Transcript National Population Health Survey

Statistics Canada National
Population Health Surveys (NPHS)
Amir Erfani, PhD.
[email protected]
Department of Sociology
Nipissing University
North Bay, Ontario, P1B 8L7
Presentation prepared for the Pre-Conference on Health Over Life Course,
October 14, 2009, University of Western Ontario
1
Outlines
 Objectives of NPHS
 Methodology
–
–
–
–
Nature of Survey
Sampling & Sample Size
Attrition & Weights
Questionnaire & Variables
 Studies that used NPHS
 Our study
 Bibliography
2
Objectives of NPHS
 Providing health measures  helping the development
of public policy
 Understanding
- factors affecting health
- Impact of health care utilization on health status
 Studying the dynamic process of health and illness over
time
 Link health survey data to administrative data (i.e., vital
statistics)
3
Nature of The Survey
 NPHS is basically a longitudinal panel survey:
-
Cycle 1 (1994/1995)
Cycle 2 (1996/1997)
Cycle 3 (1998/1999)
Cycle 4 (2000/2001)
Cycle 5 (2002/2003)
Cycle 6 (2004/2005)
Cycle 7 (2006/2007)
Cycle 8 (2008/2009)
Cycle 9 (2010/2011)
Cycle 10 (2012/2013)
 Cross-sectional survey at cycles 1-3
 Three components:
1. The Households (main component)
2. The Health Institutions (taken over by CCHS)
3. The North components (taken over by CCHS )
 This presentation is on the Household component
4
Sampling & Sample
 Target Population: household residents in the ten
Canadian provinces in 1994/1995, excluding persons
-
living on Indian Reserves and Crown Lands,
residents of health institutions,
full-time members of the Canadian Forces Bases &
some remote areas in Ontario and Quebec.
 Longitudinal Sample (the panel):
- Cycle 1 (1994/95) = 17,276 persons 4+ years old, containing
2024 children 4 years old)
- Cycle 7 (2006/07) = 10,992 individuals 11+ years old
 Full response to all Cycles 1-7
5
The Panel by Province
 Attrition rate from cycle 1 to cycle 7 = 36.4%
6
Attrition & Weights

The main Source of Attrition: Refusal & unable to trace
-

Complex Sampling Design of NPHS: stratification,
clustering, and unequal probabilities:
-

Use weights to get representative estimates
"Longitudinal Full" Weight:
-

Cycle Twinning Approach (Pooling Repeated Observations)
WT6BLF
applies to the subset of respondents who responded to all 7 cycles
(10,992 persons)
Bootstrap weights: ensure the reliability of variance
estimates
- B5lngf file for “Longitudinal Full” subset (10,992)
7
Household Component’s Questionnaire

The Questionnaire includes
1.
Core content:
-
2.
Focus Content:
-

identical questions over the cycles
changes from cycle to cycle
Questionnaire Cycle 7: collects data about
-
Health of the longitudinal respondents,
determinants of health,
socioeconomic information ,
demographic information about all members of the longitudinal
respondents’ household
8
Variables in the Questionnaire Cycle 7
Household Recode Variables
 Demographic variables of household members
- Date of birth, age, sex, marital status, education, etc.
 Dwelling characteristics
- Type of dwelling , ownership, number of bedrooms
Health Component Variables
 General Health
-
Perceived health and stress
Sleep (pattern and troubles)
Height & Weight
Body Image
9
Variables in the Questionnaire Cycle 7
 Preventive Health
- Blood pressure, pap smear, mammogram, &
reproductive health
 Health Care Utilization:
- Use of health or medical professionals and
practitioners
- Hospital & clinics
- Home Care
 Restrictions of Activities
 Mental Health
10
Variables in the Questionnaire Cycle 7
Determinants of Health





Physical Activities
UV Exposure
Repetitive Strain
Injuries
Stress
-
Ongoing problems
Work Stress
Mastery
 Medication Use
 Smoking
 Alcohol






Social Support
Language
Education
Employment
Income
Nutrition (Focus content)
– Food choice,
– Food supplement use & fruit and
vegetable consumption
– Soft Drink & Milk Consumption
 Food insecurity (Focus content)
11
Studies that used NPHS
 See Statistics Canada Health Reports. E.g.:
Explanatory Studies
- Marital breakdown and subsequent depression
- Depression and risk of heart disease
- Income and psychological distress: The role of the
social environment
Health Trends and Estimates
- Medication use among senior Canadians
- Medication use among pregnant women
- The journey to quitting smoking
- Trends in weight change among Canadian adults
12
Our Study
 Andrea Wilson & Amir Erfani. Socioeconomic History and
Preventable Disease: A Comparative Analysis of Fundamental
Cause Theory
 Research Question:
If the risk factors stratifying health are eliminated, will
socioeconomic disparities in health remain?
 Hypothesis:
SES should be more strongly associated with diseases that are
more preventable than with less preventable diseases, and SES
should have a stronger relationship to health in countries
where high economic inequality and no universal health
insurance leads to greater competition for resources.
13
Our Study
 Data: Canada NPHS (Cycles 1-5); the U.S. PSID (Panel Study of
Income Dynamics)
 Method: Latent Class Analysis
 Why did we use NPHS?
- Rich data on SES and risk factors over 5 cycles (now 7 cycles!),
allowing us to generate
- trajectories of SES (Fundamental cause),
- trajectories of alcohol consumption & smoking (risk factors)
- and to choose highly and less preventable diseases as outcome
(cardiovascular/cancer).
- Studying causal relationships is doable
- Large sample size
- Less modifications in the core longitudinal questions over the cycles
14
Trajectories of Income Levels
 Trajectories of income levels of Canadians during 1994-2003, taken
from Latent Class Analysis of income
3.5
3
2.5
2
1.5
1
0.5
Stably High
Stably Low
Increasing
Decreasing
0
1994-95
1996-97
1998-99
2000-01
2002-03
15
Bibliography
 Statistics Canada. 2008. Statistics Canada National Population Health
Survey Household Component Cycle 1 to 7 (1994/1996 to 2006/2007)
Longitudinal Document.
http://www.statcan.gc.ca/imdb-bmdi/document/3225_D5_T1_V4-eng.pdf
 Statistics Canada. 2008. National Population Health Survey Household
Component Cycle 7 (2006/2007) Questionnaire.
http://www.statcan.gc.ca/imdb-bmdi/instrument/3225_Q1_V7-eng.pdf
 Statistics Canada. 2008. Healthy Today, Healthy Tomorrow?
Findings from the National Population Health Survey, Health
Reports. Catalogue no.: 82-618-MWE, vol. 3 no. 1.
 Fitzmaurice, G.M., Laird, N.M., and Ware, J.H. 2004. Applied Longitudinal
Analysis. New York: Wiley
16