[Is an evidence-based therapy of inpatients with type 2 diabetes possible from studies used for formulating therapy...

Evidence-based guidelines are based on controlled trials and expert knowledge. Controlled trials often exclude elderly patients and those with diseases of several organs. It was the aim of this study to assess to what extent evidence-based guidelines of the German Diabetes Society (DDG) for antihyperglycaemic treatment were applicable to hospitalized patients with type 2 diabetes.

The exclusion criteria of the clinical trials listed in the guidelines of the DDG (Diabetes und Stoffwechsel 12/2003; supplement 2, 29-31) were analysed. The study cohort consisted of all patients on drug treatment of type 2 diabetes who had been hospitalized during August and September 2003 in the two medical units of the Saarbrucken University Hospital. Current data on diabetes-associated and diabetes-dependent diseases were recorded.

91 of 125 literature citations (72%) contained clinical studies of evidence class I-III. 33.3% od studies had explicitly excluded patients with renal disease, 31.1% with liver disease, 10.9% with an age >75 years, 15.2% with coronary heart disease and 12.3% with heart failure. These exclusion criteria were used regardless of the drugs used. In 153 of 982 patients (15.5%) had drug-treated type 2 diabetes mellitus, median age was 73 years. In 138 of 153 patients (90.1%) medical and and social data could be obtained. 18.1% of these patients would have been excluded because their creatinine was >1.5 mg/dl, 45.5% because they were older then 75 years, 50.7% because they had coronary heart disease, and 15.9% because of heart failure (some patients met more than one of these items).

Treatment of hospitalized patients with type 2 diabetes with cardiac, hepatic and/or renal disease or older than 75 years was not possible if medical management was based on clinical studies with an evidence level I-III.