Clinical calculator summary
Original Fardet 2014 HScore
Clinical calculator summary
Original Fardet 2014 HScore
A nine-variable weighted score with a published logistic conversion to estimated probability of adult reactive hemophagocytic syndrome.
Evidence-based context for fast calculator use
- Purpose:
- Reproduce the original HScore and equation-derived probability when all variables are explicitly assessed or marked unknown.
- Population:
- Adults investigated for reactive hemophagocytic syndrome in tertiary-hospital settings.
- Factors:
- Immunodepression, Temperature, Organomegaly, Cytopenias, Ferritin, Triglycerides, Fibrinogen, AST, Marrow hemophagocytosis
- Reference:
- Fardet L, et al. Arthritis Rheumatol. 2014;66(9):2613-2620.
HScore for Reactive HLH (2014)
Clinical Context & Background
HScore = sum of nine published weights (0-337). L = -10.390 + 0.062 x HScore; probability = exp(L) / (1 + exp(L)).Reference Data
| HScore | Published probability anchor |
|---|---|
| 90 | <1% (equation 0.8%) |
| 100 | 1% |
| 110 | 3% |
| 120 | 5% |
| 130 | 9% |
| 140 | 16% |
| 150 | 25% |
| 160 | 40% |
| 169 | 52.2% by equation; original best cutoff |
| 170 | 54% |
| 180 | 70% |
| 190 | 80% |
| 200 | 88% |
| 210 | 93% |
| 220 | 96% |
| 230 | 98% |
| 240 | 99% |
| 250 | >99% (equation 99.4%) |
Clinical Workflow
Use, Interpret, And Continue The Patient Pathway
Expand for workflow guidance, limitations, examples, and related next steps.
Clinical Workflow
Use, Interpret, And Continue The Patient Pathway
Expand for workflow guidance, limitations, examples, and related next steps.
When To Use
- Use in adults being evaluated for suspected reactive/secondary HLH when the nine source variables are available near the marrow-assessment timepoint.
- Select Unknown explicitly when a source variable was not measured; do not leave questions unanswered.
How To Interpret
- Interpret the result as an equation-derived probability estimate from the original cohort, not a categorical risk band.
- HScore >=169 was the original best cutoff with 93% sensitivity and 86% specificity, but performance varies by population and timing.
What To Do Next
- Reconcile the estimate with clinical trajectory, etiology, HLH-2004 features, alternative diagnoses, and repeat assessment where appropriate.
- Determine diagnostic and treatment decisions separately with relevant specialist input; HScore alone does not initiate therapy.
Limitations
- Not derived for pediatric or primary/genetic HLH, general-population screening, or a treatment-initiation rule.
- Unknown variables receive zero points under the source missing-data rule and can bias the estimate downward.
- Zero cytopenic lineages was not estimable in the derivation cohort; it is retained only for official-calculator compatibility with a warning.
- This is HScore, not the separate HLH-2004 diagnostic framework.
Validated Population
Retrospective adult suspected-reactive-HLH cohorts from three French tertiary university hospitals.
Cutoff is not probability
HScore 169 meets the original cutoff but converts to approximately 52.2%, not 70%.
Calculation verification history
Verified
Calculation verification history
Verified: Production browser revalidation
- Three source-backed cases passed through all nine visible production controls at scores 0, exact cutoff 169, and maximum 337.
- Equation-derived probabilities rendered as 0.0%, 52.2%, and 100.0%, with the original >=169 cutoff interpreted correctly.
- No unexpected N/A, stale control, literal undefined/null value, or browser-console error was observed.
Case-level evidence is retained in validation/browser-revalidation/hscore-hemophagocytic-lymphohistiocytosis-2026-08-03.json.
: Production browser validation
- Ten source-backed cases were exercised on the public production route through visible browser controls; 10/10 case records passed their expected-versus-observed assertions across 11 visible submissions.
- Overall browser status: failed-console. medium: Production emitted minified React error #418 during route loads/reloads used by this run.
- Case-level inputs, expected and observed results, reset/repeat behavior, failure reproductions, and console evidence are retained in the production-browser evidence record.
Case-level production evidence is retained in validation/browser-production/hscore-hemophagocytic-lymphohistiocytosis.json.
: Full validation test
- Verified all 3,888 feasible published category combinations through production and UI serialization, exact probability anchors and cutoff cases, source boundaries, strict malformed-input rejection, explicit unknown behavior, nine-variable trace reconciliation, neutral display, and public evidence wiring.
: Correction history
- Corrected the probability display to the published logistic equation (169 = 52.2%; 200 = 88.2%), removed invented risk buckets and favorable defaults, required semantic selections, added explicit missing-data and zero-cytopenia warnings, and removed treatment-initiation claims while clarifying adult reactive-HLH scope and the distinction from HLH-2004.
Verification confirms the calculator implementation against the cited model; it is not independent clinical validation, regulatory approval, or medical advice.
Frequently Asked Questions
Does HScore 169 mean a 70% probability?
No. The published logistic equation gives approximately 52.2% at 169. The 169 value was the original best cutoff, with 93% sensitivity and 86% specificity.
Is HScore the same as HLH-2004?
No. HScore is a weighted adult reactive-HLH probability model; HLH-2004 is a separate molecular-or-criteria diagnostic framework.
What happens when a variable is unknown?
The original derivation assigned missing variables zero points. This calculator requires an explicit Unknown selection and warns that the probability may be underestimated.
Evidence-based oncology decision support. Verify with clinical guidelines.