Comparative effectiveness research in the "real" world: lessons learned in a study of treatment-resistant hypertension.

Comparative effectiveness research (CER) is vital to translate new efficacious diagnostic and therapeutic approaches into effectiveness in usual clinical practice settings. Studying the practice environment in which effectiveness protocols are implemented is necessary to identify the complex challenges that can limit translation of evidence. These issues were addressed in our National Heart, Lung, and Blood Institute-funded R34, "Controlling Blood Pressure in Treatment-Resistant Hypertension (TRH): A Pilot Study.