[ERWIPA--a standardized inventory for assessment of illness-related insight in patients with schizophrenia]. / ERWIPA--ein standardisiertes Verfahren zur Erfassung des krankheitsbezogenen Wissens bei Patienten mit Schizophrenien.

55 schizophrenic patients answered a 2 x 30 items questionnaire, Item analysis showed a low discriminative power, the initial forms differing with regard to degree of difficulty. Items with discriminative power over 0.30 were arranged into two thematically similar 13 item forms of equal difficulty. The questionnaires ERWIPA-A and ERWIPA-B consist of 2 x 20 items. The first item of each from had been answered correctly by all patients from our sample. We considered six additional items because future research may to different results as far as discriminative power is concerned. The average difficulty of both ERWIPA forms is equal for both the 2 x 13 items and the 2 x 20 items version.