The Agency for Healthcare Research and Quality (AHRQ) has announced plans to solicit contracts for comparative effectiveness research projects with $300 million in ARRA funding. Separately, AHRQ has added two new chapters to its "Methods Guide for Comparative Effectiveness Reviews" under the AHRQ Effective Health Care Program: (1) Principles for Developing Guidance for Comparing Medical Interventions; and (2) Grading the Strength of a Body of Evidence when Comparing Medical Interventions. Other topics under development include: Avoiding Potential Biases when Comparing Medical Interventions; Updating Reports Comparing Medical Interventions; and Comparing Diagnostic Technologies.