Variation in elective primary cesarean delivery by patient and hospital factors

Objective: Our purpose was to describe variation in elective primary cesarean rates by nonclinical factors. Study Design: With use of California discharge data and American Hospital Association data for 1995, patients were classified into 13 mutually exclusive categories for elective primary cesarean delivery. With use of recursive partitioning algorithms, women in each category were then studied to determine whether nonclinical factors were associated with elective primary cesarean delivery. Results: A total of 463,196 women were delivered at 288 hospitals, and the elective primary cesarean delivery rate was 4.25% (19,664/463,196). Risk for elective primary cesarean delivery varied by clinical condition. The most discriminant risk factors were hospital type (malpresentation, multiple gestation, macrosomia, other hypertension), maternal age (antepartum bleeding, uterine scar, soft tissue disorder, preterm, unspecified), and teaching status (herpes, severe hypertension, unengaged head). Conclusion: This article presents methods that use administrative data to isolate and monitor the impact of nonclinical factors on the use of elective primary cesarean. (Am J Obstet Gynecol 2001;184:1521-34.)