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

Background: Cause-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.Methods: A 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.Results: Causes 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%).Conclusions: Empirical 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

The national burden of road traffic injuries in Thailand

Background: This study quantifies the burden of road traffic injuries (RTIs) in Thailand in 2004, incorporating new Thai data on mortality and the frequency and severity of long-term disability

Prognostic Significance of Changes in Heart Rate Following Uptitration of Beta-Blockers in Patients with Sub-Optimally Treated Heart Failure with Reduced Ejection Fraction in Sinus Rhythm versus Atrial Fibrillation

Background: In patients with heart failure with reduced ejection fraction (HFrEF) on sub-optimal doses of beta-blockers, it is conceivable that changes in heart rate following treatment intensification might be important regardless of underlying heart rhythm. We aimed to compare the prognostic significance of both achieved heart rate and change in heart rate following beta-blocker uptitration in patients with HFrEF either in sinus rhythm (SR) or atrial fibrillation (AF). Methods: We performed a post hoc analysis of the BIOSTAT-CHF study. We evaluated 1548 patients with HFrEF (mean age 67 years, 35% AF). Median follow-up was 21 months. Patients were evaluated at baseline and at 9 months. The combined primary outcome was all-cause mortality and heart failure hospitalisation stratified by heart rhythm and heart rate at baseline. Results: Despite similar changes in heart rate and beta-blocker dose, a decrease in heart rate at 9 months was associated with reduced incidence of the primary outcome in both SR and AF patients [HR per 10 bpm decrease—SR: 0.83 (0.75–0.91), p < 0.001; AF: 0.89 (0.81–0.98), p = 0.018], whereas the relationship was less strong for achieved heart rate in AF [HR per 10 bpm higher—SR: 1.26 (1.10–1.46), p = 0.001; AF: 1.08 (0.94–1.23), p = 0.18]. Achieved heart rate at 9 months was only prognostically significant in AF patients with high baseline heart rates (p for interaction 0.017 vs. low). Conclusions: Following beta-blocker uptitration, both achieved and change in heart rate were prognostically significant regardless of starting heart rate in SR, however, they were only significant in AF patients with high baseline heart rate

Epidemiologic Transition Interrupted: a Reassessment of Mortality Trends in Thailand, 1980-2000

BACKGROUND: In the late 1980s and early 1990s a generalized HIV epidemic affected Thailand which was relatively well controlled by an intensive national campaign by the mid 1990s. The extent to which the epidemic has slowed or possibly reversed the epidemiological transition in Thailand is relatively unknown. METHODS: Under-five mortality rates (U5MR) were determined from various sources and weighted least squares regression conducted to determine U5MR over the years 1980-2000. Direct and indirect estimates of the completeness of death registration were used to estimate mortality levels in those aged more than 5 years for the 1980-90 and 1990-2000 periods. Life tables were constructed using the various estimates to determine changes in life-expectancy between the two time periods. RESULTS: U5MR in Thailand is estimated to have been 58/1000 live births in 1980, declining to 30 in 1990 and to 23 in 2000. The vital registration system clearly underestimates U5MR. Successive surveys of Population Change (SPC) imply coverage of death registration improving from 75-77% in 1985-86 to 95% in 1995-96, partly due to a reliance on self-reported registration in the latter survey. In contrast, the General Growth Balance-Synthetic Extinction Generations (GGB-SEG) method suggests coverage worsening from 78-85% in 1980-90 to 64-72% in 1990-2000. Life tables based on SPC adjustments show continued declines in female, and to a lesser extent, male adult mortality with corresponding increases in life-expectancy at birth of around 6 years for both sexes from 1980-90 to 1990-2000. In contrast, the indirect adjustments suggest a substantial increase in male adult mortality with female adult mortality unchanged; life expectancy decreased by 4 years for males and was only marginally higher in females. CONCLUSION: Given the conflicting evidence a definitive assessment of mortality change in Thailand between 1980 and 2000 is difficult to make. Indirect adjustments, based on demographic methods point to a major reversal in mortality decline among males, and a slowing in females. If adult mortality registration has declined, and given the continued under-registration of infant and child deaths, remedial measures are urgently required if the mortality system is to better inform and monitor health development in Thailand

Integrated multisource estimates of mortality for Thailand in 2005

Estimates of mortality in Thailand during 2005 have been published, integrating multiple data sources including national vital registration and a national follow-up cluster sample, covering both deaths in health facilities (approximately one-third) and elsewhere. The methodological challenge is to make the best use of the existing data, supplemented by additional data that are feasible to obtain, in order to arrive at the best possible overall estimates of mortality. In this case, information from the national vital registration database was supplemented by a verbal autopsy survey of approximately 2.5% of deaths, the latter being used to validate routine cause-of-death data and information from medical records. This led to a revised national cause-specific mortality envelope for Thailand in 2005, amounting to 447,104 deaths. However, difficulties over standardizing verbal autopsy interpretation may mean that there are still some uncertainties in these revised estimates