Risk assessment in diabetes management: how do general practitioners estimate risks due to diabetes?

Objectives: To evaluate the ability of general practitioners (GPs) in Germany to estimate the risk of patients with diabetes developing complications. Methods: An interview study using a structured questionnaire to estimate risks of four case vignettes having diabetes-specific complications within the next 10 years, risk reduction and life expectancy potential. A representative random sample of 584 GPs has been drawn, of which 150 could be interviewed. We compared GPs’ estimates among each other (intraclass correlation coefficient (ICC) and Cohen’s (multirater-) κ) and with risks for long-term complications generated by the multifactor disease model “Mellibase”, which is a knowledge-based support system for medical decision management. Results: The risk estimates by GPs varied widely (ICC 0.21 95% CI (0.13 to 0.36)). The average level of potential risk reduction was between 47% and 70%. Compared with Mellibase values, on average, the GPs overestimated the risk threefold. Mean estimates of potential prolongation of life expectancy were close to 10 years for each patient, whereas the Mellibase calculations ranged from 3 to 10 years. Conclusions: Overestimation could lead to unnecessary care and waste of resources.