Measuring Global Health

Original Editor - Wendy Walker

Top Contributors - Wendy Walker, Rachael Lowe and Naomi O'Reilly  

Introduction

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Measuring global health is frequently defined in terms of measurement of the Global Disease Burden [GBD] which is defined as the impact of a health problem as measure by mortality, morbidity and financial cost.

Various diseases put a different amount of disease-burden on a population and has become the most common method in order to compare across nations.  When comparing GBD data from different countries, there is a marked difference between nations which are developed to a greater or lesser degree.


Global Burden of Disease (GBD) Project

The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) is the single largest and most detailed scientific effort ever conducted to quantify levels and trends in health. The study reported the health effects of more than 100 diseases and injuries in 8 regions of the world in the year 1990. Led by the Institute for Health Metrics and Evaluation (IHME) at the University of Washington, it is truly a global effort, with over 1,000 researchers from more than 100 countries, including 26 low- and middle-income countries, participating in the most recent update. The GBD provides a tool to quantify health loss from hundreds of diseases, injuries, and risk factors, so that health systems can be improved and disparities can be eliminated.

It produced estimates of mortality and morbidity by age, sex and region.

The ongoing Global Burden of Disease Study[1] is described as "The most comprehensive worldwide observational epidemiological study to date." It describes mortality and morbidity from disease and injury. It quantifies global, regional and national life expectancy, all-cause mortality and cause specific mortality for 249 causes of death, 1980-2015. It is led by the Institute for Health Metrics and Evaluation (HME), University of Washington, USA, and researchers are based throughout the world: there are more than 1,000 researchers from more than 100 countries, which includes 26 low and middle-income countries.

As well as examining 249 causes of death, it reviews 315 disease and injuries and 79 risk factors. The data is taken from 195 countries and territories between 1990 and 2015.

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Institute for Health Metrics & Evaluation. GBD 2010 Poster. http://www.healthdata.org/infographic/gbd-2010-poster

Measurement

According to Murray et al[2] quantifying the burden of disease provides a means to identify conditions and risk factors that may be relatively neglected and others for which progress is not what was expected and may be used to initiate health policy dialogues. Summary measures of global health are used to help assess the overall health of a population which typically take into account disability, mortality and morbidity data. These Health scores can also reflect perceived quality of life or functional status, including physical functioning and emotional well-being. Measuring the quality of life, in tandem with summarising physical well-being, is critical to understanding the prevalence and severity of conditions that cause significant periods of suffering but don’t directly lead to fatalities.

There are a number of measurements which can be used to measure global health.

The 3 main units of measurement are the "ALYs":

  1. The DALY (Disability-Adjusted Life Year) is frequently used as a measure of disease burden. The World Health Organisation (WHO) use DALY measurements to compare the overall health and life expectancy of various countries.
  2. The QALY (Quality-Adjusted Life Year) is a measure of disease burden which accounts for both the health-related quality of life a person is predicted to experience, and the length of life expectancy.
  3. The HALY (Health-Adjusted Life Year) includes DALYs and QALYs in order to describe morbidity and mortality rates with a single number and are often used to estimate the burden of disease and compare the impact of specific diseases/health conditions on communities.

Sarabia[3] provides a simple guide to understanding the current units of measurement and and discusses the criticism and problems with quantifying global health. 

Accurate and complete data are essential for good decision-making on health spending, for responding to countries' specific health needs and measuring progress and impact of health programmes. Countries need to have robust and reliable health information systems and generate their own data to monitor health programmes and report on progress. Global health can also be measured in relation to more specific indicators, which can be divided into those that directly measure health phenomena (e.g., diseases, deaths, use of services) and indirect measures (e.g., social development, education and poverty indicators).  The global health indicators used in developing countries for
the most part address morbidity, mortality and important precursors of both. In contrast, in developed countries a large proportion of the key health indicators reflect lifestyles and individual behaviour, such as physical exercise, smoking, diet, or substance and alcohol abuse[4]. Larson & Mercer[4] provide an overview of the more common Global Health Indicators in use to measure elements of Global Health.

WHO, together with partner organisations, developed an international collaboration, the Health Data Collaborative, to improve measurement and accountability for global public health and to support countries to have strong health information systems following the Measurement and Accountability for Results in Health Summit. The Global Reference List of 100 Core Health Indicators is a standard set of 100 indicators prioritised by the global community to provide concise information on the health situation and trends, including responses at national and global levels. This Global Reference List contains indicators of relevance to country, regional and global reporting across the spectrum of global health priorities relating to the post-2015 health goals of the Sustainable Development Goals. These include the Millennium Development Goals (MDGs) agenda, new and emerging priorities such as non-communicable diseases, universal health coverage and other issues in the post-2015 development agenda.

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Resources

A summary of the most recent GBD Study Findings, 2015 in The Lancet.

The IHME (Institute for Health Metrics and Evaluation) website provides articles and data on world health metrics. It has an impressive interactive tool which can be used to analyse data about world health levels and trends, comparing causes and risks within a country, or comparing countries, or demonstrate how disease patterns have changed over time. 

The World Health Organization website has a page on GBD and one on Global Health Observatory Data showing access to health services globally in each of WHO's 194 member states, as well as information about eqity of access.

References

  1. GBD 201 Mortality and Causes of Death Collaborators. The Lancet, 8 Oct 2016, Vol 388, No 10053, p1459-1544
  2. Murray CJ, Lopez AD. Measuring the Global Burden of Disease. New England Journal of Medicine. 2013 Aug 1;369(5):448-57
  3. Daniela Sarabia. More Than a Number: A Guide to How Global Health is Measured. 8 Sep 2016. Borgen Magazine.
  4. 4.0 4.1 Larson C, Mercer A. Global Health Indicators: An Overview. Canadian Medical Association Journal. 2004 Nov 9;171(10):1199-200.