Unwarranted Variation in Utilization of Cesarean Birth Among Low-Risk Childbearing Women.

INTRODUCTION: Unwarranted variations in care are defined as differences in utilization of health care resources that cannot be explained by patient risk factors, standards of evidence-based medicine, or patient preferences. Also known as nonmedical determinants of variation, differences in health care utilization across the United States have been well documented in the literature during the past 40 years. The purpose of the literature review is to summarize the state of the science related to the nonmedical determinants of variation in cesarean birth among low-risk childbearing women, defined within national quality standards as nulliparous women with term, singleton pregnancies in the vertex presentation.

METHODS: A literature search was performed using the electronic databases PubMed, CINAHL, Ovid MEDLINE, Google Scholar, Cochrane Database of Systematic Reviews, and ProQuest Dissertation Database. Articles published in English, with full text available, including birth in the United States after 1995, are included in the analysis. Nine studies met criteria for inclusion. Forty-four states are represented within the data, with Arizona, California, Massachusetts, New Jersey, and New York being the subject of more than one of the publications analyzed.

RESULTS: This literature review includes more than one million births, in at least 44 states between 1996 through 2009, revealing significant unwarranted variation in cesarean birth. Nonmedical determinants of variation, such as access to resources, hospital characteristics, payer source, and provider practice styles, are identified as independent predictors of increased cesarean utilization in more than half of the studies reviewed. In all studies reviewed, women of low medical risk demonstrate susceptibility to unwarranted variation in the use of cesarean birth.

DISCUSSION: Continued emphasis on the specific needs of low-risk childbearing women is necessary to decrease unwarranted variation in the use of cesarean birth in the United States. Specific attention to the costs of unwarranted variation in cesarean birth is imperative.