CCHS Workshop
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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
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
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
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
Cross-sectional and
longitudinal
Cross-sectional
National, Provincial
National, provincial/ territorial
& regional (health regions)
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
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
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.
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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
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
High proxy rate (71% in C4)
Next of kin
Institution staff
Family member
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
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
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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
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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.
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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
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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
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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)
26
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
27
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
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
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).
30
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
31
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
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
34
NPHS Household component
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
35
NPHS Content
NPHS Content
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
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
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
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