default rules and choice architecture). Respondents of Malay/Others ethnicity (vs. Chinese) were more likely to accept information government campaigns. Respondents who were 18 - 34 years old (vs 65 years and above), female, of Malay/Indian ethnicity (vs Chinese), were sufficiently physically active, and with a healthier diet based on the DASH (Dietary Approach to Stop Hypertension) score were more likely to accept nudges related to government mandated information. Respondents of Malay/Indian ethnicity (vs Chinese), and who had a healthier diet were more likely to accept default rules and choice architecture. CONCLUSION: Individuals prefer less intrusive approaches for promoting healthy lifestyle. Ethnicity and lifestyle behaviours are associated with acceptance of nudges and should be taken into consideration during the formulation and implementation of behaviourally informed health policies.

Positive mental health framework of transdiagnostic protective factors in elucidating the association between adverse childhood experiences and severe mental disorders.

OBJECTIVES: Transdiagnostic risk factors-disrupted processes common to psychopathology-link adverse childhood experiences to severe mental disorders (i.e. major depressive disorder, bipolar disorder, and schizophrenia spectrum disorders); however, transdiagnostic protective factors are understudied. The present study investigated the association between a positive mental health framework of protective intra- and interpersonal resources and severe mental disorders in individuals with adverse childhood experiences. We hypothesized that (1) individuals with adverse childhood experiences will experience more severe mental disorders and poorer intra- and interpersonal resources than those without adverse childhood experiences; (2) intrapersonal (e.g. general coping) and interpersonal resources (e.g. emotional support) will interact to predict severe mental disorders. METHODS: A total of 1929 adults participated in this population-based study. Participants were assessed for adverse childhood experiences, severe mental disorders, and intra- and interpersonal resources (general coping, general affect, emotional support, interpersonal skills, spirituality, and personal growth and autonomy) via structured interviews and self-reports. RESULTS: As hypothesized, individuals with adverse childhood experiences (62.6%) experienced more severe mental disorders and poorer intra- and interpersonal resources than those without adverse childhood experiences. Among those with adverse childhood experiences, emotional support interacted with general coping and general affect to predict severe mental disorders; general coping and general affect were negatively associated with severe mental disorders at high (+1 SD) and low (-1 SD) emotional support, respectively. CONCLUSIONS: The present study identified interactions between specific intrapersonal (i.e. general coping and general affect) and interpersonal resources (i.e. emotional support); knowing among whom and when to intervene are essential for optimal treatment of adverse childhood experiences and severe mental disorders.

Prevalence and impact of peer victimisation among youth seeking treatment at a tertiary psychiatric institution in Singapore: a cross-sectional study.

BACKGROUND: Peer victimization is common among adolescents and leads to negative consequences. However, few studies have examined the extent of peer-victimization and its correlates among adolescent patients in a psychiatric setting. The current study aimed to examine the prevalence and correlates of peer victimisation among youth with mental illness and to examine its association with depressive symptoms and health-related quality of life (HRQOL). METHODS: A sample of 239 youths aged 15-24 years were recruited from the outpatient clinics of a tertiary psychiatric hospital in Singapore using convenience sampling. All participants were administered the Multidimensional Peer Victimisation Scale (MPVS), Short Form 12 (SF-12) questionnaire and the Patient Health Questionnaire-8 (PHQ-8). The effect of MPVS  total and subscores on depression scores, quality of life subscores and quality of life total scores were examined using multiple linear regression analyses. RESULTS: The majority of the patients reported that they had experienced at least one form of peer victimisation (95.8%, n = 229) during their school years. Higher levels of 'verbal victimisation', 'attacks on property' and higher total MPVS scores were significantly associated with lower social functioning; additionally, higher levels of 'verbal victimisation' were significantly associated with lower mental component summary scores in the quality of life assessment. Higher scores on all four subscales as well as higher total scores on the MPVS were significantly associated with more severe depressive symptoms. CONCLUSIONS: Given the high prevalence of peer victimisation in our sample and its associations with more severe depressive symptoms and lower quality of life, it is vital to implement interventions that prevent peer victimisation in educational and other social settings and to provide youth with strategies to more effectively manage instances of peer victimisation.

Sources of information on diabetes and its demographic correlates: a nationwide survey among Singapore residents.

Diabetes is a major public health concern in Singapore, and the Singapore Government declared a 'War on Diabetes', which included a nationwide public health campaign. It is important to identify what sources of diabetes information reach the general population, whether this differs by socio-demographic characteristics and if the sources of information influence knowledge of diabetes to aid the successful dissemination of health information. Two thousand eight hundred ninety-five respondents were part of a population-based cross-sectional study conducted from February 2019 to September 2020. Respondents rated on a five-point scale whether they had obtained information on diabetes from eight different information sources, and responses were dichotomized into 'endorsed receiving information' or 'not endorsed receiving information'. Poisson regression models were conducted with the 'endorsement of receiving information' from each source as the outcome and socio-demographic variables as predictors. 95.9% of the study population had received information on diabetes from at least one source, and the mean number of sources was 4.2 ± 2.0. The leading source was media articles (82.1%), followed by health promotion videos/advertisements (77.9%), online websites (58.5%), books (56.5%), healthcare professionals (55.0%), radio (54.4%), public forums (27.7%) and support groups (15.5%). Endorsing a greater number of informational sources was associated with being younger, belonging to Malay or Indian instead of Chinese ethnicity, and having diabetes. An intensive nationwide diabetes awareness campaign successfully reached the public in Singapore with specific sources of information depending on socio-demographic characteristics. Findings suggest that diabetes information campaigns should utilize multiple channels for dissemination considering the different socio-demographic subgroups.

Religiosity, Religious Coping and Distress Among Outpatients with Psychosis in Singapore.

This study aimed to investigate the prevalence of religious coping and explore the association between religious coping, religiosity, and distress symptoms amongst 364 outpatients diagnosed with psychosis in Singapore. Positive and Negative Religious Coping (PRC and NRC), religiosity (measuring the constructs of Organised Religious Activity (ORA), Non-Organised Religious Activity (NORA), and Intrinsic Religiosity (IR)) and severity of distress symptoms (depression, anxiety and stress) were self-reported by the participants. The majority of participants (68.9%) reported religion to be important in coping with their illness. Additionally, multiple linear regression analyses found that NRC was significantly associated with higher symptoms of distress. In contrast, ORA was significantly associated with lower anxiety symptom scores. Overall, the study indicates the importance of religion in coping with psychosis and the potential value in incorporating religious interventions in mental health care.

Confirmatory factor analysis and measurement invariance of the English, Mandarin, and Malay versions of the SF-12v2 within a representative sample of the multi-ethnic Singapore population.

BACKGROUND: The Short Form Health Survey (SF-12v2) is an increasingly popular measure of health-related quality of life (HRQoL) in Singapore. In order to examine whether the SF-12v2 was appropriate for use in the population, the factor structure and validity of the English, Mandarin, and Malay versions were assessed in a representative sample of the general population of Singapore. METHODS: 6126 respondents were recruited for the Singapore Mental Health Study 2016 (SMHS 2016), a cross-sectional and population-based survey. Confirmatory factor analyses (CFA) were conducted to examine the fit of a two-factor model for the SF-12v2 within a representative sample and amongst the different language (English, Mandarin, Malay) subgroups. Multiple-group CFAs (MGCFA) were conducted to test measurement invariance across the different languages, ethnicities, and chronic illnesses subgroups. CFA-generated latent factor scores (FSCORE command in MPlus) were also compared with the composite scores derived from the developer's scoring method via correlations. Sociodemographic correlates of the latent physical and mental health scores were explored. RESULTS: CFA results within the full sample supported a two-factor model (RMSEA = 0.044; CFI = 0.991; TLI = 0.988; SRMR = 0.044) in which physical functioning, role physical, bodily pain and general health items loaded onto a latent physical health factor, while role emotional, mental health, social functioning, and vitality items loaded onto a latent mental health factor. Physical and mental health factors were allowed to correlate, unlike the developer's orthogonal scoring method. All standardized loadings were high and statistically significant. Both factors had high internal consistency. CFA within subsamples of English, Mandarin, and Malay languages indicated similar findings. MGCFA results indicate that measurement invariance held across the different languages, ethnicities, and those with and without chronic illnesses. CONCLUSION: The present study identified a two-factor (physical and mental health) structure within the general population and amongst the three different languages and demonstrated the measurement invariance of SF-12v2 across different subgroups. Findings indicate that algorithm-derived PCS and MCS should be interpreted with caution as they may result in inaccurate conclusions regarding the relationships between HRQoL and its correlates. Future studies using the SF-12v2 within the general population of Singapore should consider utilizing the factor structure put forth in the present study to obtain more appropriate estimates of HRQoL.

Mapping the PHQ-8 to EQ-5D, HUI3 and SF6D in patients with depression.

BACKGROUND: There is limited evidence of mapping clinical instruments to a generic preference-based instrument in Asian patient populations. The current study aims to map the eight-item Patient Health Questionnaire depression scale (PHQ-8) onto the EuroQol Five-Dimension (EQ-5D), the Health Utilities Index Mark 3 (HUI3) and the Short Form Six-Dimension (SF-6D) which helps to inform future cost-utility analyses of treatments for depression. METHODS: A total of 249 participants who had completed PHQ-8, EQ-5D, SF-6D and HUI3 questionnaires were included in the analyses. A beta regression mixture model was used to map the utility scores as a function of PHQ-8 total scores, PHQ-squared, age and gender. The predictive accuracy of the models was examined using mean absolute error and root mean square error. RESULTS: The results were compared against two common regression methods including Ordinary Least Square (OLS) and Tobit regression models. The mean age of the sample was 36.2 years (SD = 11.1). The mean EQ-5D-3L, EQ-5D-5L, HUI3 and SF-6D utility scores were 0.615, 0.709, 0.461 and 0.607, respectively. The EQ-5D-3L, EQ-5D-5L and SF-6D utility scores were best predicted by the beta mixture regression model consisting of PHQ-8 total sores, PHQ-squared, and covariates including age and gender. The HUI3 was best predicted by the OLS regression model. CONCLUSIONS: The current study provides important evidence to clinicians and researchers about the mapping algorithms that can be used in economic evaluation among patients with depression.

Extended network analysis: from psychopathology to chronic illness.

BACKGROUND: Understanding complex associations between psychopathology and chronic illness is instrumental in facilitating both research and treatment progress. The current study is the first and only network-based study to provide such an encompassing view of unique associations between a multitude of mental and physical health-related domains. METHODS: The current analyses were based on the Singapore Mental Health Study, a cross-sectional study of adult Singapore residents. The study sample consisted of 6616 respondents, of which 49.8% were male and 50.2% female. A network structure was constructed to examine associations between psychopathology, alcohol use, gambling, major chronic conditions, and functioning. RESULTS: The network structure identified what we have labeled a Cartesian graph: a network visibly split into a psychopathological domain and a physical health domain. The borders between these domains were fuzzy and bridged by various cross-domain associations, with functioning items playing an important role in bridging chronic conditions to psychopathology. CONCLUSIONS: Current results deliver a comprehensive overview of the complex relation between psychopathology, functioning, and chronic illness, highlighting potential pathways to comorbidity.

Gender difference in quality of life (QoL) among outpatients with schizophrenia in a tertiary care setting.

BACKGROUND: Patients with mental illness report lower quality of life (QoL) compared to the general population. Prior research has found several differences in clinical features and experiences of male and female patients with schizophrenia. Given these differences, it is also important to explore if there are any gender differences in terms of their QoL. This study aimed to investigate differences in QoL between and within each gender among outpatients with schizophrenia in Singapore. METHODS: A total of 140 outpatients were recruited through convenience sampling at the Institute of Mental Health, Singapore. QoL was measured using the brief version of World Health Organization Quality of Life (WHOQOL-BREF) which consists of four domains: physical health, psychological health, social relationships, and environment. QoL scores of males and females were compared using independent t-tests, and multiple linear regressions were used to examine sociodemographic correlates of QoL in the overall sample and within each gender. RESULTS: There was no significant difference in QoL domain scores between genders. Among males, Indian ethnicity (versus Chinese ethnicity) was positively associated with physical health (ß=3.03, p=0.018) while males having Technical Education/ Diploma/ A level education (versus Degree and above) were positively associated with social relationships domain (ß=2.46, p=0.047). Among females, Malay ethnicity (versus Chinese ethnicity) was positively associated with physical health (ß=1.95, p=0.026) psychological health (ß=3.21, p=0.001) social relationships (ß=2.17, p=0.048) and environment (ß=2.69, p=0.006) domains, while females who were separated/divorced (versus single) were inversely associated with psychological health (ß=- 2.80, p=0.044) and social relationships domains (ß=- 4.33, p=0.011). Females who had Secondary and below education (versus Degree and above) were inversely associated with social relationships (ß=- 2.29, p=0.028) and environment domains (ß=- 1.79, p=0.048). CONCLUSIONS: The findings show the importance of treatments targeting QoL to attend to both the clinical features of the illness as well patient's sociodemographic characteristics.