Variation in antenatal testing over time and between clinic settings
J. L. Read, R. S. Stern, L. A. Thibodeau, D. E. Geer Jr and H. Klapholz
Variation in the use of diagnostic procedures may be due to characteristics
of patients, physicians, or their environment. Testing rates for 24-hour
urinary estriol levels (EST), diagnostic ultrasound, and antepartum fetal
heart rate testing (AFHRT) were examined in 8,527 deliveries from 1975
through 1978. Over the period, utilization of EST remained constant at
about 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 using 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.
