On June 24, the U.S. Preventive Services Task Force (USPSTF) released its final recommendation statement(www.uspreventiveservicestaskforce.org) on screening older adults for abdominal aortic aneurysm (AAA). The AAFP followed suit, issuing recommendations that paralleled those of the USPSTF. Both recommendation statements were updates from the two organizations' 2005 recommendations on AAA screening.
After reviewing the evidence presented(www.uspreventiveservicestaskforce.org), the USPSTF developed its recommendations for men and women based on their smoking history, according to a news bulletin from the task force(www.uspreventiveservicestaskforce.org). The USPSTF team reviewed 2,723 abstracts and 204 full-text articles and identified four trials that addressed the benefits of one-time screening, 10 studies on the effectiveness of rescreening, seven studies addressing the harms of one-time and repeated screening, 15 trials examining the benefits of treating small AAAs, and 15 studies on the harms associated with treating small AAAs.
An AAA is a weakening in the wall of the infrarenal aorta that results in an anteroposterior diameter of 3 cm or greater, says the USPSTF evidence report. If untreated, this ballooning in the wall of the main artery that carries blood from the heart to the abdomen can rupture without warning, and the associated risk for death is as high as 75 percent to 90 percent, according to the Clinical Considerations section of the USPSTF recommendation statement.
- On June 24, the U.S. Preventive Services Task Force released its final recommendation statement on screening asymptomatic adults age 50 or older for abdominal aortic aneurysm (AAA).
- The AAFP followed suit, with both organizations recommending one-time screening for AAA in men ages 65-75 who have ever smoked.
- The AAFP and USPSTF also recommended against routinely screening for AAA in women who have never smoked.
Recommendations for Men
The AAFP and USPSTF both recommended one-time screening for AAA using ultrasonography in men ages 65-75 who have ever smoked (defined by the USPSTF as men who currently smoke or have smoked 100 cigarettes or more in the past).
"Older male smokers are at the highest risk of developing AAA," said USPSTF Co-vice Chair Albert Siu, M.D., M.S.P.H., in the news bulletin. "The good news is that, if you are a 65- to-75-year-old man who smokes or used to smoke, one-time AAA screening with an ultrasound, along with appropriate treatment, can reduce your risk of dying from rupture."
A second recommendation for men suggested clinicians selectively offer screening for AAA in men ages 65-75 who have never smoked, rather than routinely screening all men in this age group.
"There are several other risk factors for AAA, but none are as strong as smoking," said Jennifer Frost, M.D., medical director for the AAFP Health of the Public and Science Division, "so (the USPSTF) is unable to recommend universal screening in all men with a risk factor other than smoking. However, you may consider screening a male patient with multiple risk factors."
For example, Frost said she might recommend screening for a 70-year-old obese white male who has hypertension, coronary artery disease and a family history of AAA in a first-degree relative. She added that black and Hispanic men are less likely than white men to experience an AAA.
Recommendations for Women
In 2005, the AAFP and USPSTF both recommended against routine screening for AAA in all women. That recommendation has been updated and is now twofold.
First, both groups concluded that current evidence is insufficient to assess the balance of benefits and harms of screening for AAA in women ages 65-75 who have a smoking history.
Women who have ever smoked, especially current smokers, have a higher risk of AAA than those who have never smoked, Frost said. And she added that women with AAA have a higher risk of rupture than men with the condition. "However, women tend to get AAAs at an older age, when surgery is riskier and the possibility of death from other causes is higher, as well," she said.
Frost said she would consider ordering screening for AAA in a female patient who was a heavy smoker with hypertension if the patient requested it.
The USPSTF called for more research to be conducted to determine if AAA screening is beneficial for women with a smoking history.
"There was only one study that specifically looked at screening women (for AAA)," Frost said. "There were few events in these women (i.e., AAA rupture), so the study was underpowered to make recommendations on benefits versus harms. It is clear, however, that there is no benefit of screening women who have never smoked."
That sentiment was repeated by the AAFP and USPSTF in their second recommendation regarding screening in women, which suggested not routinely screening for AAA in women who have never smoked.
Among those age 50 or older, there is a dramatically higher incidence of AAA in men than women -- 3.9 percent to 7.2 percent versus 1.0 percent to 1.3 percent, respectively -- according to the USPSTF evidence report. "When the incidence is low in a population (such as AAA in women), screening is less likely to be beneficial," Frost noted.
More From the AAFP
American Family Physician: Abdominal Aortic Aneurysm
(April 1, 2006)