BMJ (Clinical Research Edition)
Objective: To determine the bias associated with frequency of visits by physicians in adjusting for illness, using diagnoses recorded in administrative databases.
Setting: Claims data from the US Medicare program for services provided in 2007 among 306 US hospital referral regions.
Design: Cross sectional analysis. Participants 20% sample of fee for service Medicare beneficiaries residing in the United States in 2007 (n=5 153 877).
Wennberg, J. E.; Staiger, D. O.; Sharp, S. M.; and Gottlieb, D. J., "Observational Intensity Bias Associated with Illness Adjustment: Cross Sectional Analysis of Insurance Claims" (2013). Open Dartmouth: Faculty Open Access Articles. 672.