Transcript CCHS Workshop

National
Population
Health
Survey
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 Bilocq
Chief NPHS
Health Statistics Division
Statistics Canada
Presentation
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


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Overview of population health surveys
NPHS description
NPHS content
NPHS Microdata and documentation
NPHS Usage
Products and Web-sites
2
Overview of Population Heath Surveys
Objectives
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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;
4
Objectives
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

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 sources
 administrative
data
5
Population Health
Surveys
1994-1999
HEALTH SURVEYS
NPHS Household
NPHS North
NPHS Institutions
Longitudinal & X-sectional
(National & Provincial)
Longitudinal & X-sectional
(Territories)
Longitudinal & X-sectional (-C3)
(National)
Since 2000
HEALTH SURVEYS
NPHS Household
NPHS Institutions
CCHS
Longitudinal
(National & Provincial)
Longitudinal
(National)
Cross-sectional
(Provinces + Territories)
Population Health Surveys
NPHS
CCHS
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Cross-sectional and
longitudinal
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Cross-sectional
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National, Provincial
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National, provincial/ territorial
& regional (health regions)
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Common, selection of
optional modules to fulfil
health regions needs, subsample, buy-ins &
supplements

North component
 Institutions component
(national)

Core, focus, buy-ins &
supplements
7
NPHS description

Institutions component

North component

Household component
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Content
NPHS

Cross-sectional (x-sec.)
 survey

given population at one point in time
Longitudinal (Long.)
 designed
to survey selected population
repeatedly over time
9
NPHS
 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.)
…
10
NPHS Institutions component
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Longitudinal & x-sectional: Cycles 1 & 2
Strictly longitudinal: Cycle 3
Target population
 Non
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.
11
NPHS Institutions component


Designed to produce national estimates only.
Cycle 1 Sampling frames
 HSD
residential care facilities list
 HSD hospitals list

Longitudinal sample
1 respondents: 2,287  longitudinal
sample.
 Cycle

Cross-sectional sample C2: Top-up
12
NPHS Institutions component
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
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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
13
NPHS Institutions component
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High proxy rate (71% in C4)
 Next of kin
 Institution staff
 Family member
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
High mortality  1/3 each cycle
Used to survey institutionalized respondents
from the household component
14
NPHS North component

Longitudinal & x-sectional C1, C2 and C3
 Longitudinal

data C3 not processed)
Target population
 household
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.
15
NPHS North component
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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 agencies
 Collection
challenges (moving/scattered
population)
16
NPHS North component


Data collection: November y1 - March y2
Paper questionnaire
 includes

most of household « core » content
Collected in person & by telephone data
17
NPHS Household component

Target population
 Household
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
18
NPHS Household component


Designed to produce provincial & national
level estimates
Cycle 1 sampling frame
 Based
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
19
NPHS Household component

Longitudinal sample
 Cycle
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.
20
NPHS Household component
Province
Nfld
P.E.I.
N.S.
N.B.
Qc
Ont.
Man.
Sask.
Alta
B.C.
Total
Longitudinal sample
Cycle 1 (1994-1995)
1,082
1,037
1,085
1,125
3,000
4,307
1,205
1,168
1,544
1,723
17,276
21
NPHS Household component

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
22
NPHS Household component
Cross-sectional samples composition
Cycle 1
Cycle 2
Cycle 3
Longitudinal
Panel
Longitudinal
Panel
Longitudinal
Panel
Excluding
Kids 0-11
Partials
Excluding
Partials
Deaths
Excluding
Partials
Deaths
Buy-in (3,000)
Buy-in (65,000)
Top-up (4,000)
Total: 17,626
Total: 17,244
Total: 81,804
NPHS Household component

C1 (1994-1995) buy-in for x-sec sample
 Ontario
( 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
24
NPHS Household component

C2 (1996-1997) buy-in for x-sec sample
 Ontario,
Manitoba, Alberta
 Sub-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
25
NPHS Household component

C3 (1998-1999) top-up for x-sec sample
 All
provinces
 To 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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NPHS Household component

Sample summary
1st three cycles, data were collected to
serve both longitudinal and x-sectional
purposes
 Longitudinal:
 For
• 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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NPHS Household component
 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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NPHS Household component
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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 minutes
 Content development (Provincial Ministries of
Health, Health Canada, data users, researchers …)
 Built in skip patterns & edits
29
NPHS Household component
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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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NPHS Household component
Cycle 1
Cycle 2
1994-1995 1996-1997
Selected people
(Health file)
Total number of household members
including the selected people
(General file)
Cycle 3
1998-1999
17,626
81,804
17,244
58,439
210,377
49,046
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NPHS Household component

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
32
NPHS Household component
Cycle 1 Cycle 2 Cycle 3 Cycle 4 Cycle 5
1994-1995 1996-1997 1998-1999 2000-2001 2002-2003
Longitudinal Full file
17,276
Full response at each cycle
15,666* 14,618**
13,582
12,546
* 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
33
NPHS Household component
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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 component
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Non-response:
 Refusal and no contact letter
 Resends in subsequent Qs
 Weights adjustment

Tracing
 Longitudinal sample only
 Provide change of address card
 Use contacts provided by respondent
 Other (Post office, Canada 411,WEB, etc.)
 If traced then interview
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NPHS Content
NPHS Content
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
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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
37
NPHS Content - All cycles
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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 *
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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
38
NPHS Content

Stress
 Self-esteem,
 Ongoing problems
 Recent life events
 Childhood & adult stressors
 Work stress
 Mastery
 Self-perceived stress
 Sense of coherence
C1, C4
C5, core as of C6
C1, C4
C1, C4
C5 core as of C6
C5 core as of C6
C4 +
C1 & C3
39
NPHS Content

Access to services, C2
 Blood pressure
 Breast feeding
 Dental visits
 Emergency services
 Eye examinations
 Flu shots
 Insurance coverage
 Alcohol dependence
+ opinion C2, C5
40
NPHS Content




Diet / Nutrition
C3, C5, C6
Family medical history C3
Self-care
C3
Smoking
 Tobacco
alternatives
 Strength
 Dependence
 Smoking initiation
C3
C5+
C6+
C6+
41
NPHS Content

Chronic conditions C4
 Arthritis
 Heart disease
 Diabetes




Sleep
C5, core as of C6
Body image C5, core as of C6
Family history: depression C6
General: Life satisfaction C6
42
NPHS Content



Coping (16 questions CCHS) C6
Household level of education C6
Added income category
C6
 $80,000
- $100,000
43
NPHS Content – Supplements

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
44
NPHS Content - Buy-in

Health Canada, Health Promotion Survey, C2
 Breast self-examination
 Sexual health
 HIV
 Nutrition choices,
 Food insecurity
 Breastfeeding
 Pregnancy
 Road safety
 Alcohol  Smoking
habits
attitude
- attitude
45
NPHS Content - Buy-in

Manitoba
 Coping

C1
Alberta
 Attitude toward parents
 Coping
 Sources of health information
 Sexual health
 Social support
 Health services / child health services
 Tanning / UV exposure
 Violence & personal safety

C1
C1 & C2
C2
C2
C2
C2
C2
C2
Health Canada
 Residence
history (20 years)
C5
46
NPHS
 Microdata
 Documentation
Microdata
Variables
Records
Share
PUMF
Master
48
NPHS Microdata

Master File
 Statistics Canada
 Research Data Centres (RDCs)
 Remote Access
 Household Cycle 1, 2 and 3
• Cross-sectional: General and health master file
 Household
Cycle 2 and 3
• Longitudinal – Full
 Household
Cycle 4 +
• Longitudinal (subsets)
49
NPHS- 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)
50
NPHS Microdata

Master File
 Institutions
Cycle 1 and 2
 Institutions
Cycle 3, 4 and 5
• Cross-sectional
• Longitudinal
• Longitudinal
 North
Cycle 1 and 2
 North
Cycle 3
• Cross-sectional
• Longitudinal
• Cross-sectional
51
NPHS Microdata

Master File
 Asthma
and Food insecurity master file available in
RDC upon request only

Share File
 To
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 share
 Household, Institutions: sharing rate  96%
 North: no provision for data sharing
52
NPHS Microdata

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
53
NPHS - Documentation

Documentation
 User
guide: PUMF
 Longitudinal documentation
• Collection, processing, response rate, weighting, variable
naming convention, etc.
 Questionnaires
 Data
dictionary
 Record layout (SAS & SPSS)
 Derived variables document
54
NPHS - Documentation

8 characters in length
1–2 variable section name
3 survey type
4 year (4, 6, 8 …)
5 variable type
6–8 variable name/number

Example: DHC6_AGE
DH: Demographic/
Hhld section
C:
Core content
6:
1996-97 cycle
_:
From question.
AGE: variable name
Will not match original 1994: conversion layouts available
55
NPHS - Usage
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Rules
Complex design
Weights
Attrition
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
57
NPHS – Usage “Rules”

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.
58
NPHS – Usage “Rules”

Master file and share files are to be
treated as confidential and must be
protected.
59
NPHS Usage – Complex Design
COMPLEX DESIGN
#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)
Province
Stratum #1
 
  
 
Stratum #2
 
 
 
60
NPHS Usage – Complex Design

Variance estimation with complex multistage
cluster sample design
 No exact formula for estimation
 Approximate approach required

Approximate methods for variance estimation:
 Taylor linearization
 Replication methods
• Balanced Repeated Replication
• Jackknife
• Bootstrap
61
NPHS Usage – Complex Design

Bootstrap weights
 Complex
survey design => no formula for variance
estimation
 Bootstrap weights are provided (500)
• For each subset of respondents

Bootvar (macros)
 Totals,
ratios, differences of ratios, linear & logistic
regression parameters
 SAS & SPSS
62
NPHS Usage – Weights

Household
 Bootstrap
weights
• All cycles , all master files , all share files
• No bootstrap weights for the PUMFs

Institutions
 Bootstrap

weights starting in C3
North
 No
bootstrap weights
 Provide SAS program to estimate variance
63
NPHS Usage - Weights
Household component Cycle 1, 2, 3

Creation of cross-sectional coordinated
bootstrap weights
 Cross-sectional
samples for C1, 2, 3 not completely
independent (include longitudinal panel members)
 Impact  reduce variance
 For General and Health files
 Master and Share files, Cycles 1, 2 and 3
 CD-ROM in RDCs
64
NPHS Usage - Weights

Post-stratification based on Census
projections
 Cycles
1, 2 based on 1991 census
 Cycles 3, 4 and 5, based on 1996 Census
• Previous files not changed
65
NPHS – Usage Attrition

Attrition longitudinal household component
 General
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)
66
NPHS – Usage Attrition
Observed attrition (Full-Master) after 5 cycles
Sexe
Province
(Cycle1)
Nfld
PEI
N.S.
N.B.
Qc
Ont.
Man.
Sask.
Alta
B.C.
Canada
Cycle 1
1994-1995
Count
1,082
1,037
1,085
1,125
3,000
4,307
1,205
1,168
1,544
1,723
17,276
Cycle 5
(Full-Master)
2002-2003
Count
%
822
24.0
803
22.6
775
28.6
824
26.8
2,189
27.0
2,990
30.6
921
23.6
922
21.1
1,111
28.0
1,189
31.0
12,546
27.4
Men
Women
Total
Cycle 1
1994-95
Count
8,047
9,229
17,276
Age groups
(years)
0 to 11
12 to 19
20 to 34
35 to 54
55 and over
Total
Cycle 5
(Full-Master)
2002-2003
Count
%
5,661 29.7
6,885 25.4
12,546 27.4
Cycle 1
1994-95
Count
2,022
1,584
4,220
5,006
4,444
17,276
Cycle 5
(Full-Master)
2002-2003
Count
%
1,676 17.1
1,053 33.5
2,739 35.1
3,570 28.7
3,508 21.1
67
12,546 27.4
NPHS – Usage Attrition
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%)
68
NPHS



Products
WEB
Contacts
NPHS Products

CANSIM II main dissemination vehicle
tabulations from NPHS 1st three
cycles table
 few longitudinal tabulations
 counts, % and confidence intervals
 national & provincial levels
 age and sex
 x-sectional


Canadian Statistics
E-Pubs: Health Indicators
70
NPHS Products

Health Reports
 STC
quarterly publication
 Wide range of analytical articles based on
the NPHS
14 (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
71
NPHS Products

Joint STC - CIHI publications
 “How
Healthy are Canadians”
 “Health Care in Canada”
• both are annual publications
72
WEB 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 statistics
 http://www.statcan.ca/cgi-
bin/downpub/freepub.cgi?subject=2966#2966
73
Contact 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]
74