Understanding autism diagnosis in primary care: Rates of diagnosis from 2004 to 2019 and child age at diagnosis

The capacity of the workforce lags behind the current demand for timely autism diagnostic assessment. Primary care providers (PCPs) are well-positioned to diagnose autism at earlier ages than providers from other disciplines. Thus, bolstering PCPs' diagnostic capabilities has been the focus of many recent capacity-building initiatives. Using data from the National Survey of Children's Health, this study aimed to evaluate whether diagnosis of autism in primary care has changed over time and whether diagnosis in primary care relates to age at autism diagnosis. Results indicated that the likelihood of being diagnosed with autism by a PCP decreased by about 2% with every passing year from 2004 to 2019 when controlling for demographic characteristics. PCPs diagnosed children approximately 1 year earlier than non-PCPs (e.g., psychiatrists and psychologists), which supports the critical role PCPs can play in timely diagnosis. Further research is needed to understand why the proportion of children diagnosed by PCPs has decreased over time; however, these findings suggest that capacity-building initiatives have not yet reached community practice. Future research should focus on the dissemination and implementation of training initiatives in community-based primary care practices.Lay abstract The current demand for autism diagnostic services exceeds the ability of the workforce to assess and diagnose children in a timely manner. One solution may be to equip primary care providers (PCPs) with the tools and expertise needed to diagnose autism within their practice. PCPs are often trusted professionals who have many touchpoints with children during early development, in which they can identify early signs of autism. Recent initiatives have focused on bolstering PCPs' diagnostic capabilities; however, no studies have examined how the rates of autism diagnosis in primary care have changed over time. We aimed to evaluate whether autism diagnosis in primary care has changed over time and how diagnosis in primary care relates to a child's age at the time of diagnosis. We found that the likelihood of a child being diagnosed by a PCP decreased by about 2% with every passing year from 2004 to 2019 when accounting for demographic characteristics. In our sample, PCPs diagnosed children approximately 1 year earlier than non-PCPs (e.g., psychologists and psychiatrists). Further research is needed to understand why the proportion of children diagnosed by PCPs decreases over time. However, this decrease suggests more work is needed to get capacity-building initiatives into community primary care practice. Though we must continue to find effective ways to build community PCPs' ability to diagnose autism, the present findings support the crucial role PCPs can play in early autism diagnosis.