Endocrine Abstracts

Background: Short Synacthen Test (SST) is widely used to assess hypothalamic-pituitary-adrenal (HPA) axis in patients on corticosteroids. This requires significant material and human resources especially as patients often require multiple tests. We performed a retrospective cohort study, followed by the implementation of QIP methodology to reduce the number of SST in this cohort of patients.

Methodology: We reviewed 167 patients who had a SST and derived a 9am cortisol cut-off of <138 nmol/l which predicted failure of SST in 100% of patients. This value included co-efficient of biological and laboratory variability of 15.2% and 3.2% respectively. Thereafter, SST was requested only for the patients with 9am cortisol >138 nmol/l. We reviewed the data on the next 38 consecutive patients on corticosteroids referred for HPA axis assessment who had 9am cortisol and evaluated the impact on the number of SST and its cost benefits.

Results: In 23(60%) patients, 9am cortisol was >138 nmol/l and 19(50%) of these patients had SST. In 15 (39%) patients 9am cortisol was <138 nmol/l and 11(29%) patients successfully avoided SST and despite appropriate communication, 4(10%) patients had unnecessary SST (all failed) which could have been avoided with stricter implementation of the protocol. 20(53%) of these patients required further SSTs during a one-year period and 9 of these were avoided. For every 100 patients on corticosteroids referred for HPA-axis assessment, we expect to avoid 39 first and 24 repeat SSTs resulting in a saving of £3118.50 (£49.50/test) and ~94 hours of time for a doctor/specialist nurse with significant reduction in waiting time for patients.

Conclusions: The use of 9am cortisol cut-off accurately and safely predicted failure of SST and led to reduction in the number of SSTs and significant saving of cost and manpower resource. We recommend other healthcare organisations to implement a similar process.