At a glance
Throughout a false-positive investigation, communication among all partners (laboratory, TB Program, and health care providers) is vital as new information is available. Consider developing policies to ensure consistent and accurate communications.
Taking Action
The laboratory should provide updates to the TB Program and healthcare providers as new information becomes available. Similarly, the TB Program and healthcare provider should keep the laboratory aware of any pertinent information regarding patients including clinical presentation and epidemiologic investigations. Forming a committee consisting of both laboratory and the TB Program representatives is beneficial for awareness and future collaboration.
If the patient is hospitalized, it is also important that the facility’s infection prevention team is aware of the concern of a false-positive result.
A suspected false-positive result should be considered "likely" if one or more of the following criteria are met:
- Genotyping shows a match with the presumed source of the false-positive result
- The investigation confirmed that the questionable isolates have a common linkage (e.g., exposed during manipulation)
- There is no other likely explanation for the findings
- The presumed misdiagnosed patient does not have a clinical presentation consistent with TB
Depending on the outcome of the false-positive investigation, it may be appropriate to update or correct patient test results. While not a substitute for clinical judgement, a thorough false-positive investigation is important to ensure healthcare providers receive accurate patient test results to consider when making patient treatment decisions. The ability to provide corrected reports may depend on the functionality of the laboratory information management system.
The laboratory should communicate with the TB Program and healthcare providers regarding progress of the investigation including specific patient test results.
Within the laboratory and outside of the laboratory, the conclusion of a false-positive investigation provides the opportunity for reeducation, additional training, or reassessment of policies and procedures. Additionally, this is an opportunity to ensure that laboratorians are performing best practices through competency training.
Laboratories should consider the importance of developing a policy related to false-positive investigations. This policy should include common steps, flags, or scenarios that the laboratory can monitor to proactively assess whether a false-positive investigation is necessary, as well as a communication plan for involved partners.
A false-positive investigation policy is necessary for consistent and accurate communication among the laboratory, TB Program, hospitals, and healthcare providers and for appropriate patient care.