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

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

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

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

Hand-Carried Cardiac Ultrasound

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

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

Other Areas of CEA Analysis

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?