Examining the association between comorbidity indexes and functional status in hospitalized medicare fee-for-service beneficiaries

Amit Kumar, James E. Graham, Linda Resnik, Amol Karmarkar, Anne Deutsch, Alai Tan, Soham Al Snih al snih, Kenneth Ottenbacher

Research output: Contribution to journalArticle

9 Citations (Scopus)

Abstract

Background. Medicare data from acute hospitals do not contain information on functional status. This lack of information limits the ability to conduct rehabilitation-related health services research. Objective. The purpose of this study was to examine the associations between 5 comorbidity indexes derived from acute care claims data and functional status assessed at admission to an inpatient rehabilitation facility (IRF). Comorbidity indexes included tier comorbidity, Functional Comorbidity Index (FCI), Charlson Comorbidity Index, Elixhauser Comorbidity Index, and Hierarchical Condition Category (HCC). Design. This was a retrospective cohort study. Methods. Medicare beneficiaries with stroke, lower extremity joint replacement, and lower extremity fracture discharged to an IRF in 2011 were studied (N= 105,441). Data from the beneficiary summary file, Medicare Provider Analysis and Review (MedPAR) file, and Inpatient Rehabilitation Facility-Patient Assessment Instrument (IRF-PAI) file were linked. Inpatient rehabilitation facility admission functional status was used as a proxy for acute hospital discharge functional status. Separate linear regression models for each impairment group were developed to assess the relationships between the comorbidity indexes and functional status. Base models included age, sex, race/ethnicity, disability, dual eligibility, and length of stay. Subsequent models included individual comorbidity indexes. Values of variance explained (R2) with each comorbidity index were compared. Results. Base models explained 7.7% of the variance in motor function ratings for stroke, 3.8% for joint replacement, and 7.3% for fracture. The R2 increased marginally when comorbidity indexes were added to base models for stroke, joint replacement, and fracture: Charlson Comorbidity Index (0.4%, 0.5%, 0.3%), tier comorbidity (0.2%, 0.6%, 0.5%), FCI (0.4%, 1.2%, 1.6%), Elixhauser Comorbidity Index (1.2%, 1.9%, 3 5%), and HCC (2.2%, 2.1%, 2.8%). Limitation. Patients from 3 impairment categories were included in the sample. Conclusions. The 5 comorbidity indexes contributed little to predicting functional status. The indexes examined were not useful as proxies for functional status in the acute settings studied.

Original languageEnglish (US)
Pages (from-to)232-240
Number of pages9
JournalPhysical Therapy
Volume96
Issue number2
DOIs
StatePublished - Feb 1 2016

Fingerprint

Fee-for-Service Plans
Medicare
Comorbidity
Replacement Arthroplasties
Rehabilitation
Inpatients
Stroke
Proxy
Lower Extremity
Linear Models
Health Services Research

ASJC Scopus subject areas

  • Physical Therapy, Sports Therapy and Rehabilitation

Cite this

Examining the association between comorbidity indexes and functional status in hospitalized medicare fee-for-service beneficiaries. / Kumar, Amit; Graham, James E.; Resnik, Linda; Karmarkar, Amol; Deutsch, Anne; Tan, Alai; Al Snih al snih, Soham; Ottenbacher, Kenneth.

In: Physical Therapy, Vol. 96, No. 2, 01.02.2016, p. 232-240.

Research output: Contribution to journalArticle

Kumar, Amit ; Graham, James E. ; Resnik, Linda ; Karmarkar, Amol ; Deutsch, Anne ; Tan, Alai ; Al Snih al snih, Soham ; Ottenbacher, Kenneth. / Examining the association between comorbidity indexes and functional status in hospitalized medicare fee-for-service beneficiaries. In: Physical Therapy. 2016 ; Vol. 96, No. 2. pp. 232-240.
@article{f76b4dfd46e4487eb9cbf95ca4e0bfe2,
title = "Examining the association between comorbidity indexes and functional status in hospitalized medicare fee-for-service beneficiaries",
abstract = "Background. Medicare data from acute hospitals do not contain information on functional status. This lack of information limits the ability to conduct rehabilitation-related health services research. Objective. The purpose of this study was to examine the associations between 5 comorbidity indexes derived from acute care claims data and functional status assessed at admission to an inpatient rehabilitation facility (IRF). Comorbidity indexes included tier comorbidity, Functional Comorbidity Index (FCI), Charlson Comorbidity Index, Elixhauser Comorbidity Index, and Hierarchical Condition Category (HCC). Design. This was a retrospective cohort study. Methods. Medicare beneficiaries with stroke, lower extremity joint replacement, and lower extremity fracture discharged to an IRF in 2011 were studied (N= 105,441). Data from the beneficiary summary file, Medicare Provider Analysis and Review (MedPAR) file, and Inpatient Rehabilitation Facility-Patient Assessment Instrument (IRF-PAI) file were linked. Inpatient rehabilitation facility admission functional status was used as a proxy for acute hospital discharge functional status. Separate linear regression models for each impairment group were developed to assess the relationships between the comorbidity indexes and functional status. Base models included age, sex, race/ethnicity, disability, dual eligibility, and length of stay. Subsequent models included individual comorbidity indexes. Values of variance explained (R2) with each comorbidity index were compared. Results. Base models explained 7.7{\%} of the variance in motor function ratings for stroke, 3.8{\%} for joint replacement, and 7.3{\%} for fracture. The R2 increased marginally when comorbidity indexes were added to base models for stroke, joint replacement, and fracture: Charlson Comorbidity Index (0.4{\%}, 0.5{\%}, 0.3{\%}), tier comorbidity (0.2{\%}, 0.6{\%}, 0.5{\%}), FCI (0.4{\%}, 1.2{\%}, 1.6{\%}), Elixhauser Comorbidity Index (1.2{\%}, 1.9{\%}, 3 5{\%}), and HCC (2.2{\%}, 2.1{\%}, 2.8{\%}). Limitation. Patients from 3 impairment categories were included in the sample. Conclusions. The 5 comorbidity indexes contributed little to predicting functional status. The indexes examined were not useful as proxies for functional status in the acute settings studied.",
author = "Amit Kumar and Graham, {James E.} and Linda Resnik and Amol Karmarkar and Anne Deutsch and Alai Tan and {Al Snih al snih}, Soham and Kenneth Ottenbacher",
year = "2016",
month = "2",
day = "1",
doi = "10.2522/ptj.20150039",
language = "English (US)",
volume = "96",
pages = "232--240",
journal = "Physical Therapy",
issn = "0031-9023",
publisher = "American Physical Therapy Association",
number = "2",

}

TY - JOUR

T1 - Examining the association between comorbidity indexes and functional status in hospitalized medicare fee-for-service beneficiaries

AU - Kumar, Amit

AU - Graham, James E.

AU - Resnik, Linda

AU - Karmarkar, Amol

AU - Deutsch, Anne

AU - Tan, Alai

AU - Al Snih al snih, Soham

AU - Ottenbacher, Kenneth

PY - 2016/2/1

Y1 - 2016/2/1

N2 - Background. Medicare data from acute hospitals do not contain information on functional status. This lack of information limits the ability to conduct rehabilitation-related health services research. Objective. The purpose of this study was to examine the associations between 5 comorbidity indexes derived from acute care claims data and functional status assessed at admission to an inpatient rehabilitation facility (IRF). Comorbidity indexes included tier comorbidity, Functional Comorbidity Index (FCI), Charlson Comorbidity Index, Elixhauser Comorbidity Index, and Hierarchical Condition Category (HCC). Design. This was a retrospective cohort study. Methods. Medicare beneficiaries with stroke, lower extremity joint replacement, and lower extremity fracture discharged to an IRF in 2011 were studied (N= 105,441). Data from the beneficiary summary file, Medicare Provider Analysis and Review (MedPAR) file, and Inpatient Rehabilitation Facility-Patient Assessment Instrument (IRF-PAI) file were linked. Inpatient rehabilitation facility admission functional status was used as a proxy for acute hospital discharge functional status. Separate linear regression models for each impairment group were developed to assess the relationships between the comorbidity indexes and functional status. Base models included age, sex, race/ethnicity, disability, dual eligibility, and length of stay. Subsequent models included individual comorbidity indexes. Values of variance explained (R2) with each comorbidity index were compared. Results. Base models explained 7.7% of the variance in motor function ratings for stroke, 3.8% for joint replacement, and 7.3% for fracture. The R2 increased marginally when comorbidity indexes were added to base models for stroke, joint replacement, and fracture: Charlson Comorbidity Index (0.4%, 0.5%, 0.3%), tier comorbidity (0.2%, 0.6%, 0.5%), FCI (0.4%, 1.2%, 1.6%), Elixhauser Comorbidity Index (1.2%, 1.9%, 3 5%), and HCC (2.2%, 2.1%, 2.8%). Limitation. Patients from 3 impairment categories were included in the sample. Conclusions. The 5 comorbidity indexes contributed little to predicting functional status. The indexes examined were not useful as proxies for functional status in the acute settings studied.

AB - Background. Medicare data from acute hospitals do not contain information on functional status. This lack of information limits the ability to conduct rehabilitation-related health services research. Objective. The purpose of this study was to examine the associations between 5 comorbidity indexes derived from acute care claims data and functional status assessed at admission to an inpatient rehabilitation facility (IRF). Comorbidity indexes included tier comorbidity, Functional Comorbidity Index (FCI), Charlson Comorbidity Index, Elixhauser Comorbidity Index, and Hierarchical Condition Category (HCC). Design. This was a retrospective cohort study. Methods. Medicare beneficiaries with stroke, lower extremity joint replacement, and lower extremity fracture discharged to an IRF in 2011 were studied (N= 105,441). Data from the beneficiary summary file, Medicare Provider Analysis and Review (MedPAR) file, and Inpatient Rehabilitation Facility-Patient Assessment Instrument (IRF-PAI) file were linked. Inpatient rehabilitation facility admission functional status was used as a proxy for acute hospital discharge functional status. Separate linear regression models for each impairment group were developed to assess the relationships between the comorbidity indexes and functional status. Base models included age, sex, race/ethnicity, disability, dual eligibility, and length of stay. Subsequent models included individual comorbidity indexes. Values of variance explained (R2) with each comorbidity index were compared. Results. Base models explained 7.7% of the variance in motor function ratings for stroke, 3.8% for joint replacement, and 7.3% for fracture. The R2 increased marginally when comorbidity indexes were added to base models for stroke, joint replacement, and fracture: Charlson Comorbidity Index (0.4%, 0.5%, 0.3%), tier comorbidity (0.2%, 0.6%, 0.5%), FCI (0.4%, 1.2%, 1.6%), Elixhauser Comorbidity Index (1.2%, 1.9%, 3 5%), and HCC (2.2%, 2.1%, 2.8%). Limitation. Patients from 3 impairment categories were included in the sample. Conclusions. The 5 comorbidity indexes contributed little to predicting functional status. The indexes examined were not useful as proxies for functional status in the acute settings studied.

UR - http://www.scopus.com/inward/record.url?scp=84956948363&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84956948363&partnerID=8YFLogxK

U2 - 10.2522/ptj.20150039

DO - 10.2522/ptj.20150039

M3 - Article

VL - 96

SP - 232

EP - 240

JO - Physical Therapy

JF - Physical Therapy

SN - 0031-9023

IS - 2

ER -