Clinical effect and cost effectiveness of screening for asymptomatic carotid stenosis : A Markov model

• Objectives:   Screening for asymptomatic carotid artery stenosis (ACAS) is controversial. The cost-effectiveness of screening depends on screening cost, ACAS prevalence, and the potential stroke reducing effect of best medical treatment (BMT). The aim of the study was to determine the threshold values for these parameters in order for screening for ACAS to be cost-effective. Material and methods: The clinical effect and cost-effectiveness of ultrasound-screening for ACAS with subsequent initiation of BMT versus not screening, was assessed in a Markov model with a life-time perspective. Key parameters; including stroke risk, all-cause mortality, and costs were based on contemporary published data, population statistics and ongoing screening programs. Prevalence of ACAS and rate of ongoing BMT was based on data from a population recently screened for ACAS. Minimum required stroke-risk reduction from BMT, incremental cost-efficiency ratio (ICER), absolute risk reduction for stroke (ARR), number needed to screen (NNS) were calculated.  Results: Screening was cost-effective at an ICER of €5744 per incremental quality adjusted life-year (QALY) gained. ARR was 135 per 100000 screened, NNS was 741 and QALYs gained were 6700 per 100000 invited. At a willingness-to-pay (WTP) threshold of €50,000 per QALY the minimum required stroke risk reduction from BMT was 22%. The assumed degree of stroke risk reduction was the most important determinant of cost-efficiency.  Conclusion: A moderate (22%) reduction in the risk of stroke from BMT was required for an ACAS screening strategy to be cost-effective at WTP of €50,000/QALY. Targeting populations with higher prevalence of ACAS could improve cost-efficiency.

Subject headings

MEDICIN OCH HÄLSOVETENSKAP  -- Hälsovetenskap -- Hälso- och sjukvårdsorganisation, hälsopolitik och hälsoekonomi (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Health Sciences -- Health Care Service and Management, Health Policy and Services and Health Economy (hsv//eng)

Keyword

cost-eefectiveness

carotid stenosis

screening

preventive treatment

Surgery

Kirurgi

Publication and Content Type

ref (subject category)

art (subject category)