Reliability and validity of the Japanese version of the Behavior Problem Inventory-Short Form

Background The Behavior Problems Inventory-Short Form (BPI-S), which assesses behavior problems in individuals with intellectual disabilities (ID), is a shorter version of the BPI-01. This study investigated the reliability and validity of the BPI-S Japanese version (BPI-S-J) for adolescents/adults with ID and behavior problems. Methods The test–retest reliability included participants with ID and behavioral problems who were enrolled in welfare services. For test–retest reliability, 42 caregivers independently responded to the BPI-S-J every two weeks. Inter-rater reliability was independently assessed using the BPI-S-J by two caregivers who were familiar with the 42 participants. The participants of the validity assessment were 227 students from special needs schools or patients with ID admitted to medical institutions. The total frequency total score was compared based on the degree of ID. To examine the criterion-related validity, we analyzed the total frequency score, the total score of the Criteria for Determining Severe Problem Behavior (CDSPB) and the total score of the Aberrant Behavior Checklist-Japanese version (ABC-J). Results The BPI-S-J of test–retest reliability was satisfactory (intra-class correlation; ICC) = 0.954), and the total score significantly (ICC = 0.721) represented good inter-rater reliability. For the validity, the BPI-S-J score of participants who had severe and profound ID was significantly higher than those who had mild and moderate ID. Significant correlations were observed between the BPI-S-J score and CDSPB score (r = 0.499), and the ABC-J score (r = 0.699), indicating adequate criterion-related validity. Conclusion This study showed the utility of the BPI-S-J to assess behavior problems in the Japanese ID population.