Positive predictive value of clinical suspicion for abdominal aortic aneurysm. Implications for use of ultrasonography.

To measure the positive predictive value (PPV) of clinical suspicion of abdominal aortic aneurysm (AAA), as confirmed by ultrasonography, we reviewed the records of 343 patients at a university medical center referred to ultrasonography for newly suspected AAA. Positive predictive value was 11.1% for large aneurysms of at least 5.0 cm and 18.7% for aneurysms of at least 3.5 cm, and was higher for men and older patients. For patients under 50 years of age, PPV was only 2.6%. Ultrasonography for clinically suspected AAA has a low positive predictive yield, particularly for men under age 50 and for women.