Validity and reliability of the Japanese version of the Rathus assertiveness schedule in day psychiatric care users with schizophrenia

Abstract

Objective: This study aimed to investigate the validity and reliability of the Japanese version of the Rathus assertiveness schedule (J-RAS) in psychiatric day care users with schizophrenia.

Subjects and Methods: We examined 715 psychiatric day care users with schizophrenia by conducting the test twice between September 2007 and February 2008 using a questionnaire-based survey. We examined construct validity and used the internal reliability test, split-half method, and test–retest method to examine reliability. The questionnaires were distributed and collected by post via the director of each facility.

Results: Of the 1272 psychiatric day care users, 715 users (56.2%) were enrolled in the study. Seven factors were extracted for construct validity. The cumulative contribution rate of these factors was 49.4% and the internal consistency of 30 items of the J-RAS was α = 0.72. The split-half method revealed a significant correlation between the total scores of the odd- and even-numbered items (r = 0.64, p < 0.01). The test–retest method revealed a significant difference between the total scores of the first and second tests of the 30 items of the J-RAS (r = 0.73, P < 0.01).

Conclusion: We confirmed the validity and reliability of the J-RAS in psychiatric day care users with schizophrenia and demonstrated its efficacy in evaluating psychiatric day care users.