2006 ICE meeting

Using Linked Data to Examine Injury and

Disability

Beth Rasch and Chris CoxNational 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 eventthe injury eventthe level of functioning following the injury event

Pre-injuryfunctioning

InjuryPost-injuryfunctioning

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 / disabilityBegin 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 sourcesRespondent 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 collectedAugments available informationProvides longitudinal component to survey data

Reduces cost (eliminates re-contact)

Data needs

Pre-injuryfunctioning

Injury

Post-injuryfunctioning

over time

Example: Linked survey data

NHIS and MEPS are health surveysMEPS is a nationally representative subsample of NHIS householdsAnnual files to link NHIS to MEPS available on request from AHRQLongitudinal weight files available on AHRQ website

http://meps.ahrq.gov/Puf/PufSearch.asp?

Key analytic variables: MEPS and NHIS

FunctioningSelf-reported function in ADLs, IADLs, movement, seeing/hearing, cognition, work, social activitiesUse of assistive equipmentTime lost from usual activities

InjuryICD diagnosis code OnsetLocationCause of injuryReceived treatmentRecovery (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 JanDec

MEPS, Panel 2, 1997-1998

1996 1997 1998MEPS, Panel 1, 1996-1997

1996 NHIS

Examining disability after injury

Identify functioning (adults) in NHISIdentify injuries in Round 1 of MEPSDetermine change in functioning in Rounds 2-5 of MEPS

All indicators are not available for each round

Example: Linkage with administrative data

1994-1998 NHIS linked with SSA Master Beneficiary Records from 1962-2003Access to restricted files through NCHS Research Data Center

Note: NHIS injury data differs before and after 1997

Key analytic variables: SSA

Benefit historyApplications for disability benefitsProgram eligibilityBenefit amountPayment status

Disabling condition

Temporal relationships

Application for benefits

and program eligibility

(1962-2003)

1994-1998 NHIS

Injury eventDisability status

after injury

No

Yes

Application for benefits

and program eligibility

(1962-2003)

Yes

No

Yes

No

History of disability

Temporal relationships

1995 NHIS1996 MEPS

Round 1

Injury event

Disability status

after injury

Yes

No

Application for benefits

and program eligibility

(1962-2003)

No

YesYes

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 pathwayUsers need to be aware of the unique analytic issues encountered when using linked files