Meeting the Challenge The National Population Health Survey and Data Access E. Hamilton UNB Libraries IASSIST 2003

Outline NPHS: Background & Confidentiality Challenges NPHS Products Dissemination Evaluating Success of Strategy Concluding Observations

Canadian Context Federal/provincial/territorial division of powers and responsibilities Health and privacy legislated at the federal level and at the provincial level

Canadian Context NPHS dissemination affected by: Statistics Canada Act and policies Privacy Act Privacy legislation at provincial levels Ethics in research guidelines

NPHS Background NHIC Task Force on the State of Health Information in Canada ( ) Identification of data gaps and related problems in sharing health information Proposal for a national health survey to provide more comprehensive information on population health status

NPHS Objectives To provide measures of health status for policy To provide data for analytic studies To provide panel data to reflect dynamic process of health and produce periodic cross-sectional estimates To provide provinces with survey capacity to supplement content or sample To allow the possibility of linking survey results to administrative data

Risks … More complete information being collection Tools and techniques available to amass personal information Increase in “ market potential ” of personal information Potential for misuse of health information Difficulty to control information use Any data safety breach potentially serious to mandate of ethical data collectors At the time of NPHS design, 67% of Canadians said they would oppose free sharing of health care information

And yet … In the NPHS conducted in 1994/95: 94% of survey respondents consented to have their data linked with administrative health records 96% consented to have data shared with provincial ministries of health. Between cycle 1 and cycle 2, NPHS retained 93% of longitudinal sample

NPHS Administration Household survey: general and health components Complex survey design using strata and based on LFS frame; Respondents to be followed for 20 years Institutional survey Northern survey Cycle 1 Household survey in the field in June 1994

NPHS Products Methodology and survey documentation, articles in Health Reports, aggregate statistics in national “ health report card ” Data products in variety of formats Workshops, grants, and seminars

NPHS Data Products YearSurveyMasterShare*PUMFComments 1994/95Household (both files)Yes Suppl. survey data available in all flavours. Dummy file for remote access for Health file InstitutionalYes NorthernYes No 1996/97Household (both files)Yes Longitudinal file for cycle 1 & 2 Dummy files for remote access InstitutionalYes NorthernYes No 1998/99Household (both files)Yes Dummy files for remote access InstitutionalYes No NorthernYes No 2000/01Household (both files)Yes No Longitudinal only; end of PUMFs; dummy files for remote access InstitutionalYes No NorthernYes No

Service Statistics Canada Website Depository Service Program Data Liberation Initiative Sales & Customized Tabulations Remote Job Submission Research Data Centres Who is eligible General public General public through DSP libraries Post-secondary academic staff & students Individuals or organizations Researchers with accepted proposals Approved researchers Conditions Available on the Internet at Available on site Restricted to teaching and research purposes Contractual; standard fees usually apply Arrangement between STC & researcher; fee charged SSHRC peer review & deemed STC employee status Products - The Daily - Canadian Statistics - Census - Community profiles - Downloadable publications - Paper publications - Electronic publications & select CDs Standard data products: aggregate databases, public use microdata files, and geography files Standard data products; custom tables that have been processed by STC;access to specialized databases Analytic syntax built by researcher using synthetic files, and STC processing Confidential data files from the longitudinal surveys begun in the 1990 ’ s, such as the NPHS, SLID, NLSCY Notes Warning: some services on the web site are fee-based Some DSP libraries provide off-site access to authenticated users Interface to CANSIM I and Trade Analyzer available through CHASS (University of Toronto) Specialized databases include CANSIM II and the Trade Analyzer Available for only select surveys; this service most developed for the NPHS Applications can be submitted through the RDC/SSHRC web site Continuum of Access to Statistics Canada Products

Challenges? Multistage cluster sample design increases complexity (bootstrap weighting and the problem of variance) Attrition in population in Institution survey Linkage issues for administrative units and files Supplement questions and buy-ins (and you thought life was complicated enough!)

Research Project Research Objective: to discover evidence of use of the NPHS, a longitudinal survey by Statistics Canada with significant confidentiality challenges Methodology: Using established peer-reviewed databases as well as grey literature searching techniques, sought out evidence of data use and knowledge transfer relating to the NPHS

Research Findings 557 Items and counting! 271 articles 105 unique journal titles 147 primary authors of articles 115 conference presentations/reports 31 theses / dissertations

Research Findings PUMFs received greatest use in file types identified Cycle 1 remains file with most research use* * Cited twice in 2003

Research Findings HHD cycle1 PUMF release HHD cycle2 PUMF release HHD cycle3 PUMF release CCHS cycle 1.1 PUMF release

Observations NPHS is a success story in getting data into the hands of analysts Though concerned with privacy, respondents trust Statistics Canada enough to allow sharing of data Complexity in design posed challenges for cross-sectional data file to preserve confidentiality

Observations Challenge with linkage & confidentiality related to recipient community (priorities, laws, protocols) Longitudinal file resolved through provision of dummy files for remote job submission & RDCs Cross-sectional analysis for lower levels of geography now available through CCHS Despite remarkable research outcomes, no reported breaches in confidentiality by research community

Future Research Completion of grey literature tracking for NPHS to date Monitoring RDC analytical output Tracking CCHS research output Identifying further “ Best Practices ” in data dissemination designed to enhance access to data while protecting confidentiality

There is more to come … Thank you for your attention!