Cell-free fetal DNA screening in the USA: a cost analysis of screening strategies

OBJECTIVES

To determine whether implementation of primary cell-free fetal DNA (cffDNA) screening would be cost-effective in the USA and to evaluate potential lower-cost alternatives.

METHODS

Three strategies to screen for trisomy 21 were evaluated using decision tree analysis: 1) a primary strategy in which cffDNA screening was offered to all patients, 2) a contingent strategy in which cffDNA screening was offered only to patients who were high risk on traditional first-trimester screening and 3) a hybrid strategy in which cffDNA screening was offered to all patients ≥ 35 years of age and only to patients < 35 years who were high risk after first-trimester screening. Four traditional screening protocols were evaluated, each assessing nuchal translucency (NT) and pregnancy-associated plasma protein-A (PAPP-A) along with either free or total beta-human chorionic gonadotropin (β-hCG), with or without nasal bone (NB) assessment.

RESULTS

Utilizing a primary cffDNA screening strategy, the cost per patient was 1017 US$. With a traditional screening protocol using free β-hCG, PAPP-A and NT assessment as part of a hybrid screening strategy, a contingent strategy with a 1/300 cut-off and a contingent strategy with a 1/1000 cut-off, the cost per patient was 474, 430 and 409 US$, respectively. Findings were similar using the other traditional screening protocols. Marginal cost per viable case detected for the primary screening strategy as compared to the other strategies was 3-16 times greater than the cost of care for a missed case.

CONCLUSIONS

Primary cffDNA screening is not currently a cost-effective strategy. The contingent strategy was the lowest-cost alternative, especially with a risk cut-off of 1/1000. The hybrid strategy, although less costly than primary cffDNA screening, was more costly than the contingent strategy.

Quality of nuchal translucency measurements correlates with broader aspects of program rigor and culture of excellence

INTRODUCTION

To determine if nuchal translucency (NT) quality correlates with the extent to which clinics vary in rigor and quality control.

METHODS

We correlated NT performance quality (bias and precision) of 246,000 patients with two alternative measures of clinic culture - % of cases for whom nasal bone (NB) measurements were performed and % of requisitions correctly filled for race-ethnicity and weight.

RESULTS

When requisition errors occurred in <5% of cases, the average MoM (multiple of the median) was 0.97. When >5% (33%), the curve lowered to 0.93 MoM (p < 0.001) with both bias and precision of measurements impaired. Likewise, for centers with NB >90%, MoM was 0.99 compared to those <10% at 0.93 (p < 0.001). Precision and bias were highly correlated (p < 0.001).

CONCLUSIONS

Rigor in NT measurements has improved, but the discussion has been confined to individuals. Progressive educational and remediation strategies need to expand to a second dimension - clinics themselves. Cross-clinic variation in NT quality exists independent of individual variation in NT quality, and two divergent indices of program rigor are associated with NT quality. Quality control must be program wide, and to effect continued improvement in the quality of NT results across time, the cultures of clinics must become a target for intervention.