Research Article
Issue Date: September/October 2020
Published Online: August 03, 2020
Updated: August 07, 2020
Test–Retest Reliability and Minimal Detectable Change of the Comprehensive Occupational Therapy Evaluation Scale (COTES) in People With Schizophrenia
Author Affiliations
  • En-Chi Chiu, OTD, PhD, is Associate Professor, Department of Long-Term Care, National Taipei University of Nursing and Health Sciences, Taipei, Taiwan.
  • Shu-Chun Lee, MS, is Occupational Therapist, Department of Occupational Therapy, Taipei City Psychiatric Center, Taipei City Hospital, Taipei, Taiwan, and Lecturer, University of Taipei, Taipei, Taiwan; A1057@tpech.gov.tw
  • Kuan-Yu Lai, MS, is Occupational Therapist, Department of Occupational Therapy, Taipei City Psychiatric Center, Taipei City Hospital, Taipei, Taiwan.
  • Fang-Yu Gu, MS, is Occupational Therapist, Department of Occupational Therapy, Taipei City Psychiatric Center, Taipei City Hospital, Taipei, Taiwan.
Article Information
Mental Health / Research Articles
Research Article   |   August 03, 2020
Test–Retest Reliability and Minimal Detectable Change of the Comprehensive Occupational Therapy Evaluation Scale (COTES) in People With Schizophrenia
American Journal of Occupational Therapy, August 2020, Vol. 74, 7405205110. https://doi.org/10.5014/ajot.2020.040154
American Journal of Occupational Therapy, August 2020, Vol. 74, 7405205110. https://doi.org/10.5014/ajot.2020.040154
Abstract

Importance: A reliable observational measure is necessary to measure clients’ behaviors as they participate in activities. The Comprehensive Occupational Therapy Evaluation Scale (COTES) is designed to measure strengths and difficulties in various behaviors that support occupational performance.

Objective: To examine the test–retest reliability of the COTES (overall score and scores on the General Behavior, Social Behavior, and Work Behavior subscales) and calculate the minimal detectable change (MDC) for people with schizophrenia.

Design: Prospective, observational study.

Setting: A psychiatric center.

Participants: COTES data for 118 people with schizophrenia were collected from occupational therapy records. Data from the initial and second COTES measurements were chosen for analysis.

Outcomes and Measures: Test–retest reliability of the overall scale and three subscales was evaluated using the intraclass correlation coefficient (ICC). The MDC was calculated on the basis of the standard error of measurement.

Results: ICCs for the overall scale and three subscales ranged from .91 to .97. The MDC values (MDC%) were 6.5 (10.5%) for the overall scale, 3.4 (13.5%) for the General Behavior subscale, 2.3 (15.2%) for the Social Behavior subscale, and 2.4 (11.0%) for the Work Behavior subscale.

Conclusion and Relevance: The COTES has good test–retest reliability. Clinicians and researchers can use the MDC values provided in this study to explain the implications of change scores for behaviors that affect occupational performance for people with schizophrenia.

What This Article Adds: The COTES has sound reliability and support for its use in determining whether people with schizophrenia make real improvements in behavior that affects occupational performance over time.