Table 3.
Sensitivity and specificity for AD/AS samples compared with published validation metrics
| Indication | CLIA laboratory | Validation studies a | ||||
|---|---|---|---|---|---|---|
| Observed sensitivity b | Sensitivity range c | Observed specificityb | Specificity rangec | Sensitivity | Specificity | |
| Trisomy 21 | 99.49% | 98.66–99.53% | 99.77% | 98.92–99.91% | 100% | 99.76% |
| Trisomy 18 | 97.23% | 94.20–98.15% | 99.69% | 99.51–99.85% | 97.37% | 99.57% |
| Trisomy 13 | 97.98% | 95.56–98.87% | 99.84% | 99.77–99.93% | 87.50% | 100% |
a
Validation performance from the MELISSA cohort,4 which included 90 trisomy 21 samples, 38 trisomy 18 samples, and 16 trisomy 13 samples; unclassified samples were treated as positives (Supplement 1).
b
Observed sensitivity and specificities were calculated using available outcome data with the cohort size adjusted for the proportion of positive cases with confirmed outcomes.
c
The low end of the range was based on the assumption that all unreported outcomes are discordant, and high end of the range was based on the assumption that all unreported outcomes are concordant.