Cost-effectiveness Of Screening For Abdominal Aortic Aneurysm Research Articles

Cost-effectiveness of a population-based AAA screening program for men over 65 years old in Iran

BackgroundScreening program tend to recognized patients in their early stage and consequently improve health outcomes. Cost-effectiveness of the abdominal aortic aneurysm (AAA) screening program has been scarcely studied in developing countries. We sought to evaluate the cost-effectiveness of a screening program for the abdominal aortic aneurysm (AAA) in men aged over 65 years in Iran.MethodsA Markov cohort model with 11 mutually exclusive health statuses was used to evaluate the cost-effectiveness of a population-based AAA screening program compared with a no-screening strategy. Transitions between the health statuses were simulated by using 3-month cycles. Data for disease transition probabilities and quality of life outcomes were obtained from published literature, and costs were calculated based on the price of medical services in Iran and the examination of the patients’ medical records. The outcomes were life-years gained, the quality-adjusted life-year (QALY), costs, and the incremental cost-effectiveness ratio (ICER). The analysis was conducted for a lifetime horizon from the payer’s perspective. Costs and effects were discounted at an annual rate of 3%. Uncertainty surrounding the model inputs was tested with deterministic and probabilistic sensitivity analyses.ResultsThe mean incremental cost of the AAA screening strategy compared with the no-screening strategy was $140 and the mean incremental QALY gain was 0.025 QALY, resulting in an ICER of $5566 ($14,656 PPP) per QALY gained. At a willingness-to-pay of 1 gross domestic product (GDP) per capita ($5628) per QALY gained, the probability of the cost-effectiveness of AAA screening was about 50%. However, at a willingness-to-pay of twice the GDP per capita per QALY gained, there was about a 95% probability for the AAA screening program to be cost-effective in Iran.ConclusionsThe results of this study showed that at a willingness-to-pay of 1 GDP per capita per QALY gained, a 1-time AAA screening program for men aged over 65 years could not be cost-effective. Nevertheless, at a willingness-to-pay of twice the GDP per capita per QALY gained, the AAA screening program could be cost-effective in Iran. Further, AAA screening in high-risk groups could be cost-effective at a willingness-to-pay of 1 GDP per capita per QALY gained.

Unfit for Repair After Screening for Abdominal Aortic Aneurysm: Do We Fail to Fulfil the Basic WHO Criterion of an Available Treatment?

In this edition of EJVES, the Gloucester group report that 18% of screen diagnosed cases of abdominal aortic aneurysms (AAAs) in need of preventive repair haven’t received repair after 3 months; 22% of these received repair later on with no 30 day post-operative deaths, so the final turn down rate was 13%. 1 The reasons are not given, but could be a sign of a kind of “intelligent waiting” where you take the chance of repair if progression is worrying, weak symptoms develop, or health conditions improve. However, “intelligent waiting” is a dangerous strategy because about 20% of patients in the current report experienced rupture. Clearly, earlier intervention seems more attractive. In addition, three major questions arise from this report if generalisation is possible. When we created a model to evaluate cost-effectiveness of screening for AAA in a modern context, we needed to know the proportion not repaired, and studied the four AAA screening randomised controlled trials; 15% didn’t receive repair. 2,3 However, these figures are mainly from the 1990s when the operative risk was 5% before endovascular aneurysm repair and the knowledge that treatment of screen detected cases carries a one third risk compared with incidentally detected cases. 4 However, initial results from the British National AAA screening programme (BNASP) reported that 26% of 417 referred patients weren’t yet repaired, and although probably biased by other factors, the proportion seems very high. 5 The first major question to be raised is whether screening is still beneficial and cost-effective. As mentioned, such rejection fractions for repair were also seen in the MASS and Viborg trials, both of which have reported efficient and cost-effective screening programmes. In order to evaluate the consequences in a modern context, 2 we ran sensitivity analyses of our modern model in which the originally used unfi tp roportion was exchanged with the proportions reported from Gloucester and the BNASP, respectively. It showed decreased efficacy from 32% to 30% and 23% reduced AAA specific mortality, respectively. Whether it remains cost-effective needs further time consuming calculations to clarify. A second major question to be raised is whether one of five or higher deemed unfit initially is acceptable according to the fundamental criteria for screening formulated by the WHO. Although some of them receive repair later, the initial refusal leaves the patients with the knowledge of having a life threatening condition with the obvious risk of losing life and quality of life. However, it seems to be correctable as the potentially maintained high rejection rate is combined with a tremendous decline in the operative risk from about 5% to about 1%. 4 We must not forget when the size criterion of 55 mm is met the condition is life threatening. If we assume the median size of referred AAAs is 6 cm and such an AAA carries an annual rupture risk of 10% with 75% overall mortality, 2,6 then survival curves of early surgery populations will cross those deemed unfit after just 1 year if the operative risk is as high as 7.5%. Modern public surveillance of results and risk of audits may have triggered this development, especially in Great Britain where individual surgeon outcomes are published. 7 Consequently, the third major question is whether we as vascular surgeons have failed by continuing to select people to repair using outdated criteria that are no longer balanced by the decreased risk of repair?

High Prevalence of Abdominal Aortic Aneurysm in Patients with Three-vessel Coronary Artery Disease

Currently, the prevalence of abdominal aortic aneurysm (AAA) in patients with coronary artery disease (CAD) and the correlation between CAD severity and AAA prevalence are not clearly known. We conducted a prospective study to determine the prevalence of AAA in patients undergoing coronary angiography and to determine the risk factors and a coronary profile associated with AAA. Over an 18-month period, abdominal aortic ultrasound was performed on 1,000 patients undergoing coronary angiography for suspected or known CAD, or prior to valve surgery. Clinical characteristics and coronary profile were collected from the patients. The overall number of previously repaired, already diagnosed, and new cases of AAA in the study population was 42, yielding a prevalence of 4.2%. Among the patients with newly detected AAAs, only two had an AAA diameter of >54 mm and were therefore treated surgically. In men aged ≥ 65 years, the prevalence reached 8.6%, while in men with three-vessel CAD it was 14.4%. Multivariate analysis showed that age ≥ 65 years (p = .003), male gender (p = .003), family history of AAA (p = .01), current smoking (p = .002), and three-vessel CAD (p < .001) were significantly associated with a higher prevalence of AAA. The prevalence of AAA was high in men aged ≥ 65 years and in those with three-vessel CAD regardless of age. While our findings do not prove the cost-effectiveness of screening for AAA in these high risk patients, they do support the usefulness of a quick ultrasound examination of the abdominal aorta during routine transthoracic echocardiography in such patients.

Screening for AAA in the USA

The United States (U.S.) was home to both the first and the largest reported abdominal aortic aneurysm (AAA) screening programs to date. Influenced by the results of four randomized trials conducted outside the U.S., the U.S. Preventive Services Task Force (USPSTF) recommended one-time AAA screening with ultrasound for men 65-75 years old who have ever smoked. After the USPSTF report, the U.S. Congress added a Medicare benefit for free, one-time AAA screening with ultrasound for men who have smoked and for men and women with a family history of AAA. Screening may be underutilized in this target population, but recommendations by American vascular societies for much broader use of screening and repair than can be justified by the available evidence are influencing practice and threaten the effectiveness and cost-effectiveness of AAA screening in the U.S.

Abdominal Aortic Aneurysm (Aaa): Cost-Effectiveness of Screening, Surveillance of Intermediate-Sized Aaa, and Management of Symptomatic Aaa

Physicians must make decisions about screening patients for abdominal aortic aneurysms (AAAs), monitoring or referring for surgery patients with AAAs of various sizes, and assessing patients with symptoms that may be related to AAAs. This review article analyzes the evidence for each scenario. The effectiveness and cost-effectiveness of screening for AAA is based on results from four randomized controlled trials. A cost-effectiveness analysis using a Markov model showed that ultrasound screening of white men beginning at age 65 is both effective and cost-effective in preventing AAA-related death. Such screening would have a small but real impact over a 20-year period in these men. For patients with a known AAA—which is often detected incidentally—the evidence clearly suggests periodic ultrasound surveillance for those with small AAAs (3.0–3.9 cm in diameter) and elective surgical repair for those with large AAAs (=5.5 cm). Two recent randomized controlled trials have shown that early surgical repair confers no survival benefit compared with periodic surveillance for patients with intermediate-sized AAAs (4.0–5.5 cm in diameter), so those patients can also be monitored. Some centers choose to increase the frequency of monitoring to every 3 to 6 months when the AAA reaches 5.0 cm. Factors to consider in assessing symptomatic patients include the high risk of life-threatening conditions, the potential increased risk of death or poor outcome with delay in diagnosis, the limitations of ultrasound in identifying whether symptoms are due to known or suspected AAA, and the timely availability of computed tomography or other imaging tests. If available, computed tomography is preferred in patients with recent or severe symptoms, since it is better at detecting retroperitoneal hemorrhage and other complications and in providing preoperative definition of the anatomy.

Screening for abdominal aortic aneurysm: a consensus statement.

Screening for abdominal aortic aneurysm: a consensus statement.

Effectiveness and cost of screening for abdominal aortic aneurysm: results of a population screening program.

We undertook this study to calculate the cost per life-year gained in the first round of a screening program for abdominal aortic aneurysm (AAA) and to estimate the costs in a subsequent round. This was an intervention study, with follow-up for ruptured aneurysms. Men older than 50 years were screened for asymptomatic AAA. Outcome measures included cost per life-year saved and number of men needed to be screened to save one life. The incidence of ruptured AAA was 2.6 per 10,000 person- years in the screening group and 7.1 per 10,000 person-years in the control group. Screening is estimated to have prevented 10.8 ruptured AAA and 8 deaths per year, gaining 51 life-years per year for the study population, and to have reduced the incidence of ruptured AAA by 64% (95% CI, 42%-77%). Each life-year gained during the first screening round cost $1107. To save one life, 1000 men need to be screened and 5 elective operations performed. We predict that a second round of screening can be cost neutral. The cost-effectiveness of screening for AAA compares favorably with screening programs for other disorders in adults.

The cost-effectiveness of a “quick-screen” program for abdominal aortic aneurysms

Background. The incidence of abdominal aortic aneurysm (AAA) is increasing, and the prognosis of ruptured AAA remains dismal. Early diagnosis and intervention are crucial. We designed this study to determine whether selected population screening with a brief “quick-screen” ultrasound could be cost-effective. Methods. A series of 25 patients with risk factors for AAA were evaluated in a blinded fashion by a quick-screen ultrasound and a full conventional study. Times and accuracy for the 2 approaches were compared. An analysis of the cost-effectiveness of screening for AAA was then performed using a Markov model. We determined the long-term survival in quality-adjusted life years and lifetime costs for a hypothetical cohort of 70-year-old males undergoing either AAA screening or not. Our measure of outcome was the cost-effectiveness ratio (CER). Results. The average time for a quick screen was one-sixth that of a conventional study (4 vs 24 minutes). The accuracy of the quick screen was 100%. In our base-case analysis, screening for AAA was cost-effective with a CER of $11,215. Society usually is willing to pay for interventions with CER of less than $60,000 (eg, CER for coronary artery bypass grafting, $9500; breast cancer screening, $16,000). In sensitivity analysis, reducing the cost of screening from $259 (approximate Medicare reimbursement) to $40 (the quick screen) improved the CER to $6850. Moreover, screening populations with increased prevalence of AAA (eg, male with family history [18%]) further improved the CER. Conclusions. Our analysis demonstrates that ultrasound screening for AAA should be offered to all males above the age of 60. Widespread screening for AAA should be adopted and reimbursed by Medicare and other insurers. (Surgery 2002;132:399-407.)