Comparative study of four evaluation criteria in a clinical trial with schizophrenic patients

In order to compare the level of agreement between four evaluation criteria, data from an 18-month clinical trial with 181 schizophrenic patients were reanalyzed. In that study, assessments of the subjects were carried out with two psychiatric rating scales, Brief Psychiatric Rating Scale and Nurses' Observation Scale for Inpatient Evaluation (BPRS and NOSIE), and two clinical evaluations (psychiatrist and nurse). Results show that there was total agreement on the four outcome measures for only half of the subjects. After further analyses, we observed that the best agreement was between the two clinical assessments. The NOSIE had poor agreement with the other criteria and appeared less sensitive to moderate levels of improvement in the patients' clinical status. These results are discussed with respect to reliability and validity issues.