Variation in antenatal testing over time and between clinic settings

Abstract

Variation in the use of diagnostic procedures may be due to characteristics of patients, physicians or their environment. Testing rates for 24-h urinary estriol levels (EST), diagnostic ultrasound and antepartum fetal heart rate testing (AFHRT) were examined in 8527 deliveries from 1975-1978. Over the period, utilization of EST remained constant at .apprx. 7% of deliveries, while ultrasound increased from 20 to 35%, and AFHRT, from 7 to 12%. This increase persisted after stratifying patients on a multivariate confounder score for 45 items of clinical information. Those receiving antenatal care in a hospital-based group practice or a resident-staffed community clinic were more likely to be tested than patients seen in private offices or a prepaid group practice.