[Interrater reliability of expert assessment by the health insurance medical service in determining eligibility for disability benefits].

In this paper, we present the first study on the inter-rater reliability of a standardised examination of functional disability, employed by the medical service of the German statutory health insurance system ("Medizinischer Dienst der Krankenversicherung", MDK). 215 elderly adults (mean age 84) living in 6 nursing homes in Munich were included in the study. They were assessed by three medical students and two nurses of the respective nursing homes using the standardised questionnaire of the MDK. Inter-rater reliability of both a summary judgement of disability and of single items, such as impairments in activities of daily living, was assessed by kappa-coefficients. Inter-rater reliability was higher for the overall assessment of disability (kappa = 0.82 between nurses, kappa = 0.57 between medical students) than for most single items. Reliability was particularly low for some items on mental status (such as "restlessness") or perceptions (particularly visual perception) which require clearer definition. This pattern was consistently observed for the two types of comparisons (inter-students, nurse-nurse) and for different subgroups of the study population.