2006 ICE meeting Using Linked Data to Examine Injury and Disability Beth Rasch and Chris Cox National Center for Health Statistics

Background Research is limited on the injury disability pathway, particularly large scale studies Determining the temporal relationships between injury and disability is challenging

Temporal relationships Ideally, we would like to know about: the level of functioning prior to the injury event the injury event the level of functioning following the injury event Pre-injury functioning Injury Post-injury functioning over time

Data gap In the U.S., national data sources that include longitudinal information on injury and disability are limited Data availability may be different in other countries Record linkage can begin to address this gap

Purpose of presentation Identify data needs for studying injury / disability Begin to examine the potential to study injury / disability using longitudinal survey data and linked administrative data sources

What is record linkage? Record linkage combines information for the same entity or individual from a variety of sources Respondent information from health surveys can be linked to administrative records (e.g. vital statistics, receipt of disability benefits, etc.)

Benefits of record linkage Increases analytic potential of health surveys for epidemiologic research Increases accuracy and detail of data collected Augments available information Provides longitudinal component to survey data Reduces cost (eliminates re-contact)

Data needs Pre-injury functioning Injury Post-injury functioning over time

Example: Linked survey data NHIS and MEPS are health surveys MEPS is a nationally representative subsample of NHIS households Annual files to link NHIS to MEPS available on request from AHRQ Longitudinal weight files available on AHRQ website

Key analytic variables: MEPS and NHIS Functioning Self-reported function in ADLs, IADLs, movement, seeing/hearing, cognition, work, social activities Use of assistive equipment Time lost from usual activities Injury ICD diagnosis code Onset Location Cause of injury Received treatment Recovery (MEPS) Seriousness of injury (MEPS)

MEPS sample design 1995 NHIS Round 1 Round 2 Round 3 Round 4 Round 5 Jan Round 1 Round 2 Round 3 Jan Dec MEPS, Panel 2, MEPS, Panel 1, NHIS

Examining disability after injury Identify functioning (adults) in NHIS Identify injuries in Round 1 of MEPS Determine change in functioning in Rounds 2-5 of MEPS All indicators are not available for each round

Example: Linkage with administrative data NHIS linked with SSA Master Beneficiary Records from Access to restricted files through NCHS Research Data Center Note: NHIS injury data differs before and after 1997

Key analytic variables: SSA Benefit history Applications for disability benefits Program eligibility Benefit amount Payment status Disabling condition

Temporal relationships Application for benefits and program eligibility ( ) NHIS Injury event Disability status after injury No Yes Application for benefits and program eligibility ( ) Yes No Yes No History of disability

Temporal relationships 1995 NHIS 1996 MEPS Round 1 Injury event Disability status after injury Yes No Application for benefits and program eligibility ( ) No Yes No History of disability Benefit status 1996 MEPS Rounds 2-5 Yes No

Summary Linked files provide a longitudinal aspect to survey data, offering additional options to study the injury disability pathway Users need to be aware of the unique analytic issues encountered when using linked files