Psychometric evaluation of the Patient Assessment of Chronic Illness Care instrument using Item analysis according to the Rasch model.

The PACIC is a well-targeted, reliable unidimensional instrument to assess patient care in alignment with the chronic care model in patients with diabetes. It is free of substantial DIF. The PACIC-20 sum score can hence be used in clinical practice for individual diagnostic. For evaluation purposes like assessment of change or group evaluations, the usage of the interval-scale level person parameters is recommended as it permits using parametric statistical analyses and provides a more accurate picture about the actual amount of change.