C R I S M A
Travel-Time Analysis for Patients with Acute Respiratory Failure
David J. Wallace MD MPHAssistant Professor of Critical Care MedicineAssistant Professor of Emergency MedicineUniversity of Pittsburgh School of Medicine
C R I S M A
No conflicts of interest
Supported by NIH NHLBI-K12-HL109068
C R I S M A
Overview
• Background
– Respiratory failure
– Volume-outcome relationship
• Time-travel analysis
C R I S M A
Acute Respiratory Failure• Condition where not enough oxygen passes
from your lungs into your blood
• Many causes
– Pneumonia, asthma, heart failure
• > 30% mortality when treated in a hospital
C R I S M A
Acute Respiratory Failure• Treatment requires mechanical ventilation
C R I S M A
C R I S M A
Annual Mechanical Ventilation Volume
Od
ds R
atio
for D
eath
2006
34% mortality
26% mortality75/year 550/year
C R I S M A
Volume-Outcome Relationship
Patients with respiratory failure who are treated at high-volume hospitals have improved outcomes
C R I S M A
Putting It All Together
• Respiratory failure has high mortality
• Respiratory failure requires specialized care
• High-volume hospitals have better outcomes
Should we concentrate patient care in high-volume hospitals?
C R I S M A
80 Hospitals 7 Regional Centers
Ideal Model Example: New Jersey
Regional Network
C R I S M A
How do you know the free market isn’t figuring this out on its own?
C R I S M A
Prescriptive Already Occurring?
C R I S M A
Objective One• For patients with acute respiratory failure,
compare travel-times from home to treating hospital, and from home to closest hospital
Treating Hospital
Closest Acute Care Hospital
C R I S M A
Objective Two• For patients with acute respiratory failure,
compare travel-times from home to treating hospital, and from home to closest high-volume hospital
Treating Hospital
High-Volume Hospital
High-Volume Hospital
C R I S M A
Methods: Patients• Pennsylvania state hospital discharge
records from 2007
• Adults with acute respiratory failure
• Patients living in Pennsylvania or within 25 miles of the state border (based on ZIP code)
• Hospital transfers excluded from analysis
C R I S M A
Methods: Hospitals• All acute care hospitals
• Hospitals with more than 400 discharges per year were classified as high-volume hospitals
• Street address used to geocode location
C R I S M A
Methods: Analysis• Unique patient ZIP code – hospital address
pairs were created using STATA software
– This was done to make computations in ArcGIS faster
• ArcGIS Network Analyst calculated travel-time from home to treating hospital, home to closest hospital, and finally home to closest high-volume hospital
C R I S M A
Results
• 31,322 adult cases of acute respiratory failure
• 132 low-volume hospitals
• 23 high-volume hospitals
C R I S M A
Results
• Median travel-time: 10 minutes 12 seconds
• Interquartile range: 4 minutes 55 seconds to 21 minutes 7 seconds
C R I S M A
Route to Treating Hospital
C R I S M A
Route to Closest Hospital
C R I S M A
Route to Closest High Volume Hospital
C R I S M A
How did the free market fare?
C R I S M A
The Low Hanging Fruit: 29%
High-Volume Hospital
Low-Volume Hospital
High-volume hospital was closest.
C R I S M A
The Excellent: 16%
Low-Volume Hospital
High-Volume Hospital
Treating hospital was not closest, but it was the closest high-volume hospital.
C R I S M A
The Understandable: 13%
Treating hospital was closest, but it was not a high-volume hospital
Low-Volume Hospital
High-Volume Hospital
C R I S M A
Needs Improvement: 15%
Treating facility was not closest, but the high-volume hospital was farther away
Low-Volume Hospital High-Volume
Hospital
Low-Volume Hospital
C R I S M A
Really Needs Improvement: 26%
Treating facility was not closest, and a high-volume hospital was closer
Low-Volume Hospital
High-Volume Hospital
C R I S M A
Summary of Actual Routes
Route Patients FrequencyHigh-Volume Hospital , but not closest hospital
5,034 16.1%
High-Volume Hospital and closest 9,203 29.4%Low-Volume Hospital and closest 4,210 13.4%Low-Volume Hospital , but not closest hospital
4,581 14.6%
Low-Volume Hospital , and High-Volume Hospital was closer
8,294 26%
C R I S M A
Conclusions
• 45% of patients with acute respiratory failure were treated at a high-volume hospital
– For 29% of patients, this was also the closest facility
• Without explicit policy or regulation, de facto regionalized care already exists for many patients with acute respiratory failure
C R I S M A
However…
• 55% of patients were not treated at high-volume hospitals
• Furthermore, 26% of patients were treated at a low-volume hospital when a high-volume hospital was closer
C R I S M A
Implications
• The majority of patients with acute respiratory failure are not getting care in high-volume hospitals
• Many patients travel farther to receive care in low-volume hospitals, a systems issue that should be targeted for improvement
C R I S M A
Co-Investigators
• Derek C. Angus
• Jeremy M. Kahn
• Kristen Kurland
• Donald Yealy
C R I S M A
www.ccm.pitt.edu/crisma
