Placental alpha-microglobulin-1 and combined traditional diagnostic test: a cost-benefit analysis.

OBJECTIVE: We sought to evaluate if the placental alpha-microglobulin (PAMG)-1 test vs the combined traditional diagnostic test (CTDT) of pooling, nitrazine, and ferning would be a cost-beneficial screening strategy in the setting of potential preterm premature rupture of membranes. STUDY DESIGN: A decision analysis model was used to estimate the economic impact of PAMG-1 test vs the CTDT on preterm delivery costs from a societal perspective. Our primary outcome was the annual net cost-benefit per person tested. Baseline probabilities and costs assumptions were derived from published literature. We conducted sensitivity analyses using both deterministic and probabilistic models. Cost estimates reflect 2013 US dollars. RESULTS: Annual net benefit from PAMG-1 was $20,014 per person tested, while CTDT had a net benefit of $15,757 per person tested. If the probability of rupture is <38%, PAMG-1 will be cost-beneficial with an annual net benefit of $16,000-37,000 per person tested, while CTDT will have an annual net benefit of $16,000-19,500 per person tested. If the probability of rupture is >38%, CTDT is more cost-beneficial. Monte Carlo simulations of 1 million trials selected PAMG-1 as the optimal strategy with a frequency of 89%, while CTDT was only selected as the optimal strategy with a frequency of 11%. Sensitivity analyses were robust. CONCLUSION: Our cost-benefit analysis provides the economic evidence for the adoption of PAMG-1 in diagnosing preterm premature rupture of membranes in uncertain presentations and when CTDT is equivocal at 34 to <37 weeks' gestation.

Placental Alpha Microglobulin-1 Compared With Fetal Fibronectin to Predict Preterm Delivery in Symptomatic Women.

OBJECTIVE: To compare the rapid bedside test for placental α microglobulin-1 with the instrumented fetal fibronectin test for prediction of imminent spontaneous preterm delivery among women with symptoms of preterm labor. METHODS: We conducted a prospective observational study on pregnant women with signs or symptoms suggestive of preterm labor between 24 and 35 weeks of gestation with intact membranes and cervical dilatation less than 3 cm. Participants were prospectively enrolled at 15 U.S. academic and community centers. Placental α microglobulin-1 samples did not require a speculum examination. Health care providers were blinded to placental α microglobulin-1 results. Fetal fibronectin samples were collected through speculum examination per manufacturer requirements and sent to a certified laboratory for testing using a cutoff of 50 ng/mL. The coprimary endpoints were positive predictive value (PPV) superiority and negative predictive value (NPV) noninferiority of placental α microglobulin-1 compared with fetal fibronectin for the prediction of spontaneous preterm birth within 7 days and within 14 days. RESULTS: Of 796 women included in the study cohort, 711 (89.3%) had both placental α microglobulin-1 and fetal fibronectin results and valid delivery outcomes available for analysis. The overall rate of preterm birth was 2.4% (17/711) within 7 days of testing and 4.2% (30/711) within 14 days of testing with respective rates of spontaneous preterm birth of 1.3% (9/703) and 2.9% (20/701). Fetal fibronectin was detected in 15.5% (110/711), and placental α microglobulin-1 was detected in 2.4% (17/711). The PPVs for spontaneous preterm delivery within 7 days or less among singleton gestations (n=13) for placental α microglobulin-1 and fetal fibronectin were 23.1% (3/13) and 4.3% (4/94), respectively (P<.025 for superiority). The NPVs were 99.5% (619/622) and 99.6% (539/541) for placental α microglobulin-1 and fetal fibronectin, respectively (P<.001 for noninferiority). CONCLUSION: Although placental α microglobulin-1 performed the same as fetal fibronectin in ruling out spontaneous preterm delivery among symptomatic women, it demonstrated statistical superiority in predicting it.

Placental Alpha-Microglobulin-1 Test in Resource-Limited Settings: A Cost-Effectiveness Analysis.

OBJECTIVE: To evaluate whether the use of placental alpha-microglobulin-1 (PAMG-1) for the diagnosis of preterm premature rupture of membranes is cost-effective in resource-limited settings. METHODS: We designed a decision-analytic model from a third-party payer's perspective to determine the cost-effectiveness of the PAMG-1 test compared with the traditional diagnostic test of pooling, Nitrazine, and ferning in diagnosing preterm premature rupture of membranes in a resource-limited setting. The primary health outcome of interest is the number of hospital transfers averted by each strategy per 1,000 patients screened. Baseline probabilities and cost assumptions were derived from published literature. We conducted sensitivity analyses using both deterministic and probabilistic models. Cost estimates reflect 2015 U.S. dollars. RESULTS: Under our baseline parameters, the use of a PAMG-1 test was the preferred cost-effective strategy. The PAMG-1 test averted hospital transfers of 447 true-negative patients per 1,000 tested at a cost of $143,407 ($320.82 per hospital transfer averted). The traditional test averted hospital transfers of 395 true-negative patients per 1,000 tested at a cost of $172,652 ($437.40 per hospital transfer averted). In a Monte Carlo simulation of 10 million trials, the PAMG-1 test was selected as the most cost-effective strategy with a frequency of 74%. The traditional test was only selected with a frequency of 26%. The "do-nothing" strategy was not selected throughout the trial. CONCLUSION: Among women presenting at resource-limited settings with a history suspicious of preterm premature rupture of membranes between 24 and 36 weeks of gestation, our analysis provides evidence suggesting that PAMG-1 is the most cost-effective testing strategy.

Prophylactic use of negative pressure wound therapy after cesarean delivery.

OBJECTIVE: To evaluate the economic benefit of prophylactic negative pressure wound therapy on a closed laparotomy incision after cesarean delivery in comparison with standard postoperative dressing. METHODS: We designed a decision-analytic model from a third-party payer's perspective to determine the cost-benefit of prophylactic application of negative pressure wound therapy compared with standard postoperative dressing on a closed laparotomy incision after cesarean delivery. Our primary outcome measure was the expected value of the cost per strategy. Baseline probabilities and cost assumptions were derived from published literature. We conducted sensitivity analyses using both deterministic and probabilistic models. Cost estimates reflect 2014 U.S. dollars. RESULTS: Under our baseline parameters, standard postoperative dressing was the preferred strategy. Standard postoperative dressing and prophylactic negative pressure wound therapy cost $547 and $804 per strategy, respectively. Sensitivity analyses showed that prophylactic negative pressure wound therapy can be cost-beneficial if it is priced below $192; standard postoperative dressing is the preferred strategy among patients with surgical site infection rate of 14% or less. If surgical site infection rates are greater than 14%, prophylactic negative pressure wound therapy could be cost-beneficial depending on the degree of reduction in surgical site infections. At a surgical site infection rate of 30%, the rate must be reduced by 15% for negative pressure wound therapy to become the preferred strategy. Monte Carlo simulation of 1,000 patients in 1 million trials showed that standard postoperative dressing was the preferred cost-beneficial strategy with a frequency of 85%. CONCLUSION: Our cost-benefit analysis provides economic evidence suggesting that negative pressure wound therapy should not be used on closed laparotomy incisions of patients with low risk of postcesarean delivery surgical site infections. However, among patients with a high risk of surgical site infections, prophylactic negative pressure wound therapy is potentially cost-beneficial.