Yawarat Porapakkham

Cause-of-death ascertainment for deaths that occur outside hospitals in Thailand: Application of verbal autopsy methods

BackgroundAscertainment of cause for deaths that occur in the absence of medical attention is a significant problem in many countries, including Thailand, where more than 50% of such deaths are registered with ill-defined causes. Routine implementation of standardized, rigorous verbal autopsy methods is a potential solution. This paper reports findings from field research conducted to develop, test, and validate the use of verbal autopsy (VA) methods in Thailand.MethodsInternational verbal autopsy methods were first adapted to the Thai context and then implemented to ascertain causes of death for a nationally representative sample of 11,984 deaths that occurred in Thailand in 2005. Causes of death were derived from completed VA questionnaires by physicians trained in ICD-based cause-of-death certification. VA diagnoses were validated in the sample of hospital deaths for which reference diagnoses were available from medical record review. Validated study findings were used to adjust VA-based causes of death derived for deaths in the study sample that had occurred outside hospitals. Results were used to estimate cause-specific mortality patterns for deaths outside hospitals in Thailand in 2005.ResultsVA-based causes of death were derived for 6,328 out of 7,340 deaths in the study sample that had occurred outside hospitals, constituting the verification arm of the study. The use of VA resulted in large-scale reassignment of deaths from ill-defined categories to specific causes of death. The validation study identified that VA tends to overdiagnose important causes such as diabetes, liver cancer, and tuberculosis, while undercounting deaths from HIV/AIDS, liver diseases, genitourinary (essential renal), and digestive system disorders.ConclusionsThe use of standard VA methods adapted to Thailand enabled a plausible assessment of cause-specific mortality patterns and a substantial reduction of ill-defined diagnoses. Validation studies enhance the utility of findings from the application of verbal autopsy. Regular implementation of VA in Thailand could accelerate development of the quality and utility of vital registration data for deaths outside hospitals.

Cause-specific mortality patterns among hospital deaths in Thailand: validating routine death certification.

BackgroundIn Thailand, 35% of all deaths occur in hospitals, and the cause of death is medically certified by attending physicians. About 15% of hospital deaths are registered with nonspecific diagnoses, despite the potential for greater accuracy using information available from medical records. Further, issues arising from transcription of diagnoses from Thai to English at registration create uncertainty about the accuracy of registration data even for specified causes of death. This paper reports findings from a study to measure validity of registered diagnoses in a sample of deaths that occurred in hospitals in Thailand during 2005.MethodsA sample of 4,644 hospital deaths was selected, and for each case, medical records were reviewed. A process of medical record abstraction, expert physician review, and independent adjudication for the selection and coding of underlying causes of death was used to derive reference diagnoses. Validation characteristics were computed for leading causes of hospital deaths from registration data, and misclassification patterns were identified for registration diagnoses. Study findings were used to estimate cause-specific mortality patterns for hospital deaths in Thailand.ResultsAdequate medical records were available for 3,316 deaths in the study sample. Losses to follow up were nondifferential by age, sex, and cause. Medical records review identified specific underlying causes for the majority of deaths that were originally assigned ill-defined causes as well as for those originally assigned to residual categories for specific cause groups. In comparison with registration data for the sample, we found an increase in the relative proportion of deaths in hospitals due to stroke, ischemic heart disease, transport accidents, HIV/AIDS, diabetes, liver diseases, and chronic obstructive pulmonary disease.ConclusionsRegistration data on causes for deaths occurring in hospitals require periodic validation prior to their use for epidemiological research or public health policy. Procedures for death certification and coding of underlying causes of death need to be streamlined to improve reliability of registration data. Estimates of cause-specific mortality from this research will inform burden of disease estimation and guide interventions to reduce avoidable mortality in hospitals in Thailand.

Verifying causes of death in Thailand: rationale and methods for empirical investigation

BackgroundCause-specific mortality statistics by age and sex are primary evidence for epidemiological research and health policy. Annual mortality statistics from vital registration systems in Thailand are of limited utility because about 40% of deaths are registered with unknown or nonspecific causes. This paper reports the rationale, methods, and broad results from a comprehensive study to verify registered causes in Thailand.MethodsA nationally representative sample of 11,984 deaths was selected using a multistage stratified cluster sampling approach, distributed across 28 districts located in nine provinces of Thailand. Registered causes were verified through medical record review for deaths in hospitals and standard verbal autopsy procedures for deaths outside hospitals, the results of which were used to measure validity and reliability of registration data. Study findings were used to develop descriptive estimates of cause-specific mortality by age and sex in Thailand.ResultsCauses of death were verified for a total of 9,644 deaths in the study sample, comprised of 3,316 deaths in hospitals and 6,328 deaths outside hospitals. Field studies yielded specific diagnoses in almost all deaths in the sample originally assigned an ill-defined cause of death at registration. Study findings suggest that the leading causes of death in Thailand among males are stroke (9.4%); transport accidents (8.1%); HIV/AIDS (7.9%); ischemic heart diseases (6.4%); and chronic obstructive lung diseases (5.7%). Among females, the leading causes are stroke (11.3%); diabetes (8%); ischemic heart disease (7.5%); HIV/AIDS (5.7%); and renal diseases (4%).ConclusionsEmpirical investigation of registered causes of death in the study sample yielded adequate information to enable estimation of cause-specific mortality patterns in Thailand. These findings will inform burden of disease estimation and economic evaluation of health policy choices in the country. The development and implementation of research methods in this study will contribute to improvements in the quality of annual mortality statistics in Thailand. Similar research is recommended for other countries where the quality of mortality statistics is poor.

Obesity and mortality among older Thais: a four year follow up study

BackgroundTo assess the association of body mass index with mortality in a population-based setting of older people in Thailand.MethodsBaseline data from the National Health Examination Survey III (NHES III) conducted in 2004 was linked to death records from vital registration for 2004-2007. Complete information regarding body mass index (BMI) (n = 15997) and mortality data were separately analysed by sex. The Cox Proportional Hazard Model was used to test the association between BMI and all-cause mortality controlling for demographic, socioeconomic, and health risk factors.ResultsDuring a mean follow-up time of 3.8 years (60545.8 person-years), a total of 1575 older persons, (936 men and 639 women) had died. A U-shaped and reverse J-shaped of association between BMI and all-cause mortality were observed in men and women, respectively. However there was no significant increased risk in the higher BMI categories. Compared to those with BMI 18.5-22.9 kg/m2, the adjusted hazard ratios (HR) of all-cause mortality for those with BMI <18.5, 23.0-24.9, 25.0-27.4, 27.5-29.9, 30.0-34.9, and ≥35.0 were 1.34 (95% CI, 1.14-1.58), 0.79 (95% CI, 0.65-0.97), 0.81 (95% CI, 0.65-1.00), 0.67 (95% CI, 0.48-0.94), 0.60 (95% CI, 0.35-1.03), and 1.87 (95% CI, 0.77-4.56), respectively, for men, and were 1.29 (95% CI,1.04-1.60), 0.70 (95% CI, 0.55-0.90), 0.79 (95% CI, 0.62-1.01), 0.57 (95% CI, 0.41-0.81), 0.58 (95% CI, 0.39-0.87), and 0.78 (95% CI, 0.38-1.59), respectively, for women.ConclusionsThe results of this study support the obesity paradox phenomenon in older Thai people, especially in women. Improvement in quality of mortality data and further investigation to confirm such association are needed in this population.

Changes in Active Life Expectancy Among Older Thais: Results From the 1997 and 2004 National Health Examination Surveys

This study aims to determine the disability prevalence and changes in active life expectancy of the Thai older people between 1997 and 2004. Data on disability of older people aged ≥60 years were obtained from the National Health Examination Surveys. Disability refers to one or more restrictions on the activities of daily living. The Sullivan method was used to calculate active life expectancy. A total of 4048 older people in 1997 and 19 372 older people in 2004 were included in the analysis. Active life expectancy at age 60 of men was 16.5 years in 1997 and 17.6 years in 2004, whereas that of women was 17.9 and 19.9 years, respectively. Women spent a greater proportion of the remaining life with disability. The proportion of active life for both genders also increased during the 7-year period suggesting an evidence of the compression of morbidity in Thai older people.

Factors associated with insomnia in older people with a mild to moderate degree of poor cognitive ability in Thailand

Aim:  To examine the prevalence and risk factors of insomnia among older adults with a mild to moderate degree of poor cognitive ability.

New developments in the analysis of mortality and causes of death.

This book on new developments in mortality analysis is a product of a joint WHO/UN research program. Part 1 examines mortality transition in terms of the causes and mechanisms of mortality decline in Europe and North America reflecting on the study of development processes in countries now undergoing development. Part 2 deals with the use of mortality data in health planning and the use of mortality and other epidemiologic information in the assessment of preventable deaths. Attention is paid to the development of an index of preventable deaths. Part 3 Methodological Developments examines intersectoral aspects of mortality projections (in terms of health care inputs) the measurement of social inequality and mortality and maternal death and its impact on the female population. Part 4 deals with cause of death analysis: estimation of global mortality patterns by cause of death trends and differentials in Thailand and maternal mortality and differentiation by cause of death. Part 5 discusses nutrition including a Southern Asia-based study of the relationship between nutritional deficiencies and infant and child mortality and a study on advances in child nutrition and health that have taken place despite slow economic development. Part 6 discusses mortality change: achievements and failures in South and East Asia a study on changing health in Japan mortality decline in Mexico and socioeconomic correlates of mortality in Pakistan. The section concludes with articles on trends and differentials in mortality in Malaysia and Thailand and a study of the effects of declining mortality and population aging in rapidly-developing Jamaica.