The Effect of the Children’s Health Insurance Program on Use of Prescription Contraceptives among Teens

Background. A growing body of literature has investigated the recent decline in teen pregnancy in the United States, yet no definitive causes have been identified. The Children’s Health Insurance Program (CHIP), passed in 1997, may be one factor contributing to this trend. By expanding eligibility for affordable health insurance among teens, CHIP may increase access to care, including family planning services. Thus, CHIP expansions have the potential to increase use of effective contraceptive methods among sexually active teens and, in turn, decrease teen fertility.

Methods. We use pooled biennial Youth Risk Behavior Surveillance System (YRBSS) data (1993-2005) and variation in state CHIP income eligibility thresholds by year and age to test the effects of CHIP eligibility expansions on the likelihood of contraceptive use and sexual activity among teens ages 15-18. Our analytic sample varies by outcome, ranging from 54,142 to 54,448 teens and representing sixteen states. We test our hypothesized mechanism, increased public health insurance coverage, using Current Population Survey Annual Social and Economic Supplement (CPS) data (1993-2005), representing 33,358 teens ages 15-18 residing in the same sixteen states. We estimate difference-in-differences models, which exploit variation in CHIP income eligibility thresholds at the state, year, and age level. Models estimate the intent-to-treat effect of CHIP expansions on contraception use during last sex, sexual activity in the past three months, and public health insurance coverage. All models include state fixed effects, year fixed effects, age indicators, individual- and state-level controls, and state-specific linear time trends, with standard errors clustered at the state-age level. We estimate effects for all teens and separately by race and sex.

Results. We find that a 100-percentage point increase in the CHIP income eligibility threshold is associated with a 2.1-2.6 percentage point increase in the likelihood that teens used contraception at last sex. We find larger effects for non-white teens (3.4-4.3 percentage points) and the largest effect for non-white female teens (4.3-5.6 percentage points), who experienced a 5.2-6.8 percent increase in contraceptive use from baseline. We find no overall effect of CHIP eligibility expansions on public health insurance coverage, but observe a 9-12 percentage point increase in Medicaid coverage among non-white teens, a 33-44 percent increase from baseline. Again, non-white female teens experienced the largest gains of 50-69 percent. We observe mixed evidence of increased sexual activity, but only in some models and only among the full sample and subgroups of white teens. We observe no change in sexual activity for non-white teens.

Conclusion. Our results find broad evidence that CHIP eligibility expansions are associated with increased rates of teen contraception use, particularly among black and Hispanic females. Increases in contraception use are largest among subgroups with large increases in public health insurance coverage. Observed changes in sexual activity, however, are limited to groups for whom we do not observe increases in coverage, and therefore may be spurious. CHIP expansions may have contributed toward the decline in teen birth rates during this period by increasing contraception use, particularly among newly-insured non-white teens.