Global Burden of Disease Estimates: Secret Recipes or Spoiled Ingredients?
Tuesday, March 12, 2013
Although counting the sick and dead in a country can seem quite dull if not morbid, these facts are critical inputs to designing any national health policy, let alone global priorities in health. Yet 85% of the world’s population still lack systems that register births and deaths along with high-quality data on causes of death.
The Global Burden of Disease (GBD) – whose first edition was commissioned by the World Bank in 1991 and whose latest edition came out in December 2012 in the Lancet – was the first systematic attempt to count the sick and dead in a rigorous way. The GBD researchers used all data sources available to them. And while this work is a landmark in global-health history and deserves praise, the underlying data the researchers use are of poor quality. For example, it’s hard to figure out how many deaths were actually counted in the latest GBD, and how many deaths were “extrapolated” from a variety of methods. What’s worse, there has been slow – if any – progress in improving the underlying data since the first GBD two decades ago.
These poor ‘raw ingredients’, the underlying raw data, are the main reason why there is such uncertainty and inaccuracy in many global-health statistics. Even with the wide application of new statistical methodologies by top-notch researchers, only so much can be done in correcting for biased and missing data. Or, put another way, even the best recipes and best chefs in the world can’t make a meal out of spoiled (or non-existent) ingredients.
- Health Care