Cost-effectiveness of coronary calcium testing to

guide statin therapy:Preliminary Results

CVD Risk Biomarker SymposiumMark J. Pletcher, MD, MPH

1/30/2012

Goals

• Compare Test-and-Treat strategies against Treat none and Treat all– For different age/sex/risk groups– Comparing different CAC score thresholds– Varying key parameters

• Statin price, time horizon, cost of testing

The CAC version of the model

Key Inputs

Key Inputs

• CAC relative risks from MESA– 0 ref– 1-100 3.61– 101-300 7.73– 300+ 9.67

NEJM 2008;358:1336-45

Key Inputs

• Prevalence of CAC, conditional on other CHD risk factors

• Integrate CAC RR’s with prevalence to get CAC category-specific absolute risk

BMC Medicine 2004;2:31

Key Inputs

• CAC scan cost– Test itself: $107.03 (vs. $200 or $300)– Physician visit to discuss results: $71.01– Total testing cost = $178.04

Other key parameters

• Statin cost– Pills $4/month = $0.13/day (vs. $1.00/day)– Extra physician visit/year = $68.97– Extra lipid panel/year = $23.44– Total annual cost = $140.96

• Time horizon– 10 years (vs. 25 years)

• Willingness to pay– $50,000/QALY

45 yo man with 5% risk

Statins = $0.13 / day

10-year horizon

Preliminary Results

45 yo man with 5% risk

Steeper “slope” (good - depends of CAC RR)

Shifted to the right (bad – depends on CAC $)

Medium effectiveness (depends on # treated, prev of CAC)

Statins = $0.13 / day

10-year horizon

Preliminary Results

45 yo man with 5% risk

Cost-effectiveness “frontier”

(i.e., Non-dominated strategies)

Statins = $0.13 / day

10-year horizon

Preliminary Results

45 yo man with 5% risk

ICER for non-dominated strategies

$152,000

$57,000Statins = $0.13 / day

10-year horizon

Preliminary Results

45 yo man with 5% risk

If willingness to pay <$50,000/QALY,

Preferred strategy = Treat none

$152,000

$57,000Statins = $0.13 / day

10-year horizon

Preliminary Results

45 yo man with 15% risk

Statins = $0.13 / day

10-year horizon

Preliminary Results

45 yo man with 10% risk

Statins = $0.13 / day

10-year horizon

$25,000/QALY

Preliminary Results

45 yo man with 7.5% risk

$55,000/QALY

$8,000/QALY

Preliminary Results

By age/risk

• Men, statins=$0.13/day, 10-year horizon• WTC >$50,000

AgeRisk 35 45 55 652.5% --- --- ---5% --- --- >0 >07.5% All >0 >0 >010% All All All All15% All All All All25% All All All All

Preliminary Results

By age/risk

• Men, statins=$0.13/day, 10-year horizon• WTC >$50,000

AgeRisk 35 45 55 652.5% --- --- ---5% --- --- >0 >07.5% All >0 >0 >010% All All All All15% All All All All25% All All All All

Preliminary Results

65 yo man with 7.5% risk

$15,000/QALY

$8,000/QALY

$78,000/QALY

Preliminary Results

By age/risk

• Women, statins=$0.13/day, 10-year horizon• WTC >$50,000

AgeRisk 35 45 55 652.5% --- --- --- ---5% >0 --- --- ---7.5% >0 >0 >0 >10010% >0 >0 All15% All >0 All25% All All All

Preliminary Results

By age/risk

• Women, statins=$0.13/day, 10-year horizon• WTC >$50,000

AgeRisk 35 45 55 652.5% --- --- --- ---5% >0 --- --- ---7.5% >0 >0 >0 >10010% >0 >0 All15% All >0 All25% All All All

Preliminary Results

65 yo Woman with 7.5% risk

$18,000/QALY

$59,000/QALY

Preliminary Results

Sensitivity analyses

• Vary statin price and time horizon

Longer time horizon

• Women, statins=$0.13/day, 25-year horizon• WTC >$50,000

Risk 35 45 55 652.5% >0 >0 >0 >1005% All >0 >0 >07.5% All All >0 All10% All All All15% All All All25% All All All

Preliminary Results

Short horizon, expensive statins

• Women, statins=$1.00/day, 10-year horizon• WTC >$50,000

Risk 35 45 55 652.5% --- --- --- ---5% --- --- --- ---7.5% --- --- --- ---10% --- --- ---15% >100 >100 >10025% >0 >0 >0

Preliminary Results

Short horizon, expensive statins (men)

• Men, statins=$1.00/day, 10-year horizon• WTC >$50,000

Risk 35 45 55 652.5% --- --- --- ---5% --- --- --- ---7.5% --- --- --- >10010% --- >0 >0 >10015% >0 >0 >0 >025% >0 >0 >0

Preliminary Results

Results

CAC testing is often cost effective!

Preliminary Results

Results

• Under what conditions is it NOT cost-effective for:

– 55 yo woman, 10% risk

– Statins = $0.13/day

– Time horizon = 10 years

Preliminary Results

By age/risk

• Women, statins=$0.13/day, 10-year horizon• WTC >$50,000

AgeRisk 35 45 55 652.5% --- --- --- ---5% >0 --- --- >07.5% >0 >0 >0 >10010% >0 >0 All15% All >0 All25% All All All

Preliminary Results

By RR/cost

• 55 yo Women, 10% risk• Statins=$0.13/day, 10-year horizon, WTC >$50,000

$/scanCAC RR $300 $200 $107.03

(Base case)x .50 All All Allx .75 All All >0Base case All >0 >0

Preliminary Results

By RR/cost

• 55 yo Women, 10% risk• Statins=$0.13/day, 10-year horizon, WTC >$50,000

$/scanCAC RR $300 $200 $107.03

(Base case)x .50 All All Allx .75 All All >0Base case All >0 >0

Preliminary Results

Base Case

$16,000/QALY

$126,000/QALY

Preliminary Results

If cost of scan = $300Preliminary Results

If CAC is half as useful

$24/QALY

$37,000/QALY

Preliminary Results

Summary

• CAC testing can be a cost-effective way to target statin therapy– Depends on the cost of the scan– Testing thresholds depend on statin price

Preliminary Results

Big questions

• How to deal with statin prices?

• What is the right time horizon?

• Statin effectiveness and CAC prediction at the tails of the age-risk distribution

To do:

• More sensitivity & Monte Carlo analyses

• Radiation-induced cancer from CAC CT

• Other downsides of testing?

• Update CAC prevalence with MESA

• ASA, and ASA+Statins (dif thresholds?)

• Lifetime horizon with delayed treatment

• Online tool…

Thanks

• Questions? Comments?