Are randomized controlled trials sufficient evidence to guide clinical practice in Type II (non-insulin-dependent) diabetes mellitus?

Randomized controlled trials (RCTs) are often considered the standard for d efining the practice of evidence-based medicine. Taken alone, they are, how ever, often insufficient to guide clinical care. Randomized controlled tria ls are clearly the best method to determine whether interventions are effic acious. They have, however, numerous limitations which make them difficult to carry out or limit applicability to routine clinical practice. Although observational studies also have inherent limitations, they provide data whi ch can help to further explain the results of randomized controlled trials. The use of observational studies to frame randomized trials can allow bett er application of randomized controlled trial results to individual patient s and can thus help to optimize delivery of care, inform clinical practice and determine the need for further such trials.