A Pre-Post Study of Individualized Programs Using the Occupational Therapy Intervention Process Model in a Psychiatric Hospital in Japan

Abstract

Background: Recent psychiatric treatment trends emphasize supporting individuals to live autonomously within the community, irrespective of the severity of mental illness. This study investigates the effects of individualized programs based on the Occupational Therapy Intervention Process Model (OTIPM) on occupational performance and social interaction skills among psychiatric inpatients.

Methodology: This pre-post study included 90 clients (schizophrenia: 46, addiction: 15, mood disorders: 11, intellectual disability: 7, others: 11) hospitalized in a psychiatric facility. Participants underwent a maximum of 10 individualized sessions using OTIPM. Outcomes assessed were the Canadian Occupational Performance Measure (COPM), Assessment of Motor and Process Skills (AMPS), and Evaluation of Social Interaction (ESI). Statistical analyses included paired t-tests and Wilcoxon signed-rank tests.

Results: Significant improvements were observed in COPM performance (p < 0.001, Cohen's d = 0.79), COPM satisfaction (p < 0.001, Cohen's d = 0.97), AMPS motor skills (p < 0.001, Cohen's d = 0.61), AMPS process skills (p < 0.001, Cohen's d = 0.59), and ESI scores (p < 0.001, Cohen's d = 0.72). Improvements were consistent regardless of the frequency of sessions or the length of hospitalization.

Conclusions: Individualized interventions based on OTIPM may effectively enhance occupational performance and social interaction skills, providing valuable support for community reintegration among psychiatric inpatients.