791 - Autism Diagnosis: Where is it Happening, with Whom, and Why?

Publication Number: 791.3882

Veronica I. Underwood Carrasco, Oregon Health & Science University, Portland, OR, United States; Christina Charlesworth, Oregon Health & Science University School of Medicine, Portland, OR, United States; Kelsey Watson, Oregon Health & Science University School of Medicine, Yachats, OR, United States; Olivia Lindly, Northern Arizona University, Flagstaff, AZ, United States; Ava Lu, Oregon Health & Science University School of Medicine, Portland, OR, United States; Katharine Zuckerman, Oregon Health & Science University School of Medicine, Portland, OR, United States

Background: In the US, formal autism diagnosis by specialty mental health (SMH) clinicians trained in autism assessment is often needed for condition-specific service access. However, long waitlists for SMH diagnostic evaluations reflect limited workforce availability. The American Academy of Pediatrics supports primary care provider (PCP) autism diagnosis to accelerate autism care access; however, it is unclear how widespread this practice is in the US or whether access to PCP diagnosis is equitable.

Objective: Use a multistate dataset of Medicaid/CHIP claims to assess frequency of PCP and SMH autism diagnosis in early childhood, association of child sociodemographic and neighborhood factors by diagnosing provider type, and whether the COVID-19 pandemic impacted PCP diagnosis rates.

Design/Methods: Using Transformed Medicaid Statistical Information System Analytic Files from 14 states with sufficient claims volume and complete data, we conducted a retrospective cohort analysis of children ages 1-5 first diagnosed with autism from 2017-2020. Taxonomy codes and well-child visit claims captured different provider types. Diagnosis by provider type (i.e., PCP vs. SMH) before and during the COVID-19 pandemic was compared by patient (age, sex, race-ethnicity) and geographic (urbanicity, state) characteristics. In pre-COVID data, we explored factors associated with a PCP diagnosis using Ordinary Least Squares regression models including state-fixed effects.

Results: PCP diagnosis varied by state, from 14.5% in North Dakota to 49.8% in Nevada, and by race-ethnicity, from 22.3% for Black children to 32.9% for Hispanic children (Figure 1). The early months of COVID show signs of a negative diagnosis trend for both PCPs and SMH . Among children who received an autism diagnosis before (n=21,368) and during (n=1,883) COVID, 25.7% and 22.9% were diagnosed by a PCP versus a SMH provider, respectively. In an adjusted model (Figure 2), we found that compared to white children, Hispanic children were more likely to be diagnosed by a PCP versus SMH pre-COVID (4.65p.p., 95% C.I. 2.1-7.21, p < 0.001).

Conclusion(s): Over 1/5 of our sampled Medicaid/CHIP-enrolled children ages 1-5 received an autism diagnosis from a PCP rather than SMH. Even so, PCP diagnosis rates varied substantially by state. Hispanic children were more likely than white children to be diagnosed by a PCP versus SMH. Additional research will include 2020-2021 data to better understand diagnosis trends during COVID and describe how to reach children who need an autism diagnosis more equitably.

Figure 1. Percent Diagnosed by PCP (vs SMH) by Race and Ethnicity
Notes. AI/AN = American Indian/Alaska Native; HI/PI = Hawaiian or Other Pacific Islander.

Figure 2. Adjusted Ordinary Least Square Regression Model: Factors Associated with PCP Diagnosis
Notes. Model also includes state fixed effects (estimates not shown); AI/AN = American Indian/Alaska Native; HI/PI = Hawaiian or Other Pacific Islander. (p.p.) = percentage points. Results show the percentage point differences relative to the respective referent group (white; female; rural).