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

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

Overview of Population Heath Surveys

4 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;

5 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

Population Health Surveys Since 2000

7 Population 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 description Institutions component North component Household component Content

9 NPHS Cross-sectional (x-sec.)  survey given population at one point in time Longitudinal (Long.)  designed to survey selected population repeatedly over time

10 NPHS Started in Conducted every two years Cycle 1 ( ): Household & Institutions & North (long, x-sec) Cycle 2 ( ): Household & Institutions & North (long, x-sec) Cycle 3 ( ): Household &North (long, x-sec), Institutions (long) Cycle 4 ( ): Household & Institutions (long.) Cycle 5 ( ): Household & Institutions (long.) Cycle 6 ( ): Household (long.) …

11 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.

12 NPHS Institutions component Designed to produce national estimates only. Cycle 1 Sampling frames  HSD residential care facilities list  HSD hospitals list Longitudinal sample  Cycle 1 respondents: 2,287  longitudinal sample. Cross-sectional sample C2: Top-up

13 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

14 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

15 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.

16 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)

17 NPHS North component Data collection: November y1 - March y2 Paper questionnaire  includes most of household « core » content Collected in person & by telephone data

18 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

19 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

20 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.

21 NPHS Household component

22 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

NPHS Household component Cross-sectional samples composition

24 NPHS Household component C1 ( ) 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

25 NPHS Household component C2 ( ) 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

26 NPHS Household component C3 ( ) top-up for x-sec sample  All provinces  To be representative of 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)

27 NPHS Household component Sample summary  For 1 st 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 Canadian population

28 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 Canadian population

29 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

30 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).

31 NPHS Household component

32 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

33 NPHS Household component

34 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

35 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

NPHS Content

37 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

38 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

39 NPHS Content Stress  Self-esteem, C1, C4  Ongoing problems C5, core as of C6  Recent life events C1, C4  Childhood & adult stressors C1, C4  Work stress C5 core as of C6  Mastery C5 core as of C6  Self-perceived stress C4 +  Sense of coherence C1 & C3

40 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

41 NPHS Content Diet / Nutrition C3, C5, C6 Family medical history C3 Self-care C3 Smoking  Tobacco alternatives C3  Strength C5+  Dependence C6+  Smoking initiation C6+

42 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

43 NPHS Content Coping (16 questions CCHS) C6 Household level of education C6 Added income category C6  $80,000 - $100,000

44 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

45 NPHS Content - Buy-in Health Canada, Health Promotion Survey, C2  Breast self-examination  Sexual health  HIV  Nutrition choices, habits  Food insecurity  Breastfeeding  Pregnancy  Road safety  Alcohol - attitude  Smoking - attitude

46 NPHS Content - Buy-in Manitoba  CopingC1 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

NPHS Microdata Documentation

48 Master Microdata Records Variables Share PUMF

49 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)

50 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)

51 NPHS Microdata Master File  Institutions 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

52 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

53 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

54 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

55 NPHS - Documentation  8 characters in lengthExample: DHC6_AGE 1–2 variable section nameDH: Demographic/ Hhld section 3 survey typeC:Core content 4 year (4, 6, 8 …)6: cycle 5 variable type_:From question. 6–8 variable name/numberAGE:variable name  Will not match original 1994: conversion layouts available

NPHS - Usage Rules Complex design Weights Attrition

57 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

58 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.

59 NPHS – Usage “Rules” Master file and share files are to be treated as confidential and must be protected.

60 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)   Province NPHS Usage – Complex Design COMPLEX DESIGN

61 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

62 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 NPHS Usage – Complex Design

63 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 NPHS Usage – Weights

64 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 NPHS Usage - Weights

65 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 NPHS Usage - Weights

66 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)

67 NPHS – Usage Attrition Observed attrition (Full-Master) after 5 cycles

68 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%)

NPHS Products WEB Contacts

70 NPHS Products CANSIM II main dissemination vehicle  x-sectional tabulations from NPHS 1 st three cycles table  few longitudinal tabulations  counts, % and confidence intervals  national & provincial levels  age and sex Canadian Statistics E-Pubs: Health Indicators

71 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

72 NPHS Products Joint STC - CIHI publications  “How Healthy are Canadians”  “Health Care in Canada” both are annual publications

73 WEB Sites NPHS questionnaires and documentation are available on STC ’s Web site at:  Main entry point for analytical products and tabular statistics  bin/downpub/freepub.cgi?subject=2966#2966

74 Contact Info Mario Bédard, Data Access Unit, Population Health Surveys Health Statistics Division, Statistics Canada (613) , France Bilocq, Chief, NPHS Health Statistics Division, Statistics Canada (613) ,