Prescribing low-dose aspirin to all women at high risk for preeclampsia and women with two or more moderate risk factors is the most cost-beneficial approach to lowering the risk of preeclampsia, according to a new study.
The study, which modeled four approaches to low-dose aspirin prophylaxis in pregnant women, shows that the approach recommended by the U.S. Preventive Services Task Force is superior to the one currently recommended by the American College of Obstetricians and Gynecologists when it comes to lowering the risk of preeclampsia and reducing costs (Obstet Gynecol 2015. doi: 10.1097/AOG.0000000000001115).
Dr. Erika F. Werner and her colleagues at Brown University, Providence, R.I., used a hypothetical cohort of four million U.S. women to analyze the effectiveness of four distinct distribution models for low-dose aspirin prophylaxis: no prophylaxis; following the ACOG recommendations; following the USPSTF recommendations; and universal prophylaxis.
©American Heart Association
Prior randomized studies have established that low-dose aspirin prophylaxis lowers the risk of preeclampsia and preterm birth, the authors wrote. “The remaining question over low-dose aspirin use in pregnancy is not a scientific one, but rather a question of health policy: Who should be treated and what are the expected risks, benefits, and costs of one policy, compared with another?”
ACOG recommends that low-dose aspirin be given to pregnant women with a history of preeclampsia necessitating delivery before 34 weeks of gestation and to women with preeclampsia in more than one prior pregnancy. The USPSTF, on the other hand, takes a broader approach, recommending that women with a history of preeclampsia and those with multiple gestation, chronic hypertension, diabetes mellitus, renal disease, or autoimmune disease should receive low-dose aspirin. Women with two or more moderate risk factors such as nulliparity, obesity, African American race, age 35 years or older, a family history of preeclampsia, or a personal history of pregnancy complications should also receive aspirin, according to the USPSTF.
Under the decision model created by the researchers, women were assumed to be 77% compliant with adhering to their aspirin regimen of 81 mg daily.
Without any aspirin prophylaxis, researchers estimated that the rate of preeclampsia in this population would be 4.18%, meaning 167,200 women would develop preeclampsia. If ACOG’s approach were followed, the rate would dip to 4.17% (166,720 women). But following the USPSTF’s recommendations would result in a 3.83% rate of preeclampsia (153,160), while universal administration of low-dose aspirin prophylaxis would result in a rate of 3.81% (152,240).
The more widespread use of aspirin would also reduce preterm births and maternal deaths, but increase significant maternal gastrointestinal bleeding events, placental abruption, and aspirin-exacerbated respiratory disease, according to the study.
In the baseline analysis, the USPSTF approach was the most cost beneficial, with a direct annual medical cost savings of more than $364 million when compared with the ACOG approach.
“Our analysis suggests that the U.S. Preventive Services Task Force approach is the most cost beneficial, achieving 94% of the possible preeclampsia rate reduction that can be obtained with aspirin while exposing only one-fourth of pregnant women to the theoretical risks of aspirin,” the researchers wrote.
When compared with the USPSTF approach, universal administration would require more than 3 million women to take aspirin to prevent 920 cases of preeclampsia, an incremental number needed to treat of 3,325. Even after taking this into account, universal coverage would still be “highly cost-effective” and would maximize reductions in preterm birth and preeclampsia, according to the researchers.
“From the standpoint of parsimony, and minimization of potential aspirin risks, the U.S. Preventive Services Task Force approach is a better approach than universal administration,” the researchers wrote. “However, universal administration, with its ease of implementation and potential to maximize the health benefits of aspirin, may in fact be the more rational and clinically pragmatic approach.”
The researchers reported having no financial disclosures.