The customer contacted the siemens customer care center (ccc) to report a discordant false negative advia centaur xp hbsag (hbsii) result.Siemens has reviewed the event data and has concluded the incident investigation.The calibration, quality control, relative light unit (rlu) data and the patient sample was not provided by the customer for further investigation by siemens.The percent agreement section of the advia centaur xp hbsii instructions for use (ifu) (10635153 revision h, 2019-07) lists the 95% confidence interval (ci) for positive agreement as 92.0% - 98.8%.A review of the complaint database found no other complaints of false negative samples with the advia centaur xp hbsii reagent lot 204.A review of field data indicates over 760 samples have recovered reactive with advia centaur xp hbsii reagent lot 204.A review of internal data indicates advia centaur xp hbsii reagent lot 204 is performing as intended.In summary, the cause of the discrepant false negative hbsii results observed by the customer with this one sample when using advia centaur xp hbsii (lot 204) could not be determined.Siemens cannot rule out pre-analytical factors, a sample issue, or normal assay performance.Based on the information provided, no product problem was identified.The hbsag instruction for use (ifu) under the limitation section states the following: "for diagnostics purposes, the advia centaur hbsagii test results should always be assessed in conjunction with the patient's medical history, clinical examination, and other findings." "it is recognized that the current methods for the detection of hepatitis b surface antigen may not detect all potential infected individuals.A nonreactive test result does not exclude the possibility of exposure to or infection with hepatitis b.A nonreactive test result in individuals with prior exposure to hepatitis b may be due to antigen levels below the detection limit of this assay or lack of antigen reactivity to the antibodies in this assay." the assay is performing within specification.No further evaluation of the device is required.
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