A Psychometric Study of the Kinetic-House-Tree-Person Scoring System for People with Psychiatric Disorders in Taiwan

Abstract

Objective/Background: The Kinetic-House-Tree-Person (KHTP) drawing test is widely used by psychiatric occupational therapists in Taiwan; however, very little support has been provided through studies examining its psychometric properties. The aim of the study is to validate a scoring system for the KHTP on a group of people with psychiatric disorders. Methods: A total of 66 individuals with psychiatric disorders were recruited for this study along with 53 college students as a comparative group. Each participant completed the KHTP test. Half of the individuals with psychiatric disorders (33 people) completed the KHTP again following a 2-week period. The KHTP scoring system contains 54 items representing drawing characteristics. Two independent raters determined the score of the drawings, with the validity and reliability of the KHTP scoring system being subsequently examined by the Rasch and traditional analysis. Results: The results reveal both validity and unidimensionality of the KHTP scoring system, demonstrating acceptable test–retest reliability. The intraclass correlation coefficient of the scoring system's inter-rater reliability was .76, with significant statistical differences found between the KHTP scores of college students and individuals with psychiatric disorders. Conclusion: The KHTP scoring system has acceptable construct validity, inter-rater reliability, and test–retest reliability. Because drawing tests have the advantage of expressing nonverbal characteristics, the scoring system should prove to be very useful for those who are unwilling or unable to communicate verbally. This study therefore provides valuable information for clinical application, particularly for the psychiatric rehabilitation professions.

Keywords

• drawings
• psychometrics
• Rasch measurement model