Health care utilization and costs following amplified versus non-amplified molecular probe testing for symptomatic patients with suspected vulvovaginitis: a US commercial payer population

Abstract

Background: Vulvovaginitis (VV) is a common reason women seek medical attention in the USA. Both the non-specific clinical presentation and risk of preterm labor or delivery necessitate accurate identification of the causative agents to guide appropriate therapy. The diagnostic accuracy of amplified molecular probe testing (AMP) has been shown to exceed that of non-amplified molecular probe (NAMP) by 20%-25%.

Objective: To evaluate the impact of diagnosis with AMP testing on health care utilization, direct costs, and health outcomes, compared with NAMP, for symptomatic patients with suspected VV from a commercial payer perspective.

Methods: Symptomatic women (aged 18-64 years) who underwent VV testing with AMP or NAMP from January 1, 2012-December 31, 2016 were identified using the Truven Health Analytics MarketScan Database; those with continuous medical and pharmacy benefit enrollment 6 months pre/post AMP or NAMP testing were included. Patients were propensity score (PS) matched and 6-month all-cause health care resource utilization, all-cause direct costs (2017 USD), risk of all-cause hospitalization, and risk of preterm labor or delivery were compared between cohorts.

Results: After PS match (N=46,810 per group, mean age 34.2 years), AMP had significantly (all P<0.0001) fewer mean hospital outpatient visits (AMP 0.9 vs NAMP 1.0), primary care physician office visits (AMP 1.1 vs NAMP 1.2), and prescription medications (AMP 7.3 vs NAMP 8.0), and a 21% reduction in risk of hospitalization (risk ratio [RR]=0.79, 95% CI= 0.75-0.83, P<0.0001). Total medical expenditures per patient were lower for AMP than NAMP (mean AMP $3,287 vs NAMP $3,555, P<0.0001). Among pregnant women (N=2,175 per group), AMP had a 12% reduction in risk of preterm labor or delivery (RR =0.88, 95% CI=0.77-0.99, P=0.041).

Conclusion: This real-world study offers evidence on the clinical utility for symptomatic patients with suspected VV diagnosed with AMP compared to NAMP - demonstrating an opportunity to improve the patient journey while delivering value-based care.

Keywords: NuSwab; amplified molecular probe testing; clinical utility; costs; health care utilization; preterm delivery; preterm labor; propensity-score matching; vulvovaginitis.

Figure 1

Patient selection criteria. Abbreviations: AMP, amplified molecular probe test; NAMP, non-amplified molecular probe test; PS, propensity score; VV, vulvovaginitis.

Figure 2

Comparison of all-cause total medical expenditures for PS-matched patients. (A) Comparison of total medical expenditures (index date+ post-index period). (B) Comparison of medical expenditure components within the post-index period. Notes: The index date is defined as the date of AMP or NAMP testing. The post-index period includes 182 days following the index date; the post-index period excludes the index date. Mean expenditures for diagnostic testing for VV on the index date were $116 and $57 for the AMP and NAMP cohorts, respectively (P<0.0001). ^aP<0.0001. Abbreviations: AMP, amplified molecular probe test; ED, emergency department; NAMP, non-amplified molecular probe test; PCP, primary care physician; PS, propensity score; VV, vulvovaginitis.