Hospital Readmissions Following Physician Call System Change: A Comparison of Concentrated and Distributed Schedules

  • Christopher J. Yarnell
    Department of Medicine, University of Toronto, Ont., Canada

    Evaluative Clinical Sciences, Sunnybrook Research Institute, Toronto, Ont., Canada
    Search for articles by this author
  • Steven Shadowitz
    Department of Medicine, University of Toronto, Ont., Canada

    Division of General Internal Medicine, University of Toronto, Ont., Canada
    Search for articles by this author
  • Donald A. Redelmeier
    Requests for reprints should be addressed to Donald A. Redelmeier, MD, MS (HSR), Sunnybrook Health Sciences Centre, G-151, 2075 Bayview Ave, Toronto, ON M4N 3M5, Canada.
    Department of Medicine, University of Toronto, Ont., Canada

    Evaluative Clinical Sciences, Sunnybrook Research Institute, Toronto, Ont., Canada

    Division of General Internal Medicine, University of Toronto, Ont., Canada

    Institute of Clinical Evaluative Sciences (ICES) in Ontario, Toronto, Canada

    Institute for Health Policy Management and Evaluation, Toronto, Ont., Canada
    Search for articles by this author



      Physician call schedules are a critical element for medical practice and hospital efficiency. We compared readmission rates prior to and after a change in physician call system at Sunnybrook Health Sciences Centre.


      We studied patients discharged over a decade (2004 through 2013) and identified whether or not each patient was readmitted within the subsequent 28 days. We excluded patients discharged for a surgical, obstetrical, or psychiatric diagnosis. We used time-to-event analysis and time-series analysis to compare rates of readmission prior to and after the physician call system change (January 1, 2009).


      A total of 89,697 patients were discharged, of whom 10,001 (11%) were subsequently readmitted and 4280 died. The risk of readmission was increased by about 26% following physician call system change (9.7% vs 12.2%, P <.001). Time-series analysis confirmed a 26% increase in the readmission rate after call system change (95% confidence interval, 22%-31%; P <.001). The increase in readmission rate after call system change persisted across patients with diverse ages, estimated readmission risks, and medical diagnoses. The net effect was equal to 7240 additional patient days in the hospital following call system change. A modest increase was observed at a nearby acute care hospital that did not change physician call system, and no increase in risk of death was observed with increased hospital readmissions.


      We suggest that changes in physician call systems sometimes increase subsequent hospital readmission rates. Further reductions in readmissions may instead require additional resources or ingenuity.


      To read this article in full you will need to make a payment

      Purchase one-time access:

      Academic & Personal: 24 hour online accessCorporate R&D Professionals: 24 hour online access
      One-time access price info
      • For academic or personal research use, select 'Academic and Personal'
      • For corporate R&D use, select 'Corporate R&D Professionals'


      Subscribe to The American Journal of Medicine
      Already a print subscriber? Claim online access
      Already an online subscriber? Sign in
      Institutional Access: Sign in to ScienceDirect


        • Shanafelt T.D.
        • Boone S.
        • Tan L.
        • et al.
        Burnout and satisfaction with work-life balance among US physicians relative to the general US population.
        Arch Intern Med. 2012; 172: 1377-1385
        • Haggerty J.L.
        • Reid R.J.
        • Freeman G.K.
        • et al.
        Continuity of care: a multidisciplinary review.
        BMJ. 2003; 327: 1219-1221
        • Guthrie B.
        • Saultz J.W.
        • Freeman G.K.
        • Haggerty J.L.
        Continuity of care matters.
        BMJ. 2008; 337: a867
        • Starmer A.J.
        • Spector N.D.
        • Srivastava R.
        • et al.
        Changes in medical errors after implementation of a handoff program.
        N Engl J Med. 2014; 371: 1803-1812
        • Hamadani F.T.
        • Deckelbaum D.
        • Sauve A.
        • Khwaja K.
        • Razek T.
        • Fata P.
        Abolishment of 24-hour continuous medical call duty in Quebec: a quality of life survey of general surgical residents following implementation of the new work-hour restrictions.
        J Surg Educ. 2013; 70: 296-303
        • Nasca T.J.
        • Day S.H.
        • Amis Jr., E.S.
        • ACGME Duty Hour Task Force
        The new recommendations on duty hours from the ACGME Task Force.
        N Engl J Med. 2010; 363: 23
        • Anderson G.F.
        • Steinberg E.P.
        Hospital readmissions in the Medicare population.
        N Engl J Med. 1984; 311: 1349-1353
        • Jencks S.F.
        • Williams M.V.
        • Coleman E.A.
        Rehospitalizations among patients in the Medicare fee-for-service program.
        N Engl J Med. 2009; 360: 1418-1428
        • Joynt K.E.
        • Jha A.K.
        A path forward on Medicare readmissions.
        N Engl J Med. 2013; 368: 1175-1177
        • Krumholz H.M.
        Post-hospital syndrome—an acquired, transient condition of generalized risk.
        N Engl J Med. 2013; 368: 100-102
        • Axon R.N.
        • Williams M.V.
        Hospital readmission as an accountability measure.
        JAMA. 2011; 305: 504-505
        • Stroud L.
        • Oulanova O.
        • Szecket N.
        • Ginsburg S.
        “The benefits make up for whatever is lost”: altruism and accountability in a new call system.
        Acad Med. 2012; 87: 1421-1427
        • Szecket N.
        • Wong H.J.
        • Wu R.C.
        • Berman H.D.
        • Morra D.
        Implementation of a continuous admission model reduces the length of stay of patients on an internal medicine clinical teaching unit.
        J Hosp Med. 2012; 7: 55-59
        • Institute for Healthcare Improvement (IHI)
        Optimizing Patient Flow: Moving Patients Smoothly Through Acute Care Settings.
        (IHI Innovation Series white paper) Institute for Healthcare Improvement, Boston2003 (Available at:) (Accessed March 13, 2016)
        • Patel M.S.
        • Volpp K.G.
        • Small D.S.
        • et al.
        Association of the 2011 ACGME Resident Duty Hour Reforms With Mortality and Readmissions Among Hospitalized Medicare Patients.
        JAMA. 2014; 312: 2364-2373
        • Choma N.N.
        • Vasilevskis E.E.
        • Sponsler K.C.
        • Hathaway J.
        • Kripalani S.
        Effect of the ACGME 16-hour rule on efficiency and quality of care: Duty Hours 2.0.
        JAMA Intern Med. 2013; 173: 819-821
        • Press M.J.
        • Silber J.H.
        • Rosen A.K.
        • et al.
        The impact of resident duty hour reform on hospital readmission rates among Medicare beneficiaries.
        J Gen Intern Med. 2011; 26: 405-411
        • Ong M.
        • Bostrom A.
        • Vidyarthi A.
        • McCulloch C.
        • Auerbach A.
        House staff team workload and organization effects on patient outcomes in an academic general internal medicine inpatient service.
        Arch Intern Med. 2007; 167: 47-52
        • Lucas B.P.
        • Trick W.E.
        • Evans A.T.
        • et al.
        Effects of 2- vs 4-week attending physician inpatient rotations on unplanned patient revisits, evaluations by trainees, and attending physician burnout: a randomized trial.
        JAMA. 2012; 308: 2199-2207
        • Berwick D.
        • Bauchner H.
        • Fontanarosa P.B.
        Innovations in health care delivery: call for papers for a yearlong series.
        JAMA. 2015; 314: 675-676
        • World Health Organization
        International Classification of Diseases: ICD-10.
        2010 (Available at:) (Accessed July 14, 2015)
        • Juurlink D.
        • Preyra C.
        • Croxford R.
        • et al.
        Canadian Institute for Health Information Discharge Abstract Database: A Validation Study.
        Institute for Clinical Evaluative Sciences, Toronto2006
        • Canadian Institute for Health Information (CIHI)
        CIHI Data Quality Study of Emergency Department Visits for 2004-2005. Vol. 2: Main Study Findings.
        CIHI, Ottawa2008
        • van Walraven C.
        • Dhalla I.A.
        • Bell C.
        • et al.
        Derivation and validation of an index to predict early death or unplanned readmission after discharge from hospital to the community.
        CMAJ. 2010; 182: 551-557
        • Kansagara D.
        • Englander H.
        • Salanitro A.
        • et al.
        Risk prediction models for hospital readmission: a systematic review.
        JAMA. 2011; 306: 1688-1698
        • Mueller S.K.
        • Donze J.
        • Schnipper J.L.
        Intern workload and discontinuity of care on 30-day readmission.
        Am J Med. 2013; 126: 81-88
        • Southern W.N.
        • Nahvi S.
        • Arnsten J.H.
        Increased risk of mortality and readmission among patients discharged against medical advice.
        Am J Med. 2012; 125: 594-602
        • Bell C.M.
        • Redelmeier D.A.
        Mortality among patients admitted to hospitals on weekends as compared with weekdays.
        N Engl J Med. 2001; 345: 663-668
        • Staples J.A.
        • Thiruchelvam D.
        • Redelmeier D.A.
        Site of hospital readmission and mortality: a population-based retrospective cohort study.
        CMAJ Open. 2014; 2: E77-E85
        • Schull M.J.
        • Hatcher C.M.
        • Guttmann A.
        • et al.
        Development of a Consensus on Evidence-Based Quality of Care Indicators for Canadian Emergency Departments.
        Institute for Clinical Evaluative Sciences, Toronto2010
        • Hyndman R.J.
        • Khandakar Y.
        Automatic time series forecasting: the forecast package for R.
        J Stat Softw. 2008; 26
        • Glazier R.H.
        • Zagorski B.M.
        • Rayner J.
        Comparison of Primary Care Models in Ontario by Demographics, Case Mix and Emergency Department Use, 2008/09 to 2009/10. ICES Investigative Report.
        Institute for Clinical Evaluative Sciences, Toronto2012
      1. Ontario Government: Newsroom. Ontario Investing in Shorter ER Wait Times. May 22, 2009. Available at: Accessed August 9, 2015.

        • Krumholz H.M.
        • Lin Z.
        • Keenan P.S.
        • et al.
        Relationship between hospital readmission and mortality rates for patients hospitalized with acute myocardial infarction, heart failure, or pneumonia.
        JAMA. 2013; 309: 587-593
        • Dimick J.B.
        • Ryan A.M.
        Methods for evaluating changes in health care policy: the difference-in-differences approach.
        JAMA. 2014; 312: 2401-2402
      2. North York General Hospital (NYGH). NYGH: about Us. 2015. Available at: Accessed August 9, 2015.

        • Payne R.A.
        • Abel G.A.
        • Guthrie B.
        • Mercer S.W.
        The effect of physical multimorbidity, mental health conditions and socioeconomic deprivation on unplanned admissions to hospital: a retrospective cohort study.
        CMAJ. 2013; 185: E221-E228
        • Koné Pefoyo A.J.
        • Bronskill S.E.
        • Gruneir A.
        • et al.
        The increasing burden and complexity of multimorbidity.
        BMC Public Health. 2015; 15: 415
        • Leppin A.L.
        • Gionfriddo M.R.
        • Kessler M.
        • et al.
        Preventing 30-day hospital readmissions: a systematic review and meta-analysis of randomized trials.
        JAMA Intern Med. 2014; 174: 1095-1107
        • Hansen L.O.
        • Young R.S.
        • Hinami K.
        • Leung A.
        • Williams M.V.
        Interventions to reduce 30-day rehospitalization: a systematic review.
        Ann Intern Med. 2011; 155: 520-528
        • Arora V.M.
        • Georgitis E.
        • Siddique J.
        • et al.
        Association of workload of on-call medical interns with on-call sleep duration, shift duration, and participation in educational activities.
        JAMA. 2008; 300: 1146-1153
        • Horwitz L.I.
        • Lin Z.
        • Herrin J.
        • et al.
        Association of hospital volume with readmission rates: a retrospective cross-sectional study.
        BMJ. 2015; 350: h447
        • Costa A.P.
        • Poss J.W.
        • Peirce T.
        • Hirdes J.P.
        Acute care inpatients with long-term delayed-discharge: evidence from a Canadian health region.
        BMC Health Serv Res. 2012; 12: 172
        • Calvillo-King L.
        • Arnold D.
        • Eubank K.J.
        • et al.
        Impact of social factors on risk of readmission or mortality in pneumonia and heart failure: systematic review.
        J Gen Intern Med. 2013; 28: 269-282
        • Donzé J.
        • Lipsitz S.
        • Bates D.W.
        • Schnipper J.L.
        Causes and patterns of readmissions in patients with common comorbidities: retrospective cohort study.
        BMJ. 2013; 347: f7171
        • Hamar G.B.
        • Rula E.Y.
        • Wells A.
        • Coberley C.
        • Pope J.E.
        • Larkin S.
        Impact of a chronic disease management program on hospital admissions and readmissions in an Australian population with heart disease or diabetes.
        Popul Health Manag. 2013; 16: 125-131
        • Dhalla I.A.
        • O'Brien T.
        • Morra D.
        • et al.
        Effect of a postdischarge virtual ward on readmission or death for high-risk patients: a randomized clinical trial.
        JAMA. 2014; 312: 1305-1312
        • Kaboli P.J.
        • Go J.T.
        • Hockenberry J.
        • et al.
        Associations between reduced hospital length of stay and 30-day readmission rate and mortality: 14-year experience in 129 Veterans Affairs hospitals.
        Ann Intern Med. 2012; 157: 837-845
        • van Walraven C.
        • Bennett C.
        • Jennings A.
        • Austin P.C.
        • Forster A.J.
        Proportion of hospital readmissions deemed avoidable: a systematic review.
        CMAJ. 2011; 183: E391-E402
        • van Walraven C.
        • Jennings A.
        • Taljaard M.
        • et al.
        Incidence of potentially avoidable urgent readmissions and their relation to all-cause urgent readmissions.
        CMAJ. 2011; 183: E1067-E1072
        • Hu J.
        • Gonsahn M.D.
        • Nerenz D.R.
        Socioeconomic status and readmissions: evidence from an urban teaching hospital.
        Health Aff (Millwood). 2014; 33: 778-785
        • Patel M.S.
        • Volpp K.G.
        • Small D.S.
        • et al.
        Association of the 2011 ACGME resident duty hour reforms with mortality and readmissions among hospitalized Medicare patients.
        JAMA. 2014; 312: 2364-2373
        • Engel K.G.
        • Heisler M.
        • Smith D.M.
        • Robinson C.H.
        • Forman J.H.
        • Ubel P.A.
        Patient comprehension of emergency department care and instructions: are patients aware of when they do not understand?.
        Ann Emerg Med. 2009; 53: 454-461.e15
        • Romano M.J.
        • Segal J.B.
        • Pollack C.
        The association between continuity of care and the overuse of medical procedures.
        JAMA Intern Med. 2015; 175: 1148-1154
        • Greysen S.
        • Detsky A.S.
        Understanding the value of continuity in the 21st century.
        JAMA Intern Med. 2015; 175: 1154-1156
        • Darley J.M.
        • Bibb L.
        Bystander intervention in emergencies: diffusion of responsibility.
        J Pers Soc Psychol. 1968; 8: 377-383
        • Bibb L.
        • Williams K.
        • Harkins S.
        Many hands make light the work: the causes and consequences of social loafing.
        J Pers Soc Psychol. 1979; 37: 822-832
        • Horwitz L.I.
        • Moriarty J.P.
        • Chen C.
        • et al.
        Quality of discharge practices and patient understanding at an academic medical center.
        JAMA Intern Med. 2013; 173: 1715-1722
        • Martin S.K.
        • Farnan J.M.
        • Flores A.
        • Kurina L.M.
        • Meltzer D.O.
        • Arora V.M.
        Exploring entrustment: housestaff autonomy and patient readmission.
        Am J Med. 2014; 127: 791-797
        • Devlin M.K.
        • Kozij N.K.
        • Kiss A.
        • Richardson L.
        • Wong B.M.
        Morning handover of on-call issues: opportunities for improvement.
        JAMA Intern Med. 2014; 174: 1479-1485
        • Nyweide D.J.
        • Anthony D.L.
        • Bynum J.W.
        • et al.
        Continuity of care and the risk of preventable hospitalization in older adults.
        JAMA Intern Med. 2013; 173: 1879-1885
        • Gilovich T.
        • Ross L.
        The Wisest One in the Room: How You Can Benefit From Social Psychology's Most Powerful Insights.
        1st ed. Simon & Schuster, Toronto2015
        • Wang H.
        • Robinson R.D.
        • Johnson C.
        • et al.
        Using the LACE index to predict hospital readmissions in congestive heart failure patients.
        BMC Cardiovasc Disord. 2014; 14: 97
        • Reed D.A.
        • Fletcher K.E.
        • Arora V.M.
        Systematic review: association of shift length, protected sleep time, and night float with patient care, residents' health, and education.
        Ann Intern Med. 2010; 153: 829-842
        • Cavallo A.
        • Ris M.D.
        • Succop P.
        The night float paradigm to decrease sleep deprivation: good solution or a new problem?.
        Ergonomics. 2003; 46: 653-663
        • Landrigan C.P.
        • Rothschild J.M.
        • Cronin J.W.
        • et al.
        Effect of reducing interns' work hours on serious medical errors in intensive care units.
        N Engl J Med. 2004; 351: 1838-1848
        • Parshuram C.S.
        • Amaral A.C.
        • Ferguson N.D.
        • et al.
        • Canadian Critical Care Trials Group
        Patient safety, resident well-being and continuity of care with different resident duty schedules in the intensive care unit: a randomized trial.
        CMAJ. 2015; 187: 321-329
        • McMahon G.T.
        • Katz J.T.
        • Thorndike M.E.
        • Levy B.D.
        • Loscalzo J.
        Evaluation of a redesign initiative in an internal-medicine residency.
        N Engl J Med. 2010; 362: 1304-1311
        • Volpp K.G.
        • Shea J.A.
        • Small D.S.
        • et al.
        Effect of a protected sleep period on hours slept during extended overnight in-hospital duty hours among medical interns: a randomized trial.
        JAMA. 2012; 308: 2208-2217
        • Spellberg B.
        • Sue D.
        • Chang D.
        • Witt M.
        Change in intern calls at night after a work hour restriction process change.
        JAMA Intern Med. 2013; 173: 707-709
        • McAlister F.A.
        • Bakal J.A.
        • Majumdar S.R.
        • et al.
        Safely and effectively reducing inpatient length of stay: a controlled study of the General Internal Medicine Care Transformation Initiative.
        BMJ Qual Saf. 2014; 23: 446-456
        • Rajaram R.
        • Chung J.W.
        • Jones A.T.
        • et al.
        Association of the 2011 ACGME resident duty hour reform with general surgery patient outcomes and with resident examination performance.
        JAMA. 2014; 312: 2374-2384
        • Jamal M.H.
        • Doi S.A.
        • Rousseau M.
        • et al.
        Systematic review and meta-analysis of the effect of North American working hours restrictions on mortality and morbidity in surgical patients.
        Br J Surg. 2012; 99: 336-344
        • Shetty K.D.
        • Bhattacharya J.
        Changes in hospital mortality associated with residency work-hour regulations.
        Ann Intern Med. 2007; 147: 73-80
        • Norby K.
        • Siddiq F.
        • Adil M.M.
        • Haines S.J.
        The effect of duty hour regulations on outcomes of neurological surgery in training hospitals in the United States: duty hour regulations and patient outcomes.
        J Neurosurg. 2014; 121: 247-261

      Linked Article

      • Readmission Among Hospitalized Patients: An Important Health Care Issue
        The American Journal of MedicineVol. 130Issue 3
        • Preview
          “Hospital Readmissions Following Physician Call System Change: A Comparison of Concentrated and Distributed Schedules” is an interesting research article by Yarnell et al1 published in the July issue of The American Journal of Medicine. It was interesting in terms of assessing the changes in the physician call system that affect the quality of health care. But I would like to emphasize a few important details that are important in terms of outcome and future research studies.
        • Full-Text
        • PDF