Advanced-practice sonography in obstetrics and gynecology: a pilot study investigating the efficacy of the ultrasound practitioner.

Advanced-practice (AP) ultrasonography by an AP sonographer or ultrasound practitioner is an emerging allied health profession. The efficacy of this professional in sonographic diagnosis has not been evaluated. This report describes a comparison of the efficacies of diagnosis using a traditional approach and diagnosis by the AP sonographer. Between 1991 and 1995, the authors performed a retrospective, case-controlled study. Patients were evaluated with either (1) a sonographer-based method (limited supervision with perinatal consultation as necessary) or 2) a sonologist-dominant method (direct supervision by a radiologist). Demographic information, ultrasonographic findings, delivery information, and data outcomes were compared. Multiple statistical methods were used and p < 0.05 was considered significant. Of 840 patients studied, 420 were evaluated with the sonographer-based method and 420 with a sonologist-dominant method. There was no significant difference in any potentially predisposing maternal risk factor (except maternal age and education), medical history, variable relevant risk factors associated with the current pregnancy, characteristics associated with delivery, or prenatal ultrasonographic variable. The evaluation of diagnostic efficacy for birth defects showed no difference. The sensitivity and specificity of diagnosis using the sonographer-based method were 100% and 94.7% for the detection of fetal abnormalities, respectively, and 100% and 91.4%, for the sonologist-dominant method. The diagnostic efficacy of the AP sonographer or ultrasound practitioner was found to be similar to that of the traditional sonographer-sonologist model. While, intuitively, there are significant advantages to multiple observers, the experienced, well-trained AP sonographer can function independently, with only discretionary consultation and assistance.