Screening for type 2 diabetes mellitus in patients with mental illness: application of a self-assessment score for diabetes mellitus risk.

Various methods for diabetes risk assessment have been developed over a decade, but they were not evaluated in patients with mental illness. This study examined the feasibility and utility of a self-assessment score for type 2 diabetes mellitus (DM2) risk among patients with mental illness. DM2 risk was assessed by patients with mental illness as well as clinicians via a self-assessment questionnaire, and the resulting scores were compared to each other as well as with actual diagnosis. Of 100 patients, nine patients were newly revealed to have DM2 and 34 patients have pre-DM2. Patients tended to underreport risk factors - obesity and physical activity - so perceived to have lower risk. Sensitivity of the self-assessment score was different when used by patients and by clinicians despite correlation coefficient of 0.82. Based on positive predictive values, we may expect one out of two patients who have high scores actually have DM2 or pre-DM2. Also, the discrimination capability was reasonably high (AUC=0.79), comparable to its performance observed in general populations. The self-assessment score has potential as a simple and adjunct tool to identify a high risk group of DM2/pre-DM2 among persons with mental illness, especially, when used together with health care providers.