What happened to the valid POEMs? A survey of review articles on the treatment of type 2 diabetes.

OBJECTIVE: To evaluate systematically the review literature on type 2 diabetes to assess transmission of the findings of the United Kingdom prospective diabetes study (UKPDS), an important source of recent valid patient oriented evidence that matters (POEMs).

DESIGN: Inception cohort analysis of the recent medical literature.

STUDIES REVIEWED: Thirty five reviews on treatment of type 2 diabetes.

MAIN OUTCOME MEASURES: Presentation of three types of information from UKPDS in review articles: recommendations based on patient oriented outcomes of study; recommendations contradicted by patient oriented outcomes of study; and recommendations based on disease oriented outcomes for which no patient oriented evidence exists.

RESULTS: Only six of the reviews included the POEM that tight blood glucose control had no effect on diabetes related or overall mortality. Just seven mentioned that metformin treatment was associated with decreased mortality. Most (30) of the reviews did not report that diabetic patients with hypertension benefit more from good blood pressure control than good blood glucose control. No review pointed out that treatment of overweight patients with type 2 diabetes with insulin or sulphonylurea drugs had no effect on microvascular or macrovascular outcomes. Thirteen reviews recommended drugs as first line treatment for which we do not have patient oriented outcomes data. The average validity assessment score was 1.3 out of a possible score of 15 (95% confidence interval 0.9 to 1.8).

CONCLUSIONS: Review articles on the treatment of type 2 diabetes have not accurately transmitted the valid POEM results of the UKPDS to clinicians. Clinicians relying on review articles written by experts as a source of valid POEMs may be misled.