This report from The National Academy for State Health Policy examines claims-based data to identify pros and cons of medical home initiatives.  

From the executive summary:

This State Health Policy Briefing summarizes the advantages and disadvantages of using claims-based data to evaluate patient-centered medical home initiatives. A Medicaid-based medical home initiative in Oklahoma and a multi-payer medical home pilot in Rhode Island are highlighted. Both states are using a mixture of claims-based data and supplementary resources like patient or provider surveys and data collected from electronic medical records to evaluate their medical home programs. Understanding the potential uses and limitations of both claims data and other data sources that can aid evaluators will help states to design appropriate evaluative criteria for their medical home programs. 

Full Report: Evaluating the Patient-Centered Medical Home: Potential and Limitations of Claims-Based Data (PDF | 190 KB)  

 The National Academy for State Health Policy. (2010). Evaluating the Patient-Centered Medical Home: Potential and Limitations of Claims-Based Data. Stanek, M. and Takach, M.