Dietary patterns associated with hypertension risk among adults in Thailand: 8-year findings from the Thai Cohort Study.

OBJECTIVE: Dietary intake is a leading risk factor for hypertension. We aimed to assess longitudinal associations between overall dietary patterns and incident hypertension among adults in Thailand. DESIGN: Prospective large Thai Cohort Study (TCS) conducted nationwide from 2005 to 2013. Dietary patterns were identified using factor analysis based on usual intake of fourteen food groups. Multivariable logistic regression assessed associations between dietary patterns and hypertension prevalence and incidence. SETTING: Emerging hypertension and changing diets in Thailand. SUBJECTS: TCS participants who were normotensive at baseline in 2005. RESULTS: Among 36293 participants without hypertension at baseline, 1831 reported incident hypertension (5·1 % incidence) at follow-up. Two dietary patterns were identified: 'Modern' and 'Prudent'. The Modern dietary pattern (high intakes of roasted/smoked foods, instant foods, canned foods, fermented fruits/vegetables, fermented foods, soft drinks, deep-fried foods) was associated with increased incident hypertension (comparing extreme quartiles, OR for incident hypertension=1·51; 95 % CI 1·31, 1·75 in 2013). The Prudent dietary pattern (high intakes of soyabean products, milk, fruits, vegetables) was not associated with incident hypertension in a fully adjusted model. The association between the Modern dietary pattern and hypertension was attenuated by BMI. CONCLUSIONS: Modern dietary pattern was positively associated with hypertension among Thai adults. BMI had a great impact on the relationship between the Modern dietary pattern and incidence of hypertension. Reduction of Modern diets would be expected to prevent and control hypertension. Such a strategy would be worth testing.

Relationship between 8-year weight change, body size, and health in a large cohort of adults in Thailand.

BACKGROUND: Overweight and obesity have been shown to be risk factors for a range of non-communicable diseases, especially cardio-metabolic conditions, worldwide. But less is known about the effects of weight change on adults' overall health and wellbeing, particularly in transitional low- and middle-income countries. This study aimed to assess the relationship between 8-year weight change and measures of self-assessed health among Thai adults. METHODS: Data were collected from Thai adults aged 25-40 years (n = 27,003) enrolled in the Thai cohort Study and surveyed in 2005, 2009, and 2013. We used self-reported weight and height measurements at baseline and 2013, as well as three standard health questions regarding overall health, energy, and emotion asked at the two time points, to investigate the effects of weight change on health. RESULTS: Between 2005 and 2013, 6.0% of participants lost more than 5% of their baseline weight; 38.5% were stable (<5% loss to 5% gain); 23.0% slightly gained weight (>5%-10%); 22.8% gained moderate weight (>10%-20%); and 9.4% had heavy weight gain (>20%). Moderate (>10%-20%) and heavy weight gain (>20%) were both associated with an increased risk of reporting 'poor or very poor' overall health in 2013 among participants who had a normal body mass index (BMI) (adjusted odds ratio [AOR] 1.39; 95% confidence interval [CI], 1.13-1.71 and AOR 1.44; 95% CI, 1.09-1.90, respectively), were overweight (AOR 1.53; 955 CI, 1.01-2.29 and AOR 1.82; 95% CI, 1.04-3.19, respectively) or had obesity (AOR 2.47; 95% CI, 1.74-3.51 and AOR 3.20; 95% CI, 2.00-5.16, respectively) in 2005. Weight gain of over 20% also had a negative impact on energy level among cohort members with a normal BMI in 2005 (AOR 1.36; 95% CI, 1.11-1.65) and among participants with obesity in 2005 (AOR 1.93; 95% CI, 1.38-2.71). For those who were underweight, had a normal BMI, or had obesity at baseline, weight loss of more than 5% was associated with reporting emotional problems. Excessive weight gain adversely impacted participants who were underweight or had obesity at baseline. CONCLUSION: Our study found that weight change, in particular weight gain, was associated with negative health outcomes, and this effect appeared to increase at higher levels of body size. The present findings may be useful to promote weight maintenance and healthy lifestyles.

Low back pain and limitations of daily living in Asia: longitudinal findings in the Thai cohort study.

BACKGROUND: Low back pain (LBP) is a major cause of disability throughout the world. However, longitudinal evidence to relate low back pain and functional limitations is mostly confined to Western countries. In this study, we investigate the associations between low back pain and functional limitations in a prospective cohort of Thai adults. METHODS: We analysed information from the Thai Cohort Study of adult Open University adults which included 42,785 participants in both 2009 and 2013, with the majority aged 30 to 65 years and residing nationwide. We used multivariate logistic regression to explore the longitudinal associations between LBP in 2009 and 2013 ('never': no LBP in 2009 or 2013; 'reverting': LBP in 2009 but not in 2013; 'incident': no LBP in 2009 but LBP in 2013; and 'chronic': reporting LBP at both time points) and the outcome of functional limitations relating to Activities of Daily Living (ADL) in 2013. RESULTS: Low back pain was common with 30% of cohort members reporting low back pain in both 2009 and 2013 ('chronic LBP'). The 'chronic LBP' group was more likely than the 'never' back pain group to report functional limitations in 2013: adjusted odds ratios 1.60 [95% Confidence Interval: 1.38-1.85] for difficulties getting dressed; 1.98 [1.71-2.30] for walking; 2.02 [1.71-2.39] for climbing stairs; and 3.80 [3.38-4.27] for bending/kneeling. Those with 'incident LBP' or 'reverting LBP' both had increased odds of functional limitations in 2013 but the odds were not generally as high. CONCLUSIONS: Our nationwide data from Thailand suggests that LBP is a frequent public health problem among economically productive age groups with adverse effects on the activities of daily living. This study adds to the limited longitudinal evidence on the substantial impact of low back pain in Southeast Asia.

Psychosocial job characteristics, wealth, and culture: differential effects on mental health in the UK and Thailand.

BACKGROUND: Most research on the influence of psychosocial job characteristics on health status has been conducted within affluent Western economies. This research addresses the same topic in a middle-income Southeast Asian country, enabling comparison with a Western benchmark. METHODS: We analysed and compared the Health Survey for England conducted in 2010 and the Thai Cohort Study data at 2005 baseline for workers aged 35-45 years. Multivariate logistic regression was used to assess relationships between psychosocial job characteristics and health, measured as Adjusted Odd Ratios (AOR), controlling for potential covariates in final analyses. RESULTS: In both UK and Thai working adults, psychological distress was associated with job insecurity (AOR 2.58 and 2.32, respectively), inadequate coping with job demands (AOR 2.57 and 2.42), and low support by employers (AOR 1.93 and 1.84). Job autonomy was associated with psychological distress in the UK samples (AOR 2.61) but no relationship was found among Thais after adjusting for covariates (AOR 0.99). Low job security, inability to cope with job demands, and low employer support were associated with psychological distress both among Thai and UK workers. CONCLUSIONS: Job autonomy was an important part of a healthy work environment in Western cultures, but not in Thailand. This finding could reflect cultural differences with Thais less troubled by individualistic expression at work. Our study also highlights the implications for relevant workplace laws and regulations to minimise the adverse job effects. These public health strategies would promote mental health and wellbeing in the population.

Physically and psychologically hazardous jobs and mental health in Thailand.

This paper investigates associations between hazardous jobs, mental health and wellbeing among Thai adults. In 2005, 87 134 distance-learning students from Sukhothai Thammathirat Open University completed a self-administered questionnaire; at the 2009 follow-up 60 569 again participated. Job characteristics were reported in 2005, psychological distress and life satisfaction were reported in both 2005 and 2009. We derived two composite variables grading psychologically and physically hazardous jobs and reported adjusted odds ratios (AOR) from multivariate logistic regressions. Analyses focused on cohort members in paid work: the total was 62 332 at 2005 baseline and 41 671 at 2009 follow-up. Cross-sectional AORs linking psychologically hazardous jobs to psychological distress ranged from 1.52 (one hazard) to 4.48 (four hazards) for males and a corresponding 1.34-3.76 for females. Similarly AORs for physically hazardous jobs were 1.75 (one hazard) to 2.76 (four or more hazards) for males and 1.70-3.19 for females. A similar magnitude of associations was found between psychologically adverse jobs and low life satisfaction (AORs of 1.34-4.34 among males and 1.18-3.63 among females). Longitudinal analyses confirm these cross-sectional relationships. Thus, significant dose-response associations were found linking hazardous job exposures in 2005 to mental health and wellbeing in 2009. The health impacts of psychologically and physically hazardous jobs in developed, Western countries are equally evident in transitioning Southeast Asian countries such as Thailand. Regulation and monitoring of work conditions will become increasingly important to the health and wellbeing of the Thai workforce.

The associations between unhealthy behaviours, mental stress, and low socio-economic status in an international comparison of representative samples from Thailand and England.

BACKGROUND: Socioeconomic status is a recognised determinant of health status, and the association may be mediated by unhealthy behaviours and psychosocial adversities, which, in developed countries, both aggregate in low socioeconomic sectors of the population. We explored the hypothesis that unhealthy behavioural choices and psychological distress do not both aggregate in low socioeconomic status groups in developing countries. METHODS: Our study is based on a cross-sectional comparison between national population samples of adults in England and Thailand. Psychological distress was assessed using the General Health Questionnaire (GHQ-12) or three anxiety-oriented items from the Kessler scale (K6). Socioeconomic status was assessed on the basis of occupational status. We computed a health-behaviour score using information about smoking, alcohol consumption, fruit and vegetable consumption, and physical activity. RESULTS: The final sample comprised 40,679 participants. In both countries and in both genders separately, there was a positive association between poor health-behaviour and high psychological distress, and between high psychological distress and low socioeconomic status. In contrast, the association between low socioeconomic status and poor health-behaviour was positive in both English men and women, flat in Thai men, and was negative in Thai women (likelihood ratio test P <0.001). CONCLUSION: The associations between socioeconomic status, behavioural choices, and psychological distress are different at the international level. Psychological distress may be consistently associated with low socioeconomic status, whereas poor health-behaviour is not. Future analyses will test whether psychological distress is a more consistent determinant of socioeconomic differences in health across countries.

Longitudinal associations between oral health impacts and quality of life among a national cohort of Thai adults.

BACKGROUND: There is limited evidence on the association between oral health and general health in middle-income countries. This study analysed data from 60,569 adult students enrolled at Sukhothai Thammathirat Open University and residing throughout Thailand who reported oral health impacts at the 2005 baseline and 2009 health status based on Short Form (SF-8) survey. FINDINGS: In 2005, 16.4% had difficulty chewing and/or swallowing, 13.4% reported difficulty speaking and/or discomfort with social interaction, and 10.8% of the cohort reported having pain associated with teeth or dentures. Cohort members reporting one or more oral health impacts in 2005 had lower SF-8 mean scores in 2009. In particular, monotonic dose-response gradients in 2005-2009 associations based on multivariate linear regression were found between an increase in number of oral impacts (0, 1, 2, 3) and a decline in SF-8 Physical Component Summary scores (adjusted means of 50.5, 49.2, 48.6, 47.9) as well as SF-8 Mental Component Summary scores (adjusted means of 43.2, 40.9, 40.3, 38.6) in younger cohort members. Similar dose response gradients were found in older cohort members. CONCLUSIONS: We found strong association between oral health impacts and adverse health and quality of life among Thai adults. This finding confirms that oral health is one of the key determinants of population health.

Physical and mental health among caregivers: findings from a cross-sectional study of Open University students in Thailand.

BACKGROUND: Caregivers constitute an important informal workforce, often undervalued, facing challenges to maintain their caring role, health and wellbeing. Little is known about caregivers in middle-income countries like Thailand. This study investigates the physical and mental health of Thai adult caregivers. METHODS: This report derives from distance-learning students working and residing throughout Thailand and recruited for a health-risk transition study in 2005 (N=87,134) from Sukhothai Thammathirat Open University. The cohort follow-up questionnaire in 2009 (N = 60,569) includes questions on caregiver status which were not available in 2005; accordingly, this study is confined to analysis of the 2009 data. We report cross-sectional associations between caregiver status and health. RESULTS: Among the study participants in 2009, 27.5% reported being part-time caregivers and 6.6% reported being full-time caregivers. Compared to male non-caregivers, being a part-time or full-time male caregiver was associated with lower back pain (covariate-Adjusted Odds Ratios, AOR 1.36 and 1.67), with poor psychological health (AOR 1.16 and 1.68), but not with poor self-assessed health. Compared to female non-caregivers, being a part- or full-time female caregiver was associated with lower back pain (AOR 1.47 and 1.84), psychological distress (AOR 1.32 and 1.52), and poor self-assessed health (AOR 1.21 and 1.34). CONCLUSIONS: Adult caregivers in Thailand experienced a consistent adverse physical and mental health burden. A dose-response effect was evident, with odds ratios higher for full-time caregivers than for part-time, and non-caregivers. Our findings should raise awareness of caregivers, their unmet needs, and support required in Thailand and other similar middle-income countries.

Happiness, Mental Health, and Socio-Demographic Associations Among a National Cohort of Thai Adults.

Research on happiness has been of interest in many parts of the world. Here we provide evidence from developing countries; this is the first analysis of happiness among a cohort of Thai distance learning adults residing throughout the country (n = 60,569 in 2009). To measure happiness, we tested use of the short format Thai Mental Health Indicators (TMHI), correlating each domain with two direct measures of happiness and life satisfaction. Several TMHI domains correlated strongly with happiness. We found the mental state and the social support domains moderately or strongly correlated with happiness by either measure (correlation coefficients 0.24-0.56). The other two TMHI domains (mental capacity and mental quality) were not correlated with happiness. Analysis of socio-demographic attributes and happiness revealed little effect of age and sex but marital status (divorced or widowed), low household income, and no paid work all had strong adverse effects. Our findings provide Thai benchmarks for measuring happiness and associated socio-demographic attributes. We also provide evidence that the TMHI can measure happiness in the Thai population. Furthermore, the results among Thai cohort members can be monitored over time and could be useful for comparison with other Southeast Asian countries.

Health, well-being, and social indicators among monks, prisoners, and other adult members of an Open University Cohort in Thailand.

This study has brought together two seemingly socially extreme population subgroups to compare their health and social well-being. These groups had in common restricted living arrangements and aspirational enrollment. As well, they are part of the population-based Thai Cohort Study (TCS) of 87,134 adult Open University students residing throughout the country. Analysis was restricted to men aged 20-39 years resulting in 711 monks, 195 prisoners and 29,713 other cohort members. For physical health, we have found certain conditions such as tuberculosis or malaria much more common among prisoners, while goiter and liver diseases were more common among monks. This could be due to prison living arrangements for the former and region of residence for the latter. For other social outcomes, lower trust, higher economic stress and lower personal well-being was noted for prisoners compared to other groups. Findings here with regard to spirituality and religion are encouraging with almost no difference reported between prisoners and other cohort members implying that trust-building and other social intervention for prisoners could be activated through prevalent religious beliefs and practices and with continuing support from Thai prison authorities.

Oral Health-Related Quality of Life among a large national cohort of 87,134 Thai adults.

BACKGROUND: Oral health has been of interest in many low and middle income countries due to its impact on general health and quality of life. But there are very few population-based reports of adult Oral Health Related Quality of Life (OHRQoL) in developing countries. To address this knowledge gap for Thailand, we report oral health findings from a national cohort of 87,134 Thai adults aged between 15 and 87 years and residing all over the country. METHODS: In 2005, a comprehensive health questionnaire was returned by distance learning cohort members recruited through Sukhothai Thammathirat Open University. OHRQoL dimensions included were discomfort speaking, swallowing, chewing, social interaction and pain. We calculated multivariate (adjusted) associations between OHRQoL outcomes, and sociodemographic, health behaviour and dental status. RESULTS: Overall, discomfort chewing (15.8%), social interaction (12.5%), and pain (10.6%) were the most commonly reported problems. Females were worse off for chewing, social interaction and pain. Smokers had worse OHRQoL in all dimensions with Odds Ratios (OR) ranging from 1.32 to 1.51. Having less than 20 teeth was strongly associated with difficulty speaking (OR = 6.43), difficulty swallowing (OR = 6.27), and difficulty chewing (OR = 3.26). CONCLUSIONS: Self-reported adverse oral health correlates with individual function and quality of life. Outcomes are generally worse among females, the poor, smokers, drinkers and those who have less than 20 teeth. Further longitudinal study of the cohort analysed here will permit assessment of causal determinants of poor oral health and the efficacy of preventive programs in Thailand.

Factors associated with self-reported number of teeth in a large national cohort of Thai adults.

BACKGROUND: Oral health in later life results from individual's lifelong accumulation of experiences at the personal, community and societal levels. There is little information relating the oral health outcomes to risk factors in Asian middle-income settings such as Thailand today. METHODS: Data derived from a cohort of 87,134 adults enrolled in Sukhothai Thammathirat Open University who completed self-administered questionnaires in 2005. Cohort members are aged between 15 and 87 years and resided throughout Thailand. This is a large study of self-reported number of teeth among Thai adults. Bivariate and multivariate logistic regressions were used to analyse factors associated with self-reported number of teeth. RESULTS: After adjusting for covariates, being female (OR = 1.28), older age (OR = 10.6), having low income (OR = 1.45), having lower education (OR = 1.33), and being a lifetime urban resident (OR = 1.37) were statistically associated (p < 0.0001) with having less than 20 teeth. In addition, daily soft drink consumptions (OR = 1.41), current regular smoking (OR = 1.39), a history of not being breastfed as a child (OR = 1.34), and mother's lack of education (OR = 1.20) contributed significantly to self-reported number of teeth in fully adjusted analyses. CONCLUSIONS: This study addresses the gap in knowledge on factors associated with self-reported number of teeth. The promotion of healthy childhoods and adult lifestyles are important public health interventions to increase tooth retention in middle and older age.

Early diagnosis of kala-azar in Bangladesh: Findings from a population based mixed methods research informing the post-elimination era.

BACKGROUND: Global annual reports of visceral leishmaniasis or kala-azar ("black fever") reduced from 200,000 cases in 2012 to 23,804 in 2015. India, Bangladesh and Nepal reported 80% of the global cases in 2012, but 39% in 2015. We sought to identify major amenable barriers to early diagnosis of kala-azar in peripheral areas of Mymensingh district, an area of Bangladesh that was highly endemic for kala-azar. METHODS: We conducted sequential exploratory mixed methods research. Qualitative data were first derived from in-depth interviews and focus group discussions among 29 patients diagnosed with kala-azar, their families, and neighbours. Preliminary results from qualitative analysis were used to design a structured questionnaire, which was administered to collect data on the processes leading to the diagnosis of kala-azar from 102 patients. Qualitative and quantitative data were integrated consistent with the chronology for kala-azar patients seeking care. The study was conducted from September 2011 to May 2012 in Fulbaria and Gaffargaon sub-districts of Mymensingh. RESULTS: The median delay from fever onset to confirmatory diagnosis of kala-azar was 60 days, with 38% of the cases diagnosed within 30 days. Public health facilities and Gaffargaon sub-district achieved high proportions of early diagnosis. Individual barriers to early diagnosis were low awareness of symptoms and treatment facilities, poverty, and traditional beliefs. Other factors were the remoteness of health care centres, wet season transport difficulty, mis-diagnosis as typhoid, limited availability of rK-39 testing at the community level, and the inclusion of splenomegaly in the case definition. CONCLUSIONS: Targeted community awareness campaigns appropriate for underprivileged communities will increase care seeking and consequently diagnosis. Improved diagnostic guidelines and a strong referral chain for kala-azar will accelerate diagnosis. These steps will contribute significantly to the National Kala-azar Elimination Program of Bangladesh, especially during the post-elimination era.

Socioeconomic status, sex, and obesity in a large national cohort of 15-87-year-old open university students in Thailand.

BACKGROUND: As obesity increases, middle-income countries are undergoing a health-risk transition. We examine the association between socioeconomic status (SES) and emerging obesity in Thailand, and ascertain if an inverse relationship between SES and obesity has appeared. METHODS: The data derived from 87 134 individuals (54% female; median age, 29 years) in a national cohort of distance-learning Open University students aged 15-87 years and living throughout Thailand. We calculated adjusted odds ratios for associations of SES with obesity (body mass index, >or=25) across 3 age groups by sex, after controlling for marital status, age, and urbanization. RESULTS: Obesity increased with age and was more prevalent among males than females (22.7% vs 9.9%); more females were underweight (21.8% vs 6.2%). Annual income was 2000 to 3000 US dollars for most participants. High SES, defined by education, income, household assets, and housing type, associated strongly with obesity-positively for males and inversely for females-especially for participants younger than 40 years. The OR for obesity associated with income was as high as 1.54 for males and as low as 0.68 for females (P for trend <0.001). CONCLUSIONS: Our national Thai cohort has passed a tipping point and assumed a pattern seen in developed countries, ie, an inverse association between SES and obesity in females. We expect the overall population of Thailand to follow this pattern, as education spreads and incomes rise. A public health problem of underweight females could emerge. Recognition of these patterns is important for programs combating obesity. Many middle income countries are undergoing similar transitions.

Prescribing behaviour of village doctors under China's New Cooperative Medical Scheme.

In 2003, China introduced a new community-based rural health insurance called the New Cooperative Medical Scheme (NCMS). In 2005, to assess the NCMS effects on village doctors' prescribing behaviour, we compared an NCMS county and a non-NCMS county in Shandong Province. We collected information from a representative total of 2271 patient visits in 30 village health stations (15 per county). The average number of drugs prescribed (4.6 in the NCMS county vs. 3.1 in the non-NCMS county) and use of antibiotics (72.4% vs. 59.3%) and injections (65.1% vs. 56.3%) were high in both counties, and higher in the NCMS county. Within NCMS villages, prescribing for insured vs. uninsured patients showed a similar pattern with more drugs, antibiotics and injections for those insured. Overall, for NCMS patients, the prescription excess was about equal in value to their 20% fee discount. We conclude that over-prescribing is common in villages and worse with NCMS health insurance, raising concerns for health service quality and drug-use safety. We propose that the NCMS should be redesigned with incentives for service quality improvement. A stricter regulatory environment for doctors' prescriptions is needed in rural China to counter irrational drug use.

Change in mean height of Thai military recruits from 1972 through 2006.

BACKGROUND: Records in Western countries reveal that adult height has been increasing over the last 250 years. These height gains have been biologically associated with healthier childhoods, less illness, and longer life spans-a health-risk transition. To measure such progress in Thailand we studied height change over the last 3 decades. METHODS: We analyzed height records for 33 000 21-year-old male military recruits, sampling 1000 per year from 1972 through 2006. We compared the height trend in Thailand to those noted in Europe, and discuss the former in the context of improvements in living circumstances in Thailand. RESULTS: Over 35 years, mean height increased from 164.4 to 169.2 cm, an increment of nearly 5 cm. The height increase was negligible in the first decade (1972-1981), but substantially accelerated after that. In the period after 1990 the increase exceeded 3 cm. A similar overall height gain in Britain occurred over a much longer period (1750-1886). CONCLUSIONS: The increase in height among Thai men is biological evidence that a Thai health-risk transition-defined by both changing risks and outcomes-is well underway for height. Military recruits born during the 1960s through the 1980s had progressively healthier childhoods. Over this period child nutrition improved, infection and mortality rates declined, and preventive health services expanded. The combined effect of these factors is indicated by the increased adult height of Thai military recruits.

Used and foregone health services among a cohort of 87,134 adult open university students residing throughout Thailand.

There are limited data on the frequency of foregone health service use in defined populations. Here we describe Thai patterns of health service use, types of health insurance used and reports of foregone health services according to geo-demographic and socioeconomic characteristics. Data on those who considered they had needed but not received health care over the previous year were obtained from a national cohort of 87,134 students from the Sukhothai Thammathirat Open University (STOU). The cohort was enrolled in 2005 and was largely made up of young and middle-age adults living throughout Thailand. Among respondents, 21.0% reported use of health services during the past year. Provincial/governmental hospitals (33.4%) were the most attended health facilities in general, followed by private clinics (24.1%) and private hospitals (20.1%). Health centers and community hospitals were sought after in rural areas. The recently available government operated Universal Coverage Scheme (UCS) was popular among the lower income groups (13.6%), especially in rural areas. When asked, 42.1% reported having foregone health service use in the past year. Professionals and office workers frequently reported 'long waiting time' (17.1%) and 'could not get time off work' (13.7%) as reasons, whereas manual workers frequently noted it was 'difficult to travel' (11.6%). This information points to non-financial opportunity cost barriers common to a wide array of Thai adults who need to use health services. This issue is relevant for health and workplace policymakers and managers concerned about equitable access to health services.

Measuring and decomposing inequity in self-reported morbidity and self-assessed health in Thailand.

BACKGROUND: In recent years, interest in the study of inequalities in health has not stopped at quantifying their magnitude; explaining the sources of inequalities has also become of great importance. This paper measures socioeconomic inequalities in self-reported morbidity and self-assessed health in Thailand, and the contributions of different population subgroups to those inequalities. METHODS: The Health and Welfare Survey 2003 conducted by the Thai National Statistical Office with 37,202 adult respondents is used for the analysis. The health outcomes of interest derive from three self-reported morbidity and two self-assessed health questions. Socioeconomic status is measured by adult-equivalent monthly income per household member. The concentration index (CI) of ill health is used as a measure of socioeconomic health inequalities, and is subsequently decomposed into contributing factors. RESULTS: The CIs reveal inequality gradients disadvantageous to the poor for both self-reported morbidity and self-assessed health in Thailand. The magnitudes of these inequalities were higher for the self-assessed health outcomes than for the self-reported morbidity outcomes. Age and sex played significant roles in accounting for the inequality in reported chronic illness (33.7 percent of the total inequality observed), hospital admission (27.8 percent), and self-assessed deterioration of health compared to a year ago (31.9 percent). The effect of being female and aged 60 years or older was by far the strongest demographic determinant of inequality across all five types of health outcome. Having a low socioeconomic status as measured by income quintile, education and work status were the main contributors disadvantaging the poor in self-rated health compared to a year ago (47.1 percent) and self-assessed health compared to peers (47.4 percent). Residence in the rural Northeast and rural North were the main regional contributors to inequality in self-reported recent and chronic illness, while residence in the rural Northeast was the major contributor to the tendency of the poor to report lower levels of self-assessed health compared to peers. CONCLUSION: The findings confirm that substantial socioeconomic inequalities in health as measured by self-reported morbidity and self-assessed health exist in Thailand. Decomposition analysis shows that inequalities in health status are associated with particular demographic, socioeconomic and geographic population subgroups. Vulnerable subgroups which are prone to both ill health and relative poverty warrant targeted policy attention.