In the Literature: Research You Need to Know
In This Edition
Literature At A Glance
A guide to this month’s studies
- Screening for AAA
- Adverse events in atrial fibrillation
- Biological treatment of inflammatory bowel diseases
- Steroid treatment of inflammatory bowel diseases
- Levofloxacin for H. pylori
- Natural history of tako-tsubo cardiomyopathy
- Predicting postoperative pulmonary complications
- Code status and goals of care in the ICU
New Screening Strategy To Identify Large Abdominal Aortic Aneurysms
Clinical question: Can an effective scoring system be developed to better identify patients at risk for large abdominal aortic aneurysms (AAA)?
Background: Screening reduces AAA-related mortality by about half in men aged >65. The United States Preventive Services Task Force (USPSTF) has recommended screening for AAA in men aged 65 to 75 with a history of smoking. However, more than 50% of AAA ruptures occur in individuals outside this patient cohort, and only some AAAs detected are large enough to warrant surgery.
Study design: Retrospective, observational cohort study.
Setting: More than 20,000 screening sites across the U.S.
Synopsis: Researchers collected demographics and risk factors from 3.1 million people undergoing ultrasound screening for AAA by Life Line Screening Inc. At the screening visit, subjects completed a questionnaire about their health status and medical history. Screening data also included diameter of the infrarenal abdominal aorta. To construct and test a risk model, the screened individuals were randomly allocated into two equal groups: a data set used for model development and one for validation.
Most of the AAAs greater than 5 cm in diameter discovered were in males (84.4%) and among subjects with a smoking history (83%). Other risk factors for large AAAs included advanced age, peripheral arterial disease, and obesity. The authors estimate that there are about 121,000 people with >5.0 cm aneurysms in the general population. Current guidelines would detect only 33.7% of the existing large AAAs. Study limitations include possible selection bias, as a majority of patients were self-referred. Also, the database did not include all comorbidities that could affect the risk of AAA. The self-reported nature of health data might cause misclassification of a patient’s true health status.
Bottom line: A screening strategy based on a newly developed scoring system is an effective way to identify patients at risk of large abdominal aortic aneurysms.
Citation: Greco G, Egorova NN, Gelijns AC, et al. Development of a novel scoring tool for the identification of large >5 cm abdominal aortic aneurysms. Ann Surg. 2010;252(4):675-682.
