Study challenges abdominal artery screenings

A Medicare program to screen certain beneficiaries for potentially dangerous bulges on the main abdominal artery has had only limited impact, according to a new study.

Researchers found that a year after the program took off, there was only a modest increase in screening rates. What's more, there was no drop in artery repairs and ruptures or overall deaths, they report in the Archives of Internal Medicine.

Bulges on the main artery in the abdomen, so-called abdominal aortic aneurysms, can rupture and cause serious complications, such as a heart attack or even death.

Since January 2007, men with a history of smoking have been eligible for a free abdominal ultrasound to detect aneurysms when they enroll in Medicare.

The screenings follow guidelines from the U.S. Preventive Services Task Force (USPSTF), an expert panel with federal support, which say men between 65 and 75 should get screened if they have smoked more than 100 cigarettes in the life.

The Screening Abdominal Aortic Aneurysm Very Efficiently (SAAAVE) Act also offers the ultrasound test to women with a family history of aneurysms, allowing doctors to either monitor the size of the bulge or surgically repair it if it's large.

Researchers found that in 2004 - before the free screenings were offered - 7.6 percent of eligible 65-year-old men were getting screened. That number increased to 9.6 percent in 2008, a year after the screenings were offered.

The majority of that increase, however, seems to come from screenings that were not reimbursed under the Act, which paid for the tests through Medicare.

That means the increase may not be due to the SAAAVE Act at all.

"From the paper, we can't say the SAAAVE Act caused this modest increase in abdominal ultrasound use - we suspect they are related, but can't prove it's direct," said Dr. Jacqueline Shreibati from the Stanford University School of Medicine in California, the study's lead author.

According to the researchers, the screenings have been shown in earlier studies to reduce aneurysm-related deaths, but not overall death rates.

To see what impact, if any, the Act was having, the researchers looked at data on a sample of Medicare enrollees spanning from 2003 to 2009.

Overall, screenings increased the most - 2 percentage points - among 65-year-old men from 2004 to 2008. Meanwhile, screenings only increased 0.7 percentage points for 70-year-old and 76-year-old men, and 0.9 percentage points for 65-year-old women.

When the researchers looked at who paid for the ultrasounds after 2007, however, they found fewer than 3 percent were paid for through the SAAAVE Act.

Furthermore, the researchers said they "did not find any clinical benefit" associated with the screenings, which means the ultrasounds weren't linked to a reduction in the number of hospitalizations or deaths.

To screen or not to screen

According to Shreibati, the new study was done on the assumption that screening was important. However, two commentaries published with the new report suggest screenings may do more harm than good and that it may be time to rethink the screenings altogether.

Dr. Russell Harris, a co-author of one of the commentaries, was a member of the USPSTF when it gave the screening test the thumbs up in 2005.

"I voted for the recommendation that you have there," said Harris, who oversees the prevention program at the University of North Carolina School of Public Health in Chapel Hill. "To be honest, if I were still on the Task Force, it would be a different kind of vote this time,"

In their commentary, Harris and his colleagues write that research suggests the burden of aneurysms is decreasing, screenings typically find aneurysms below the threshold for surgery, and there may be psychological effects from being diagnosed with an aneurysm that's not treated right away.

Cost can also be an issue with an abdominal ultrasound costing a few hundred dollars.

But Harris acknowledged the commentary is not a comprehensive overview of the existing evidence on screening and that there are some benefits to doing the tests. The point is that revisiting the screening guidelines is a good idea, he said.

One of the potential benefits of screening, according to the study's senior researcher, is that it can find other conditions related to the aneurysm, which can improve survival.

"I think it's important to follow recommendations that are evidence based and I think that's what the USPSTF tries its best to do," said Dr. Matthew Mell, a vascular surgeon at Stanford.