Association between type of health insurance and elective cesarean deliveries: New Jersey, 2004-2007

Abstract

Objectives: I examined the relationship between insurance coverage, which may influence physician incentives and maternal choices, and cesarean delivery before labor.

Methods: I analyzed hospital discharge data for mothers without previous cesarean deliveries in New Jersey between 2004 and 2007, with adjustment for maternal age, race, marital status, and maternal, fetal, and placental conditions.

Results: Nearly 1 in 7 women (13.9%) had a cesarean delivery without laboring. Insurance status was strongly associated with cesarean birth. Women insured by Medicaid (adjusted relative risk [ARR] = 0.88; 95% confidence interval [CI] = 0.84, 0.91) or self-paying (ARR = 0.81; 95% CI = 0.78, 0.85) had a significantly lower likelihood, and women insured by BlueCross (ARR = 1.06; 95% CI = 1.03, 1.09) or standard commercial plans (ARR = 1.06; 95% CI = 1.02, 1.10) had a significantly higher likelihood of cesarean delivery than did women insured by commercial health maintenance organizations. These associations persisted in subsets restricted to lower-risk women and in qualitative sensitivity analyses for a hypothetical single, binary, unmeasured confounder.

Conclusions: Insurance status has a small, independent impact on whether a woman without a previous cesarean delivery proceeds to labor or has a cesarean delivery without labor.

FIGURE 1

Sensitivity analysis for the strength of unmeasured confounding sufficient to fully explain observed association between insurance type and prelabor cesarean delivery in lowest-risk women: New Jersey, 2004–2007. Note. HMO = health maintenance organization. The analysis assumed hypothetical binary unmeasured confounder with prevalence of 40% among well-insured women and plotted combinations of strengths of association (between the confounder and the outcome of prelabor cesarean delivery and between the confounder and the exposure of commercial, HMO, and BlueCross insurance) that would be sufficient to fully explain the observed association between insurance and prelabor cesarean delivery among 185 828 women without prior cesarean delivery and without any of 26 maternal, fetal, and placental conditions coded as diagnoses during hospital admission. The analysis aggregated 38 400 women with Medicaid or self-pay primary insurance, of whom 326 (0.85%) underwent a prelabor cesarean delivery, and 147 428 women with commercial HMO, BlueCross, or commercial primary insurance, of whom 2591 (1.76%) underwent a prelabor cesarean delivery, yielding an odds ratio of 2.09 for the event.