Psychometric properties of a new occupational therapy cognitive outcome measure for Thai older adults with cognitive impairments

Abstract

Background: Occupational therapy (OT) cognitive interventions requires a standardised cognitive outcome measure to help explain the effectiveness of the interventions. Now, there is a lack of measures to use for Thai older adults with cognitive impairments. Therefore, a new Occupational Therapy Cognitive Outcome Measure (OTCOM) for Thai older adults with cognitive impairments was developed to support evidence-based OT cognitive interventions. Objectives: To examine the psychometric properties including internal consistency, inter-rater and intra-rater reliability, known-group construct validity, concurrent validity, and responsiveness of the OTCOM. Materials and methods: A prospective cohort design was used in this study. One hundred and ten older adults; sixty-one older adults with cognitive impairments and forty-nine older adults without cognitive impairments, were recruited. The Cronbach’s alpha coefficient was calculated for internal consistency. Intraclass correlation coefficient (ICC) was used to analyse rater reliability. Analyses of concurrent and known-group construct validity were done using Pearson correlation and independent t-test, respectively. Both effect size (ES) and standardised response mean (SRM) were calculated for responsiveness of the OTCOM. Results: The results showed good internal consistency (α=0.88), and excellent inter-rater and intra-rater reliability (ICC=0.99). A high correlation between the OTCOM and the Dynamic Lowenstein Occupational Therapy Cognitive Assessment-Geriatric (DLOTCA-G) and the Thai Cognitive-Perceptual Test (Thai-CPT) was found, indicating good concurrent validity. There was a significant difference between older adults with cognitive impairments and without cognitive impairments, suggesting good construct validity by the known-group method. Responsiveness was shown as large ES and SRM in the total score. Conclusion: The OTCOM showed good psychometric properties, making it useful in OT practice after revisions.