Archives of Physical Medicine and Rehabilitation
Volume 89, Issue 10 , Pages 1903-1906, October 2008

Impact of Comorbidities on Stroke Rehabilitation Outcomes: Does the Method Matter?

Presented in part to the Veterans Affairs Health Services Research and Development Service, February 16–17, 2006, Washington, DC.

  • Dan R. Berlowitz, MD, MPH

      Affiliations

    • Center for Health Quality, Outcomes and Economic Research, Bedford VA Hospital, Bedford, MA
    • Boston University Schools of Public Health and Medicine, Boston, MA
    • Corresponding Author InformationCorrespondence to Dan R. Berlowitz, MD, MPH, CHQOER (152), Bedford VA Hospital, 200 Springs Rd, Bedford, MA 01730
    • ,
  • Helen Hoenig, MD

      Affiliations

    • Physical Medicine and Rehabilitation Service, Durham Veterans Affairs Medical Center, Durham, NC
    • Duke University Medical Center, Durham, NC
    • ,
  • Diane C. Cowper, PhD

      Affiliations

    • Rehabilitation Outcomes Research Center, North Florida/South Georgia Veterans Health System, Gainesville, FL
    • University of Florida, Gainesville, FL
    • ,
  • Pamela W. Duncan, PhD

      Affiliations

    • Duke Center for Clinical Health Policy Research, Durham, NC
    • Duke University Medical Center, Durham, NC
    • ,
  • W. Bruce Vogel, PhD

      Affiliations

    • Rehabilitation Outcomes Research Center, North Florida/South Georgia Veterans Health System, Gainesville, FL
    • University of Florida, Gainesville, FL

Abstract 

Berlowitz DR, Hoenig H, Cowper DC, Duncan PW, Vogel WB. Impact of comorbidities on stroke rehabilitation outcomes: does the method matter?

Objectives

To examine the impact of comorbidities in predicting stroke rehabilitation outcomes and to examine differences among 3 commonly used comorbidity measures—the Charlson Index, adjusted clinical groups (ACGs), and diagnosis cost groups (DCGs)—in how well they predict these outcomes.

Design

Inception cohort of patients followed for 6 months.

Setting

Department of Veterans Affairs (VA) hospitals.

Participants

A total of 2402 patients beginning stroke rehabilitation at a VA facility in 2001 and included in the Integrated Stroke Outcomes Database.

Interventions

Not applicable.

Main Outcome Measures

Three outcomes were evaluated: 6-month mortality, 6-month rehospitalization, and change in FIM score.

Results

During 6 months of follow-up, 27.6% of patients were rehospitalized and 8.6% died. The mean FIM score increased an average of 20 points during rehabilitation. Addition of comorbidities to the age and sex models improved their performance in predicting these outcomes based on changes in c statistics for logistic and R2 values for linear regression models. While ACG and DCG models performed similarly, the best models, based on DCGs, had a c statistic of .74 for 6-month mortality and .63 for 6-month rehospitalization, and an R2 of .111 for change in FIM score.

Conclusions

Comorbidities are important predictors of stroke rehabilitation outcomes. How they are classified has important implications for models that may be used in assessing quality of care.

Key Words: Cerebrovascular accident, Comorbidity, Rehabilitation, Risk adjustment

List of Abbreviations: ACG, adjusted clinical group, CI, confidence interval, DCG, diagnosis cost group, ICD-9-CM, International Classification of Diseases, Ninth Revision, Clinical Modification, ISOD, Integrated Stroke Outcomes Database, VA, Veterans Affairs

 

 Supported by the Office of Research and Development Rehabilitation Research and Development Service, Department of Veterans Affairs (grant no. B3105-R).

 No commercial party having a direct financial interest in the results of the research supporting this article has or will confer a benefit on the authors or on any organization with which the authors are associated.

 Reprints not available from the authors.

PII: S0003-9993(08)00526-1

doi:10.1016/j.apmr.2008.03.024

Archives of Physical Medicine and Rehabilitation
Volume 89, Issue 10 , Pages 1903-1906, October 2008

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