Assessment of Pediatric Bipolar Spectrum Disorder Symptoms: Differential Item Functioning Based on Sex
Creators: name: Rodda, Phoebe
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2024

description: Bipolar Spectrum Disorders (BPSDs) are a vital public health concern, severely reducing quality of life and functioning (Kessler et al., 2005), and occur in children and adolescents as well as adults (Van Meter et al., 2019). Youth with BPSDs often present with significant impairment in quality of life, and clinical characteristics that show continuity with BPSDs in adults (Youngstrom et al., 2008). Proper assessment of BPSDs in youth is crucial for early diagnosis and intervention. Current literature describes the devastating impact that BPSDs can have on youth populations, especially if they go undiagnosed and untreated (Birmaher, 2013). There is great need for unbiased, clinically valid, and widely accessible screening tools to help better detect BPSDs in pediatric populations. This is a secondary analysis of data gathered via NIH R01MH066647. Youths between 5 and 18 years of age seeking outpatient mental health services and their caregivers were recruited from either an academic clinic at Case Western Reserve University/University Hospitals of Cleveland or a community clinic at Applewood Centers in Cleveland, Ohio (N=806). Youth were 52% male and 48% female; 25% identified as being European American, 68% African American, 2.1% Hispanic, 0.5% Asian or Pacific Islander, and 4.5% “Other”. Caregivers completed the PGBI 10M, 10Da, and 10Db scales (Depue et al., 1981; Youngstrom et al., 2008; Youngstrom et al., 2021). Linear regression analysis screened for differential item functioning (DIF) based on the biological sex. Statistically significant (p<0.005) uniform DIF was detected in PGBI 10M items #2 (p=0.0017, t=3.15), #3 (p=0.003, t=-2.98), and #8 (p=0.0045, t=2.85). No PGBI 10Da or 10Db items had significant DIF once the cutoff for statistical significance was lowered to reduce the probability of a type I error. However, marginal DIF was detected in 10Da item #3 (p=0.013, t=-2.50). The estimated maximum total contribution of DIF to total score on the PGBI 10M was 0.66 points, which is less than the minimal important difference for the 10M, making the DIF on this scale unlikely to be clinically concerning (Youngstrom et al., 2020). Results supported our hypothesis that statistically significant sex DIF would be found within the PGBI subscales. However, we identified DIF in fewer items than hypothesized, and its magnitude was not clinically concerning, supporting the utility of these three PGBI subscales as screening measures for pediatric mania and depression. Importantly, we are not able to determine if the DIF we detected was benign (indicative of true differences between males and females) or adverse (indicative of measurement bias) (Breslau et al., 2008; Teresi & Fleishman, 2007; Zumbo, 2007). Future studies examining the nature and generalizability of this DIF are needed, as are projects screening for DIF based on other demographic variables. By developing clinical screening tools that are unbiased, clinically sound, and accessible, we can help to ensure that youth with BPSDs receive treatment and resources that are vital to their wellbeing.