We read with great interest the review by Verlohren and Droge on the diagnostic value of angiogenic and antiangiogenic factors in the differential diagnosis of preeclampsia.
We noted that the INSPIRE trial is incorrectly mentioned in Table 1 as a retrospective observational study. INSPIRE was a pragmatic randomized clinical trial assessing the real world performance of the test when incorporated into clinical practice in comparison with standard clinical assessment alone. The level of evidence and the implications for future guideline derivation are significantly different between a retrospective observational study and a randomized clinical trial, and we believe that this error should be corrected. Furthermore, it should be noted that the INSPIRE-reported negative predictive value of 100% (95% confidence interval [CI], 97.1–100) to rule out preeclampsia in 7 days (cutoff soluble fms-like tyrosine kinase-1/placental growth factor [sFlt-1/PlGF] ratio ≤38) corresponds to the incorporation of the test into standard clinical practice, that is, clinical judgment with the knowledge of the test result. The test alone has a negative predictive value of 99.2% (95% CI, 95.8–100). Finally, we have also recently reported (in a posthoc analysis of the INSPIRE trial) the performance of a sFlt-1/PlGF ratio ≥85, showing that this confers a positive predictive value of 71.4% (95% CI, 51.3%–86.8%) for ruling in preeclampsia within 4 weeks.
A.S.C. and M.V. received speaker fees from Roche Diagnostics. This is classified as a modest disclosed relationship. The remaining authors report no conflict of interest.
The authors report no funding sources.