All study procedures and retrospective data collection were approved by the Institutional Review Board at Lurie Children’s Hospital.
Youth and caregivers (N = 301) were referred by primary care pediatricians for an outpatient psychiatric evaluation. Pediatricians making these referrals were part of a program called Mood, Anxiety, ADHD Collaborative Care (MAACC)  designed to train and expedite mental health care access in small- to medium-sized community pediatric practices. Patients and caregivers were referred by their pediatrician for evaluation between June 2018 and October 2020. Table 1 includes patient demographics. Youth (ages 7-18 years, M = 12.93; SD = 3.02) and their caregivers completed measures in English or Spanish. Thirteen caregivers used the Spanish Language PROMIS and SCARED measures; all other youth measures were completed in English. A smaller sample of youth and caregivers (n = 52) who had completed measures 2-3 weeks prior to the diagnostic interview were asked to repeat the PROMIS A-SF measure on the date of the diagnostic interview to assess test-retest reliability.
PROMIS Anxiety Short Forms 2.0 (PROMIS A-SF)
The PROMIS A-SF measures were created to assess anxiety for children ages 8-17 and caregiver proxy from ages 5-17 [14, 15]. Likert response total scores range from 8 to 40 (1 = "never" to 5 = "almost always"). Summed raw scores and associated T-Scores (M = 50, SD = 10) are provided on the Health Measures website (https://www.healthmeasures.net/search-view-measures?task=Search.search). There are no established clinical cut off scores for the PROMIS A-SF, although T-score severity levels of mild-moderate and moderate-severe have been described by Carle et al.  in a large sample.
Screen for Child Anxiety Related Emotional Disorders (SCARED)
The SCARED is a 41-item questionnaire designed to assess a variety of anxiety symptoms occurring over the prior three months, with parallel caregiver- and child-report versions . The SCARED allows for calculation of a total anxiety score (0-82) and has a five-dimension structure, with subscale scores for panic/somatic anxiety, SEP, GAD, SOC, and school avoidance. The SCARED has demonstrated discriminant validity between anxious and non-anxious youth, strong internal consistency (coefficient α of approximately .90), and favorable psychometrics in treatment-seeking samples [9, 10, 12, 21, 22].
Anxiety Disorders Interview Schedule for DSM-IV: Child and Parent Versions (ADIS-IV-C/P)
The ADIS-IV-C/P  are semi-structured diagnostic interviews used to assess psychopathology among youth ages 6-18, with a particular emphasis on anxiety disorders. Clinical Severity Ratings (CSR) ranging from 0 to 8 are assigned by the clinician for each diagnosis with the ADIS-IV-C/P, with a CSR of 4 or greater representing symptoms and distress/interference at a level that meets full diagnostic criteria. There is strong evidence supporting the reliability, validity, and sensitivity to clinical change for the ADIS-IV-C/P . Test-retest reliability for anxiety disorder diagnoses for both parent and child reports is excellent (ƙ coefficients, .80 to .92) , and interrater agreement for anxiety disorders diagnosed with the ADIS-IV-C/P is strong (ƙ coefficients, .80 to 1.0) . The ADIS-IV-C/P modules for Attention Deficit Hyperactivity Disorder, Oppositional Defiant Disorder, Separation Anxiety, Generalized Anxiety, Social Anxiety, Panic Disorder, and Depression were administered to all youth and caregivers.
Procedure & Data Collection
Patients were referred to MAACC for further mental health evaluation by their pediatrician. Patients were initially screened by telephone for appropriateness of referral (e.g., age 7-18 years, no autism or developmental disorders, not recently engaged in higher levels of care, etc.). All patients and caregivers received the PROMIS A-SF and SCARED (among other clinical measures not included in this study) by mail or accessed online through a secure portal prior to their appointment. Directions were given to both the caregiver and youth to complete the measures prior to the diagnostic intake. The psychologist was occasionally presented with completed paper measures at intake if the patient did not complete measures digitally. This procedure represented the typical evidence based assessment process in a busy outpatient clinic described by Youngstrom and colleagues  and Ford-Paz et al. . A licensed psychologist administered the ADIS-IV-C/P anxiety modules with the child or adolescent and at least one caregiver/guardian. Although inter-rater reliability was not tracked, the psychologist and program psychiatrist, both trained in ADIS-IV administration, discussed findings for all new diagnostic evaluations.
Descriptive statistics were completed for the sample in addition to test-retest reliability with a subset (n = 52) participants who repeated measures. All analyses were conducted using STATA 15.1 .
Pearson’s correlation coefficients were calculated to assess concurrent validity between the PROMIS A-SF and the SCARED (Total Score, Panic, GAD, Separation, Social Anxiety). Pearson correlations of ≥ .9 are described as very high; .7-.89, high; .5-.69, moderate; .3-.49, low; < 3, negligible .
Clinician-completed ADIS-IV structured interviews were administered to caregivers and youth and used to identify anxiety-related diagnoses of GAD, SEP, or SOC. The category of “any anxiety disorder” included children meeting criteria for any of those three anxiety disorders. ROC analyses were performed to determine how well the PROMIS and SCARED measures could distinguish between the presence or absence of each disorder. Panic disorder was not included because there were too few cases (n = 2) to allow for analyses. The Area Under the Curve (AUC) is the metric for the best overall classification ability for each diagnosis. AUC values are typically evaluated on the following scale: 0.9-1.0 excellent; 0.80-0.9.89 good; 0.70-0.79 fair; 0.60-0.69 poor; 0.50-0.59 fail. Sensitivity (SE), specificity (SP), and positive predictive values (PPV) were calculated for the PROMIS A-SF.
The percent of missing data was low for SCARED and PROMIS A-SF measures. Youth and Caregiver measures for SCARED-Total, Panic, GAD, SEP, SOC, and School Avoidance subscales had less than 13% missing data. Missing data for the youth and caregiver measures of the PROMIS A-SF Total Scores was less than 6%. To determine if the data were Missing Completely at Random (MCAR), Little’s test was performed and was not found to be significant (p = .57). As a result, imputation was not needed and pairwise deletion was used to manage missing data.