3 Variable AHT
- 3 Variable Calculator Applying AHT Definitional Criteria
- Estimated probability of abuse based on:
1. Respiratory Compromise
2. Torso, ear, or neck bruising
3. Bilateral or interhemispheric subdural hemorrhage
Frequently Asked Questions for Providers
To inform your clinical decisions to either launch or forego an abuse evaluation.
As a source of additional data that will help you make an optimal decision.
At or near the time of admission to the pediatric intensive care unit (PICU), when initial history, physical examination, and head imaging studies are complete.
For children under 3 years of age hospitalized for intensive care of acute, closed, traumatic, head injuries confirmed by initial CT or MR imaging. The probability calculators should not be applied to patients with pre-existing brain malformation, disease, infection, or hypoxia-ischemia; or to patients with head injuries resulting from collisions involving a motor vehicle.
Prospective data regarding 973 acutely head-injured patients under 3 years of age hospitalized for intensive care across the PediBIRN network’s 18 participating sites.
It’s easy. The user selects one of two methods for defining AHT and answers three or four simple questions. The calculators return an evidence-based, patient-specific estimate of abuse probability.
Absent a gold standard, AHT was defined in two different ways, applying: (1) the PediBIRN network’s longstanding AHT definitional criteria, and (2) physicians final diagnoses of definitive or probable AHT. Physicians can apply either method, or both methods.
By applying Bayes’ theorem (pre-test odds x likelihood ratio = post-test odds). Pre-test odds of AHT were based on the overall prevalence of AHT in the study population. Likelihood ratios were calculated for every patient subpopulation distinguished by a different combination of the CDR’s three or four predictor variables. Post-test odds of AHT were converted to probability estimates using simple math.
Yes. Applying AHT definitional criteria, the prevalence (pretest probability) of AHT in the PediBIRN study population (N=973) was 44%. Applying physicians’ final diagnoses, the prevalence was 51%.
Yes, users will be able to adjust a sliding scale for AHT prevalence.
They are evidence-based estimates only. They are provided to inform clinical judgment, not replace it. Suspicion of AHT should not be based on only three or four variables. The presenting history, past and family medical history, psychosocial risk assessment, results of tests to confirm or exclude medical mimics, and input from investigators must also be considered.
We can also provide information about the positive yield of abuse evaluations observed in equivalent patients who were evaluated for abuse.