By Sarah DeWeerdt
Childhood vaccination rates are increasing, but not as quickly as many governments around the world have claimed. That's the conclusion of a new study by researchers at the UW Institute for Health Metrics and Evaluation (IHME).
The exhaustive effort, led by UW Professor of Global Health and IHME Director Christopher Murray, compared official government reports with data from house-to-house surveys to track the number of children who received the diphtheria, tetanus and pertussis (DTP3) vaccine between 1986 and 2006.
The researchers compiled data from 193 countries overall, zeroing in on 51 nations that received funding from the Global Alliance on Vaccines and Immunizations (GAVI), which pays governments $20 for each child that is newly vaccinated. In recent years, such pay-for-performance incentives have become a common element of global public health problems, but some observers have worried that they might lead governments to overstate their progress.
The new study confirms and quantifies the problem. Altogether, Murray and his colleagues found, the countries that received funding from GAVI reported that 13.9 million additional children were immunized. But the independent surveys showed that the actual number of additional immunizations was only about half that, 7.4 million.
"To counteract this problem requires not only independent monitoring, but also a system that is based on rigorous, empirical measurements using the best scientific methods available," says Murray. And in fact, that's precisely the mission of the IHME, which was formed in 2007 to improve the quality of information about public health and the performance of health-care systems.
IHME representatives will participate in a task force to help improve GAVI's monitoring and evaluation practices.