1 / 14

Population Health Model (POHEM) AMI

Population Health Model (POHEM) AMI. Acknowledgements: CCORT for collaboration and funding. 2001. …….. …….. …….. …….. …….. …….. …….. …….. …….. …….. ……. POHEM example. Starting Population: Canadian Community Health Survey 2001 (CCHS)

ada
Download Presentation

Population Health Model (POHEM) AMI

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Population Health Model (POHEM)AMI Acknowledgements: CCORT for collaboration and funding.

  2. 2001 …….. …….. …….. …….. …….. …….. …….. …….. …….. …….. …….. POHEM example Starting Population: Canadian Community Health Survey 2001 (CCHS) cross-sectional representation of the Canadian population aged 18+ VARIABLE age sex province health region immigration status education level income quartile body mass index smoking status diabetic status HUI total cholesterol* HDL* blood pressure* Survey sample weight *imputed from Canadian Heart Health Surveys (1986-1992) • At beginning of each year: • update risk factor profile • evaluate hazard of developing disease •  none in 2001 • evaluate hazard of dying •  2051 VALUE 44 male Ontario York non-immigrant post-secondary Q4 (richest) 32.2 kg/m2 (obese) smoker non-diabetic 0.96 high low high 100.32

  3. 2002 age sex province health region immigration status education level income quartile body mass index smoking status diabetic status HUI total cholesterol HDL blood pressure 2001 …….. …….. …….. …….. …….. …….. …….. …….. …….. …….. …….. …….. POHEM example Starting Population: Canadian Community Health Survey 2001 (CCHS) cross-sectional representation of the Canadian population aged 18+ 2002.3 UA CHF AMI2 AMI AMI at age 45.3 Now at risk of 2nd AMI, CHF, UA, ...

  4. 2003 … 2002 2001 …….. …….. …….. …….. …….. …….. …….. …….. …….. …….. …….. …….. …….. …….. POHEM example Starting Population: Canadian Community Health Survey 2001 (CCHS) cross-sectional representation of the Canadian population aged 18+ 2023.1 2028.4 2002.3 UA CHF Death at age 71.2 AMI2 CHF OA AMI Congestive Heart Failue at age 66.1 in year 2023 Osteoarthritis at age 69.4 in year 2028 period of comorbidity from living with OA and CHF

  5. 2002 … 2001 …….. …….. …….. …….. Death …….. …….. …….. …….. …….. …….. …….. …….. …….. …….. …….. POHEM example Starting Population: Canadian Community Health Survey 2001 (CCHS) cross-sectional representation of the Canadian population aged 18+ 2003 …….. …….. >100,000 records on CCHS representing over 20 million Canadians in 2001 Plus New Immigrants and New 18 year olds in subsequent years = 1 hour on a PC New 18 year olds New Immigrants

  6. Data Sources • Canadian Community Health Survey (2000/01) • cross-sectional • representative of household population • starting population for POHEM (2001) • National Population Health Survey • longitudinal from 1994-2004 (6 cycles) • model individual’s change in BMI, Smoking • Many other data sources • survey, administrative, census, registry, vital, literature

  7. Upstream health determinants Intermediate risk factors Intermediate diseases Sequalae Death Smoking NPHS 1994-2004 Alcohol Sex transition models 2nd AMI Total cholesterol & HDL Region S(t) Nutrition S(t) blood pressure Obesity AMI* Congestive Heart Failure Death Income S(t) S(t) S(t) Diabetes Education Physical activity survival data for each transition incidence rates by province, age and sex Unstable Angina initial values & transition models Health Person-Oriented Information (HPOI) (HIRD) Registered Persons database for Ontario (ICES) (CCORT I) initial values CCHS 2001 Vital statistics (and other POHEM disease modules) Cdn Heart Health Surveys 1986-92 competing risk of death from other causes Coronary Heart Disease: Acute Myocardial Infarction (AMI) Causal pathway age (time) *incidence-risk equation based on Framingham risk function (Wilson 1998) for “index” AMI events

  8. How POHEM Generates an Incident Case of AMI • Data Analysis and Input to POHEM: • incidence rates (I) are estimated from administrative data by age, sex and province • Framingham risk function, obtained from literature, relates risk factors to incidence •  (beta coefficients from Wilson 1998) vary by risk factor categories • α represents baseline risk by age, sex, province, calibrated to reproduce observed incidence rates (I) and takes into account the distribution of the risk factors in the population • initial values of risk factors from national surveys • models of change in risk factors based on trends from national surveys • POHEM selects a record from CCHS in simulation year 2001: • male, age 44, Ontario, smoker, non-diabetic, high total cholesterol, low HDL, medium blood pressure... • Lookup baseline risk and risk factor coefficients from input parameter table. • Evaluate the probability (p) of AMI • using the Framingham risk function • (with rescaling): • p = F/(1+F) = 0.877 • Convert p to an annualized hazard (h): • h = -ln(1-p) = 2.09 • Generate a uniform random number (u) between 0 and 1 • u = 0.975 • Convert u to an annualized hazard (h*): • h* = -ln(1-u) = 3.69 • Transform the proportional hazards to a waiting time: • t = ( h* / h ) = 1.76 years • AMI does not occur at age 44 in year 2001. • POHEM ages the person forward to next birthday and re-evaluates risk of AMI (steps 2-8). • Repeated for every record on CCHS, births and new immigrants αmale,44,ON = 0.00138 βsmoker = 0.523 βnon-diab = 0 βchol-high = 0.657 βHDL-low = 0.497 βBP-med = 0.283

  9. Trends in overnight hospitalizations for new AMI cases (External Validation) POHEM projections of AMI, Ontario Data source: HPOI (hospital discharge abstract database); POHEM projections superimposed

  10. First AMIs projected* to increase in all provinces *POHEM projections

  11. Age-standardized rate of AMI projected to decline  reduced impact from risk factors

  12. POHEM (age 18+) CCHS (age 18+) CTUMS (age 15+) Chart 1 Percentage of current smokers , Canada excluding territories, 2000 to 2006 % Sources: Population Health Model (POHEM); Canadian Tobacco Use Monitoring Survey (CTUMS); Canadian Community Health Survey cycles 1.1, 2.1, 3,1 (CCHS)

  13. POHEM: Overall causal flow Age Sex Region Income Education Obesity Intermediate risk factors Upstream health determinants Intermediate diseases Diseases Treatment Death Death TIME (AGE and YEAR) Health-related Quality of life (e.g., HUI) Coronary Heart Disease Alcohol Surgery, Drug, Lifestyle Depression Age Sex Ethnicity Stroke Smoking ABS Region Peripheral Vascular Disease Cholesterol Amputation Hyper- tension Diabetes Diabetic Retinopathy Nutrition Income Cataract surgery... Blood pressure Kidney Disease Dialysis Education Obesity Osteoarthritis Surgery, Drugs Physical activity other risk factors other diseases 25 Cancers Surgery, Radio/Chemo/Hormonal therapy Initial state assigned from CCHS (+CHHS) competing risk of death from other causes

More Related