national population health survey 2004 congress of the humanities and social sciences all congress...

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2004 Congress of the Humanities and Social Sciences

All Congress Symposium - A Journey through data: the riches of the RDCs

Part 3 - Population Health: The National Population Health Survey (NPHS)

June 2, 2004, Winnipeg

France BilocqChief NPHS

Health Statistics Division

Statistics Canada

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PresentationPresentation

Overview of population health surveys NPHS description NPHS content NPHS Microdata and documentation NPHS Usage Products and Web-sites

Overview of Population Heath SurveysOverview of Population Heath Surveys

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ObjectivesObjectives

Aid in the development of public policy; Understand the determinants of health; Collect data on the economic, social,

demographic, occupational and environmental correlates of health;

Increase the understanding of the relationship between health status and health care utilization;

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ObjectivesObjectives

Follow a panel of people to reflect the dynamic processes of health (NPHS);

Provide a means to supplement content and sample;

Provide the possibility of linking survey data to other data sourcesadministrative data

Population Health Population Health SurveysSurveys

NPHS Household

Longitudinal & X-sectional(National & Provincial)

NPHS North

Longitudinal & X-sectional(Territories)

NPHS Institutions

Longitudinal & X-sectional (-C3)(National)

HEALTH SURVEYS

1994-1999

Since 2000

HEALTH SURVEYS

NPHS Household

Longitudinal(National & Provincial)

NPHS Institutions

Longitudinal(National)

CCHS

Cross-sectional(Provinces + Territories)

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Population Health SurveysPopulation Health Surveys

NPHS

Cross-sectional and longitudinal

National, Provincial North component Institutions component

(national)

Core, focus, buy-ins & supplements

CCHS

Cross-sectional

National, provincial/ territorial & regional (health regions)

Common, selection of optional modules to fulfil health regions needs, sub-sample, buy-ins & supplements

NPHS descriptionNPHS description

Institutions component North component Household component Content

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NPHSNPHS

Cross-sectional (x-sec.)survey given population at one point in time

Longitudinal (Long.)designed to survey selected population

repeatedly over time

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NPHSNPHS

Started in 1994-1995 Conducted every two years

Cycle 1 (1994-1995): Household & Institutions & North (long, x-sec)

Cycle 2 (1996-1997): Household & Institutions & North (long, x-sec)

Cycle 3 (1998-1999): Household &North (long, x-sec), Institutions (long)

Cycle 4 (2000-2001): Household & Institutions (long.)

Cycle 5 (2002-2003): Household & Institutions (long.)

Cycle 6 (2004-2005): Household (long.)

…

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NPHS NPHS Institutions componentInstitutions component

Longitudinal & x-sectional: Cycles 1 & 2Strictly longitudinal: Cycle 3

Target populationNon autonomous residents of long term (more

then 6 months) health care establishments (4+ beds) in all provinces

• excludes the territories, Indian Reserves and Canadian Forces Bases, correctional facilities, prisons, young offender facilities, orphanages and religious institutions.

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Designed to produce national estimates only. Cycle 1 Sampling frames

HSD residential care facilities listHSD hospitals list

Longitudinal sampleCycle 1 respondents: 2,287 longitudinal

sample. Cross-sectional sample C2: Top-up

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Field operations conducted by STC Data collection: Jan y2 - May y2 Paper questionnaires

Institution control form • Ask about Institution policies

Respondent questionnaire• based on household « core » content• mostly in-person interviews

Collected mainly in person

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High proxy rate (71% in C4) Next of kinInstitution staffFamily member

High mortality 1/3 each cycle Used to survey institutionalized respondents

from the household component

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NPHS NPHS North componentNorth component

Longitudinal & x-sectional C1, C2 and C3Longitudinal data C3 not processed)

Target populationhousehold residents aged 12 + living in each

territory (+ Nunavut in C3)• excludes Indian reserves, Canadian Forces Bases

and unorganized or extreme remote areas

Designed to produce estimates at the territory level.

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C1 Sample size: 2,000 Cross-sectional sample C2 and C3: top-up Integrated NPHS / NLSCY survey

reduce respondent burden Field operations conducted by Yukon & NWT

statistical agenciesCollection challenges (moving/scattered

population)

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Data collection: November y1 - March y2 Paper questionnaire

includes most of household « core » content Collected in person & by telephone data

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NPHSNPHS Household componentHousehold component

Target populationHousehold residents all ages in all provinces

• excludes Indian reserves, Canadian Forces Bases and some remote areas in northern Québec & Ontario

Children aged 0-11 (2,022) collected via NLSCY in C1 and « repatriated » in NPHS in C2

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Designed to produce provincial & national level estimates

Cycle 1 sampling frameBased on Labour Force Survey (LFS) frame &

Enquête sociale et de santé (Québec only)• Sample of households• One member selected per household at collection

longitudinal panel

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Longitudinal sampleCycle 1 responding selected members +

children from NLSCY formed the NPHS longitudinal panel 17,276.

Subsequent cycles from C2 and on

Survey same panel of respondents.

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Province Longitudinal sample Cycle 1 (1994-1995)

Nfld 1,082 P.E.I. 1,037 N.S. 1,085 N.B. 1,125 Qc 3,000 Ont. 4,307 Man. 1,205 Sask. 1,168 Alta 1,544 B.C. 1,723 Total 17,276

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NPHS x-sectional samples:Longitudinal sample (panel)

• 17,276 respondents selected in C1• Except 0-11 in C1, partials and deaths

Buy-ins ($) (C1+C2)• Sample bought by provinces to increase

geographical resolution

Top-ups (C3)• Sample to complement the panel to obtain good x-

sectional representation

NPHS Household componentNPHS Household component Cross-sectional samples compositionCross-sectional samples composition

Cycle 1 Cycle 2 Cycle 3

Longitudinal Longitudinal Longitudinal Panel Panel Panel

Excluding Excluding ExcludingKids 0-11 Partials PartialsPartials Deaths Deaths

Buy-in (3,000) Buy-in (65,000) Top-up (4,000)

Total: 17,626 Total: 17,244

Total: 81,804

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C1 (1994-1995) buy-in for x-sec sampleOntario ( 1500 hhlds) & Manitoba ( 400

hhlds)• Sub-provincial geography (health district/region)

N.B. ( 150 hhlds) & B.C. (800 hhlds)• Increase coverage of certain areas only

Sampling: RDD method for B.C. LFS design elsewhere

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C2 (1996-1997) buy-in for x-sec sampleOntario, Manitoba, AlbertaSub-provincial geography (health district/region)

• Ont.: 6 major regions with sub-regions (37,800 hhlds)• Man.: 11 regions ( 11,200 hhlds, incl. 0-11)• Alta.: 17 regions ( 13,500 hhlds, incl. 0-11)

Sampling: RDD method

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C3 (1998-1999) top-up for x-sec sampleAll provincesTo be representative of 1998-1999 population

• Added births and immigrants – Selected from LFS rotate-out samples ( 1,300 hhlds)

• Added Cycle 1 non-respondents, unable to trace– ( 2,800 hhlds)

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Sample summaryFor 1st three cycles, data were collected to

serve both longitudinal and x-sectional purposes

Longitudinal:• 17,276 (same sample for all cycles)• Results drawn from the longitudinal data will

always relate to the 1994-1995 Canadian population

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Cross-sectional:• Longitudinal + supplementary samples• Supplementary samples:

– provincial buy-ins and/or top-up samples– not followed up from one cycle to the other

• Results drawn from the cross-sectional always refers to the years data were collected e.g. C3 data represents the 1998-1999 Canadian population

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Field operations conducted by STC Data collection: June y1 - June y2

Q1-Q4 plus Q5• operational reasons / seasonality

Questionnaire Computer Assisted Interview 55 minutesContent development (Provincial Ministries of

Health, Health Canada, data users, researchers …)Built in skip patterns & edits

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Collected in-person for C1, by telephone from C2 and on

From C1 to C3 (longitudinal & X-sectional): Two questionnaires : General & Health

• «General» used to collect health data from all household members

– household composition may be different from one cycle to the other

• «Health» used to collect more detailed health data from 1 selected member (include longitudinal panel member).

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Cycle 1 Cycle 2 Cycle 31994-1995 1996-1997 1998-1999

Selected people 17,626 81,804 17,244(Health file)

Total number of household membersincluding the selected people 58,439 210,377 49,046(General file)

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From C4 and on (longitudinal only)One questionnaire

• Combines general and health questionnaires– Roster of household members like for C123– Household information collected from longitudinal

respondent to derive household related characteristics

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Cycle 1 Cycle 2 Cycle 3 Cycle 4 Cycle 51994-1995 1996-1997 1998-1999 2000-2001 2002-2003

Longitudinal Full file 17,276 15,666* 14,618** 13,582 12,546Full response at each cycle

* C2 Master file: 15,670 records, 4 records miscoded to deceased ==> non-response

** C3 Master file: 14619 records, 1 record miscoded to deceased ==> non-response

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NPHS Household componentNPHS Household component

Interviewer training, manuals, guide Respondents’ relations strategy

Introduction letter Gifts (Calendar, fridge magnet, medical wallet kit)Brochure Newspaper clip (C6)Thank you letter

• Roulette with NPHS results

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NPHS Household componentNPHS Household component

Non-response: Refusal and no contact letterResends in subsequent QsWeights adjustment

TracingLongitudinal sample onlyProvide change of address cardUse contacts provided by respondentOther (Post office, Canada 411,WEB, etc.)If traced then interview

NPHS ContentNPHS Content

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Common to all cycles Changes: focus, addition, brought back… Supplements - separate data outputs

C1 Health Promotion Survey (Health Canada)C2 asthma (Health Canada)C3 Food Insecurity (HRDC)

Buy-In

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NPHS Content - All cyclesNPHS Content - All cycles

Alcohol consumption Blood pressure check Chronic conditions * Drug use General Health Health Care Utilisation * Health Status (HUI) Height / weight Injuries Insurance (not C1) Mental Health Physical activities Restriction of activities *

Repetitive strain (not C1) Self-perceived health Smoking Social support Two-week disability (not C4...) * Women’s / Preventive health Household composition * Education * Income * Labour force * Socio-demographic

characteristics * Survey administration

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StressSelf-esteem, C1, C4Ongoing problems C5, core as of C6Recent life events C1, C4Childhood & adult stressors C1, C4Work stress C5 core as of

C6Mastery C5 core as of C6Self-perceived stress C4 +Sense of coherence C1 & C3

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Access to services, C2Blood pressureBreast feedingDental visitsEmergency servicesEye examinationsFlu shotsInsurance coverage Alcohol dependence + opinion C2, C5

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Diet / Nutrition C3, C5, C6 Family medical history C3 Self-care C3 Smoking

Tobacco alternatives C3Strength C5+Dependence C6+ Smoking initiation C6+

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Chronic conditions C4ArthritisHeart diseaseDiabetes

Sleep C5, core as of C6 Body image C5, core as of C6 Family history: depression C6 General: Life satisfaction C6

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Coping (16 questions CCHS) C6 Household level of education C6 Added income category C6

$80,000 - $100,000

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NPHS Content – NPHS Content – SupplementsSupplements

Health Canada, Health Promotion Survey C1 Alcohol during pregnancy Breastfeeding Body image Health care services Injury prevention Nutrition choices, habits Sexual health Smoking - attitude Sources of health information

C2: Health Canada, Asthma C3: HRDC, Food insecurity

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NPHS NPHS Content - Buy-inContent - Buy-in

Health Canada, Health Promotion Survey, C2Breast self-examinationSexual health HIVNutrition choices, habitsFood insecurityBreastfeedingPregnancyRoad safety Alcohol - attitude Smoking - attitude

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NPHS Content - Buy-inNPHS Content - Buy-in

Manitoba Coping C1

Alberta Attitude toward parents C1 Coping C1 & C2 Sources of health information C2 Sexual health C2 Social support C2 Health services / child health services C2 Tanning / UV exposure C2 Violence & personal safety C2

Health Canada Residence history (20 years) C5

NPHSNPHS

MicrodataDocumentation

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Master

MicrodataMicrodata

RecordsVariables

SharePUMF

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NPHS MicrodataNPHS Microdata

Master FileStatistics CanadaResearch Data Centres (RDCs)Remote AccessHousehold Cycle 1, 2 and 3

• Cross-sectional: General and health master fileHousehold Cycle 2 and 3

• Longitudinal – Full Household Cycle 4 +

• Longitudinal (subsets)

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NPHS- MicrodataNPHS- Microdata

As of C4: Master file: contains all panel members (17,276)

4 subsets of respondents (flags, sampling weights and bootstrap weights) 1. Longitudinal Square (complete panel; 17,276 records)

2. Longitudinal Full- Master (Complete response in all cycles)

3. Longitudinal Full Extreme - Master (Complete response in extreme cycle e.g. for C5: C1 and C5)

4. Longitudinal Full - Share (Complete response in all 5 cycles + agree to share; 12,221 records)

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Master FileInstitutions Cycle 1 and 2

• Cross-sectional • Longitudinal

Institutions Cycle 3, 4 and 5• Longitudinal

North Cycle 1 and 2• Cross-sectional• Longitudinal

North Cycle 3• Cross-sectional

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Master FileAsthma and Food insecurity master file available in

RDC upon request only

Share FileTo be used by share partners: Health Canada and

provincial Ministries of health Same pattern as Master except for supplements.Only contains respondents who agreed to shareHousehold, Institutions: sharing rate 96%North: no provision for data sharing

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Public Use Microdata File (PUMF)Household Cycles 1, 2 and 3, General and health

• Cross-sectional only

Institution Cycles 1 and 2• Cross-sectional only

Health Promotion Survey (Supplement C1)• Available in RDC upon request

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NPHS - DocumentationNPHS - Documentation

DocumentationUser guide: PUMFLongitudinal documentation

• Collection, processing, response rate, weighting, variable naming convention, etc.

QuestionnairesData dictionaryRecord layout (SAS & SPSS)Derived variables document

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NPHS - DocumentationNPHS - Documentation

8 characters in length Example: DHC6_AGE

1–2 variable section name DH: Demographic/ Hhld section

3 survey type C: Core content

4 year (4, 6, 8 …) 6: 1996-97 cycle

5 variable type _: From question.

6–8 variable name/number AGE: variable name

Will not match original 1994: conversion layouts available

NPHS - UsageNPHS - Usage

Rules Complex design Weights Attrition

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NPHS – Usage “Rules”NPHS – Usage “Rules”

Only statistical aggregates may be published

Aggregates released must not identify a person, business or organisation directly or indirectly

Information can not be released before the official release by Statistics Canada

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Respondent information can not be linked to administrative health records without consent to do so from the respondent (linking question)Share partners obtain link file upon request

• For respondents who agreed to both sharing and linking data.

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Master file and share files are to be treated as confidential and must be protected.

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Stratum #1

Stratum #2

#1: Each province was divided into strata

#2: Clusters selected within strata (PPS sampling) (1st stage)

#3: Dwellings selected within clusters (2nd stage)

#4: Respondent selected within responding dwellings (3rd stage)

ProvinceProvince

NPHS NPHS Usage – Complex DesignUsage – Complex Design

COMPLEX DESIGN

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Variance estimation with complex multistage cluster sample designNo exact formula for estimationApproximate approach required

Approximate methods for variance estimation:Taylor linearizationReplication methods

• Balanced Repeated Replication• Jackknife• Bootstrap

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Bootstrap weightsComplex survey design => no formula for variance

estimationBootstrap weights are provided (500)

• For each subset of respondents

Bootvar (macros)Totals, ratios, differences of ratios, linear & logistic

regression parametersSAS & SPSS


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Household Bootstrap weights

• All cycles , all master files , all share files• No bootstrap weights for the PUMFs

InstitutionsBootstrap weights starting in C3

North No bootstrap weightsProvide SAS program to estimate variance

NPHS NPHS Usage – WeightsUsage – Weights

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Household component Cycle 1, 2, 3 Creation of cross-sectional coordinated

bootstrap weightsCross-sectional samples for C1, 2, 3 not completely

independent (include longitudinal panel members) Impact reduce varianceFor General and Health filesMaster and Share files, Cycles 1, 2 and 3 CD-ROM in RDCs

NPHS NPHS Usage - WeightsUsage - Weights

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Post-stratification based on Census projectionsCycles 1, 2 based on 1991 censusCycles 3, 4 and 5, based on 1996 Census

• Previous files not changed

NPHS NPHS Usage - WeightsUsage - Weights

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NPHS – Usage AttritionNPHS – Usage Attrition

Attrition longitudinal household componentGeneral definition

Loss in sample size due to deaths, non-response, movements out-of-scope and untraceable situations

NPHS definition: Loss in sample size due to non-response and

untraceable situations– No out-of-scope– Deaths are considered as a response

(analytical value)

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Cycle 1 1994-95

Cycle 5 (Full-Master)

2002-2003 Sexe

Count Count % Men 8,047 5,661 29.7 Women 9,229 6,885 25.4 Total 17,276 12,546 27.4

Cycle 1 1994-1995


2002-2003

Province (Cycle1)

Count Count % Nfld 1,082 822 24.0 PEI 1,037 803 22.6 N.S. 1,085 775 28.6 N.B. 1,125 824 26.8 Qc 3,000 2,189 27.0 Ont. 4,307 2,990 30.6 Man. 1,205 921 23.6 Sask. 1,168 922 21.1 Alta 1,544 1,111 28.0 B.C. 1,723 1,189 31.0 Canada 17,276 12,546 27.4

Observed attrition (Full-Master) after 5 cycles

Cycle 1 1994-95


2002-2003

Age groups (years)

Count Count % 0 to 11 2,022 1,676 17.1

12 to 19 1,584 1,053 33.5

20 to 34 4,220 2,739 35.1

35 to 54 5,006 3,570 28.7

55 and over 4,444 3,508 21.1

Total 17,276 12,546 27.4

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A different look at attrition Use any combination of 2 consecutive cycles as

the unit of analysis (person-year unit).

From Cycle 4 Master file: • Potential sample of 51,828 (3*17,276) person-year units• Reduced to 44,700 because of non-response (86%)

From Cycle 5 Master file: • Potential sample of 69,104 (4*17,276) person-year units• Reduced to 58,080 because of non-response (84%)

NPHS NPHS

Products WEB Contacts

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NPHS ProductsNPHS Products

CANSIM II main dissemination vehiclex-sectional tabulations from NPHS 1st three

cycles tablefew longitudinal tabulationscounts, % and confidence intervalsnational & provincial levelsage and sex

Canadian Statistics E-Pubs: Health Indicators

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Health ReportsSTC quarterly publicationWide range of analytical articles based on

the NPHS14 (4), released

• Repetitive strain injuries.

15 (1) released, Daily January 21, 2004 Stress, health and the benefit of social support Incident arthritis in relation to excess weight

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Joint STC - CIHI publications“How Healthy are Canadians”“Health Care in Canada”

• both are annual publications

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WEB SitesWEB Sites

NPHS questionnaires and documentation are available on STC ’s Web site at:www.statcan.ca/health_surveys

Main entry point for analytical products and tabular statisticshttp://www.statcan.ca/cgi-bin/downpub/

freepub.cgi?subject=2966#2966

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Contact InfoContact Info

Mario Bédard, Data Access Unit, Population Health Surveys

Health Statistics Division, Statistics Canada (613) 951-8933,

[email protected] [email protected]

France Bilocq, Chief, NPHS Health Statistics Division, Statistics Canada

(613) 951-6956, [email protected]

national population health survey 2004 congress of the humanities and social sciences all congress...

Documents

household institutions

institutions long cycle

health care utilization

nphs crosssectional

health status

determinants of health

person slide

time slide