Original Study| Volume 22, ISSUE 12, P2447-2453.e5, December 2021

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Functional Status Across Post-Acute Settings is Associated With 30-Day and 90-Day Hospital Readmissions

Published:August 30, 2021DOI:



      To examine the association between cocalibrated functional scores across post-acute care settings and the subsequent risk of hospital readmission.


      Retrospective cohort study.

      Setting and Participants

      We analyzed 781,021 fee-for-service Medicare beneficiaries discharged to either inpatient rehabilitation facilities (IRFs), skilled nursing facilities (SNFs), or home health agencies (HHA) after an acute hospital stay for stroke (N = 143,277), lower extremity joint replacements (512,577), and hip/femur fracture (125,167) between January 1, 2013, and August 31, 2014.


      Functional items from IRF-PAI, MDS, and OASIS were categorized into self-care and mobility domains. We cocalibrated admission functional scores across post-acute settings and divided scores into 4 functional levels using quartiles (Q1-Q4, with Q4 representing the most independent function). The primary outcomes were 30-day and 90-day hospital readmissions (yes/no) after an initial post-acute stay.


      Patients who were more dependent in self-care and mobility at the initial post-acute setting were significantly more likely to experience hospital readmission [eg, hazard ratios of 30-day readmission in stroke: 1.54 (95% confidence interval [CI] 1.47-1.61), 1.18 (95% CI 1.14-1.23), and 1.12 (95% CI 1.08-1.16) for Q1, Q2 and Q3, compared to Q4]. We found similar results for risk of 90-day hospital readmission across impairment conditions.

      Conclusions and Implications

      Patients who were more functionally dependent at the initial post-acute setting had a higher risk to readmit to the hospitals after discharging from the post-acute setting for 30 and 90 days, compared with patients who were more functionally independent. This finding is consistent across impairment conditions and post-acute settings. Future research should determine effective strategies of maintaining and facilitating functional performance across post-acute settings to optimize long-term patient outcomes.


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        • United States Congress
        Improving Medicare Post-Acute Transformation (IMPACT) Act of 2014. 113 USC.
        (Available at:) (Accessed January 2020)
        • Centers for Medicare and Medicaid Services
        Hospital Readmissions Reduction Program (HRRP).
        (Available at:)
        • United States Congress
        The Patient Protection and Affordable Care Act. 42 USC.
        (Available at:) (Accessed January 2020)
        • Agency for Healthcare Research and Quality
        AHRQ national scorecard on hospital-acquired conditions: Final results for 2014 through 2017.
        (Available at:) (Accessed January 2020)
        • Leslie D.L.
        • Marcantonio E.R.
        • Zhang Y.
        • et al.
        One-year health care costs associated with delirium in the elderly population.
        Arch Intern Med. 2008; 168: 27-32
        • Gill T.M.
        • Allore H.G.
        • Gahbauer E.A.
        • Murphy T.E.
        Change in disability after hospitalization or restricted activity in older persons.
        JAMA. 2010; 304: 1919-1928
        • Ponzetto M.
        • Zanocchi M.
        • Maero B.
        • et al.
        Post-hospitalization mortality in the elderly.
        Arch Gerontol Geriatr. 2003; 36: 83-91
        • Lakshminarayan K.
        • Schissel C.
        • Anderson D.C.
        • et al.
        Five-year rehospitalization outcomes in a cohort of patients with acute ischemic stroke.
        Stroke. 2011; 42: 1556-1562
        • Stein L.K.
        • Agarwal P.
        • Thaler A.
        • et al.
        Readmission to a different hospital following acute stroke is associated with worse outcomes.
        Neurology. 2019; 93: e1844-e1851
        • Friedman B.
        • Jiang H.J.
        • Elixhauser A.
        Costly hospital readmissions and complex chronic illness.
        Inquiry. 2008; 45: 408-421
        • Kurtz S.M.
        • Lau E.C.
        • Ong K.L.
        • et al.
        Hospital, patient, and clinical factors influence 30- and 90-day readmission after primary total hip arthroplasty.
        J Arthroplasty. 2016; 31: 2130-2138
        • Hills J.
        • Sivaganesan A.
        • Khan I.
        • et al.
        Causes and timing of unplanned 90-day readmissions following spine surgery.
        Spine (Phila Pa. 1976; 2018: 991-998
        • Wan C.S.
        • Reijnierse E.M.
        • Maier A.B.
        Risk factors of readmissions in geriatric rehabilitation patients: Resort.
        Arch Phys Med Rehabil. 2021; 102: 1524-1532
        • Middleton A.
        • Kuo Y.F.
        • Graham J.E.
        • et al.
        Readmission patterns over 90-day episodes of care among Medicare fee-for-service beneficiaries discharged to post-acute care.
        J Am Med Dir Assoc. 2018; 19: 896-901
        • Li C.Y.
        • Karmarkar A.
        • Adhikari D.
        • et al.
        Effects of age and sex on hospital readmission in traumatic brain injury.
        Arch Phys Med Rehabil. 2018; 99: 1279-1288.e1
        • Li C.Y.
        • Karmarkar A.
        • Kuo Y.F.
        • et al.
        A comparison of three methods in categorizing functional status to predict hospital readmission across post-acute care.
        PLoS One. 2020; 15: e0232017
        • Centers for Medicare and Medicaid Services
        IMPACT Act standardized patient assessment data elements.
        (Available at:)
        • Centers for Medicare and Medicaid Services
        IMPACT Act of 2014 data standardization & cross setting measures.
        (Available at:
        Date: 2021
        Date accessed: June 4, 2020
        • Burke R.E.
        • Whitfield E.A.
        • Hittle D.
        • et al.
        Hospital readmission from post-acute care facilities: Risk factors, timing, and outcomes.
        J Am Med Dir Assoc. 2016; 17: 249-255
        • Courtney M.D.
        • Edwards H.E.
        • Chang A.M.
        • et al.
        A randomised controlled trial to prevent hospital readmissions and loss of functional ability in high risk older adults: A study protocol.
        BMC Health Serv Res. 2011; 11: 202
        • Covinsky K.E.
        • Palmer R.M.
        • Fortinsky R.H.
        • et al.
        Loss of independence in activities of daily living in older adults hospitalized with medical illnesses: Increased vulnerability with age.
        J Am Geriatr Soc. 2003; 51: 451-458
        • Research Data Assistance Center (ResDAC)
        Master beneficiary summary file (MBSD) base.
        (Available at:)
        Date accessed: August 31, 2021
        • Centers for Medicare and Medicaid Services
        Provider of services current files | CMS.
        (Available at:) (Accessed April 2020)
        • Centers for Medicare and Medicaid Services
        IRF-PAI | CMS.
        (Available at:) (Accessed April 2020)
        • Centers for Medicare and Medicaid Services
        Minimum data Set (MDS) 3.0 Resident assessment Instrument (RAI) manual | CMS.
        (Available at:) (Accessed March 2021)
        • Centers for Medicare and Medicaid Services
        OASIS user Manuals | CMS.
        (Available at:) (Accessed April 2020)
        • Centers for Medicare and Medicaid Services
        Outcome measures | CMS.
        (Available at:) (Accessed April 2020)
        • Centers for Medicare and Medicaid Services
        Readmission measures methodology.
        (Available at:) (Accessed April 2020)
        • Mallinson T.R.
        • Deutsch A.
        • Heinemann A.W.
        • Bateman J.
        Comparing function across post-acute rehabilitation settings after co-calibration of self-care and mobility items.
        (Paper presented at: ACRM-ASNR Annual Conference) Canada, Vancouver2012
        • Masters G.N.
        Common-person equating with the Rasch model.
        Appl Psych Meas. 1985; 9: 73-82
        • Smith R.M.
        • Taylor P.A.
        Equating rehabilitation outcome scales: Developing common metrics.
        J Appl Meas. 2004; 5: 229-242
        • Hong I.
        • Goodwin J.S.
        • Reistetter T.A.
        • et al.
        Comparison of functional status improvements among patients with stroke receiving postacute care in inpatient rehabilitation vs skilled nursing facilities.
        JAMA Netw Open. 2019; 2: e1916646
        • Fuller R.L.
        • Hughes J.S.
        • Goldfield N.I.
        Adjusting population risk for functional health status.
        Popul Health Manag. 2016; 19: 136-144
        • Vos L.
        • Whiteneck G.G.
        • Ngan E.
        • et al.
        Rasch analysis of postconcussive symptoms: Development of crosswalks and the brain injury Symptom scale.
        Arch Phys Med Rehabil. 2019; 100: 1844-1852
        • Velozo C.A.
        • Byers K.L.
        • Wang Y.C.
        • Joseph B.R.
        Translating measures across the continuum of care: Using Rasch analysis to create a crosswalk between the functional independence measure and the Minimum data Set.
        J Rehabil Res Dev. 2007; 44: 467-478
        • Li C.Y.
        • Romero S.
        • Bonilha H.S.
        • et al.
        Linking existing instruments to develop an activity of daily living item bank.
        Eval Health Prof. 2018; 41: 25-43
        • Wang Y.C.
        • Byers K.L.
        • Velozo C.A.
        Validation of FIM-MDS crosswalk conversion algorithm.
        J Rehabil Res Dev. 2008; 45: 1065-1076
        • Li C.Y.
        • Romero S.
        • Simpson K.N.
        • et al.
        Linking existing instruments to develop a continuum of care measure: Accuracy comparison using function-related group classification.
        Qual Life Res. 2017; 26: 2563-2572
        • Centers for Medicare and Medicaid Services
        2015 Measure Information about the 30-day all-cause hospital readmission measure, calculated for the value-based payment modifier program.
        (Available at:)
        • Freburger J.K.
        • Chou A.
        • Euloth T.
        • Matcho B.
        Variation in acute care rehabilitation and 30-day hospital readmission or mortality in adult patients with pneumonia.
        JAMA Netw Open. 2020; 3: e2012979
        • Dodson J.A.
        • Hajduk A.M.
        • Murphy T.E.
        • et al.
        Thirty-day readmission risk model for older adults hospitalized with acute myocardial infarction.
        Circ Cardiovasc Qual Outcomes. 2019; 12: e005320
        • Li C.Y.
        • Karmarkar A.
        • Kuo Y.F.
        • et al.
        Impact of self-care and mobility on one or more post-acute care transitions.
        J Aging Health. 2020; 32: 1325-1334
        • Pashikanti L.
        • Von Ah D.
        Impact of early mobilization protocol on the medical-surgical inpatient population: An integrated review of literature.
        Clin Nurse Spec. 2012; 26: 87-94
        • Falkenstein B.A.
        • Skalkowski C.K.
        • Lodise K.D.
        • et al.
        The economic and clinical impact of an early mobility program in the trauma intensive care unit: A quality improvement project.
        J Trauma Nurs. 2020; 27: 29-36
        • Bergbower E.A.S.
        • Herbst C.
        • Cheng N.
        • et al.
        A novel early mobility bundle improves length of stay and rates of readmission among hospitalized general medicine patients.
        J Community Hosp Intern Med Perspect. 2020; 10: 419-425
        • Fisher S.R.
        • Kuo Y.F.
        • Sharma G.
        • et al.
        Mobility after hospital discharge as a marker for 30-day readmission.
        J Gerontol A Biol Sci Med Sci. 2013; 68: 805-810
        • Medicare Learning Network Connects: National provider Call
        Implementing the IMPACT Act: Status update & activities.
        (Available at:)
        • Mukamel D.B.
        • Ladd H.
        • Nuccio E.
        • et al.
        Home health care quality, its costs and implications for home health value-based purchasing.
        Med Care Res Rev. 2020; (1077558720974528)
        • Lieberman D.
        Pitfalls of using administrative data for research.
        Dig Dis Sci. 2010; 55: 1506-1508
        • Cheng H.G.
        • Phillips M.R.
        Secondary analysis of existing data: Opportunities and implementation.
        Shanghai Arch Psychiatry. 2014; 26: 371-375