TST-TIMING-ERR-04 medical protocol_error ai_generated true

AI instructs a nurse to read a tuberculin skin test (TST) at 24 hours instead of the required 48-72 hours, leading to false-negative result

ID: medical/tuberculin-skin-test-timing

Also available as: JSON · Markdown · 中文
92%Fix Rate
84%Confidence
1Evidence
2024-08-05First Seen

Version Compatibility

VersionStatusIntroducedDeprecatedNotes
CDC TB Guidelines 2023 active — — —
Epic Stork v2024.1 active — — —
QuantiFERON-TB Gold Plus v2.0 active — — —

Root Cause

The AI output stated 'Read TST after 24 hours' based on a misinterpretation of CDC guidelines, which mandate reading at 48-72 hours; early reading misses delayed-type hypersensitivity reactions, causing false negatives.

generic

中文

AI输出'24小时后读取TST'，基于对CDC指南的误解；指南要求48-72小时后读取；过早读取会遗漏迟发型超敏反应，导致假阴性。

Official Documentation

https://www.cdc.gov/tb/publications/guidelines/testing.htm

Workarounds

  1. 95% success Document the invalid TST (read at 24h) as 'uninterpretable' in the EHR. Order a new TST and schedule a return visit at 48-72 hours. Provide patient with written instructions: 'Do not read the test yourself; return to clinic exactly 48-72 hours after placement.' 
    Document the invalid TST (read at 24h) as 'uninterpretable' in the EHR. Order a new TST and schedule a return visit at 48-72 hours. Provide patient with written instructions: 'Do not read the test yourself; return to clinic exactly 48-72 hours after placement.'
  2. 90% success If the patient cannot return, switch to IGRA (QuantiFERON-TB Gold Plus) as a single-visit alternative. Order in EHR: 'IGRA for LTBI screening, reason: TST reading window missed.' 
    If the patient cannot return, switch to IGRA (QuantiFERON-TB Gold Plus) as a single-visit alternative. Order in EHR: 'IGRA for LTBI screening, reason: TST reading window missed.'
  3. 85% success Implement a hard stop in the nursing documentation system: if TST reading time is <48 hours, block finalization and display: 'TST reading invalid: must be 48-72 hours after placement. Re-enter time or order repeat test.' 
    Implement a hard stop in the nursing documentation system: if TST reading time is <48 hours, block finalization and display: 'TST reading invalid: must be 48-72 hours after placement. Re-enter time or order repeat test.'

中文步骤

  1. Document the invalid TST (read at 24h) as 'uninterpretable' in the EHR. Order a new TST and schedule a return visit at 48-72 hours. Provide patient with written instructions: 'Do not read the test yourself; return to clinic exactly 48-72 hours after placement.'
  2. If the patient cannot return, switch to IGRA (QuantiFERON-TB Gold Plus) as a single-visit alternative. Order in EHR: 'IGRA for LTBI screening, reason: TST reading window missed.'
  3. Implement a hard stop in the nursing documentation system: if TST reading time is <48 hours, block finalization and display: 'TST reading invalid: must be 48-72 hours after placement. Re-enter time or order repeat test.'

Dead Ends

Common approaches that don't work:

  1. 80% fail

    The test must be read within the 48-72 hour window; a 24-hour reading is invalid and cannot be 'corrected' by a later reading because the induration may have already peaked and subsided.

  2. 75% fail

    Chest X-ray is not a substitute for TST; it detects active disease, not latent infection. A negative X-ray does not rule out latent TB.

  3. 60% fail

    IGRA is an alternative, but the invalid TST should be documented and the patient informed; IGRA may not be covered by insurance if TST was already performed.