Primary adrenal insufficiency in the United States: diagnostic error and patient satisfaction with treatment.

Background The objective of the study was to assess the diagnostic process, access to care and treatment adequacy for primary adrenal insufficiency (PAI) patients from a US-based online registry. Methods The National Adrenal Diseases Foundation (NADF) patient registry from 2015 to 2016 was used for a cross-sectional assessment of PAI patients. Five hundred and forty-one adults met the study inclusion criteria (US residents, age >20, self-reported physician diagnosis of PAI and replacement dosing for cortisol). Issues in diagnosis, comorbid conditions, symptoms, with demographic and socioeconomic characteristics were determined. Disease management assessment included medication dose, patient satisfaction with function, and education. Factors associated with adrenal crisis were noted. Results The cohort was predominantly female (83%), non-Hispanic White (97%), and well-educated (94% > high school education). A majority (57%) of patients reported difficulty with initial diagnosis, while 27% felt that their current steroid replacement was not adequate. Comorbid thyroid disease and other autoimmune conditions were common among PAI patients in the registry. More than three-quarters (78%) of patients used hydrocortisone for glucocorticoid replacement with a mean dose of 24.4 (standard deviation [SD]: 8.7) mg. Mean dose of hydrocortisone has declined over time following current treatment recommendations. Conclusions Timely, accurate diagnosis remains a problem for patients with primary adrenal insufficiency in an affluent, well-educated US cohort. Episodes of adrenal crisis are common and replacement steroid treatment is not always effective for patient function. Comprehensive information about outcomes of care for PAI in the US remains limited and the establishment of a research-specific registry to foster future research may be desirable. Patient registry data is a valuable source of information on diagnostic error and outcomes of care in rare diseases.