Journal of Medical Systems

, 37:9930 | Cite as

Migration of Patients Between Five Urban Teaching Hospitals in Chicago

  • William L. Galanter
  • Andrew Applebaum
  • Viveka Boddipalli
  • Abel Kho
  • Michael Lin
  • David Meltzer
  • Anna Roberts
  • Bill Trick
  • Surrey M. Walton
  • Bruce L. Lambert
Original Paper


To quantify the extent of patient sharing and inpatient care fragmentation among patients discharged from a cohort of Chicago hospitals. Admission and discharge dates and patient ZIP codes from 5 hospitals over 2 years were matched with an encryption algorithm. Admission to more than one hospital was considered fragmented care. The association between fragmentation and socio-economic variables using ZIP-code data from the 2000 US Census was measured. Using validation from one hospital, patient matching using encrypted identifiers had a sensitivity of 99.3 % and specificity of 100 %. The cohort contained 228,151 unique patients and 334,828 admissions. Roughly 2 % of the patients received fragmented care, accounting for 5.8 % of admissions and 6.4 % of hospital days. In 3 of 5 hospitals, and overall, the length of stay of patients with fragmented care was longer than those without. Fragmentation varied by hospital and was associated with the proportion of non-Caucasian persons, the proportion of residents whose income fell in the lowest quartile, and the proportion of residents with more children being raised by mothers alone in the zip code of the patient. Patients receiving fragmented care accounted for 6.4 % of hospital days. This percentage is a low estimate for our region, since not all regional hospitals participated, but high enough to suggest value in creating Health Information Exchange. Fragmentation varied by hospital, per capita income, race and proportion of single mother homes. This secure methodology and fragmentation analysis may prove useful for future analyses.


Health information exchange Health information technology Fragmentation of care 



This project was supported by grant number U18HS016973 from the Agency for Healthcare Research and Quality. The content is solely the responsibility of the authors and does not necessarily represent the official views of the Agency for Healthcare Research and Quality. This project was also supported by the Chicago Health Information Technology Regional Extension Center (CHITREC).

Conflict of Interest

The authors declare that they have no conflicts of interest.


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Copyright information

© Springer Science+Business Media New York 2013

Authors and Affiliations

  • William L. Galanter
    • 1
    • 10
  • Andrew Applebaum
    • 2
  • Viveka Boddipalli
    • 3
  • Abel Kho
    • 4
    • 5
  • Michael Lin
    • 6
  • David Meltzer
    • 7
  • Anna Roberts
    • 5
  • Bill Trick
    • 8
  • Surrey M. Walton
    • 9
  • Bruce L. Lambert
    • 9
  1. 1.Department of MedicineUniversity of Illinois at Chicago (UIC)ChicagoUSA
  2. 2.Department Computer ScienceUniversity of California DavisDavisUSA
  3. 3.Department of MedicineUniversity of WisconsinMadisonUSA
  4. 4.Department of MedicineNorthwestern UniversityChicagoUSA
  5. 5.Chicago Health Information Technology Regional Extension CenterChicagoUSA
  6. 6.Department of MedicineRush University Medical CenterChicagoUSA
  7. 7.Department of MedicineUniversity of ChicagoChicagoUSA
  8. 8.Department of MedicineJohn H. Stroger Hospital of Cook CountyChicagoUSA
  9. 9.Department Pharmacy Administration (UIC)ChicagoUSA
  10. 10.Department of MedicineChicagoUSA

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