NRSA Trainees Research Conference Slide Presentation (Text Version)
By by Thomas W. Concannon, David M. Kent, Sharon-Lise Normand, et al.
On June 24, 2006, Thomas Concannon and associates made a slide presentation on voluntary physician switching by hiv-infected individuals at the 12th Annual National Research Service Award (NRSA) Trainees Research Conference. This is the text version of the slide presentation. Select to access the slide presentation (PowerPoint® File, 1.4 MB).
Slide 1
Emergency Transport and Inter-hospital Transfer in ST-Segment Elevation Myocardial Infarction
Thomas W. Concannon, M.A.1,
David M. Kent, M.D., M.S.2, Sharon-Lise Normand, Ph.D.3,
Joseph P. Newhouse, Ph.D.3, Robin Ruthazer, M.P.H.,2
John L Griffith, Ph.D.2, Joni R. Beshansky, R.N., M.P.H.2
John B. Wong, M.D., Ph.D.2, Harry P. Selker, M.D., M.S.P.H.2
Funded by the Agency for Healthcare Research and Quality (RO1 HS010282 and T32 HS00060-12).
1. Ph.D. Program in Health Policy, Harvard University.
2. Institute for Clinical Research and Health Policy Studies, Tufts-New England Medical Center.
3. Division of Health Care Policy Research and Education, Harvard Medical School.
Slide 2
Background
Image of a heart labeled "Heart Attack" with coronary arteries, healthy muscle, and dying muscle indicated. A detailed cutout section shows a blood clot and cholesterol plaque forming within an artery.
Heart attack may be caused by the formation of a blood clot that blocks normal blood flow to heart muscle.
ST = segment elevation myocardial infarction (STEMI).
Slide 3
Background
May be treated with:
- Angioplasty, involving the insertion of a catheter into the affected blood vessel and inflation of a balloon to manually clear the clot.
- Thrombolytic therapy, involving the administration of a clot-busting drug.
Slide 4
Background
Angioplasty can only be performed in specialized hospital settings.
Thrombolysis can be performed in any hospital emergency department.
Slide 5
Background—Thrombolysis or Angioplasty?
Angioplasty yields superior outcomes in average 30-day mortality and in other clinical endpoints.
However, thrombolysis remains the standard of care in most settings.
Slide 6
Background—Study Question
What is the impact on mortality of targeting angioplasty to high benefit patients?
Slide 7
Methods—Objective
Evaluate 3 Policy Options
Closest Hospital Policy
Transport to closest hospital, treat with locally available therapy.
Universal Angioplasty Policy
Transport to closest angioplasty-capable hospital, treat with angioplasty.
Targeted Angioplasty Policy
Transport to closest hospital, evaluate, treat locally or transfer for angioplasty.
Slide 8
Methods—Outcomes of Interest
Primary Outcome
- Patient 30 day mortality.
Secondary Outcome
Slide 9
Methods—Predictive Model
Recently developed and validated predictive instrument:
- Predicts 30-day mortality with angioplasty and with thrombolysis.
- Easily obtainable characteristics of patients.
- Incorporated onto the output of an EKG.
Slide 10
Methods—Predictive Model
Probability of 30-day mortality with thrombolysis.
Image of medical chart for "John Doe," showing electrocardiograph (EKG) results. 30-day mortality with thrombolysis is projected as 11.3%.
Slide 11
Methods—Predictive Model
Probability of 30-day mortality with angioplasty.
Image of medical chart for "John Doe," showing electrocardiograph (EKG) results. 30-day mortality with angioplasty is projected as 7.3%.
Slide 12
Methods—Predictive Model
Maximum time delay at which the benefit with angioplasty disappears.
Image of medical chart for "John Doe," showing electrocardiograph (EKG) results. Time Interval to Mortality Equivalence (TIME) is given as 149 minutes.
Slide 13
Methods—Simulation Model
Image of a sample regional census map, with the locations of hospitals marked by a red "H" and the location of a sample patient designated "C-PORT subject #183" highlighted in the southwestern corner of the map. The following details for C-PORT subject #183 are noted:
Age: 79.
Systolic blood pressure: 116.
No history of diabetes.
Moderately severe heart attack.
93 minutes from symptom onset to Emergency Department arrival.
Location: Census block #2010.
Time [of heart attack]: Monday at 3:30 am.
Slide 14
Methods—Closest Hospital Policy
Image of a sample regional census map, with the locations of hospitals marked by a red "H" and labeled by name. The closest hospital to C-PORT subject #183, described in Slide 13, is indicated by a red arrow and is labeled "Charleton Methodist." The time of heart attack is noted as Monday at 3:30 am, and C-PORT subject #183 arrives at Charleton Methodist hospital at 5:03 am—93 minutes after the heart attack occurred.
Further notes on the sample event are: "Treated with thrombolysis. Probability of death = .095."
Slide 15
Methods—Universal Angioplasty Policy
Image of a sample regional census map, with the locations of hospitals marked by a red "H" and labeled by name. In this scenario, C-PORT subject #183, described in Slide 13, is taken to a hospital farther away, indicated by a blue arrow and labeled "Baylor UMC." The time of heart attack is again noted as Monday at 3:30 am, and C-PORT subject #183 arrives at Baylor UMC hospital at 5:25 am—115 minutes after the heart attack occurred, and 22 minutes later than he would have arrived at Charleton Methodist hospital.
However, further notes on the sample event indicate: "Treated with angioplasty.
Probability of death = .0733."
Slide 16
Methods—Targeted Angioplasty Policy
Image of a sample regional census map, with the locations of hospitals marked by a red "H" and labeled by name. In this scenario, C-PORT subject #183, described in Slide 13, is taken first
to Charleton Methodist, arriving at 5:03 am, then is transferred to Baylor UMC, arriving at 5:31 am; the journey is indicated by yellow arrows. The time of heart attack is again noted as Monday at 3:30 am, and the two legs of the patient's journey take 93 and 28 minutes respectively.
Further notes on the sample event indicate: "Treated with angioplasty.
Probability of death = .0738."
Slide 17
Results—30-Day Mortality
| Method | N | % Treated with Angioplasty
(95% CI) | % Mortality
at 30 Days
(95% CI) |
|---|
| Closest
Hospital | 2000 | 30.4
(28.5, 32.4) | 5.3
(4.3, 6.3) |
| Universal
Angioplasty | 2000 | 100 | 4.2*
(3.3, 5.1) |
| Targeted
Angioplasty | 2000 | 45.5
(43.5, 47.6) | 4.2*
(3.3, 5.1) |
Slide 18
Results—Hospital Volumes
Closest Hospital Policy
Bar chart titled "Hospital Volumes in the Closest Hospital Policy (N=2000)," depicting Hospitals, numbered 1 to 16 by Frequency. Hospitals 1 and 2 are noted as "Full-time," 3-14 are "Part-time," and 15 and 16 are "No Angioplasty." Hospitals 2, 6, 8, 12, and 16 have a low frequency of less than 50. Hospitals 1, 9, 11, and 14 have a frequency of approximately 100. Hospitals 4, 5, 10, and 13 have a frequency near 200, and 3, 7, and 15 are over 200. Hospital 15 has the highest frequency.
Slide 19
Results—Hospital Volumes
Universal Angioplasty Policy
Bar chart titled "Hospital Volumes in the Universal Angioplasty Policy (N=2000)," depicting Hospitals, numbered 1 to 16 by Frequency. Hospitals 1 and 2 have the highest frequencies of 800 and approximately 650 respectively. Hospitals 3 through 14 have very low frequencies; hospitals 15 and 16 have nothing.
Slide 20
Results—Hospital Volumes
Targeted Angioplasty Policy
Bar chart titled "Hospital Volumes in the Targeted PCI Policy (N=2000)," depicting Hospitals, numbered 1 to 16 by Frequency. Hospitals 1 and 2 have the highest frequencies, both just under 400. Hospitals 3 through 16 have lower frequencies; 3, 7, and 15 approach 200, and others are in the 50-100 range.
Slide 21
Results—Summary
A policy of targeting angioplasty to high benefit patients could capture much or all of the procedure's potential benefit while avoiding dramatic effects on hospital volumes.
Slide 22
Conclusions
- Inter-patient variation in the risks and benefits of angioplasty may be an important factor in decisions about the appropriate course of treatment.
- More information is needed on how this variation affects the tradeoff between early treatment and specialized treatment.
- Further study is needed to determine the best approach for allocating angioplasty.
Current as of August 2006
Internet Citation:
Concannon TW, Kent DM, Normand S, et al. Emergency Transport and Inter-hospital Transfer in ST-Segment Elevation Myocardial Infarction. Text Version of a Slide Presentation. Agency for Healthcare Research and Quality, Rockville, MD. http://www.ahrq.gov/fund/training/concannontxt.htm
540 Gaither Road Rockville, MD 20850