Population vascular screening advocated for overall mortality reduction and QoL improvement
Triple vascular screening reduces overall mortality by a significant 7 percent at the end of 5 years and provides greater life-year gains at lower costs than existing European cancer screening programmes, late-breaking results of a large-scale population-based Danish study have shown.
The VIVA (Viborg Vascular) trial, a prospective randomized controlled trial in 50,156 men aged 65 to 74 years (of whom half were invited to screening and the other half were controls) in the Central Denmark region, found that combined screening for abdominal aortic aneurysm (AAA), peripheral artery disease (PAD) and hypertension resulted in one life saved for every 169 men screened without causing serious harms such as postoperative mortality or diabetes and renal failure from extra initiation of pharmacological therapy. [Lancet 2017, doi: http://dx.doi.org/10.1016/S0140-6736(17)32250-X]
“Our study found vascular screening to be highly cost-effective, with a life-year and a quality-adjusted life-year gained at the cost of €6,872 and €2,148, respectively, against a threshold willingness-to-pay of €40,000 (based on 2014 prices),” reported principal investigator Professor Jes Lindholt of the Department of Cardiothoracic & Vascular Surgery, Odense University Hospital, Denmark, at the European Society of Cardiology Congress 2017 held in Barcelona, Spain.
“Men in the screening group also reported moderately higher quality of life [QoL] than those in the control group, with no significant difference in anxiety or depression observed between the groups,” he added.
In the trial, three out of four invited men attended screening. Out of those screened, 22 percent had positive test results: 3 percent had AAA, 11 percent had PAD, and 10 percent had unknown hypertension. Men who tested positive for AAA and/or PAD had a confirmatory test and were advised on lifestyle modifications, with 33 percent started on low-dose aspirin (75 mg/day) and/or simvastatin 40 mg/day. Those with an aneurysm >50 mm in diameter were referred to a vascular surgeon to assess the need for elective repair, and half of those with aneurysms >55 mm underwent repair within 5 years. Men with suspected hypertension were referred to their GP, with antihypertensive treatment initiated in one-third.
“The rate of overdiagnosis was estimated at 11 percent, caused mainly by false-positive findings for hypertension. This rate is low in comparison with breast cancer screening programmes, in which 19 to 57 percent of individuals could be overdiagnosed,” explained Lindholt. “Moreover, the consequence of overdiagnosis in vascular screening is restricted to psychological distress and noninvasive procedures, whereas in breast cancer screening overdiagnosis can lead to unnecessary biopsies and mastectomies.”
“The risk of overtreatment was also not associated with harm,” remarked discussant Professor Andrew Kates of the Washington University School of Medicine, St. Louis, Missouri, US.
In the study, 52 percent of individuals who underwent surgery and 88 percent of those who received pharmacological therapy were estimated to be overtreated on the basis of not obtaining a net benefit in life expectancy, without taking other potential benefits into consideration.
“Overdiagnosis, overtreatment and psychological distress are unavoidable harms of any kind of screening. However, our study found that the benefits of triple vascular screening far outweigh the harms,” stated Lindholt.