A "tandem-reflex” strategy minimizes results delivery time for couples undergoing carrier screening

Abstract

To determine the impact of the “tandem reflex” strategy on turnaround-time and test utilization. Expanded carrier screening aims to detect couples at risk for having children with severe and profound Mendelian disorders. As many couples are pregnant or actively trying to conceive while undergoing carrier screening, obtaining screening results in a timely manner is important. Reproductive partners are typically tested in a sequential manner: the female partner is tested first and if she is a carrier, her partner is tested for the condition(s) for which she was found to be a carrier. In current practice, this commonly necessitates a subsequent visit to a physician for submission of the partner’s sample, such that the time to receive a combined couple report is roughly double the time it takes to receive an individual carrier screening report. This need for a secondary sample submission imposes workflow challenges to the clinic and patients, reduces the likelihood of the partner getting screened, and thus may hamper detection of at-risk couples. To minimize turnaround-time and maximize the detection of at-risk couples, we implemented a “tandem reflex” strategy wherein both partners submit samples in tandem, but are tested sequentially, with the second partner’s sample tested only if the first partner was found to be a carrier. Retrospective data analysis. The time between a reproductive couple’s submission of its first sample to the delivery of a combined report was measured before and after implementation of the “tandem reflex” strategy. Samples submitted and tested simultaneously were also analyzed for unnecessary partner testing. Before implementing the “tandem reflex” strategy, the average time for a sequentially tested couple to receive a full couple-based carrier screening report was approximately 34 days (95th percentile 70 days, N = 11,434 couples). After implementing the tandem-reflex strategy, the average wait time for a couple to receive their combined report was reduced to approximately 15 days (95th percentile 25 days, N = 383 couples), with individual reports returned within 11 days (95th percentile just under 21 days). Among 9,718 couples for which samples were submitted and tested simultaneously, 41% of females were negative for all tested conditions; in this scenario, the tandem reflex strategy would not have triggered testing of the male partner. The “tandem reflex” strategy decreased by half the turnaround-time for receiving a combined carrier screening report compared to sequential testing, resulting in the timely receipt of crucial information for reproductive and pregnancy management.