ACTH Stimulation Testing Is Often Unnecessary After Appropriate Patient Preparation Prior to Screening Cortisol Measurement
Authors' conclusion
Careful attention to pre-test patient preparation and implementation of a lower cortisol threshold may significantly reduce the number of stimulation tests needed to screen for AI.
Study context
- Population
- Patients with ACTH stimulation testing (Short Synacthen Test [SST]) for suspected adrenal insufficiency (AI)
- Participants
- 835 patients
- Exposure
- Screening morning cortisol vs optimally collected cortisol (after removal of confounding medications) for predicting AI
- Outcome
- Discrimination of serum cortisol for AI on SST (AUC; 100% sensitivity threshold)
Methodological detailsretrospective chart review, ROC curve analysis
- Retrospective chart review
- ROC curve analysis
Main finding
As reported in the abstract
Discrimination for AI
| Group | AUC | 100% sensitivity threshold | SSTs saved | Additional tests saved |
|---|---|---|---|---|
| Screening cortisol | 0.80 (95% CI, 0.77-0.82; p < 0.001) | 262 nmol/L | 112 (13.4% of all tests) | |
| Optimally collected cortisol | 0.89 (95% CI, 0.87-0.91; p < 0.0001) | 246 nmol/L | another 4.8% of all tests |
AUC
Screening cortisol0.80 (95% CI, 0.77-0.82; p < 0.001)
Optimally collected cortisol0.89 (95% CI, 0.87-0.91; p < 0.0001)
100% sensitivity threshold
Screening cortisol262 nmol/L
Optimally collected cortisol246 nmol/L
SSTs saved
Screening cortisol112 (13.4% of all tests)
Optimally collected cortisol— not stated in the abstract
Additional tests saved
Screening cortisol— not stated in the abstract
Optimally collected cortisolanother 4.8% of all tests
Observational data: associations, not effects.
Further findings
Correlation between screening morning cortisol and optimally collected cortisol
- Poor correlation, r
- 0.34 (95% CI, 0.25-0.42)
Passed the SST
- Patients who passed the SST
- n = 756; 90.5%
Original publication
ACTH Stimulation Testing Is Often Unnecessary After Appropriate Patient Preparation Prior to Screening Cortisol Measurement. Clin Endocrinol (Oxf). Published 28 January 2026. doi:10.
Composed by AI from the published abstract and checked against it. How Briefs are made →