What type of estimation is best?
Many researchers are not using the best estimation method
Health studies frequently cluster people, communities, or health systems by region, but these groups may have common characteristics that could result in biases when comparing regions. To prevent biases, different methods are used to improve estimation of clustered data, two of which are common (random- and fixed-effects estimation), and one of which is less common (within-between estimation). The results of this study show that the within-between method has been underused, particularly on certain types of data.
Innovation: This is the first time the properties of the within-between estimation method have been examined. To test all three estimation methods, the authors created over 16,000 unique scenarios to mimic real-world datasets. These findings will help statisticians use the appropriate estimation method to produce rigorous, precise, and unbiased health analyses.
Estimating child mortality in Zambia
District-level estimates reveal large inequalities in levels of under-5 mortality in Zambia
Birth history data are frequently used to estimate child mortality in developing countries. These data have been used to estimate mortality at the national level, but they are less effective at estimating mortality at the subnational level. In order to do this, the authors combined birth history methods and small area estimation models to estimate district-level under-5 mortality in Zambia from 1980 to 2010, showing which regions are performing best and which are falling behind.
Innovation: This study is the first to combine birth history data with small area methods to estimate under-5 mortality at a subnational level over time. The results point to the need for subnational estimates and show that national estimates alone are insufficient for monitoring and evaluation. While child mortality declined in Zambia, the magnitude of the decline varied across districts, and the study revealed large inequalities in progress on child mortality within Zambia. These findings can help promote further reductions of under-5 mortality, as lessons learned from districts with the greatest progress can be applied to those with the least.
Estimation of district-level under-5 mortality in Zambia using birth history data, 1980-2010. Spatial and Spatio-temporal Epidemiology, October 2014.
The burden of disease in the Kingdom of Saudi Arabia
Three studies reveal areas of concern for Saudis
Overall, the Kingdom of Saudi Arabia (KSA) saw an increased burden of non-communicable diseases between 1990 and 2010. In 2010, elevated body mass index was the leading risk factor for disease in both males and females. Almost 29% of Saudis were found to be obese, and obesity is strongly linked with diabetes, high cholesterol, and hypertension, among other causes of health loss. Diabetes data from KSA show that over 13% of Saudi adults have diabetes, and almost 60% of these people are undiagnosed.
Innovation: As part of a partnership between the KSA Ministry of Health and IHME, IHME is creating a database of the burden of diseases, injuries, and risk factors for KSA at the national and local levels, using Global Burden of Disease (GBD) methods. These results provide baseline data pointing to areas for intervention in the Kingdom and call upon the government and community members to prioritize investment to prevent and treat the diseases most affecting Saudis.
Obesity and associated factors - Kingdom of Saudi Arabia, 2013. Preventing Chronic Disease, October 2014.
Status of the diabetes epidemic in the Kingdom of Saudi Arabia, 2013. International Journal of Public Health, October 2014.
Burden of disease, injuries, and risk factors in the Kingdom of Saudi Arabia, 1990–2010. Preventing Chronic Disease, October 2014.
The global burden of severe periodontitis
Results point toward need for public health attention
Severe periodontitis, an inflammation of the gums that can cause tooth loss as well as serious health problems, is the sixth-most prevalent condition in the world. Between 1990 and 2010, the global age-standardized prevalence of severe periodontitis remained static. However, the prevalence of severe periodontitis increases with age, and global life expectancy is getting longer, leading to a predictable increasing burden of severe periodontitis in years to come.
Innovation: Data on the incidence of severe periodontitis are scarce. The authors collected and consolidated all available data about severe periodontitis and generated prevalence and incidence estimates for all countries, 20 age groups, and both sexes for 1990 and 2010. This understanding of the trends in severe periodontitis is critical for dental health care planning and resource allocation, especially as the burden of severe periodontitis will likely increase with the aging global population.
Global burden of severe periodontitis in 1990-2010: a systematic review and meta-regression. Journal of Dental Research, September 2014.
How should we monitor progress toward universal health coverage?
Effective coverage is a suitable metric to monitor universal health coverage
Universal health coverage includes the availability of affordable care, access to quality services, and potential for capacity building, but there is a lack of empirical evidence for assessing and informing policies related to universal health coverage. Global organizations, including the World Health Organization, have called for concerted efforts to achieve universal health coverage, but how should progress toward this goal be monitored?
Innovation: In this paper, the authors review the concept of effective coverage. In contrast to crude coverage, which measures only whether someone can access an intervention or the use of that intervention, effective coverage unites the need for the intervention, the use of that intervention, and its quality. The authors feel that the comprehensiveness of effective coverage makes it suitable for monitoring universal health coverage, in that it can provide a better understanding of whether, and how well, a health system is delivering services to its populations.
Effective coverage: a metric for monitoring universal health coverage. PLoS Medicine, September 2014.
How well are vaccination resources being tracked?
Information is relatively complete, but improvements can be made in vaccine resource tracking systems
In 2010, more than US $2 billion in development assistance for health was spent on vaccinations in low- and middle-income countries, representing a rapid growth in funding since 2000. Due to this rapid growth, the World Health Assembly called for the establishment of a comprehensive vaccine resource tracking system. The authors set out to assess the strengths and weakness of existing tracking systems.
Innovation: Decision-makers have had little information about the validity, accessibility, costs, and coverage of vaccine tracking methods. The authors’ objective was to identify how effectively and comprehensively resources devoted to immunizations are being tracked. While they found that relative to other areas in health, information about vaccine-related resources is fairly advanced, there is room for improvement, including streamlining data collection processes, checking datasets for implausible values, and developing visualization tools to make data easily interpretable by stakeholders.
Vaccine resource tracking systems. BMC Health Services Research, September 2014.
Deaths from liver cirrhosis on the rise
Globally, liver cirrhosis caused more than 1 million deaths in 2010
Liver cirrhosis is a major cause of global health burden. According to the GBD 2010 study, liver cirrhosis caused 1.2% of all disability-adjusted life years and 1 million deaths globally in 2010. The results show that deaths from liver cirrhosis have increased steadily over the past 30 years, with variations in mortality levels between regions and countries driven by levels of alcohol consumption and infections from hepatitis B and C.
Innovation: Since the original GBD study in 1990, there has been no comprehensive assessment of liver cirrhosis mortality. Using methodological advances from the GBD 2010 study, the authors systematically collected all available data to estimate liver cirrhosis mortality, with uncertainty, by age, sex, country, and year for 1980 to 2010. These data are critical for policymakers to address this growing problem, especially in areas where liver cirrhosis is a particular health priority, including Central Asia, Central Europe, Eastern Europe, and Central Latin America.
Liver cirrhosis mortality in 187 countries between 1980 and 2010: a systematic analysis. BMC Medicine, September 2014.