HOME UTERINE MONITOR USE AS PRETERM LABOR SCREEN: "INSUFFICIENT EVIDENCE" EXISTS

HOME UTERINE MONITOR USE AS PRETERM LABOR SCREEN: "INSUFFICIENT EVIDENCE" EXISTS "to recommend for or against home uterine activity monitoring (HUAM) as a screening test for preterm labor in high-risk pregnancies," the U.S. Preventive Services Task Force says in a policy statement published in the July 21 Journal of the American Medical Association. USPSTF is an advisory group of physicians and other scientists appointed by the HHS assistant secretary for health to evaluate clinical preventative services. USPSTF's conclusion on HUAM use is based on a "preliminary" review of existing data on the effectiveness of home uterine activity monitors in preventing preterm births. The review, which also was published in the July 21 JAMA, evaluated seven studies, including "a nonrandomized observational study and six randomized, controlled trials of women at risk for preterm labor [that] compared birth outcomes with and without the use of HUAM." In the review, USPSTF states: "Although randomized, controlled trials...report an association between HUAM and decreased rates of preterm birth, low birth weight, and neonatal morbidity, the designs of these studies raise questions about the completeness of the evidence and about whether observed effects are due to HUAM or other factors (e.g., nursing contact)." The task force notes several weaknesses of the trials, including "high attrition and exclusion rates, poor control for nursing contact, and inconsistent methods of data analysis." In the policy statement, the group concludes that "there is an urgent need" for trials that "demonstrate clearly whether HUAM is effective in improving important clinical outcomes, such as neonatal morbidity and mortality." USPSTF says that future studies must have "adequate sample size, randomization, blinding, controls for attrition and loss to followup, complete reporting of results, and calculations of statistical significance based on proper denominators." In addition, the trials should address "clinical outcomes (e.g., preterm birth, neonatal morbidity) rather than surrogate measures (e.g., cervical dilation)." USPSTF also suggests that "to resolve confusion about the specific role of the technology, the study designs should permit comparisons between intensive home nursing contact, intensive home nursing contact with monitoring, and normal care." Data on risk factors also is required, the task force adds, "to better define the probability of preterm labor in populations with different risk profiles," USPSTF says. "Until this evidence becomes available, routine clinical use of HUAM is unjustified on scientific grounds," USPSTF asserts. A committee of the American College of Obstetricians and Gynecologists came to a similar conclusion in an opinion disseminated in conjunction with its September 1992 newsletter. The eight-member Committee on Maternal Obstetrics: Maternal and Fetal Medicine stated that home uterine activity monitoring should be "investigational" until "a prospective, randomized, blinded clinical study of sufficient size" is conducted to validate its usefulness in the prevention of premature birth. FDA currently is working on guidelines for studies that support premarket approval applications for home uterine monitor devices. A draft of the guidance was presented for discussion at an April 30 meeting of FDA's obstetrics and gynecology devices panel. The draft would require data on the primary outcome measures of cervical dilation and effacement, as well as secondary measures, such as gestational age at delivery and perinatal morbidity and mortality ("The Gray Sheet" May 10, p. 9). In a July 20 press release commenting on the JAMA article, Tokos, the only firm that has a HUAM device approved for a preterm indication, said that the task force's findings were "misleading" since they suggest "that frequent provider contact alone (without HUAM) may be as effective in early detection of preterm labor as the combination of the HUAM device and frequent provider contact." Tokos adds: "The definitive study -- accepted by [FDA] in granting marketing approval of the [Tokos] Genesis for women with a history of preterm delivery -- evaluated home uterine activity monitoring without frequent provider contact and demonstrated that monitoring alone led to earlier detection of preterm labor" (emphasis Tokos'). Women & Children First, a coalition of 5,000 women with high-risk pregnancies, also took issue with USPSTF's conclusions. "It is discouraging to keep hearing from a small group of physicians" who "still want one more study before they acknowledge the value of HUAM," the group says. "There are thousands of high-risk mothers in this coalition who were not able to recognize...preterm labor contractions but who were treated successfully because their physicians used HUAM."