Chitr Sitthi-Amorn

Association of psychosocial risk factors with risk of acute myocardial infarction in 11 119 cases and 13 648 controls from 52 countries (the INTERHEART study): case-control study

BACKGROUND Psychosocial factors have been reported to be independently associated with coronary heart disease. However, previous studies have been in mainly North American or European populations. The aim of the present analysis was to investigate the relation of psychosocial factors to risk of myocardial infarction in 24767 people from 52 countries. METHODS We used a case-control design with 11119 patients with a first myocardial infarction and 13648 age-matched (up to 5 years older or younger) and sex-matched controls from 262 centres in Asia, Europe, the Middle East, Africa, Australia, and North and South America. Data for demographic factors, education, income, and cardiovascular risk factors were obtained by standardised approaches. Psychosocial stress was assessed by four simple questions about stress at work and at home, financial stress, and major life events in the past year. Additional questions assessed locus of control and presence of depression. FINDINGS People with myocardial infarction (cases) reported higher prevalence of all four stress factors (p<0.0001). Of those cases still working, 23.0% (n=1249) experienced several periods of work stress compared with 17.9% (1324) of controls, and 10.0% (540) experienced permanent work stress during the previous year versus 5.0% (372) of controls. Odds ratios were 1.38 (99% CI 1.19-1.61) for several periods of work stress and 2.14 (1.73-2.64) for permanent stress at work, adjusted for age, sex, geographic region, and smoking. 11.6% (1288) of cases had several periods of stress at home compared with 8.6% (1179) of controls (odds ratio 1.52 [99% CI 1.34-1.72]), and 3.5% (384) of cases reported permanent stress at home versus 1.9% (253) of controls (2.12 [1.68-2.65]). General stress (work, home, or both) was associated with an odds ratio of 1.45 (99% CI 1.30-1.61) for several periods and 2.17 (1.84-2.55) for permanent stress. Severe financial stress was more typical in cases than controls (14.6% [1622] vs 12.2% [1659]; odds ratio 1.33 [99% CI 1.19-1.48]). Stressful life events in the past year were also more frequent in cases than controls (16.1% [1790] vs 13.0% [1771]; 1.48 [1.33-1.64]), as was depression (24.0% [2673] vs 17.6% [2404]; odds ratio 1.55 [1.42-1.69]). These differences were consistent across regions, in different ethnic groups, and in men and women. INTERPRETATION Presence of psychosocial stressors is associated with increased risk of acute myocardial infarction, suggesting that approaches aimed at modifying these factors should be developed.

Lipid Profile, Plasma Apolipoproteins, and Risk of a First Myocardial Infarction Among Asians : An Analysis From the INTERHEART Study

OBJECTIVES This study sought to determine the prevalence of lipid and lipoprotein abnormalities and their association with the risk of a first acute myocardial infarction (AMI) among Asians. BACKGROUND Patterns of lipid abnormalities among Asians and their relative impact on cardiovascular risk have not been well characterized. METHODS In a case-control study, 65 centers in Asia recruited 5,731 cases of a first AMI and 6,459 control subjects. Plasma levels of lipids and apolipoproteins in the different Asian subgroups (South Asians, Chinese, Southeast Asians, and Japanese) were determined and correlated with the risk of AMI. RESULTS Among both cases and controls, mean low-density lipoprotein cholesterol (LDL-C) levels were about 10 mg/dl lower in Asians compared with non-Asians. A greater proportion of Asian cases and controls had LDL-C </=100 mg/dl (25.5% and 32.3% in Asians vs. 19.4% and 25.3% in non-Asians, respectively). High-density lipoprotein cholesterol (HDL-C) levels were slightly lower among Asians compared with non-Asians. There was a preponderance of people with low HDL-C among South Asians (South Asia vs. rest of Asia: cases 82.3% vs. 57.4%; controls 81% vs. 51.6%; p < 0.0001 for both comparisons). However, despite these differences in absolute levels, the risk of AMI associated with increases in LDL-C and decreases in HDL-C was similar for Asians and non-Asians. Among South Asians, changes in apolipoprotein (Apo)A1 predicted risk better than HDL-C. ApoB/ApoA1 showed the strongest association with the risk of AMI. CONCLUSIONS The preserved association of LDL-C with risk of AMI among Asians, despite the lower baseline levels, suggests the need to rethink treatment thresholds and targets in this population. The low HDL-C level among South Asians requires further study and targeted intervention.

Genetic diversity and population structure of Plasmodium falciparum in Thailand, a low transmission country

BackgroundThe population structure of the causative agents of human malaria, Plasmodium sp., including the most serious agent Plasmodium falciparum, depends on the local epidemiological and demographic situations, such as the incidence of infected people, the vector transmission intensity and migration of inhabitants (i.e. exchange between sites). Analysing the structure of P. falciparum populations at a large scale, such as continents, or with markers that are subject to non-neutral selection, can lead to a masking and misunderstanding of the effective process of transmission. Thus, knowledge of the genetic structure and organization of P. falciparum populations in a particular area with neutral genetic markers is needed to understand which epidemiological factors should be targeted for disease control. Limited reports are available on the population genetic diversity and structure of P. falciparum in Thailand, and this is of particular concern at the Thai-Myanmar and Thai-Cambodian borders, where there is a reported high resistance to anti-malarial drugs, for example mefloquine, with little understanding of its potential gene flow.MethodsThe diversity and genetic differentiation of P. falciparum populations were analysed using 12 polymorphic apparently neutral microsatellite loci distributed on eight of the 14 different chromosomes. Samples were collected from seven provinces in the western, eastern and southern parts of Thailand.ResultsA strong difference in the nuclear genetic structure was observed between most of the assayed populations. The genetic diversity was comparable to the intermediate level observed in low P. falciparum transmission areas (average HS = 0.65 ± 0.17), where the lowest is observed in South America and the highest in Africa. However, uniquely the Yala province, had only a single multilocus genotype present in all samples, leading to a strong geographic differentiation when compared to the other Thai populations during this study. Comparison of the genetic structure of P. falciparum populations in Thailand with those in the French Guyana, Congo and Cameroon revealed a significant genetic differentiation between all of them, except the two African countries, whilst the genetic variability of P. falciparum amongst countries showed overlapping distributions.ConclusionPlasmodium falciparum shows genetically structured populations across local areas of Thailand. Although Thailand is considered to be a low transmission area, a relatively high level of genetic diversity and no linkage disequilibrium was found in five of the studied areas, the exception being the Yala province (Southern peninsular Thailand), where a clonal population structure was revealed and in Kanchanaburi province (Western Thailand). This finding is particularly relevant in the context of malaria control, because it could help in understanding the special dynamics of parasite populations in areas with different histories of, and exposure to, drug regimens.

The prevalence of obesity, risk factors and associated diseases in Klong Toey slum and Klong Toey government apartment houses

The epidemiological study in low socioeconomic area of Bangkok, Klong Toey slum residents (n = 976) and apartment house residents (n = 906) of both sexes revealed the prevalence rates of overweight of 25.5% and 30.5%, obesity 10% and 11.1%; hypertension 17.3%; and 14%; diabetes 4.5% and 5.9%; IGT 6.1% and 4.4%; total abnormal GTT 10.6% and 10.3%; hypercholesterolemia 14.1% and 12%; hypertriglyceridemia 24.8% and 22.7%; low HDL-C 3.1% and 1.8%; hyperuricemia 7.7% and 10.4% respectively. The prevalence rates of the related diseases and conditions were increased when BMI was over 25 in both populations except for those with abnormal GTT and hyperuricemia in the slum residents. Concerning risk factors, discriminant analysis disclosed diastolic blood pressure (DBP) and atherogenic index as the first two factors significantly associated with overweight and obesity (BMI greater than 25) in both populations. Restructuring of the health service delivery system and care-taker re-educating together with production of meaningful mass communication media are needed for promotion of health care, prevention of these non-communicable diseases and their sequelae by non-pharmacological approach.

The Role of Media and Communication in Improving the Use of Drugs and Other Technologies

Policy makers, health care providers, and the general public need valid information about the benefits and harmful effects of drugs and technologies to be able to make rational choices in their acquisition, distribution, and use. Effective communication is important for quality choices of drugs and other technologies. In effective communication, the choice of messages and media must correspond to the culture and beliefs of the target groups to make them comprehend and adopt the conclusions. Messages must be presented on a regular basis. Most regulatory agencies do not have enough resources to mount effective communication programs. Private advertising agencies and other stakeholders have definite roles. Valid knowledge must be the basis of dialogues to reduce emotional disputes among various benefit groups in society.

Effectiveness of advance directives for the care of terminally ill patients in Chiang Mai University Hospital, Thailand

The key hypothesis behind advance directives (ADs) proposes that, if an intervention enhances a persons right to choose, a dying person will not opt for expensive, life-prolonging medical care and an ethically acceptable saving of resources will result. In order to assess the acceptability and effectiveness of ADs in reducing cardiopulmonary resuscitation (CPR) attempts and in-hospital death among terminally ill patients in a tertiary care hospital in northern Thailand, a non-randomized, controlled intervention study using an after-only unequivalent control group design was conducted. The majority of the subjects and the surrogates preferred to employ ADs in expressing their preferences on CPR and there was a high level of agreement between the subjects and surrogates on the decision. The use of ADs appeared to be effective in reducing futile CPR attempts and the in-hospital mortality rate among subjects during the index hospitalization. Advance directives were accepted well in this study setting.

Technology assessment. Old, new, and needs-based.

Recent health reports, including the 1993 World Development Report, have emphasized the importance of integrating the needs of the population into technology assessment. This paper reviews previous approaches to technology assessment and identifies the missing link between technology and its impact on the physical, emotional, and social needs of the community, namely needs-based technology assessment. It stresses the key role played by issues of equity and community values in making technology decisions. A number of models for needs-based technology assessment are described.

Globalization and health viewed from three parts of the world

In recent years Thailand’s economy has becomeincreasingly dependent on international forces (1).Withthisexposurehavecomeadvancesinhealthcaretechnologyand improvements in living standards,aswell as increasing disparities between social groups(2) and exposure to health risks from other parts ofthe world (3, 4).Prior to 1997, when the economy was strong,there was intense competition for a share of thehealth market. Resources were invested in specu-lative markets with potential for large expansion.Private hospital beds increased from 8066 in 1982to 21 297 in 1992 and 34 973 in 1996. The numberof specialized doctors in private hospitals increased,leading to shortages in the public sector (5). Thecultureoffreeenterprisebroughtwithitanenlarged middle class, insurance coverage forhospitalization, tax incentives for private healthcare, heavy investment in advanced health technol-ogy for private sector use, and an internal ‘‘braindrain’’, at the expense of public health (5, 6).Aggressive promotion increased the demand forexpensive imported medicines and procedures (7,8). The cost of medical care for civil servants andstate employees has quadrupled in the last sevenyears, reflecting the lack of adequate governance inthe health care business sector (5, 9). Meanwhilethe share of the underprivileged in the country’soverall wealth was decreasing (4). The slump of1997, followed by devaluation of the baht, andrecession with its concomitant negative healthimpact, reflects the country’s overdependence oncheap labour and foreign investment, and conse-quent inability to control and protect its owneconomy.Direct health effectsPerhapsthemostimportant directeffectofglobaliza-tiononhealthinThailandisunequalaccesstomedicalcare by different social groups. The rise in importedsophisticated technologies has increased costs andnecessitated new training. An analysis made in 1996found that the average cost of medical care peradmission was 1558 bahts for health cardholders(rural) and 9981 bahts for civil servants (privileged), asixfold difference (10). If these facilities were treatingsimilar diseases, explanations are needed for the hugevariation. The economic gap might create demandunrelatedtoneedanddistortmarketcompetition.Theorganization of health service delivery was obscure,and there were no rules governing the payment ofproviders. Unequal access to care was reflected byunequal health status (2). Infant mortality in thepoorestregionswastwiceashighasintherichestones.Second, there are increasing problems ofenvironmental pollution. These include inadequatetreatmentofrawsewage(forinstance,intouristareas),and the notorious air pollution in Bangkok and otherbig cities(11).Environmentaldegradation anddisrup-tion of the ecosystem have led to frequent floods andchangesindisease vectorbehaviour.Theconstructionof a dam in the North-eastern region, financed by aloan from a development bank, has caused naturaldisasters affecting food production (12).Third, concerns about new infections and theresurgence of old ones have been on the rise.Internationaltradeandtravelareshapingthepatternsof epidemics. The plague scare in India had world-wide reverberations. The nipah virus outbreak inMalaysia caused concerns in Thailand (13). Choleraepidemics can inflict enormous costs on a countryandthisresultsinattemptstohidethembycallingthedisease‘‘severediarrhoea’’.Thecostsassociatedwithcontrolling HIV infection continue to rise. Fears offoot and mouth disease have affected meat con-sumption. The control of new dangers of this kindwill require global cooperation but many aspects ofcontrol have to be country-specific.Fourth, globalization has brought with itunhealthy lifestyles. Health has been damaged bythepromotionoffashionabledrugs,foodsandotherconsumer products such as tobacco, alcohol,melatonin and Viagra. Fifth and finally, globalizationbringswithitmanyconcernsabouthealthethics.Forinstance, the options for genetic manipulation andthepatentingofthetechnologieswillhavedirectandfar-reaching effects on health and social well-being.

Health Transition and Needs-Based Technology Planning and Implementation

Investment in health can offer additional benefits to development independent of economic improvement. Many technologies have been useful in improving the health of the people in the past. However, rapid and often unpredictable change has contributed to the inequity, inefficiency, and rising cost of health care. This paper outlines why a needs-based approach to assessing any new technology in the health sector is essential. To respond to changing needs, capacities within the health care system, several of which are described here, must be strengthened. Needs-based technology planning and implementation is affordable and feasible and is crucial in order that both health as a basic human right and good health at low cost can be attained.