Adrenal Insufficiency in Australia: Is it Possible that the Use of Lower Dose, Short-Acting Glucocorticoids has Increased the Risk of Adrenal Crises?

Abstract

Morbidity from adrenal insufficiency (AI) in Australia is poorly described. The objective of this study was to evaluate AI morbidity patterns in adults between 1999/2000 and 2011/2012 using national databases. A descriptive study of hospitalisations for AI and adrenal crises (AC) in adults and trends in prescriptions for 2 short-acting glucocorticoids (GC) was designed. The setting was the Australian healthcare system. Main outcome measures are the trends in hospitalisation and prescription rates. There were 7,378 hospital admissions for treatment of AI in adults between 1999/00 and 2011/12. Of these, 29.5% were for an AC. Admission rates for AC increased from 9.5 to 12.4 admissions/10(6)/year (p < 0.05). There was a 5.8% decrease in admission rates for AI (excluding AC), from 27.0 to 25.5/10(6)/year (p = ns). Short-acting GC [hydrocortisone (HCT) and cortisone acetate (CA)] prescription rates increased significantly (p < 0.001) from 3,176.1/10(6) to 3,463.8/10(6). Prescription rates for CA decreased by 22.4% (p < 0.001) but HCT prescription rates increased to 77.1% (p < 0.001). The increase in AC admission rates was positively correlated with the rise in both the total GC prescription rate (r = 0.63, p < 0.05) and the HCT prescription rate (r = 0.74, p< 0.01). Over the 13-year study period, there was a 30.8% increase in hospitalisation rates for ACs and a concomitant 77.1% increase in prescribing of HCT. The association between AC events and HCT use and/or reduced effective GC dose is plausibly causal, but confirmatory studies are required before suggesting any change to GC replacement in AI.