Most of these studies stratified their ultrasound findings according to AAA diameter. Results The data from the 15 studies of asymptomatic patients undergoing screening ultrasound were pooled. The studies screened between 50 and 426 patients from a particular population. Thus, more than half the AAAs were missed on physical examination. The authors stratified some of the data according to the diameter of the aorta, allowing them to determine sensitivity for various diameters.
Sensitivity increases with increasing diameter.
The search strategy was clearly described. The authors graded the evidence of the papers according to their own criteria, which they stated. They examined only those studies that considered abdominal palpation and ultrasound screening for asymptomatic individuals, but only patients at high risk for AAAs were screened. The authors were a little vague in defining high-risk patients, making it difficult to know which population was examined. The 15 studies were deemed to be of sufficient similarity of design to allow for assessment of statistical similarity.