south east public health information group tuesday, 9 th december 2014 “modelling future health...

South East Public Health Information Group

Tuesday, 9th December 2014

“Modelling Future Health Trends”

Dr Jürgen C Schmidt, Principal EpidemiologistEnglish Burden of Disease team

2 JC Schmidt, Modelling Future Health Trends

Data flows in PHE


Current modelling in PHE

What do we mean by modelling?Simulation and modelling provide public health science with means for testing and experimenting with potential improvements and future scenarios. Several types of models might be used in the future, including: models for accountability and management; population effects models; prevalence models; and systems dynamics models. Public health agencies will look to modelling and simulation techniques to understand the ‘future state’ of public health conditions under alternative demographic, economic and technological assumptions.

(The future of public health: A horizon scan; 2013 RAND Corporation)


Current situation in PHE• Infectious disease (outbreak and control) modelling, with Health

Protection • Prevalence modelling, with different Knowledge and Intelligence

Teams, building upon previous PHO work• Scenario modelling, Health Checks, with Health and Wellbeing • Economic modelling

Context:• Knowledge strategy• Digital Strategy• R&D Strategy• Integrated Health Intelligence • Strategic Group on Modelling


Strategic Group on Modelling.. ensure that PHE has the capacity to deliver high-quality, robust modelling in epidemiology, health economics, [..] to answer corporate queries; this capacity is internal, and complemented as appropriate by external support; the process for identifying the need for a modelling input, and the implementation of it follows a stringent set of procedures and is in-built into individual directorates’ work programmes. This Strategic Group will produce consensus on definitions, work programmes, utilisation of resources, and capacity building.”


Micro-simulation• Computer model of a specified population• Simulations specifically target relationship between

individuals’ evolving risk factors and disease incidence. • Risk factor distributions determined by past and

current trends• Model can simulate and compare the impact and cost

of various public health interventions. • Individuals can give birth and die in the model, they

can be exposed to risk factors and contract, survive and die from particular diseases based on risks or probabilities.

• Events compete to occur in each simulated life• Individual life trajectories are simulated until death.


UK Health Forum simulation model 2014 - 2034• Obesity-related diseases: e.g. CHD, stroke, T2DM,

cancers Smoking-related diseases: CHD, COPD, stroke, cancers

• Risk factors scenarios (obesity, smoking, salt consumption and blood pressure) ‘steady progress’, ‘best case’, ‘worst case’.

• Prevalence of risk factors by age group and sex, social class and income quintile

• Incidence and prevalence cases avoided or gained given each agreed scenario

• Quality Adjusted Life Years (QALY) and Disability Adjusted Life Years (DALY)

• Indicative impact on healthcare/public sector costs



“steady progress “

Projected overweight and obesity prevalence in 18-65 year old males, steady progress


“worst case”

Projected overweight and obesity prevalence in 18-65 year old males, worst case


Cumulative incidence cases added and avoided per 100,000 relative to steady

progress scenario in 2034


Costs added and avoided relative to steady progress scenario in 2034

Health Checks • to create a microsimulation model of the Health Checks process• how do changes to attendance at Health Checks (either by

changing inclusion criteria or other targeting) affect both the risk profile of those attending and health outcomes

• baseline population taken from HSE• individuals are given trajectories in metabolic risk factors over time• initially focus on Qrisk to cardiovascular diseases (IHD and stroke

considered separately), diabetes, lung cancer and dementia• working but not finalised version of the model February 2015• report by May; journal article submitted soon after• model publicly available with a graphical user interface (GUI)


Current issues

• “All models are wrong”• Clarity of scope• Data• Assumptions• Technical limitations• Technical expertise• IT firepower

• Univariate model, no interaction, no feedback loops, no multiple conditions or effects, the idea that each aspect of a complicated disease control strategy can be managed and evaluated separately


What nextUK Health Forum MIDRIF model •multi-disease, multi-risk factor micro-simulation model simulating the lives and related medical costs of virtual people in the presence of Multiple Interacting Diseases and Risk Factors. •Diseases are modelled with varying complexity depending on the availability of suitable data. •Complex diseases can have multiple dynamic stages. •Multi-stage diseases modelling allows for more accurate cost analyses and the assessment of preventative health care interventions.


PHE‘s Population Health model:• Definition: health outcomes of a group of individuals, and their

distribution, factors influencing population health, and the policy and programme implications of the population health model identified

• simultaneous impact of multiple factors requires a multi-level model

• a given factor may influence health differently according to different environmental, social economic conditions, and other factors.

• Importance of attributable risk at population level rather than the relative risk at individual level

• population health model to include• social factors (inequalities, support, cohesion, structure, stress), • natural environment, • socioeconomic factors (material resources at the individual level,

income inequality at the contextual level), • biology and early childhood development• built environment (e.g., transportation)


Population Health Model


Population health is “the aggregate health outcome of health adjusted life expectancy (quantity and quality) of a group of individuals, in an economic framework that balances the relative marginal returns from the multiple determinants of health.This definition proposes a specific unit of measure of population health and also includes consideration of the relative cost-effectiveness of resource allocation to multiple determinants.

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Data provided

Description UK data sourced Region Years Age Sex IMD

Live births, all-cause mortality, mortality by cause morbidity data & population denominators

ONS Yes Yes Yes Yes No

Cancer Incidence Cancer registries Yes Yes Yes Yes NoRenal replacement therapy UK Renal registry Yes Yes Yes Yes NoHospital treatment by deprivation groups HES Yes Yes Yes Yes YesCommon psychiatric conditions Adult Psychiatric Morbidity Survey Yes Yes Yes Yes NoDementia estimates Cognitive Ageing and Function Study UK only Yes Yes No YesProgramme Budgeting NHS England Yes Yes No No NoGP patient survey GP patient survey for England Yes Yes Yes Yes YesEducation (years per capita) Labour Force Survey Yes Yes No No NoGross domestic product per capita Quarterly National Accounts Yes Yes No No NoLitres of alcohol per adult HMRC & General Lifestyle Survey Yes Yes No No NoMeasles vaccination coverage & DTP3 coverage PHE Yes Yes No No NoSmoking prevalence & Cigarettes consumed per adult HSE Yes Yes Yes Yes Yes Mean BMI, total cholesterol & systolic blood pressure HSE Yes Yes Yes Yes Yes Diabetes prevalence HSE/QOF Yes Yes Yes Yes Yes Mean estimated salt intake (g/day) NDNS Yes Yes Yes Yes Yes Kcal & grams of nuts and seeds/ fruit/ whole grains/ vegetables/ red meat/ milk/ sugary drinks consumed per capita per day

NDNS Yes Yes No Yes YES

Total Kcal & grams consumed per capita per day NDNS Yes Yes No No NoPopulation density ONS Yes Yes No No NoAir pollution GOV.UK UK Only Yes No No NoNumber of 2 & 4 wheeled vehicles per capita GOV.UK Yes Yes No No No

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Summary of England data send to IHME from PHE

JC Schmidt, Modelling Future Health Trends

south east public health information group tuesday, 9 th december 2014 “modelling future health...

Documents

future of public health

future health trendsjc

future health trendswhat

health checks

health economics

control modelling

robust modelling

modelling input