NEW YORK (GenomeWeb) – The Institute for Quality and Efficiency in Health Care (IQWiG) in Cologne, Germany, a contractor for the German government, has issued its final report on noninvasive prenatal diagnostics to detect fetal trisomies 13, 18, and 21 in high-risk pregnancies.
The report, posted on the institute's website last week, was commissioned last year by the Federal Joint Committee (G-BA), which represents doctors, hospitals, patients, and health insurance funds in Germany and makes decisions on healthcare, as part of an evaluation process to decide about possible reimbursement of NIPD for high-risk pregnancies by Germany's public health insurance.
Based on 22 studies on the diagnostic features of NIPD, of which 17 have potential bias, the report states, the sensitivity for detecting trisomy 21 is 99.13 percent and the specificity is 99.95 percent. That number might in fact be lower if failed tests, which were not included, are considered as well. The authors were unable to "robustly estimate" the sensitivity and specificity of NIPD for detecting trisomies 13 and 18 from the available studies.
If NIPD to detect trisomy 21 were to be used as a second-line test in pregnant women with increased risk only, the total number of invasive tests — and the associated risk of miscarriage — could be "probably reduced" compared to the current state, according to the report. However, this would leave trisomy 21 fetuses in low-risk women undetected.
Using NIPD as a first-line test in all women, on the other hand, would detect almost all fetuses with trisomy 21 and would lead to additional invasive tests in low-risk women, though the total number of invasive tests would stay below the current number. However, the report notes, the inclusion of failed NIPD tests might reverse this scenario and the total number of invasive tests might climb.
These calculations can provide a "rough impression" of the possible effects of NIPD, the report concludes, but more detailed quantitative predictions cannot be made because of a lack of information, for example about the uptake of current prenatal diagnostics, in particular first-trimester screening, in Germany.
Based on the IQWiG report and input from stakeholders, The G-BA plans to make its decision about reimbursement of NIPT in the summer of 2019.