CRP screening to target statin eligibility ‘not cost-effective’
MedWire News: Using high-sensitivity C-reactive protein (hs-CRP) levels to guide eligibility for statin therapy in primary prevention is not cost-effective, say US investigators in the journal Circulation.
"Although hs-CRP screening is preferable to current [National Cholesterol Education Program (NCEP)] Adult Treatment Panel (ATP) III guidelines, simply starting statin therapy at lower risk levels without hs-CRP screening would further improve clinical outcomes at acceptable cost, making it the optimally cost-effective strategy," they say.
Keane Lee (Santa Clara Medical Center, California) and team used Markov modelling to simulate the usefulness of hs-CRP for selecting lower-risk individuals (such as those with a 10-year Framingham risk of <10%) who would benefit from statin treatment.
In the hs-CRP screening strategy, the authors assumed that screening for elevated hs-CRP would be added to basic cardiovascular risk assessment starting at a specific age in those without an indication for statin therapy according to NCEP-ATP III guidelines and that treatment would be initiated in people with hs-CRP level of 2.0 mg/l or greater.
The hs-CRP screening strategy was compared with the current NCEP-ATP III clinical practice guidelines, which recommend statin therapy for primary prevention in individuals with a 10-year Framingham risk of over 20% or with diabetes mellitus.
They also tested a third strategy, in which statin therapy was started in all individuals at or above specific predicted risk thresholds estimated by the 10-year Framingham risk score, without resorting to hs-CRP screening.
If all statins were assumed to be equally effective regardless of hs-CRP status, the third strategy - ie, risk-based treatment without hs-CRP testing - was the most cost-effective strategy, Lee et al report.
However, if normal hs-CRP levels were assumed to identify a subgroup who would not benefit from statin therapy - ie, less than 20% relative risk reduction - then the hs-CRP screening strategy was most cost-effective.
The strategy endorsed by current NCEP-ATP III guidelines was the most cost-effective only if the harms from statin use were assumed to be greater than generally recognized. "Even slight increases in harms from treatment would make current NCEP-ATP III guidelines the optimal strategy for primary prevention," the authors admit.
They say that more research is needed to define the long-term safety of statins and to determine whether hs-CRP can identify nonresponders to statin therapy.
"Any potential harms from statin use beyond those currently recognized would offset the potential benefits of lowering the current NCEP-ATP III guidelines risk thresholds for statin treatment," they conclude.
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By Joanna Lyford