The epidemiology of primary and secondary adrenal malignancies and associated adrenal insufficiency in hospitalised patients: an analysis of hospital admission data, NSW, Australia.

Adrenal insufficiency (AI) causes considerable morbidity but may remain undiagnosed in patients with adrenal malignancy (AM). The epidemiology of AI and adrenal crises (AC) in AM is uncertain. This was a retrospective study examining hospital admission data from 2006 to 2017. All admissions to all hospitals in NSW, Australia over this period with a principal or comorbid diagnosis of an adrenal malignancy were selected. Data were examined for trends in admissions for AM and associated AI/AC using population data from the corresponding years. There were 15,376 hospital admissions with a diagnosis of AM in NSW over the study period, corresponding to 1281 admissions/year. The AM admission rate increased significantly over the study period from 129.9/million to 215.7/million (p < 0.01). An AI diagnosis was recorded in 182 (1.2%) admissions, corresponding to an average of 2.1/million/year. This rate increased significantly over the years of the study from 1.2/million in 2006 to 3.4/million in 2017 (p < 0.01). An AC was identified in 24 (13.2%) admissions with an AI diagnosis. Four patients (16.7%) with an AC died during the hospitalisation. Admission with a diagnosis of AM has increased over recent years and has been accompanied by an increase in AI diagnoses. While AI is diagnosed in a small proportion of patients with AM, ACs do occur in affected patients.