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Overview of the 2016-2025 National Health Interview Survey Sample - - PowerPoint PPT Presentation
Overview of the 2016-2025 National Health Interview Survey Sample - - PowerPoint PPT Presentation
Overview of the 2016-2025 National Health Interview Survey Sample Design Chris Moriarity, Van Parsons, Kim Jonas NCHS/Census Bureau 2019 Joint Statistical Meetings July 31, 2019 Presentation outline National Health Interview Survey (NHIS)
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NHIS features
A major source of official U.S. statistical information about the health of U.S. residents Personal visit interview survey,
- perating continuously since 1957
Annual sample size as of 2016 if no sample cuts/augmentations: ~87,500 persons in ~35,000 completed household interviews
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NHIS sample design periods
Each sample design period is ~10 years long, based on information from previous decennial census Most recent completed period: 2006-2015, based on Census 2000 Current: 2016-2025(?), based on 2010 Census
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Some historic NHIS sample design features
Emphasis on producing precise national estimates - sample allocation by state approximately proportional to state population size Most NHIS sample designs have sampled in all U.S. States and D.C. (an exception: the 1985-1994 design)
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2016 NHIS sample redesign: several major changes
Build in more flexibility to increase/decrease overall sample and/or shift sample allocations by State from year to year, if desired (lead time required to implement) New source of sample addresses
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How did we implement the increased flexibility?
Selected a large initial sample, called the "super sample", of groups of addresses Assigned "entry orders" to govern which pieces come in/go out if there is a change in an annual sample size, and/or changes in the distribution of the sample
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Super sample selection preparation
Independent sampling in each U.S. state and D.C. Geographic areas (one or more contiguous counties) defined to delineate interviewer travel boundaries (personal visit survey) Geographic areas assigned to one
- r two groups (strata) in each state
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Super sample selection
In each state/stratum, groups of addresses defined within the geographic areas Selection of a systematic sample
- f groups of addresses
Where the selected address groups were located determined which geographic areas were in the super sample
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Different sampling mechanism than previous NHIS sample designs
Previously, the geographic areas were primary sampling units (PSU) First, a sample of PSUs would be selected, then a sample of address groups would be selected within the sampled PSUs
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Previous sampling mechanism inhibits flexibility
We discovered in the previous NHIS sample design period that having a fixed sample of PSUs was not optimal if funding was provided for large-scale sample augmentation More efficient sample augmentation possible with current sampling mechanism
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NHIS sample address source, 1985-2015
Sample addresses for the 1985-94, 1995-2005, and 2006-2015 NHIS sample designs came primarily from field listing The Census Bureau can share NHIS sample addresses with NCHS NCHS uses the addresses for other surveys, record linkage, etc.
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2016 NHIS sample design: change in sample address source
Other demographic surveys conducted by the Census Bureau moved toward using the Master Address File (MAF) as the main source of sample addresses NCHS had been sharing costs for NHIS field listing; NCHS could not afford the full cost of listing
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2016 NHIS sample design address source: address list
NCHS did not want to use MAF addresses for NHIS because MAF addresses are confidential, they cannot be shared NHIS now using a commercial address list (from MSG) as main sample address source, beginning in 2016
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Issues to address when using a commercial address list
Accuracy, geocoding quality, coverage of areas like college dormitories, etc. How to do periodic updates How to select annual samples that do not overlap with previous ones
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2013-4 MSG list research by the Census Bureau
Coverage: MAF record linkage results allowed NCHS/Census to make more informed decisions about where to use the MSG list No-stat addresses/filtering: Census's research showed that inclusion of some "no-stat" addresses provided better coverage, and guided development
- f filtering algorithm for inclusion
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Working with the commercial address list
Geocoding: Census Bureau doing independent geocoding Periodic updates come from vendor; sample of "new growth" selected annually MSG list used in areas identified by Census Bureau's research; independent listing elsewhere
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