Evaluating the Low-Dose ACTH Stimulation Test in Children: Ideal Times for Cortisol Measurement
Bibliographic record
Abstract
CONTEXT: Central adrenal insufficiency (AI) can be diagnosed with the low-dose ACTH stimulation test (LDST). Protocols determining timing of cortisol sampling vary, with 30 minutes after stimulation being most common. OBJECTIVES: To determine optimal times to draw cortisol levels and factors predicting timing of peak cortisol levels in children undergoing LDST. DESIGN: Retrospective chart review of LDSTs between February 2014 and September 2017. SETTING: The Children's Hospital of Eastern Ontario. PATIENTS: Patients 3 months to 20 years who underwent LDSTs. INTERVENTION: LDSTs were performed with cortisol levels at 0, 15, 30, and 60 minutes after 1 μg cosyntropin. Cortisol values <18 μg/dL (500 nmol/L) determined AI. MAIN OUTCOME MEASURES: The incremental value of testing cortisol at 15 or 60 minutes, in addition to the standard 30-minute sample, was estimated. RESULTS: A total of 221 patients met inclusion criteria. The mean age was 9.7 years, and 32% were female. Peak cortisol levels were 19%, 67%, and 14% at 15, 30, and 60 minutes, respectively. One false positive LDST result would be prevented for every 24 (95% CI, 13 to 46) or 55 (95% CI, 22 to 141) patients tested at 15 or 60 minutes in addition to the standard 30-minute test. Of the 122 patients who passed the LDST, discontinuing the 15- and 60-minute samples would have misdiagnosed 12 patients (9.8%). Glucocorticoid exposure, age, and body mass index z scores were independent predictors of peak cortisol timing. CONCLUSION: Although the majority of patients peak 30 minutes after cosyntropin administration, testing cortisol levels at 15 and 60 minutes reduces the risk of false positive LDSTs.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.004 | 0.004 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".