Public Health Epidemiology in Ontario and Statistics Canada – Opportunities / Challenges / Questions

Michael Wolfson

Statistics Canada

October 15, 2007

Statistics Canada Provides:

• a wide variety of data

• geographic data infrastructure

• various summary indicators

• analytical studies and reports

• record linkage capacity

• simulation modeling tools

(ont web site)

(http://www.health.gov.on.ca/transformation/providers/information/im_resources.html)

Ontario Government Tools

• “The Health Analysts Toolkit”

• “Ontario Health Planning Survey Guide”

• “Ontario Health Planning Data Guide”

• produced by Health Systems Intelligence Project of the Ontario MOHLTC – Jan 2006

• provides an excellent review of many data sets, including those from Statistics Canada

Champlain LHIN - Map

Champlain / NW LHINs - Pop

Champlain LHIN - SES

Champlain LHIN - HS

Champlain LHIN - RFs

Champlain LHIN - Chronic

Definitions

• cross-sectional survey (CCHS etc.)> provides a “snapshot” of a population at a certain

point in time

• longitudinal survey (NPHS)> surveys the same group of people repeatedly over

time> provides dynamic information on the “trajectories”

followed by a population> Permits examination of cause-effect relationships

CCHS “.1’s” – Objectives

• Support pan-Canadian health surveillance > nationally-comparable population health data for

provinces and health regions

• Support health research on small populations and rare characteristics 

• Make information readily available to a diversified user community in a timely fashion

• Offer a flexible survey instrument, including a rapid response option for emerging issues

CCHS “.1” Design

• large sample: originally ~ 130,000 respondents per year, every other year> Stratified to produce estimates for sub-provincial

health regions, provinces, territories & Canada> Residents of private households aged 12+

• mix of personal and telephone interviews> Interview of 40-45 minutes

• broad range of content

• household basics – demography, SES

• common content (30 minutes)> asked of all respondents> Core content (20 minutes) included in questionnaire

every year> Theme content (10 minutes) rotates according to

consensus-based long-term plan

• optional content (10 minutes)

CCHS “.1’s” – Content

CCHS “.1” Example Results - Smoking

Example of optional content selection CCHS 2.1

Proportion of Total Sample Asked Optional Module, Canada, Provinces and Territories - %Canadian Community Health Survey 2.1 (2003)

Module Canada NL PE NS NB QC ON MB SK AB BC YK NT NUAlcohol dependence / abuse 12 - - - - - - - - - 100 - - -Blood pressure check 16 - 100 100 - - - - 16 100 - - 100 100Breast examinations 22 - - - - - 30 - - - 100 - 100 -Breast self examinations 9 100 - - - - 17 - - - - - - -Changes made to improve health 37 100 100 100 100 3 25 100 - 100 - 100 100 -Colorectal cancer screening 29 100 - - - - 33 - 63 - 100 - - -Contacts w/mental health professionals72 100 100 - 100 100 100 - - 100 - - 100 -Dental visits ** 72 - 100 - - 100 77 - 32 100 100 - - -Depression 38 100 100 - 100 - 58 - 20 100 - 100 100 100Dietary supplement use 3 100 - - - - - - - - - - - -Distress 30 - - - 100 100 13 - - - - 100 100 100Driving & safety ** 54 - - 100 - 3 100 100 29 100 - 100 100 -Eating troubles 15 - - - - - 31 - 100 - - - - -Food choices 77 100 - 100 100 3 100 100 100 100 100 100 - 100Food insecurity 62 100 - 100 100 100 20 - 24 100 100 100 100 100Health care system satisfaction 57 - - - 100 100 100 - - - - - - -Health Utility Index ** 34 100 100 100 100 100 - - - - - - - -Home safety 4 - - - - - 10 - 22 - - - - -Illicit drug use 23 - - - - 3 13 - 100 - 100 - - -Leisure activities 4 - - 100 - - - - - - - - - -Mastery 1 - - - - 3 - - - - - - - 100

Example of optional content selectionCCHS 2.1 (cont’d)

Proportion of Total Sample Asked Optional Module, Canada, Provinces and Territories - %Canadian Community Health Survey 2.1 (2003)

Module Canada NL PE NS NB QC ON MB SK AB BC YK NT NUMedication use ** 39 - - - - 97 13 - 36 - 100 - - -Nicotine dependence 40 - - - - 100 7 - 100 100 - 100 100 -Oral health (optional) ** 36 - - - - - 73 - 8 - 100 - - -Patient satisfaction ** 14 - 100 100 100 - 16 - - - - - - -Physical check-up 26 - 100 - - 100 7 - - - - - - -Physician counseling (smoking) 17 - - - - - 3 - 100 100 - 100 - -Problem gambling 7 - - - - 3 10 - 56 - - - - -Prostate cancer screening 38 100 - - 100 - 59 - 15 - 100 - 100 -Psychological well-being 0 - - - - - - - - - - - - 100Satisfaction w/availability of services 41 - - - - 100 60 - - - - - - -Satisfaction w/life 10 - - - - - - - - 100 - 100 - -Sedentary activities 44 - - - - - 49 100 7 100 100 - 100 -Self-esteem 6 - - 100 - - 8 - - - - - 100 -SF-36 6 - - - - - - 100 - - - - - -Smoking cessation aids 44 - - - - 100 20 - 100 100 - 100 100 -Social support 5 100 100 - - - - - - - - - - -Stages of change (smoking) 33 100 - - - 100 7 - 100 - - 100 100 -Suicidal thoughts and attempts 38 - - - 100 - 56 - 100 100 - - 100 100Tobacco alternatives 16 - - - - - - - 100 100 - 100 - -Use of protective equipment 32 - - - - - 68 - 8 100 - - - -Work stress 12 100 - - - - 27 - 15 - - - - -

CCHS “.1” - Survey Redesign

• Continuous collection> started in Jan. 2007> ~65,000 respondents per year, every year> non-overlapping 2-month collection periods

• Questionnaire / Content> Common content split into theme and core content> Long-term plan for theme content> Maintain optional content> Capacity to include a maximum of 2 min. of extra content “on

the fly” (Rapid Response)

• Data will be available more often> Annual data release

CCHS “.1” Theme Content Long-term plan

2007 2008 2009 2010 2011 2012Health

Services Access

Chronic Disease

ScreeningTBD TBD TBD TBD

Health Living Injury Prevention Mental Well-Being

CORE CONTENT

OPTIONAL CONTENT

2007-08

OPTIONAL CONTENT

2009-10

OPTIONAL CONTENT

2010-11

Rapid Response - $ (max of 2 minutes)

CCHS “.2” – Objectives

• (originally in intervening years)

• support in-depth research on specific topics or themes> cycle 1.2 (2002) → Mental Health and Well-being> cycle 2.2 (2004) → Nutrition> (cycle 3.2 → CHMS) > cycle 4.2 (2008) → Healthy Aging

• provincial level (only) detail

CCHS Cycle 1.2 (2002) Mental Health & Well-being – Objectives

• estimate prevalence in the general population of selected mental health disorders

• provide information on the utilization of mental health services and perceived health needs

• provide data on the disability / impact associated with mental health problems to both individuals and society

• examine links between mental health and social, demographic, geographic and economic characteristics

CCHS Cycle 1.2 (2002) – Design

• Target population:> persons aged 15+ living in private dwellings in the ten

provinces (excludes territories)• Sample size ~37,000 respondents• Personal interview

> limited (14%) telephone follow-up> telephone, non-proxy only

• Five mental health disorders assessed> major depression, mania disorder, panic disorder, social phobia and

agoraphobia> as well as alcohol and illicit drug dependence

• Supplement on Canadian Forces> also assessed GAD and PTSD> active members and reserves

CCHS 1.2 - Mental Health & Well Being

• Alcohol use & dependence• Chronic Conditions• Distress• Eating troubles• Gambling• General health• Height & weight• Illicit drug use & dependence• Medication use• Physical activities• Psychological well-being• Restriction of activities• Services• Social support• Spirituality• Stress• Two-week disability• Work stress

• Screening (diagnostic modules)• Depression• Mania• Panic disorder• Social phobia• Agoraphobia

• Administration• Income• Labour force• Socio-demographics

Results from the CCHS Cycle 1.2 (2002) - Measured Mental Disorders or Substance

Dependence / Past 12 Months

Population Aged 15+ Covered in CCHS 1.2 25,000,000 %

Major depression 1,200,000 4.8

Mania disorder 240,000 1.0

Panic disorder 380,000 1.5

Agoraphobia 180,000 0.7

Social anxiety disorder (Social phobia) 750,000 3.0

Alcohol dependence 640,000 2.6

Illicit drugs dependence 190,000 0.8

Total - Any measured disorder or substance dependence 2,700,000 10.6

CCHS Cycle 2.2 (2004) Nutrition – Objectives

• estimate the distribution of usual dietary intake > in terms of food groups, dietary supplements, nutrients and eating

patterns through a dietary recall computer application> for a representative sample of Canadians at provincial and national

levels• measure the prevalence of household food insecurity

among various population groups in Canada• gather anthropometric measurements

> body height and weight• collect correlate information

> physical activity> selected health conditions> socio-demographic characteristics

CCHS Cycle 2.2 (2004) Nutrition – Design

• Target population> persons of all ages living in private dwellings in the ten

provinces (excluding the territories)

• Sample size ~35,000• 1/3 of respondents asked second dietary recall to

provide information on usual intake> personal interview for the 1st interview> telephone interview for the 2nd recall interview

• Stratified by 10 provinces and 15 age-sex groups corresponding to Dietary Reference Intake groupings

CCHS Cycle 2.2 (2004) Nutrition – Content

Food consumption• 24-hour dietary recall

> USDA Automated Multiple Pass Methodology

> Modified for Canadian marketplace

> All foods and beverages> 5 steps - improve chances of

recalling all foods eaten1. Quick List2. Forgotten Foods3. Time and Occasion4. Detail Cycle5. Final Probe

• 2nd interview> 10,000 of 35,000 respondents> 24-hour recall only

Other topics• Alcohol Consumption (age 12+)• Children’s Physical Activity (age 6 to 11)• Chronic Conditions (all)• Fruit and Vegetable Consumption (age 6 mo.+)• General Health (age 12+)• Household Food Security (all)• Measured Height and Weight (age 2+)• Physical Activity (age 12+)• Sedentary Activity (age 12 – 17)• Self Reported Height and Weight (10% sample,

age 18+)• Smoking (age 12+)• Vitamin and Mineral Supplements (all)• Women’s Health (women age 9+)

• Socio-Demographics (all)• Labour Force (age 15 – 75)• Income (all)

Results from CCHS Cycle 2.2 (2004) % above upper end of recommended range of total calories from

fat, by age group and sex,

population aged 4+, Canada excluding territories

2. Significantly different from estimate for previous age group of same sex (p < 0.05) Notes : Estimates of energy intake include calories from alcoholic beverages. Based on usual consumption. Excludes women who were pregnant or breastfeeding. E = use with caution / F = too unreliable to be published

Data source : 2004 Canadian Community Health Survey: Nutrition

Results from CCHS Cycle 2.2 (2004) distribution of BMI, population aged 12 to 17,

Canada excluding territories, 1978/79 and 2004

CCHS Cycle 4.2 Healthy Aging

Objectives• factors, influences and processes that contribute

to healthy aging• health, social and economic determinants

Design• respondents aged 55+• sample size – to be determined• collection July 2008 to May 2009 • computer Assisted Personal Interview (CAPI)• possible link to CLSA / longitudinal survey

Health Services Access Survey (HSAS)

• Fill gap in “Quality of service” indicator area> Access to 24/7 first contact health services> Waiting times for key diagnostic and treatment services

• HSAS 2001> Collected as follow-up supplement to CCHS (.1)> 14,210 respondents> representative national-level estimates> sample buy-ins (P.E.I., Alta., B.C.)

• HSAS 2003 & 2005> Integrated in CCHS (.1): sub-sample of 32,000+ respondents> representative provincial-level estimates

• HSAS 2007> CCHS (.1) 2007 annual theme> Asked of a sub-sample of 32,000+ respondents

• Future uncertain….

Joint Canada / United States Survey of Health (JCUSH) -

ObjectivesObjectives• Examine Canada-US differences in health status and use of

health care services• Identify possible areas for collaboration in questionnaire design /

developmentDesign• Conducted jointly by Statistics Canada (STC) and the National

Center for Health Statistics (NCHS) • Target population 18+ in private dwellings• Collection: fall 2002 to spring 2003• All interviews by telephone, conducted from STC regional offices• Sample size ~3,500 Canada / ~5,200 US• Standard approach across both countries

Canadian Health Measures Survey (CHMS) – Background

• high-priority topics – e.g. environmental toxins, metabolic syndrome, physical fitness, other CHD risk factors – can only be assessed through direct physical measures

• other high priority health information collected through self-report surveys or administrative records is subject to reporting error – e.g. obesity, hypertension

• directly measured attributes can be measured more precisely / reported on continuous scales

• estimate the numbers of individuals in Canada with selected health conditions, characteristics, and elevated levels of major risk factors

• estimate the distributional patterns of selected diseases, risk factors and protective characteristics

• monitor trends, based to the extent possible on available historical data• ascertain relationships among risk factors, protective behaviours, and

health status• explore emerging public health issues and new measurement

technologies• assess the validity of prevalence estimates based on self- and proxy-

reported information• collect a nationally representative sample of genetic material and other

covariates for future genetic research• provide a potential platform and infrastructure for ongoing physical

measures surveys and add-on studies• share our experience with others

CHMS – Objectives

• combination of household interview + direct measures completed in mobile exam clinic

• national estimates, n = 5,000 over 2 years• atypical sample design – 15 clusters selected

from 97% of population (due to cost, logistics)• Ages 6-79 (6-11, 12-19, 20-39, 40-59, 60-79)• 2007-2009 in the field

CHMS – Parameters

National Population Health Survey (NPHS) – Objectives

• Support research into the dynamic processes of health > Provide data for analytical studies that will assist

in understanding the determinants of health

• Evaluate the relationships between socio-economic and demographic characteristics of individuals with their health status and its evolution over time

• Aid in the development of public health policy

NPHS – Household Component

• Main component of NPHS> persons in private households in the ten provinces> first cycle in 1994-95 → every two years

• Cross-sectional sample> served cross-sectional purposes: 1994, 1996, 1998

• subset of questionnaire – all members of household• detailed health information – selected household respondent

• Longitudinal sample> same selected household respondent revisited each cycle> 17,276 respondents initially> detailed health information from selected respondent> socio-demographic information on household each cycle

• including household composition, income, education

NPHS – Other Components

• Intended to complement main NPHS household component

• Institutions component> Residents of long-term care institutions (4+ beds) in the ten

provinces> 5 cycles of data: 1994-95 → every two years to 2002-03> Sample ~2,200 respondents → national level data> High mortality: ~1/3 of respondents each cycle

• North component> Household residents in each territory> 3 cycles of data, 1994-95 → every two years to 1998-99> Sample ~2,000 respondents → territorial level data> Territories covered by the CCHS “.1’s” since 2000

Cross-sectional vs longitudinal findingsShift work and the health of males

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Source: NPHSN. B. bars represent 95% confidence intervals;

colour change occurs at mean relative risk

Cross-sectional results: The odds of having been diagnosed with a chronic disease did not differ for men who worked shift compared with those working a regular daytime schedule

Longitudinal results: Working shift was associated with increased health risks over time. Working a non-standard schedule in 94/95 was predictive of developing chronic diseases over the next 4 years.

Some Other Survey Data Sets

• population census – disability screener

• major surveys> HALS / PALS – Health / Participation and Activity

Limitations Surveys (post-censal)> NLSCY – National Longitudinal survey of Children and

Youth

• related surveys> SHS/FAMEX – Survey of Household Spending,

formerly FAMily EXpenditure survey> GSS – General Social Survey

Cancer Registration In Canada

• Originated at varying times across country

Provincial level 1st : 1935 BC & Sask

• NCIRS: 1969 - 1991 at Statistics Canada

• 1992 : CCR established – new standards

Canadian Cancer Registry (CCR)

Key Features• Reference Year - 1992• Person Oriented Data Set

- Person & Tumor Records - Data Definitions/Standards

• National Coverage• Internal Duplicate Protocol• CMDB Linkage & Clearance

CCR: How it is used

• Calculate cancer incidence and survival statistics

• Occupational, environmental and other medical follow-up studies

• Production of the Canadian Cancer Statistics monograph

• Research programs i.e. tobacco control, product safety, workplace health and safe environments

• Assess the impact of new technologies and treatments

self health a

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self health b

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type of smokerecumen mapcchs type of smokerecumene map

An Almost Familiar World Map

www.worldmapper.org; cartogram algorithm: Mark Newman

Area Proportional to Population

Area Proportional to GDP 2002

Area Proportional to HIV(prevalence ages 15 – 49)

Area Proportional to “Unhealthy Life”(LE – HALE)

Health Indicators

• joint Statistics Canada / CIHI set> equity dimension – needs development

• Performance Indicators pursuant to First Ministers’ Health Accords> FPT process – moribund

• note Ontario Indicators

• QUESTION: what others?

Data Access

• print publications

• web site – tables, studies, maps

• microdata files (sometimes)> public use> via remote job submission> via the Research Data Centres> via the Ontario MOHLTC

• QUESTION: what modes of access would be most useful

Challenges

• small area estimates

• hypothesis testing

• choice of content areas

• measuring health status and health outcomes

• comparability – beyond Canada?

• beyond monitoring? (to causality / modeling)

Definition - Health Outcome

health status “before”

health status “after”

health intervention

other factors

change in health status attributable to a health intervention (for an individual)

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Men

Women

Changes in Life Expectancy (LE) and Health-Adjusted Life Expectancy

(HALE) by Cause, Canada

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IHD

Lung cancer

Breast cancer

Stroke

COPD

Colorectal cancer

Diabetes

Melanoma

Osteoarthritis

Mental disorders

Men

Women

(Source: Manuel et al, ICES and Health Canada, NPHS)

HALELE

Example of NPHS Analysis Using LifePaths / POHEM

• LifePaths and POHEM ( = Statistics Canada’s POpulation HEalth Model) – microsimulation-based projection tools

• projecting disability prevalence> in the context of population aging, and> declining fertility rates,> rising divorce rates,> and recent trends in the levels of disability who will look after future frail elderly

Disability Definitions – Motivation

• define disability severity levels in terms of likely predictors of need for services

• focus on activities commonly associated with use of home care services, e.g. everyday housework, grocery shopping, meal preparation, and personal care

• use projections of these disability levels as rough proxy for inferred “population at risk” for service needs such as home care – if not from close relatives, then either purchased or from government

Disability Definitions – SpecificsDisability Definitions – Specifics(based on McMaster HUI3, most severe level)(based on McMaster HUI3, most severe level)

> No disability

> Mild disability• Mobility problem but do not need any help

• Dexterity problem but do not need any help from someone else (may or may not use special equipment)

• Somewhat forgetful and little difficulty in thinking

• Moderate and/or severe pain prevents performing some or few activities

> Moderate disability• Requires wheel chair or mechanical support to walk

• Dexterity problem and need help to perform some tasks

• Very forgetful and a lot of difficulty in thinking

• Severe pain prevents performing most activities

> Severe disability• Can not walk or need help from others to walk

• Dexterity problem and need help for most or all tasks

• Unable to remember or think

Estimation of Disability Dynamics

• data source: 1994, 1996, 1998 and 2000 waves of longitudinal NPHS (n = 287 to 12,733)

• look at pairs of “triples” for dynamics – two overlapping sets of 3 waves for each individual> 1994 – 1996 – 1998, and 1996 – 1998 - 2000> recognizes a degree of duration dependence (i.e. nests and

tests naïve first order Markov assumption)> allows assessment of unobserved person-specific factors

• look at improvements or deteriorations only> not a limiting assumption given modeling in continuous time

• use cross-validation to assess choice of specification (opportunistic, given bootstrap weights)

Disability Status Transition Matrix

None Mild Mod Severe Inst’n Dead n obs

None 0.91 0.07 0.02 0.00 0.00 0.01 22,401

Mild 0.54 0.32 0.10 0.01 0.00 0.02 2,783

Moderate 0.24 0.21 0.34 0.09 0.02 0.10 1,255

Severe 0.10 0.07 0.20 0.34 0.08 0.22 341

Disability Transition Hazard Regressions – Functional Forms

• age (cubic spline), prior disability• + (A) simple individual level variance• + (B) individual level variance covariates (education,

nuptiality, immigration)• + (C) other covariates (year, sex, education, nuptiality,

immigration)• results:

> prior disability matters (i.e. 2nd order Markov)> (A) and (B) matter; (C) not

• how to assess: use replicated “out of sample predictions” based on 500 bootstrap weight vectors

DALY

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AGE

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Sub-Sample of 100 Simulated Life Paths

4 life paths

95 life paths

vertical axis = 1.0 x years without disability + 0.8 x years with mild + 0.6 x moderate + 0.4 x severe +

0.2 x institutionalized

horizontal axis = 1.0 x years of age

Projected Canadian Disability

Prevalences from 2001 to 2021

Simulated Disability-Institutional Status by Age: 2021 Male Female

-300,000 -200,000 -100,000 0 100,000 200,000 300,0000

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Simulated Disability-Institutional Status by Age: 2001 Male Female

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• darker blue = more severe disability, and ultimately institutionalization

• triangles indicate (roughly) total 65+ population, and “healthy” 65+

Concluding Comments

• Statistics Canada has a great deal of data

• Ontario appears to be using much of it well

• There are important areas of new development

> evolution of CCHS

> new CHMS

> linkage of major surveys to provincial health care records

• There are also questions

> accessibility of data

> priority content needs

> potential of new tools – e.g. mapping, simulation models