An application of a new evidence grading system to research on the chronic care model.

Methodological quality undergirds all evidence-based medicine because without strong evidence supporting or refuting the efficacy of an intervention, the movement toward basing medical decisions and practice on scientific evidence is not sustainable. Recently, the consensus that had existed regarding the hierarchy of evidence produced by a study design was challenged on the basis that existing guidelines failed to properly define key terms, weight the merits of certain non-randomized controlled trials, and employ a comprehensive list of study design limitations to render evaluative conclusions, to name a few of the challenges. The present study introduces a new grading system that overcomes, or at the very least greatly diminishes, these challenges.