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Cost-Effectiveness Analysis and Echocardiography. Ali R. Rahimi, MD MPH October 10, 2007. Background. Expenditures in healthcare are increasing Resources – people, time, facilities, equipment, and knowledge – are scarce Choices need to be made daily regarding their deployment.
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Cost-Effectiveness Analysis and Echocardiography Ali R. Rahimi, MD MPH October 10, 2007
Background • Expenditures in healthcare are increasing • Resources – people, time, facilities, equipment, and knowledge – are scarce • Choices need to be made daily regarding their deployment
Economic Evaluation in Medicine • Systematic analysis to identify relevant alternatives • Screening/Diagnosis, Treatment, or Rehab • Understand different viewpoints • Patient, Institution, State, Federal, etc… • Measurement to avoid uncertainty • Real Costs and Opportunity Costs Drummond, MF et al. Methods for the Evaluation of Health Care Programs. 1997 Oxford Medical Publications.
Economic Evaluation in Medicine Definition: • “The comparative analysis of courses of action in terms of both their costs and consequences.” • Linkage of Costs and Consequences • Comparative to allow decision making among choices • even efficacious diagnostic or therapeutic approaches Drummond, MF et al. Methods for the Evaluation of Health Care Programs. 1997 Oxford Medical Publications.
Cost-Effectiveness Analysis • Definition: • “incremental cost of a program from a particular viewpoint is compared to the incremental health effects of the program” • Health effects via natural units • BP or LDL improvement • Cases found or averted (e.g., HCM, Thrombus) • Lives saved or life-years gained • Cost per unit of effect Drummond, MF et al. Methods for the Evaluation of Health Care Programs. 1997 Oxford Medical Publications.
Review of the Literature • Hand-Held Cardiac Ultrasound • Stress Echo versus SPECT Imaging
Premise: • Standard Echo (SE) when physical exam is inconclusive for diagnosis or severity of disease • Complete SE is an expensive test, requiring skilled personnel and done days after initial outpatient visit • Hand-carried cardiac ultrasound (HCU) device can provide reliable and timely information while providing potential health and cost benefit
Hand-Carried Cardiac Ultrasound • Methods: • Prospective Study 222 patients, 9/15/04 to 12/15/04, outpatient cardiology practice in Rome, Italy • 8 cardiologists 4 level II and 4 level III by ASE requirements • History/Physical HCU when SE indicated for specific clinical “?” • Cardiologist reassessed to “confirm” or “cancel” initial SE request • SE done by an independent sonographer and read by a cardiologist blinded to the HCU result • Findings of each study were then compared
Hand-Carried Cardiac Ultrasound • OptiGo Portable Device (Phillips) • 2.5 MHz phased array transducer • 2D, color-flow doppler, and calipers
Hand-Carried Cardiac Ultrasound • HCU Protocol: “Flexible” Exam in less than 2 minutes • Linear measurements if visually abnormal • For LVH, “IVS” and “posterior” wall were noted • LVEF > 50% - normal in absence of segmental WMA • RV evaluated for both dimension and function • Valve regurgitation qualitatively estimated using color degree on four steps and noted if more than mild • Valve stenosis both 2D and color doppler were described • Pericardial effusion detected as echo free space between pericardium • SE Protocol: • Per ASE recommendations with second harmonic images analyzed per department of cardiology protocol
Hand-Carried Cardiac Ultrasound • Main reason for confirming SE was due to lack of spectral doppler modality for determining LV diastolic dysfunction • HCU cancellation of 34/108 SE requests (31%)
Hand-Carried Cardiac Ultrasound • Cost-Evaluation: • SE € 62 and HCU € 6.94 • Cancellation of 34 SE € 1872 saved • Avoidance of 2nd office visit € 442 saved • Total Cost Savings = € 2142 per 100 patients referred for echocardiography
Hand-Carried Cardiac Ultrasound • Limitation: • HCU device used had limited color doppler function, preventing a comprehensive echo exam • Agreement between HCU and SE was only 73% • HCU missed 9 LV hypertrophies, 1 mild pericardial effusion • HCU had false-positive diagnosis in 12 patients (10 were considered to have mild LVH and 2 with RV dilatation) • SE diagnosed 8 patients with PAH not detected by HCU
Objective: • Assess accuracy of HCU in predicting a normal study and its cost-effectiveness in reducing SE on hospital inpatients • Many patients for Echo have no cardiac pathology • ID those who are normal to decrease SE referrals
Inpatient HCU • Methods: • District General Hospital – 2000 SE’s/year • 157 consecutive inpatients • Mean age 68 (range: 18-97) years • 61% Male • HCU (OptiGo) at bedside as part of clinical assessment • SE was subsequently performed on all patients • Main outcome measures: • Accuracy of HCU in determining a normal or abnormal study • Cost-Effectiveness Analysis
Inpatient HCU • Costs • Unit cost of SE based on sonographer’s fee, transportation and device depreciation = £ 66.15 • Purchase cost of device = £ 6000 • Cardiologist hourly fee = £ 18.00 • HCU scan (10 minutes), writing report and depreciation = £ 4.00/scan
Inpatient HCU Prediction of Normal Scan Prediction of Normal LV function Prediction with Specific Request for LV function
Inpatient HCU • HCU predicted normal valvular function • 84% sensitivity, 86% specificity, 93% PPV and 71% NPV (82% agreement, k = 0.61, 95% CI 0.49-0.74) • HCU missed 4 patients with abnormalities • 1 moderate LVH • 1 severe Aortic Stenosis • 1 moderate mitral regurgitation • 1 mild LV dilatation • 3 of the 4 findings were in studies requested with no specific reason • Studies with no specific reason had 33% sensitivity, 87% specificity, 77% PPV and 87% NPV
Inpatient HCU • Cost-Evaluation: • Yearly Cost for 2000 SE = £ 132, 300 • Yearly Cost for 2000 POC HCU = £ 8,000 • POC HCU 29% completely normal studies • Potential Cost Saving = £ 30,367 • 29% reduction in workload for department • POC HCU for LV Function requests (64%) 22% normal • Potential Cost Saving = £ 23,986 • 22% reduction in workload for department
Inpatient HCU • Limitations: • Generalizability and External Validity • Cardiology Fellows as sonographer • Missed findings with resulting cost-risk • Thus, individuals with a higher pre-test probability for an abnormal study (i.e., known LV dysfunction or valvular disease) should undergo first-line SE
Review of the Literature • Hand-Held Cardiac Ultrasound • Stress Echo versus SPECT Imaging
Purpose: • compare prognostic accuracy and incremental cost-effectiveness [(CE ratios <$50,000 per life year saved (LYS)] of exercise echo and SPECT imaging in symptomatic, intermediate risk patients
Exercise Echo vs. SPECT • Methods: • Enrolled 9521 Intermediate risk patients with stable angina (Canadian Class I or II) • 4884 referred for exercise echo • 4637 referred for SPECT imaging • Referral centers included: Cleveland Clinic Foundation, University of Indiana, Asheville Cardiology Associates, Hartford Hospital, Cedars-Sinai Medical Center, and St. Louis University Health Sciences Center • Pre-Test clinical risk defined by an estimated predicted rate of cardiac death or MI derived from a Cox proportional hazards model • Intermediate Risk 1% to ≤ 3% per year
Exercise Echo vs. SPECT • Cost-Effectiveness Analysis: • Echo vs. SPECT in patients with Intermediate Duke Treadmill Score = $39,506/LYS • SPECT vs. Echo in patients with prior history of CAD = $32,381/LYS • Lead to greater use of anti-ischemic drugs and revascularization therapy additional 1.4 LYS
Exercise Echo vs. SPECT • Cost-Effectiveness Sub-Analysis: • Echo vs. SPECT with risk of cardiac event < 2%/year $20,565/LYS • In this population, if achieve 100% utilization of exercise echo 60% cost savings or $2564/patient over 3 years compared to 100% utilization of SPECT • Stress induced WMA resulted in earlier referral for catheterization and subsequent improved life expectancy
Exercise Echo vs. SPECT • Cost-Effectiveness Sub-Analysis: • SPECT vs. Echo in individuals with known CAD $32,381/LYS and a gain in life expectancy of 1.1 years • Secondary to greater frequency and reduced time to revascularization
Comments/Discussion • Study of 59 Indications for TTE/TEE ---------------------------------------------------------------------- • Developing Teaching Tools and Provider Education • Use of 3-D Echo – may cut costs? • Future Studies – Ideas?