CHICAGO – The placental alpha-microglobulin-1 test is superior from a cost-benefit perspective to the combined traditional diagnostic test of pooling, nitrazine, and ferning for screening in the setting of questionable preterm premature rupture of membranes, Dr. Nelson C. Echebiri reported at the annual meeting of the American Congress of Obstetricians and Gynecologists.
The PAMG-1 also should be used if the traditional test result is equivocal or inconclusive, he said.
The cost of PAMG-1 is about $85, compared with $14 for the traditional diagnostic test. Because of the added expense, testing all patients who present with possible preterm premature rupture of membranes (PROM) and those whose diagnosis is obvious would be counterproductive, Dr. Echebiri said.
The PAMG-1 test is easy to use and has been shown in multiple studies to have high sensitivity and specificity for detecting PAMG-1 – a marker for amniotic fluid. Dr. Echebiri said he felt the test would be a good noninvasive alternative to the invasive standard test of indigo carmine dye injection into the amniotic cavity.
For the study, a decision analysis was constructed to estimate the cost benefit of the PAMG-1 test as compared with the traditional test with respect to preterm delivery costs, which average $47,000. The analysis was based on the setting of potential preterm PROM at 34 weeks to less than 37 weeks of gestation as applied to 1,000 theoretical patients, 1,000 times each. Cost estimates reflected 2013 dollars.
When used according to the decision analysis, the estimated annual net benefit with the noninvasive placental alpha-microglobulin-1 (PAMG-1) test was $12,215/person tested, compared with $4,737/person tested using the traditional test. The PAMG-1 test was cost-beneficial in cases in which the probability of preterm PROM was less than 42% (net savings of $5,000-$32,000 per person tested vs. $5,000-$9,000 per person with the traditional test.
The PAMG-1 test was not associated with any savings in cases with 44% or greater probability of preterm PROM, said Dr. Echebiri of the University of Buffalo, N.Y., whose paper received a Donald F. Richardson Memorial Prize Paper Award as one of the best papers by a junior fellow at the meeting.
Dr. Echebiri reported having no disclosures.