Emerging methods in comparative effectiveness and safety: symposium overview and summary.

BACKGROUND: Interest in new methods for comparative effectiveness, drug and patient safety, and related studies is burgeoning. The advent of Medicare Part D for outpatient prescription drugs has drawn significant attention to the need for efficient ways to monitor the potential benefits and harms of pharmaceuticals. These trends prompted the Effective Health Care program at the Agency for Healthcare Research and Quality and its DEcIDE (Developing Evidence to Inform Decisions about Effectiveness) network to examine innovative approaches for such investigations through an invitational symposium in June 2006.
RESULTS: Conference papers covered numerous points about ways to structure both interventional and database-oriented studies, particularly those concerned with adverse drug events, to avoid bias in those studies, and to apply advanced statistical tools to exploit the information from these studies to their fullest. Of particular importance are: (1) using new types of experimental designs, including cluster randomization, delayed designs, pragmatic trials, and practice-based investigations that incorporate the natural variation of data from routine clinical practice; (2) finding efficient ways to use different types of databases-eg, Department of Veterans Affairs files, Centers for Disease Control and Prevention surveillance files, Medicaid claims data, and state hospital data-for examining initiation, persistence, and adherence, and the benefits and adverse events of pharmaceutical use; and (3) inventing or refining ways to decrease the threats to validity of analyses relying on administrative or other observational data, particularly through propensity scoring, inverse probability weighting, risk adjustment, and direct or indirect methods for synthesizing comparative effectiveness information.