IHI 90-Day R&D Project Final Summary Report: Counties of Interest: Achieving Better- or Worse-Than-Expected Health Outcomes. Cambridge, MA: Institute for Healthcare Improvement; January 2011.

The intent of this 90-day R&D project was to identify counties in the US with health outcomes significantly better or worse than one would expect based in their socioeconomic status. Once these counties were identified, we sought to understand what drivers may have led to those results. We developed a method for identifying counties that have a high probability of being outliers, identifying 17 counties with better-than-expected health outcomes and 11 counties with worse-than-expected health outcomes. The statistical analysis was complemented with qualitative investigation and interviews.