A Population health approach to reducing observational intensity bias in health risk adjustment: cross sectional analysis of insurance claims

British Medical Journal
Wennberg, DE, Sharp SM, Bevaan, G, Skinner JS, Gottlieb D

Per capita medical spending and utilization varies extensively among healthcare regions, as reported in the Dartmouth Atlas of Healthcare, the NHS Atlas of Variation, and the Spanish Atlas of Variability. These variations have raised major concerns about the effectiveness and equitable distribution of healthcare services, and led naturally to an important question: “To what extent can variations be explained by differences in illness of the regions’ populations?”