Back to Basics, 2016 POPULATION HEALTH : Vital & Health Statistics Dr. Nicholas Birkett School of Epidemiology, Public Health and Preventive Medicine

LMCC Links Links to three objectives: 03/ Assessing and Measuring Health Status at the Population Level 78.1Concepts of Health and its Determinants 78.7Health of Special Populations

03/20163 Important Questions What are the main causes of illness or death in Canada? –Common things are common using epidemiology can help you run a better clinical practice Hippocrates

03/20164 Important Questions How have disease incidence and mortality changed in Canada in the past 20 years? –Little good information on disease incidence except for reportable diseases and cancer (cancer registries) –Lots of information on mortality

03/20165 TOPICS Demography, population dynamics Mortality Morbidity Summary measures of population health Aboriginal health Many slides present information on key diseases and causes of death

03/20166 Population Dynamics, 2007 CanadaNfldNunavut % aged >6514% Total fertility1.7 Birth rate/1, Death rate/1, Rate of Natural Increase/1, CanadaNfldNunavut % aged >6514%15% Total fertility Birth rate/1, Death rate/1, Rate of Natural Increase/1, CanadaNfldNunavut % aged >6514%15%3% Total fertility Birth rate/1, Death rate/1, Rate of Natural Increase/1,

03/20167 Some definitions Dependency ratio –a measure of the degree to which a population ‘dependent’ –Usually based on the number under age 15 and over age 65 –Compares to the number between age 15 and 65. Total Fertility rate –Average number children expected to be born to a women IF: Current fertility patterns hold throughout her lifetime.

World Health Report, 2012 (data mostly from 2009) Population (x 1,000) Growth (%) Dependency ratio % % aged > 60 Total Fertility rate LE at birth (both sexes) P dying < 5 yrs (per 1000) Afghan- istan Canada34, China France Japan USA Population (x 1,000) Growth (%) Dependency ratio % % aged > 60 Total Fertility rate LE at birth (both sexes) P dying < 5 yrs (per 1000) Afghan- istan Canada34, China France Japan USA310, Population (x 1,000) Growth (%) Dependency ratio % % aged > 60 Total Fertility rate LE at birth (both sexes) P dying < 5 yrs (per 1000) Afghan- istan 31, Canada34, China France Japan USA310, Population (x 1,000) Growth (%) Dependency ratio % % aged > 60 Total Fertility rate LE at birth (both sexes) P dying < 5 yrs (per 1000) Afghan- istan 31, Canada34, China France Japan126, USA310, Population (x 1,000) Growth (%) Dependency ratio % % aged > 60 Total Fertility rate LE at birth (both sexes) P dying < 5 yrs (per 1000) Afghan- istan 31, Canada34, China1,348, France Japan126, USA310, Population (x 1,000) Growth (%) Dependency ratio % % aged > 60 Total Fertility rate LE at birth (both sexes) P dying < 5 yrs (per 1000) Afghan- istan 31, Canada34, China1,348, France62, Japan126, USA310, /20168

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10 Population Pyramids

03/ Population Pyramids Canada, Ontario Newfoundland Yukon

Some measures of population health 1203/2016

13 Measures of Population Health (1) Mortality rates –crude Overall all-cause mortality rate –specific mortality rate for a specific group (men), disease (lung cancer), etc. –standardized Mortality rate adjustment to take account of the aging population 03/2016

14 Mortality data Life expectancy: –average age at death if current mortality rates continue. Derived from a life table. Potential Years of Life Lost (PYLL): –subtract age at death from some “acceptable” age of death. –Sum up over a group estimates ‘potential’ years of life lost due to early death Places more emphasis on causes that kill at younger ages. 03/2016

15 Impact of different causes of death in Canada 2001: Mortality rates and PYLL Source: Statistics Canada 03/2016

16 Measures of population health (2) Mortality is a ‘crude’ measure of population health Need to consider –morbidity –quality of life –disability –and so on. 03/2016

17 Measures of population health (3) Many other measures have been developed Quality Adjusted Life Years (QALYs) –Years lived are weighted according to quality of life, disability, etc. Two ‘classes’ of these types of measures: –Health expectancies point up from zero –Health gaps point down from ideal 03/2016

Some more theory 03/201618

19 Standardization (1) The (made-up) mortality from prostate cancer was: –1950: 50/100,000 –2000: 100/100,000 Were men dying from prostate cancer at twice the rate in 2000? NO! 03/2016

20 Standardization (2) Population is older in 2000 than Distorts the comparison. Standardization adjusts for age differences Always should be used when presenting incidence and mortality trends in a population BUT NOTE: twice as many men will need treatment for prostate cancer in /2016

21 Standardization (3) The essential idea –If only the two populations had the same age distribution, we’d be OK –Let’s fake things out. –Define a standard population –For each of your two populations, figure out how many deaths would have occurred if only the population were the same as the standard one. –Now, compare the two rates 03/2016

22 Standardization (4) Direct: –yields age-standardized rate (ASMR) Indirect: –yields standardized mortality ratio (SMR) You don’t need to know how to do this 03/2016

23 Attributable Risks (1) Would like to know the amount of a disease which might be prevented if we eliminate a risk Tricky area since there are several measures with similar names. –Attributable risk –Attributable fraction –Population Attributable Risk –and so on Gives an upper limit on amount of disease which we can prevent. Meaningful only if association is causal. 03/2016

24 Attributable Risks (2) Two main targets for these measures The amount of disease due to exposure in the exposed subjects. The same as the risk difference. The proportion of risk attributed to the exposure in the general population –depends on Risk due to exposure How common the exposure is. 03/2016

25 Attributable risks (3) ExpUnexp Risk Difference or Attributable Risk I exp I unexp RD = AR = I exp - I unexp 03/2016

Attributable risks (3) Exp Unexp Attributable Risk, population I exp I unexp Population I pop

Attributable risks (4) Exp Unexp Attributable Risk, population I exp I unexp Population I pop Exposure is uncommon

Attributable risks (5) Exp Unexp Attributable Risk, population I exp I unexp Population I pop Exposure is common

Attributable risks (6) Risk in the population is a weighted average of –risk in exposed people –risk in unexposed people. The weight is the prevalence of the risk factor in the population:

30 Attributable risks (4) ExpUnexp Population Attributable Risk I exp I unexp I pop Population 03/2016

General (All-Causes) Mortality

03/ # deaths in Canada from ; men and women. Population got: Bigger Older

03/ # deaths in Canada from ; men and women.

03/ Mortality RATES in Canada from ; men and women.

03/ Mortality RATES in Canada from ; men and women.

03/ Infant Mortality,

03/ Infant Mortality,

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4003/2016

41 Rectangularization of the mortality curve

Cause-Specific Mortality

03/ Leading causes of death (2009) Cause Cancer Lung9(M); 8(F)7.8 - Breast5 (F)4.2 (F) - Prostate3 (M)3.1 (M) Cardiovascular Ischemic heart Other circulatory Stroke65.9 Respiratory disease77.0 Injuries44.3 Diabetes42.9 Alzheimer’s disease22.6 Suicide1.6

03/ CANCER: 30.3% Circ Disease: 27.6% † † Pneumonia & influenza grouped with respiratory disease. Would increase infectious % to about 3.4%.

03/ CANCER: 29.8% Circ Disease: 29.0% † † † Pneumonia & influenza grouped with respiratory disease. Would increase infectious % to about 3.5%. { EXTERNAL CAUSES: 4.8%+

03/ CANCER: 31.6% Circ Disease: 27.3% † † † Pneumonia & influenza grouped with respiratory disease. Would increase infectious % to about 3.3%. { EXTERNAL CAUSES: 3.4%+

03/ Cancer Cluster Cardio- vascular Cluster ‘Other’ Cluster

03/ ‘Other’ Cluster

03/ Suicide Crime

03/201650

03/ Cancer and Age Age-Specific Mortality Rates for All Cancers by Sex, Canada, 2003 Surveillance Division, CCDPC, Public Health Agency of Canada

03/ Cancer and Age Age-Specific Incidence Rates for All Cancers by Sex, Canada, 2003 Surveillance Division, CCDPC, Public Health Agency of Canada

03/ Time trends in Males IncidenceMortality

03/ Time trends in Males (up to 2013) IncidenceMortality NOTE:NHL is not listed in my source for these rates. No idea why not.

03/ Time trends in Females IncidenceMortality

03/ Time trends in Females (up to 2013) IncidenceMortality

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Income Inequalities in Health

Income Inequalities SES (socio-economic status) –Lower  worse health Life expectancy 6.6 years lower in the poorest group. –Complex causal pathway Nutrition Race Habits Environmental/occupational Access to/use of health/preventive services Political isolation Others 60 03/2016

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Income adequacy quintiles Men Women Remaining Life Expectancy at age 25. Based on 10-year follow-up to 1991 census 03/201662

Remaining life expectancy at age 25, MenWomen Total, all quintiles Quintile 1 (lowest) Quintile Quintile Quintile Quintile 5 (highest) Difference Q5-Q /

Probability of survival to age 75 (conditional on surviving to age 25), MenWomen Total, all quintiles Quintile 1 (lowest) Quintile Quintile Quintile Quintile 5 (highest) Difference Q5-Q /

Summary Measures of Population Health Combine mortality and a measure of morbidity

03/ Impact of Chronic Diseases CategoryMortalityMorbidity Cancer85%15% Cardiovascular79%21% Diabetes37%63% Respiratory33%67% Neuropsychiatric8%92% Musculoskeletal7%93% Sense organs0%100%

03/ Summary Measures of Population Health Indicator Type Life (Survival)Health-Adjusted Life (Survival) GapYears of Life Lost (YLL) Disability-Adj Life Years (DALY) ExpectancyLife Expectancy (LE) Health-Adj Life Expectancy (HALE)

03/ Life Expectancy and Health-Adjusted Life Expectancy Gender Indicator MalesFemalesDifference LE HALE Difference HALE always < LE Females live longer (but gap is narrowing) Females suffer more morbidity

03/ Disability-Adjusted Life-Years Lost

03/ Which Chronic Diseases? Cancer CHD Diabetes Respiratory Neuro-Psych Musculoskeletal Sensory

03/ Deaths vs Prevalence, Canada Different scales!

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Aboriginal Health

Population Pyramids 03/201674

Age-specific Fertility Rates 03/201675

Percentage of Live Births by Age Group of Mother 03/201676

Crude Mortality Rate 03/201677

Age-adjusted Mortality Rate 03/201678

Age-specific Mortality Ratio 03/201679

Life Expectancy at Birth in Years, by Sex 03/201680

Leading Causes of Death (age- standardized) 03/201681

Potential Years of Life Lost (PYLL) 03/ First NationsCanada

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