No spirometer needed for the screening call. Enter age, smoking history, and two cheap
symptom/risk-factor scores — the console flags who should get a spirometry test next, it does not replace one.
1 · Patient — Screening Inputs
Symptom and risk-factor inputs only. No FEV1/FVC reading required at this stage.
55
12
5
430
Smoker
Non-smoker
Yes
No
Result — Screening Call + Severity Estimate
Logistic-regression screen decides the class; linear-regression estimate grades predicted FEV1% (both distilled from the trained SVM/SVR pair, see footer).
NORMAL
AT-RISK
OBSTRUCTED
Confidence in screening call—
Estimated FEV1 (% predicted)—
30 (severe)110 (normal)
ROUTINE — monitor
No obstructive signal detected.
screen
Human-in-command: this screen flags who should get a spirometry (FEV1/FVC) test next —
it does not diagnose COPD. Confirmed obstruction, once flagged, still needs the actual test.
2 · Medical resource planning — COPD / pulmonary population
🌍 GLOBAL COVERAGE — planning anchored to the real health-system spend of 24 countries. Choose your market; COPD-cohort cost, bed-days and avoidable spend re-compute in your economy.
Annual care cost (pulmonary cohort)—
Expected inpatient bed-days / yr—
Cost avoidable via early cessation / bronchodilator—
P1 · NASNurses for follow-up (@500/nurse)—
Spirometry referrals to pre-empt (shadow cohort)—
Ties the individual call to the system view: every At-risk patient flagged here becomes a spirometry referral and nurse-follow-up load (Project 1). Catching airflow limitation early — before COPD — is where the avoidable cost lives.
The system flags who needs a spirometry test. A clinician makes every call.PRAS surfaces its own uncertainty and hands the judgement to a human — augmenting the clinician, never replacing them.
How the numbers are derived — data vintage & method
Data sources & vintage
L1 · Airflow model
Author’s doctoral thesis — Vol.1 Ch.3 “Lung Ventilation Modeling & Assessment” (damped-oscillator R/C indices). Single illustrative case, so L1 substitutes real GOLD spirometry (disclosed).
L2 · Spirometry / severity
101 real GOLD-consistent COPD patients (FEV1/FVC, severity labels). Normal class = documented ATS/ERS reference (FEV1/FVC ≈ 0.80 ± 0.05) — a disclosed modelling assumption, not real controls.
L3 · Population risk
300 real asthma-cohort patients (smoking / comorbidity signal).
Umbrella 24-country per-capita anchors (WHO / World Bank, compiled mid-2026, SGD), wired into the market-planning panel above (patients × COPD severity multiplier 1.0 / 1.5 / 3.0 × per-capita anchor; avoidable = At-risk × per-capita × 45% early-cessation effect).
Method — illustrative screening scaffold, not billed figures:
Screening call
logistic-regression surrogate of the full SVM (6 features: age, smoking, pack-years, CAT, asthma, peak flow) — 99.1% agreement with the full SVM (ACC 96.3%, macro-F1 0.90).
Severity estimate
linear-regression surrogate of the SVR predicting FEV1% predicted — R²=0.85 vs the full SVR.
Cost method
wired into the market-planning panel above: patients × COPD severity multiplier (Normal 1.0 / At-risk 1.5 / COPD-Obstructed 3.0) × per-capita anchor; avoidable = At-risk × per-capita × 45% (early smoking-cessation / bronchodilator effect). Per-capita anchors: WHO / World Bank, compiled mid-2026, SGD.
Cohort is the synthetic PRAS-RP dataset (6,000 patients). Every row carries the SYNTHETIC label; a clinician makes every call.
What this is. A screening-only console: predicts a 3-class pulmonary risk band
(Normal / At-risk / COPD-Obstructed) and an estimated FEV1% from age, smoking history,
symptom burden (CAT score), asthma comorbidity, and peak flow — deliberately excluding the
actual FEV1/FVC spirometry reading, so it can be used before a spirometer is involved, to
decide who needs one.
Champion models (server-side, full precision). SVM classifier (screening-only 6-feature
set) — 96.3% accuracy, macro-F1 0.90, ROC-AUC (OvR) 0.986. Per-class recall: Normal 99%,
At-risk 97%, COPD-Obstructed 70% — the model reliably catches Normal and At-risk, but
under-catches confirmed obstruction from symptoms alone. That is the honest, expected finding for
a screening tool built without a spirometry reading: severe disease still needs the actual test to
confirm, not a symptom-based guess. SVR severity regressor (same 6 features, predicting FEV1%
predicted) — R²=0.61, MAE=7.98.
Browser distillation. This page runs a logistic-regression surrogate of the SVM
(99.1% agreement with the full model on held-out data) and a linear-regression surrogate of the
SVR (R²=0.85 vs the full model) — same distillation pattern as the RRAS/DRAS consoles,
so the browser needs no server and no Python at runtime.
Data sources (5-layer evidence stack, PRAS-RP synthetic cohort, 6,000 patients).
L1+L2 spirometry/severity: 101 real COPD patients (GOLD-consistent FEV1/FVC, COPD severity
labels) for the At-risk/Obstructed classes; the Normal class uses a documented ATS/ERS population
reference (FEV1/FVC ≈ 0.80 ± 0.05) since the real cohort has no healthy controls —
this is a modelling assumption, not real patient data. L3 population: 300 real asthma-cohort
patients for smoking/comorbidity signal. L4 utilisation: 15,108 real respiratory hospital
encounters (130-hospital dataset, ICD-9 490–496/466/480–488/786 subset;
readmit30=8.1%, mean LOS=4.2 days), resampled by class. L5 economics: Umbrella 24-country
per-capita anchors (WHO / World Bank, compiled mid-2026, SGD), wired into the market-planning
panel above — patients × COPD severity multiplier (1.0 / 1.5 / 3.0) × per-capita anchor,
avoidable = At-risk × per-capita × 45% early-cessation effect. Illustrative planning figures, not
billed costs.
Theoretical grounding. Thesis Vol.1 Ch.3 “Lung Ventilation Modeling and
Assessment”, S3.12–3.13, develops a damped-oscillator model of lung volume in terms of
airflow-resistance (R) and compliance (C), proposing R/C-derived indices for differential
diagnosis of obstructive lung disease — the same theoretical role Vol.1 Ch.1 played for DRAS
and Vol.2 App.G played for RRAS. Unlike those two, Ch.3 does not contain a multi-subject R/C
table to resample from (only a single two-lung illustrative case) — so this console's L1
layer substitutes real GOLD-consistent spirometry for resampled thesis kinetics. That substitution
is disclosed here, not hidden.
Status: SYNTHETIC cohort and distilled screen — a research scaffold, not a validated
clinical tool. ⚠ Human-in-command: every flag is a prompt for a clinician-ordered test, not a
diagnosis.