injury and poisoning estimates from the national health interview survey -why they differ from other...
TRANSCRIPT
Injury and Poisoning Estimates from the National Health
Interview Survey-Why They Differ from Other
EstimatesManon Boudreault MPH, Margaret Warner PhD, and Lois Fingerhut,
MA
National Center for Health Statistics
U.S. DEPARTMENT OF HEALTH AND HUMAN SERVICES
Centers for Disease Control and Prevention
Office of Analysis and Epidemiology
2005 National Injury and Prevention and Control Conference, Denver, CO
Overview
•National Health Interview Survey-Questionnaire History
-Current data
•Other Injury Data from NCHS-Comparison of data sources
•Linking NHIS files and public-use data files
•All medically-attendedmedically-attended injuries occurring to any family member during the 3 month period prior to the interview are asked about from an adult family member.
•Uses a multistage sample designed to represent the U.S. civilian non-institutionalizedcivilian non-institutionalized population
•Collected throughout the year, nearly 40,000 households are visited (info on over 90,000 personsinfo on over 90,000 persons))
NHIS
NHIS Strengths
•More detailed information:
circumstances, cause, and location of episode (64% of the adult episodes are self-reported)
•Nearly complete external cause codes
•Largest range of data available in one system
•Linkable with other national data sets
Data prior to the redesigned 1997 NHIS
•Placement, phrasing and number of questions
•Recall period
•Severity threshold
Prior years are not directly comparable due to:
25% injuries due to these and other changes(1995 to 1997)
Analysis of Recall Bias•Questionnaire recall period …past 2
weeks? (before 1997) to… past 3 months? (current)
•More severe injuries (fractures and sprains/strains) showed similar numbers whether recall was 2 weeks or 3 months.
•Further analyses showed drop in reporting minor injuries after 5 weeks.
“Recall Bias”
Fewer minor injuries reported
Annual estimates (NHIS) of injury and poisoning
episodes
0
5
1 0
1 5
2 0
2 5
3 0
3 5
4 0
1 9 9 7 1 9 9 8 1 9 9 9 2 0 0 0 2 0 0 1 2 0 0 2 2 0 0 3
I n j u r i e s P o i s o n i n g sEpisodes in millions
Year
Same questions
Nearly same questions
Detailed questionnaire history: http://www.cdc.gov/nchs/about/otheract/injury/presentations.htm
“Packed” question
2000-03: DURING THE PAST THREE MONTHS, that is since {91 days before today date}, {were/was} {you/anyone in the family} injured or poisoned seriously enough that {you/they} got medical advice or treatment?
Three questions in one:
1) Were you injured?
2) Were you poisoned?
3) Did you seek medical advice?
“Unpacked” question- NHIS 2004
During the past three months, that is since {January 2}, did you have an injury where any part of your body was hurt, for example, with a broken bone, sprain, burn, wound, bruise, or animal or insect bite?
During the past three months, that is since {January 2}, were you poisoned by swallowing or breathing in a harmful substance such as bleach, carbon monoxide, or too many pills or drugs?
Did you talk to or see a medical professional about this {injury/poisoning}?
Annual estimates (NHIS) of injury and poisoning episodes
0
5
1 0
1 5
2 0
2 5
3 0
3 5
4 0
1 9 9 7 1 9 9 8 1 9 9 9 2 0 0 0 2 0 0 1 2 0 0 2 2 0 0 3 2 0 0 4
I n j u r i e s P o i s o n i n g sEpisodes in millions
Year
*
Same questions
Nearly same questions
New questions
*
*Preliminary data, anticipated substantial increase based on revised questions.
Important Factors Related to NHIS Estimates
•Recall period effects reporting of minor injuries
•Proxy reporting for all children and 36% of adult i/p episodes
•Relatively few intentional injuries reported
•Total treatment may not be reported
•Institutionalized population not captured, e.g., nursing homes
•Acute injury episodes rather than chronic injury
Age in years
Institution Community
Number of visits per 100 persons
65-79 41 8
80+ 37 14
Annual rate of injury-related ED visits for seniors by patient
residence: 2001-2002
From the NCHS 2004 Data Users Conference Presentation Overview of the NAMCS and NHAMCS by Linda McCaig and David Woodwellhttp://www.cdc.gov/nchs/ppt/ahcd/Sess_10_Intro_NAMCS_WOODWELL_&_McCAIG.ppt
Institution is defined as a nursing home or other institution, such as a prison,mental hospital, group home for the mentally or physically disabled. Source: NCHS, NHAMCS-ED
Injury poisoning episodes (all), pain/swelling* due to injury (adults), and some disability due to injury
(adults): 1997-2003
0
5
1 0
1 5
2 0
2 5
3 0
3 5In millions
Injury/poisoning episodes-all ages-(I/p file)
Adults- *pain/ache/stiffness/swelling due to injury-(sample adult file)
Adults w/some disability due to injury-(sample adult file)
1997 1998 1999 2000 2001 2002 2003
i/p episodes
disability
pain
Some disability due to injury: 1997-2003
0
2
4
6
8
1 0
1 2
1 4
1 9 9 7 1 9 9 8 1 9 9 9 2 0 0 0 2 0 0 1 2 0 0 2 2 0 0 3
1 y e a r o r l e s s > 1 y e a r
Number of adults in millions
*Selected from a printed condition list as “fracture/bone/joint injury” and/ or “other injury” (sample adult section/file)
Injury condition duration:
Household InterviewNHIS episodes
(2002)23.7 million
episodesNHIS
Treatment reported (2002)
Medical Records-2002 Estimates
NHIS
NHAMCS
ED visits33.0 million 13.1 million
NHAMCS
OPD visits10.2 million 3.0 million
NAMCS
Dr. visits99.2 million 8.2 million
NHDS-discharges
1.8 million 1.0 million
Injury-related treatment: NHIS/other NCHS surveys
Treatment reported in the NHIS
•All treatment received most likely not reported—only 16 percent of those hospitalized with a fracture also reported a visit to a doctor.
•Compared with other NCHS treatment administrative databases, differences in frequency were greatest for physician-based office visits.
•Fracture ED visits and reported fracture NHIS ED visits were the most similar (1.4 times the NHAMCS-ED).
Medical Records-Based Data
• More accurate accounting of total treatment / healthcare utilization
• Treatment, procedures, and prescribed drug information available
• Collection limited to what’s entered on form/medical chart
• Automated collection systems may differ (NHDS)
• Injury mechanism/cause often unspecified
Strengths Limitations
NHIS episodes 2.6%
NHAMCS
ED visits 26%
NHAMCS
OPD visits 49%
NAMCS
Dr. visits 45%
NHDS-discharges 36%
Percent with unspecified cause of injury: 2002
NHIS-Public Use Data Files
•For estimated annual injury and poisoning episodes:
-Person file-Injury and poisoning episode file-Injury verbatim file
•Using SAS, STATA, SPSS
NHIS Links Expand Scope of Available Injury Data
•More within NHIS
-Sample adult
-Sample child
•External links to NHIS
-Medical Expenditure Panel Survey (MEPS)/NHIS linkage
-National Death Index (NDI)/NHIS linkage
NHIS Injury/Poisoning Episodes linked with NHIS
Sample Adult File •Sample Adult Questionnaire
-Cigarette smoking- physical activity-alcohol consumption- height and weight-gender specific questions-specific and chronic conditions -respiratory ailments-sensory impairment-mental health-health care access and utilization
NHIS Links with Other National Data Sets
• MEPS/NHIS Link-1995 NHIS/1996 MEPS to 2002 MEPS/2001 and 2000 NHIS links
-Health services used, cost of services, and how paid.
• NDI/NHIS Link-2004 linked file includes NHIS survey years 1986-2000 with mortality follow-up through 2002
-Age at NHIS interview, -underlying and multiple cause of death-Other variables by special request (e.g.,
occupation)
http://www.cdc.gov/nchs/about/major/nhis/nhismep.htmhttp://www.cdc.gov/nchs/r&d/nchs_datalinkage/nhis_data_linkage_activities.htm
National Health Interview Survey
• Much more detailed info on cause /circumstances
• Provides national estimates collected from persons not records
• Largest range of data available in one system
• Responses to specific prevention questions
• Linking to other major data systems
• Proxy reporting
• Recall bias
• Intentional injuries masked or underreported
• Missing institutionalized population (e.g., nursing homes)
Strengths Limitations
Questions or additional [email protected]
NHIS: www.cdc.gov/nchs/about/major/nhis/quest_data_related_doc.h
tm
Injury Data and Resources Website!
http://www.cdc.gov/nchs/injury.htm