Using CCW Data for Prevalence Studies of
Alzheimer’s Disease and Related Dementias
(ADRD)
Presented by
Galina Khatutsky, Edith G. Walsh and Nancy T. McCall
RTI International
James E. Leonard and Wendy Funk
Kennell and Associates, Inc
.
AcademyHealth Annual Meeting
Chicago, Illinois
June 29, 2009
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RTI International is a trade name of Research Triangle Institute
Study Consultants
• Malaz Boustani, MD, MPH,
Indianapolis Discovery Network for Dementia,
Healthy Aging Brain Center at Wishard Senior Care,
IU School of Medicine, Regenstrief Institute, National
Institute on Aging
• Christopher Murtaugh, PhD,
Center for Home Care Policy and Research, Visiting
Nurse Service of New York.
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Study Goals
• Document issues in studying ADRD using various
data sources, focusing on Medicare data (literature
review)
• Test the usability and explore new opportunities
available in the Medicare Chronic Condition
Warehouse (CCW) for the study of ADRD
– The CCW supports analyses combining Medicare
claims and clinical assessment data from home health
and nursing facilities, resulting in a unique and
powerful resource for ADRD analyses
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Chronic Condition Data Warehouse (CCW)
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A data source well suited for studying ADRD and other conditions;
summary flags for 21 chronic conditions
Medicare data for institutional and non-institutional services for
FFS Medicare beneficiaries.
Files linked on beneficiary level: continuum of care across settings
– Medicare beneficiary claims (final action)
– Medicare enrollment
– Clinical and in-person assessments for
• Home Health recipients
• Nursing Facility residents
• Inpatient Rehab residents
– Medicare Current Beneficiary Survey (MCBS)
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Funded by CMS and available to researchers
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CCW: Overview
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Database developed in response to Medicare Modernization Act
– Calendar year 1999 forward
• Enhanced 5% Sample (1999-2004)
– Once in, always in, regardless of changes in Medicare Health
Insurance Claim Number (HICN)
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Beginning in 2005, CCW contains 100% data,
– Enhanced 5% data can still be obtained
• Significant advantage over routine Medicare 5% sample data for
longitudinal analyses
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Chronic Conditions in CCW
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Alzheimer’s Disease
Alzheimer’s Disease and Related Disorders or Senile Dementia
Acute Myocardial Infarction
Ischemic Heart Disease
Osteoporosis
RA/OA (Rheumatoid Arthritis/Osteoarthritis)
Stroke / Transient Ischemic Attack
Female Breast Cancer
Colorectal Cancer
Prostate Cancer
Lung Cancer
Endometrial Cancer
Atrial Fibrillation
Cataract
Chronic Kidney Disease
Chronic Obstructive Pulmonary Disease
Depression
Diabetes
Glaucoma
Heart Failure
Challenges estimating the future disease
burden of ADRD
• ADRD prevalence is generally under-reported
• Published rates vary significantly due to different
methodologies and data sources
• There are challenges to identifying ADRD from
Medicare claims or any other single data source
• Each data source offers unique information and
identifies a different population subset
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Identifying Persons with ADRD Using
Medicare Claims
Strengths
• Available for entire FFS Medicare population across care
settings
• Useful for calculating prevalence of treatment for a condition
(claims-based treated prevalence)
Challenges
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Selecting appropriate diagnostic codes
Determining look-back periods
Selecting appropriate Medicare claims files
Avoiding potential bias
– Undercounting if treatment is for other conditions and ADRD diagnosis
is not recorded during episode
– Overcounting if an ADRD diagnostic code is a “rule out”
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Studying ADRD Using the CCW
• Appropriate for ADRD research due to combination of
claims data and in-person clinical assessments for
– Medicare beneficiaries in nursing facilities: Minimum Data
Set (MDS)
– Medicare beneficiaries receiving home health: Outcome
and Assessment Information Set (OASIS)
• Allows diagnostic validation across data sources
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Research Questions
• What is the prevalence in calendar year 2005 of Alzheimer’s
Disease and related dementias (ADRD) in the Medicare
population comparing
– Fee-for-service (FFS) claims data?
– Claims plus in-person clinical assessment data from
• Nursing facilities (MDS)?
• Home health (OASIS)?
• How much agreement is there between claims-based and
assessment-based diagnoses of ADRD?
• What is the value in using assessment data for prevalence
estimates?
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Medicare Claims
• Claims-based Alzheimer's’ Disease and Related
Dementias (ADRD) flag
– 3 year look back period
– At least one claim from hospital inpatient, hospital outpatient,
physician, skilled nursing facility or home health files
– Any diagnosis within a claim, not restricted to primary diagnoses
• Diagnostic flags are based on diagnosis ICD-9 codes;
determined by CMS together with a panel of experts
– ADRD ICD-9 codes: 331.0; all other dementia codes in the 290,
331, and 294 series; and 797
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Nursing Home Minimum Data Set (MDS)
• Allows prevalence estimates for those without acute
care Medicare claims related to ADRD
• Completed routinely, regardless of payor (Medicare,
Medicaid or private pay) and includes:
– ADRD diagnosis entered by RNs
• Check-off items for AD or other dementias
– Spaces to enter additional ICD-9 diagnostic codes
– Measure of cognitive function: Cognitive Performance Scale
(CPS)
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Variables derived from the Nursing Home
Minimum Data Set (MDS)
• Diagnoses (ADRD) collected for nursing facility
residents
• Cognitive Performance Scale (0 -6)
0 = intact
1 = borderline intact
2 = mild impairment
3 = moderate impairment
4 = moderately severe impairment
5 = severe impairment
6 = very severe impairment
– validated MDS measure of cognitive impairment commonly
used to assign residents into easily understood cognitive
performance categories
• Details on CPS are available in
Morris, Fries, Morris et.al., "MDS Cognitive Performance Scale" J. Gerontology:
Medical Sciences 49(4):M174-M182 (July) 1994.
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Home Health Outcome and Assessment
Information Set (OASIS)
• Allows prevalence estimates for those with Medicare
home health utilization
• Completed at each start and resumption of care
episode, and at follow-up
• Diagnoses and associated ICD-9-CM codes on each
home care episode entered by RNs or therapists
– Measures of cognitive function
– ADRD may be undercounted
• ADRD diagnosis is rarely a reason/focus for home health
episode
• Persons with ADRD diagnosis may not be considered as
“improving” and so ADRD diagnosis may not be recorded
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Variables derived from Outcome and
Assessment Information Set (OASIS)
• Diagnoses of dementia
• Behavioral symptoms of cognitive impairment
– Memory deficit: failure to recognize familiar
persons/places, inability to recall events of past 24
hours, memory loss significant enough that supervision
is required
– Impaired decision making: failure to perform usual
activities of daily living (ADL) or instrumental activities
of daily living (IADL), inability to appropriately stop
activities, safety jeopardized through actions
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Study Sample (n=88, 476)
• Medicare beneficiaries in the CMS Chronic Condition Data
Warehouse (CCW)
– Enhanced 5% Medicare sample
AND
– Medicare Part A and Part B, full FFS coverage
AND
– MDS clinical assessment present
AND
– OASIS clinical assessment present
– Reference year 2005
– Look back period 3 years
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Analysis Plan
• Compare ADRD prevalence for persons with all 3
types of records using:
– Diagnosis only (identified using claims, Nursing Home
Assessments (MDS), Home Health Assessments
(OASIS), or any combination of these sources)
– Diagnosis or behavioral/cognitive impairment
(identified in MDS or OASIS)
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ADRD Prevalence for Study Sample Varies By
Data Source Combinations (percent)
• Claims-based diagnoses
40.1
• MDS-based diagnoses
• MDS-based diagnosis or CPS>1
6.5
39.0
• OASIS-based diagnoses
• OASIS-based diagnoses or
symptoms of cognitive impairment
2.0
• All sources combined
54.3
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17.1
Agreement Between Data Sources in
Identifying ADRD
Good Agreement
Claims/All other Sources
KAPPA Coefficient
0.720
Moderate Agreement
Claims / both MDS sources
0.507
Claims / MDS Cognitive Performance Scale
0.489
Fair Agreement
Claims / both OASIS Sources
0.252
Claims / OASIS Behavioral Symptoms
0.240
Slight Agreement
Claims / MDS Diagnosis
0.181
Claims /OASIS Diagnosis
0.056
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Limitations
• These multiple data sources are only available for the
most impaired subsets of the Medicare populationusers of home health and nursing facility care
• Some of the lack of agreement may relate to disease
progression and when in the 3 year time period the
Medicare claims, OASIS or MDS use occurred
• Measures of cognitive impairment may indicate
conditions other than ADRD
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Conclusions
• Each individual source of data appears to underestimate the prevalence of ADRD
• Medicare claims data appear to capture about ¾ of
beneficiaries with ADRD
• Diagnoses from nursing facility and home health data
appear limited
– Perhaps due to lack of incentive to list a complete set of
diagnoses
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Conclusions
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Addition of cognitive impairment measures from home health or
nursing facility assessment data substantially increases
prevalence estimates within each data source
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Addition of nursing home and home health assessment data
produces an 35% increase in prevalence over claims-only
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Combination of MDS diagnoses and CPS produces prevalence
estimates comparable to claims-only
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Agreement between all other data sources combined and claims
based identification of ADRD is good, however each separate
source compared with claims has moderate agreement at best
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A combination of data sources seem to be the best way to create
a more accurate estimate of prevalence: CCW provides an
effective way to conduct studies comparing data sources or to
maximize identification and track beneficiaries over time
http://www.resdac.umn.edu/CCW/data_available.asp
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