ℹ️ About This Model — methodology, assumptions & caveats (click to expand)
What this is
A synthetic GP population health simulator designed for educational and research use. It models a 10,000-patient list with demographic characteristics representative of a Harrow, NW London practice — one of the most ethnically diverse boroughs in England.
The simulator allows exploration of how population-level interventions affect mortality and disease prevalence over time, using a monthly tick engine with probabilistic incident and death events.
Clinical foundations
Mortality rates: ONS England & Wales life tables, with comorbidity multipliers from published literature (UKPDS, DAPA-HF, EMPEROR, EMPA-REG)
Condition prevalence: Calibrated against QOF 2022/23 national averages, adjusted for Harrow ethnicity profile
QRISK: Simplified scoring based on QRISK3 variables (age, sex, ethnicity, BMI, SBP, cholesterol, comorbidities, smoking)
CHA₂DS₂-VASc: Standard ESC scoring for AF anticoagulation decisions
Ethnicity risk: South Asian CVD multipliers from Bhopal et al.; Pakistani T2DM 3× risk from Bradford/Leicester cohort data; Black HTN elevation from UK Biobank
Intervention evidence base
Polypill: TIPS/PolyIran trials — ~25% MI reduction, ~20% stroke reduction for statin + antihypertensive combinations
Intensive DM: DAPA-HF (dapagliflozin 26% HF reduction), EMPEROR-Reduced (empagliflozin 25% HF reduction), UKPDS (intensive glucose control 24% MI reduction)
COVID wave: ONS COVID-19 mortality by age — age 70+ hazard ratio ~3× baseline; Long COVID prevalence ~10% exposed (REACT-2)
Limitations
Synthetic patients — not real individuals
Simplified QRISK (not validated algorithm)
No socioeconomic gradient within ethnicities
Drug side-effects and discontinuation not modelled
Multi-morbidity interaction effects simplified
⚠️ Educational & research use only. This simulator uses synthetic data and approximated clinical parameters. It is not validated for clinical decision-making, service planning, or commissioning. Results should not be used to guide treatment of individual patients or to make resource allocation decisions without reference to primary evidence and local epidemiological data.
🏥 Developed at a Harrow, NW London GP practice using Claude AI (Anthropic). Built to support population health education, public health training, and scenario planning discussions among clinical colleagues. The model is open-source and freely shareable — if you adapt or extend it, please retain this methodology note. Feedback and suggestions welcome.
Speed: 4×Space1mo Y1yr Aauto Escmodal
Preparing simulations…
Shaded band on mortality chart shows 10th–90th percentile range across 20 random seeds with current interventions active.
🧑🤝🧑 Harrow Demographics & Ethnicity Profile — click to adjust
40%
30%
20%
5%
35%
⚠ Changes take effect on Reset or Rebuild Population
3
13%
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Deprivation and lifestyle factors affect baseline comorbidity prevalence and incident rates.
🔬 Interventions — any combination active simultaneously
💰 Cost & Value Analysis — active interventions only (NHS reference costs 2023/24; indicative only)
Intervention
Patients treated
Est. annual cost
Est. admissions avoided/yr
Est. savings/yr
Net position
⚠️ Indicative estimates only. Drug costs: BNF/NHS Drug Tariff 2024. Admission costs: NHS National Schedule of NHS Costs 2023/24.
Avoided admissions calculated from published trial effect sizes scaled by current uptake × adherence settings.
No allowance for GP/pharmacist time, monitoring, or adverse effects. Not for commissioning decisions without validated health economic modelling.
📊 Scenario Comparison
Saved curves overlay on the mortality chart →
Population Pyramid
Cumulative Deaths (scenario comparison)
Condition Prevalence (%)
⚖️ Health Inequality Gap
Cumulative deaths per 1,000 patients — most deprived quintile (score 4–5) vs least deprived (score 1–2)
Each patient has an individual deprivation score distributed around the practice mean. Adjust interventions and uptake sliders to watch the gap narrow — or widen. The shaded red area is the inequality gap. Source: Marmot Review 2010; PHE Health Equity reports.
Patient List (10,000)
▶ Simulation running — pause to browse patients
Age: –
#
Name
Age
Sex
Ethnicity
Conditions
QRISK
Meds
Harrow GP Population Health Simulator · Open source · Built with Claude AI ·
GitHub ·
📝 Share feedback / how you used this tool ⚠️ Educational and research use only. Not validated for clinical decision-making or commissioning.