Get access

When Comorbidity, Aging, and Complexity of Primary Care Meet: Development and Validation of the Geriatric CompleXity of Care Index

Authors

  • Lillian Min MD, MSHS,

    Corresponding author
    1. Geriatrics Research, Education and Clinical Care Center, Veterans Affairs Ann Arbor Healthcare System, Ann Arbor, Michigan
    • Division of Geriatrics, Department of Medicine, School of Medicine, University of Michigan, Ann Arbor, Michigan
    Search for more papers by this author
  • Neil Wenger MD,

    1. Division of General Internal Medicine and Health Services Research, Department of Medicine, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, California
    2. RAND Health, Santa Monica, California
    Search for more papers by this author
  • Anne M. Walling MD, PhD,

    1. Division of General Internal Medicine and Health Services Research, Department of Medicine, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, California
    2. RAND Health, Santa Monica, California
    Search for more papers by this author
  • Caroline Blaum MD, MS,

    1. Department of Medicine, Langone Medical Center, New York University, New York, New York
    2. Department of Population Health, Langone Medical Center, New York University, New York, New York
    Search for more papers by this author
  • Christine Cigolle MD, MPH,

    1. Division of Geriatrics, Department of Medicine, School of Medicine, University of Michigan, Ann Arbor, Michigan
    2. Geriatrics Research, Education and Clinical Care Center, Veterans Affairs Ann Arbor Healthcare System, Ann Arbor, Michigan
    Search for more papers by this author
  • David A. Ganz MD, PhD,

    1. Division of General Internal Medicine and Health Services Research, Department of Medicine, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, California
    2. RAND Health, Santa Monica, California
    3. Division of Geriatrics, Department of Medicine, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, California
    4. Greater Los Angeles Veterans Affairs Healthcare System, Los Angeles, California
    Search for more papers by this author
  • David Reuben MD,

    1. Division of Geriatrics, Department of Medicine, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, California
    Search for more papers by this author
  • Paul Shekelle MD, PhD,

    1. Division of General Internal Medicine and Health Services Research, Department of Medicine, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, California
    2. RAND Health, Santa Monica, California
    3. Greater Los Angeles Veterans Affairs Healthcare System, Los Angeles, California
    Search for more papers by this author
  • Carol Roth RN, MPH,

    1. RAND Health, Santa Monica, California
    Search for more papers by this author
  • Eve A. Kerr MD, MPH

    1. Division of General Internal Medicine, Department of Medicine, School of Medicine, University of Michigan, Ann Arbor, Michigan
    2. Center for Clinical Management Research, Veterans Affairs Ann Arbor Healthcare System, Ann Arbor, Michigan
    Search for more papers by this author

Address correspondence to Dr. Lillian Min, Division of Geriatrics, Department of Medicine, University of Michigan, 300 North Ingalls Bldg Wing E, Room 966, Ann Arbor, MI 48109. E-mail: lmin@med.umich.edu

Abstract

Objectives

To develop and validate the Geriatric CompleXity of Care Index (GXI), a comorbidity index of medical, geriatric, and psychosocial conditions that addresses disease severity and intensity of ambulatory care for older adults with chronic conditions.

Design

Development phase: variable selection and rating by clinician panel. Validation phase: medical record review and secondary data analysis.

Setting

Assessing the Care of Vulnerable Elders-2 study.

Participants

Six hundred forty-four older (≥75) individuals receiving ambulatory care.

Measures

Development: 32 conditions categorized according to severity, resulting in 117 GXI variables. A panel of clinicians rated each GXI variable with respect to the added difficulty of providing primary care for an individual with that condition. Validation: Modified versions of previously validated comorbidity measures (simple count, Charlson, Medicare Hierarchical Condition Category), longitudinal clinical outcomes (functional decline, survival), intensity of ambulatory care (primary, specialty care visits, polypharmacy, number of eligible quality indicators (NQI)) over 1 year of care.

Results

The most-morbid individuals (according to quintiles of GXI) had more visits (7.0 vs 3.7 primary care, 6.2 vs 2.4 specialist), polypharmacy (14.3% vs 0% had ≥14 medications), and greater NQI (33 vs 25) than the least-morbid individuals. Of the four comorbidity measures, the GXI was the strongest predictor of primary care visits, polypharmacy, and NQI (< .001, controlling for age, sex, function-based vulnerability).

Conclusion

Older adults with complex care needs, as measured by the GXI, have healthcare needs above what previously employed comorbidity measures captured. Healthcare systems could use the GXI to identify the most complex elderly adults and appropriately reimburse primary providers caring for older adults with the most complex care needs for providing additional visits and coordination of care.

Ancillary