INTRODUCTION: Adult growth hormone deficiency (GHD) is an endocrine disorder associated with increased morbidity and poor quality of life. The purpose of this study was to describe the clinical characteristics, treatment patterns, and prevalence of individuals at risk for adult GHD and individuals with confirmed adult GHD in the United States (US). METHODS: Using Veradigm Network electronic health records linked to claims, this study identified adults with a high likelihood of adult GHD based on having ≥ 1 of the following between January 1, 2017 and December 31, 2021: diagnosis of hypopituitarism or ≥ 1 related condition, such as Cushing disease, ≥ 3 pituitary hormone deficiencies other than GHD, ≥ 3 pituitary hormone treatments other than growth hormone (GH), or ≥ 1 prescription for GH. Index date was the earliest qualifying event. Individuals were stratified by GH level on or before index date: confirmed adult GHD (<
3 ng/mL), at risk for adult GHD (no test result), ruled-out (≥ 3 ng/mL). RESULTS: US prevalence of adult GHD was estimated to be between 0.2 (confirmed) and 37.0 (confirmed + at-risk) per 100,000. Among 268 individuals with confirmed adult GHD and 54,310 at risk for adult GHD, mean age was 50 years old, and a majority were female. GH treatment was initiated in 9.7% of confirmed individuals and 3.1% of those at risk for adult GHD. Among confirmed and at-risk individuals, prevalence of endocrine-related conditions was higher in treated individuals, whereas prevalence of several metabolic and cardiovascular comorbidities was higher in those untreated. Only 32.2% of individuals who initiated treatment during the follow-up period were persistent until the end of follow-up. CONCLUSIONS: Our findings report US prevalence of adult GHD and suggest that adult GHD is commonly underdiagnosed in the US. Factors contributing to low rates of adult GHD diagnosis and treatment warrant further research.