Valid, robust, easy to construct, and easy to interpret measure that could be used by any state health department for any health outcome

Five years in the making and available at no charge, the Public Health Disparities Geocoding Project Monograph gives officials and researchers for the first time a systematic way to monitor health disparities across a wide range of outcomes using basic socioeconomic information.

Most national health disease databases fail to include critical information about people’s jobs, incomes, education, and assets—despite how powerfully these factors influence well-being. Why? The sources from which the databases are drawn, such as cancer registries and notifiable disease surveillance systems, do not collect socioeconomic data. The shortfall leaves public health officials disadvantaged when investigating why some groups of people suffer worse health than others.

“Social inequalities in health, however real, can be ignored and made invisible if the data to document them are not collected,” said Nancy Krieger, principal investigator of the project and an associate professor in the Department of Society, Human Development, and Health at the Harvard School of Public Health (HSPH).

Working in cooperation with the public health departments of Massachusetts and Rhode Island, the HSPH team sifted through reams of public health and census records to determine two things: what kind of socioeconomic information--when applied to what kind of group--would consistently tell officials something useful about health disparities. The answers could prompt public health officials to rethink their usual approaches to monitoring health inequalities.

The researchers found that poverty calculated at the geographic level of the census tract (about 4,000 people) emerged as a powerful detector of health disparities. The finding held true when tested for a number of health outcomes. People living in impoverished parts of Massachusetts had mortality rates 1.3 to 1.4 times higher than residents in wealthy neighborhoods. Children in poor Rhode Island neighborhoods were more than nine times as likely to get lead poisoning than children in richer communities. Residents in poor regions of Massachusetts faced more than eight times the risk of contracting tuberculosis than people living in well-off neighborhoods in the state.

“Our goal was to come up with a valid, robust, easy to construct, and easy to interpret measure that could readily be used by any state health department for any health outcome,” said Krieger.