{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,4]],"date-time":"2026-06-04T13:10:55Z","timestamp":1780578655006,"version":"3.54.1"},"reference-count":36,"publisher":"Oxford University Press (OUP)","issue":"2","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"published-print":{"date-parts":[[2016,2,1]]},"abstract":"<jats:sec>\n                  <jats:title>Background<\/jats:title>\n                  <jats:p>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.<\/jats:p>\n               <\/jats:sec>\n               <jats:sec>\n                  <jats:title>Objective<\/jats:title>\n                  <jats:p>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).<\/jats:p>\n               <\/jats:sec>\n               <jats:sec>\n                  <jats:title>Design<\/jats:title>\n                  <jats:p>This was a retrospective cohort study.<\/jats:p>\n               <\/jats:sec>\n               <jats:sec>\n                  <jats:title>Methods<\/jats:title>\n                  <jats:p>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\u2013Patient 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.<\/jats:p>\n               <\/jats:sec>\n               <jats:sec>\n                  <jats:title>Results<\/jats:title>\n                  <jats:p>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%).<\/jats:p>\n               <\/jats:sec>\n               <jats:sec>\n                  <jats:title>Limitation<\/jats:title>\n                  <jats:p>Patients from 3 impairment categories were included in the sample.<\/jats:p>\n               <\/jats:sec>\n               <jats:sec>\n                  <jats:title>Conclusions<\/jats:title>\n                  <jats:p>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.<\/jats:p>\n               <\/jats:sec>","DOI":"10.2522\/ptj.20150039","type":"journal-article","created":{"date-parts":[[2015,11,13]],"date-time":"2015-11-13T01:58:26Z","timestamp":1447379906000},"page":"232-240","source":"Crossref","is-referenced-by-count":29,"title":["Examining the Association Between Comorbidity Indexes and Functional Status in Hospitalized Medicare Fee-for-Service Beneficiaries"],"prefix":"10.1093","volume":"96","author":[{"given":"Amit","family":"Kumar","sequence":"first","affiliation":[{"name":"A. Kumar, PT, MPH, PhD, Division of Rehabilitation Sciences, University of Texas Medical Branch, 301 University Blvd, Rte 1137, Galveston, TX 77555-1137 (USA)."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"James E.","family":"Graham","sequence":"additional","affiliation":[{"name":"J.E. Graham, PhD, DC, Division of Rehabilitation Sciences, University of Texas Medical Branch."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Linda","family":"Resnik","sequence":"additional","affiliation":[{"name":"L. Resnik, PT, PhD, Department of Health Services, Policy and Practice, Brown University, Providence, Rhode Island, and Providence VA Medical Center, Providence, Rhode Island."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Amol M.","family":"Karmarkar","sequence":"additional","affiliation":[{"name":"A.M. Karmarkar, PhD, MPH, Division of Rehabilitation Sciences, University of Texas Medical Branch."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Anne","family":"Deutsch","sequence":"additional","affiliation":[{"name":"A. Deutsch, RN, PhD, CRRN, RTI International, Washington, DC, and Rehabilitation Institute of Chicago, Chicago, Illinois."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Alai","family":"Tan","sequence":"additional","affiliation":[{"name":"A. Tan, MD, PhD, Institute for Translational Sciences, University of Texas Medical Branch."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Soham","family":"Al Snih","sequence":"additional","affiliation":[{"name":"S. Al Snih, MD, PhD, Division of Rehabilitation Sciences, University of Texas Medical Branch, and Sealy Center on Aging, University of Texas Medical Branch."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Kenneth J.","family":"Ottenbacher","sequence":"additional","affiliation":[{"name":"K.J. Ottenbacher, PhD, OTR, Division of Rehabilitation Sciences, University of Texas Medical Branch, and Sealy Center on Aging, University of Texas Medical Branch."}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"286","reference":[{"key":"2019123002480271200_B1","doi-asserted-by":"crossref","first-page":"58","DOI":"10.1097\/00000446-200601000-00032","article-title":"Functional decline in hospitalized older adults","volume":"106","author":"Graf","year":"2006","journal-title":"Am J Nurs"},{"key":"2019123002480271200_B2","doi-asserted-by":"crossref","first-page":"220","DOI":"10.1111\/j.1532-5415.1991.tb01632.x","article-title":"Hospital-associated deconditioning and dysfunction","volume":"39","author":"Hoenig","year":"1991","journal-title":"J Am Geriatr Soc"},{"key":"2019123002480271200_B3","doi-asserted-by":"crossref","first-page":"1263","DOI":"10.1111\/j.1532-5415.2004.52354.x","article-title":"Prevalence and outcomes of low mobility in hospitalized older patients","volume":"52","author":"Brown","year":"2004","journal-title":"J Am Geriatr Soc"},{"key":"2019123002480271200_B4","doi-asserted-by":"crossref","first-page":"579","DOI":"10.1111\/j.1532-5415.1986.tb05763.x","article-title":"Cognitive impairment: can it predict the course of hospitalized patients?","volume":"34","author":"Fields","year":"1986","journal-title":"J Am Geriatr Soc"},{"key":"2019123002480271200_B5","doi-asserted-by":"crossref","first-page":"1187","DOI":"10.1001\/jama.279.15.1187","article-title":"Importance of functional measures in predicting mortality among older hospitalized patients","volume":"279","author":"Inouye","year":"1998","journal-title":"JAMA"},{"key":"2019123002480271200_B6","doi-asserted-by":"crossref","first-page":"775","DOI":"10.1111\/j.1532-5415.1988.tb04259.x","article-title":"Predictors of immediate and 6-month outcomes in hospitalized elderly patients: the importance of functional status","volume":"36","author":"Narain","year":"1988","journal-title":"J Am Geriatr Soc"},{"key":"2019123002480271200_B7","first-page":"407","article-title":"Factors predicting return home of hospitalized aged patients","volume":"16","author":"Sabartes","year":"1999","journal-title":"An Med Interna"},{"key":"2019123002480271200_B8","doi-asserted-by":"crossref","first-page":"1688","DOI":"10.1001\/jama.2011.1515","article-title":"Risk prediction models for hospital readmission: a systematic review","volume":"306","author":"Kansagara","year":"2011","journal-title":"JAMA"},{"key":"2019123002480271200_B9","doi-asserted-by":"crossref","first-page":"875","DOI":"10.1093\/gerona\/glr247","article-title":"Hospital readmission in persons with stroke following postacute inpatient rehabilitation","volume":"67","author":"Ottenbacher","year":"2012","journal-title":"J Gerontol A Biol Sci Med Sci"},{"key":"2019123002480271200_B10","doi-asserted-by":"crossref","first-page":"89","DOI":"10.1002\/pds.3674","article-title":"Measuring frailty using claims data for pharmacoepidemiologic studies of mortality in older adults: evidence and recommendations","volume":"23","author":"Kim","year":"2014","journal-title":"Pharmacoepidemiol Drug Saf"},{"key":"2019123002480271200_B11","unstructured":"Centers for Medicare & Medicaid Services. 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