The Behavior Problems Inventory (BPI-01) in community-based adults with intellectual disabilities: reliability and concurrent validity vis-à-vis the Inventory for Client and Agency Planning (ICAP).

Reliability and concurrent validity of the Behavior Problems Inventory (BPI-01; Rojahn et al., 2001) was examined in a sample of 130 community residing adults with mild to profound intellectual disabilities with high rates of behavior problems and concurrent mental health problems. The BPI-01 and the Inventory for Client and Agency Planning (ICAP; Bruininks et al., 1986) were administered twice within a mean time interval of 7.8 weeks by 20 trained and experienced staff members. All three BPI-01 subscales had high inter-rater agreement (Self-Injurious Behavior [SIB]: mean ICC=.84; Stereotyped Behavior: mean ICC=.75; Aggressive/Destructive Behavior: mean ICC=.82), and stable test-retest reliability (SIB, mean ICC=.91; mean Stereotyped Behavior, mean ICC=.89, and Aggressive/Destructive Behavior, mean ICC=.88); internal consistency ranged from poor (SIB: alpha=.61) to excellent (Stereotyped Behavior, alpha=.90). Using the ICAP as criterion measure, the BPI-01 showed robust convergent validity. Solid relationships between BPI-01 subscales and corresponding ICAP subscales corroborated the concurrent validity of the BPI-01.