This test is not 100% accurate, with a considerable false-negative rate even with repeat testing.

We use this property to establish experiment-wide false-positive and false-negative rates (Figure 2a).

It is more relevant to optimize with respect to false-positive and false-negative rates.

Estimates are that there will always be a relatively high Pap false-negative rate - at least 10 to 15 percent.

Thus, some experts recommend obtaining a follow up ultrasound at 4-6 weeks to reduce the false-negative rate of the initial ultrasound.

In one series, CT scans had an 80% false-negative rate for regional metastases.

The high false-negative rate probably led to a failure to detect some symbiont transcripts.

Mammography has a false-negative (missed cancer) rate of at least 10 percent.

"We do have a high false-negative rate," he said in a telephone interview.

One retrospective single-institution study of 22 patients reported a false-negative rate of 11%.