Cost-Effectiveness of 10-Year Risk Thresholds for Initiation of Statin Therapy for Primary Prevention of Cardiovascular Disease

Shayne Kreutzer, Mercer University College of Pharmacy

According to the 2013 American College of Cardiology and the American Heart Association (ACC/AHA) Guidelines on the Treatment of Blood Cholesterol to Reduce Atherosclerotic Cardiovascular (ASCVD) Risk in Adults, the goals are to prevent cardiovascular disease (CVD), improve the management of people who have these disease through professional education and research, and develop guidelines, standards, and policies that promote optimal patient care and CV health. According to the guidelines, it was never intended to be a comprehensive approach to lipid management for purposes other than ASCVD risk reduction. It is suggested that ASCVD is a build-up of sticky, cholesterol-rich plague and over time will harden/narrow the arteries, which might lead to a heart attack or stroke1

Title: Cost-effectiveness of 10-Year Risk Thresholds for Initiation of Statin Therapy for Primary Prevention of Cardiovascular Disease2
Design Microstimulation model to project lifetime health conditions and CVD-related costs
Objective To estimate the cost-effectiveness of various 10-year ASCVD risk thresholds that could be used in the ACC/AHA cholesterol treatment guidelines
Study Groups No ASCVD threshold vs ASCVD risk (> 30, 20, 20, 15, 10, 7.5, 5, 4, 3, 2, 1)
Methods Developed a CVD microsimulation model to project the lifetime health outcomes and CVD-related costs of one million hypothetical adults in the United States. Weighted sampling of individuals from the fasting data samples of the 2005 – 2006, 2007 – 2008, and 2009 – 2010 waves of the nationally representative National Health and Nutrition Examination Surveys populated the model. Model input parameters were estimated based on extensive literature reviews and model calibration methods.
Duration 2005 – 2010
Primary Outcome Measure Estimated ASCVD events prevented and incremental costs per quality-adjusted life-year (QALY) gained
Baseline Characteristics ACC/AHA ASCVD risk threshold Adults statin eligible, % CVD eventsa, b Life expectancy, years QALYsc ICER* (US $/QALY
No ASCVD threshold 8 0.4493 81.237 17.276 1 [Reference]
> 30.0 34 0.4437 81.265 17.287 Extended dominanced
> 20.0 36 0.4405 81.293 17.299 Extended dominance
> 15.0 39 0.4384 81.315 17.309 24,000/QALY
> 10.0 44 0.4365 81.341 17.320 30,000/QALY
> 7.5 48 0.4353 81.356 17.327 37,000/QALY
> 5.0 57 0.4344 81.371 17.333 57,000/QALY
> 4.0 61 0.4340 81.377 17.335 81,000/QALY
> 3.0 67 0.4337 81.382 17.336 140,000/QALY
> 2.0 75 0.4334 81.386 17.337 830,000/QALY
> 1.0 87 0.4333 81.389 17.336 Strong dominancee
Treat all adults with statins 100 0.4332 81.391 17.334 Strong dominancee
a – values indicate proportion of all adults that experience this outcome at some point in their lifetime. Results for statin-induced diabetes cases and CVD events corresponded to the average lifetime risk of experiencing each of these outcomes for individuals in the model population

b – defined as nonfatal or fatal: myocardial infarction, angina, cardiac arrest or stroke

c – discounted 3%

d – extended dominance:: other, more effective strategies have lower cost-effectiveness ratios than this strategy

e – Extended dominance: other strategies are less costly and more effective than this strategy. Based on recommendations, strategies that are dominated by either mechanism (strong dominance or extended dominance) are eliminated from further consideration in a cost-effectiveness analysis.

* – Incremental cost-effectiveness ratio (ICER)

Results ACC/AHA ASCVD Risk Threshold, % CVD eventsa, b ICER (US $/QALY)
No ASCVD threshold 0.4493 1 [Reference]
> 30.0 0.4437 Extended dominanced
> 20.0 0.4405 Extended dominanced
> 15.0 0.4384 7,400/QALY
> 10.0 0.4365 12,000/QALY
> 7.5 0.4353 15,000/QALY
> 5.0 0.4344 27,000/QALY
> 4.0 0.4340 38,000/QALY
> 3.0 0.4337 72,000/QALY
> 2.0 0.4334 460,000/QALY
> 1.0 0.4333 Strong dominancee
Treat all adults with statins 0.4332 Strong dominancee
Adverse Events Common Adverse Events: N/A
Serious Adverse Events: N/A
Percentage that Discontinued due to Adverse Events: N/A
Study Author Conclusions In this microsimulation model of US adults aged 45 to 70 years, the current 10-year ASCVD risk threshold (≥7.5% risk threshold) used in the ACC/AHA cholesterol treatment guidelines has an acceptable cost-effectiveness profile (ICER, $37 000/QALY), but more lenient ASCVD thresholds would be optimal using cost-effectiveness thresholds of $100 000/ QALY (≥4.0% risk threshold) or $150 000/QALY (≥3.0% risk threshold).

This model-based analysis suggested that health benefits associated with the 10-year ASCVD risk threshold of 7.5% or higher used in the ACC/AHA guidelines is worth the additional cost to achieve health gains for patients. The use of statins in patients who fall under no ASCVD risk threshold should be informed by evidence policies and patient preferences, because it is important to allow for patient consent. Patients might be more apt to stating early statin therapy or possibly opposed, given the cost benefit analysis or percent of CVD events.

References

  1. Stone NJ, Robinson JG, Lichtenstein AH, et al. 2013 ACC/AHA guideline on the treatment of blood cholesterol to reduce atherosclerotic cardiovascular risk in adults: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines. J Am Coll Cardiol. 2014;63(25 Pt B):2889-934.
  2. Pandya A, Sy S, Cho S, Weinstein MC, Gaziano TA. Cost-Effectiveness of 10-Year Risk Thresholds for Initiation of Statin Therapy for Primary Prevention of Cardiovascular Disease. JAMA. 2015;314(2):142-150.
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