Observational intensity bias associated with illness adjustment: cross sectional analysis of insurance claims

BMJ: February 21, 2013

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). Read more