• An operational criteria checklist for psychotic illness and computer programs designed to be used in conjunction with it constitute the OPCRIT system. This provides a simple and reliable method of applying multiple operational diagnostic criteria in studies of psychotic illness. The development of the OPCRIT system and an assessment of reliability are described. Diagnostic agreement between three raters is excellent. Item-by-item agreement, although less good, still achieves reasonable reliability despite the problem of low base rates for some items.
McGuffin P, Farmer A, Harvey I. A Polydiagnostic Application of Operational Criteria in Studies of Psychotic IllnessDevelopment and Reliability of the OPCRIT System. Arch Gen Psychiatry. 1991;48(8):764-770. doi:10.1001/archpsyc.1991.01810320088015