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Last Known Well — Abstraction Tool

TJC v2026B  ·  ASR-IP-1 · ASR-OP-1 · STK-4  ·  Discharges 3Q26–4Q26

LKW Resolution Grid

Enter what you find in the chart for each source. The tool resolves your final abstraction values using spec priority rules.

ℹ️
How to useFill in each row with what the chart shows — dates, times, whether LKW/normal is explicitly stated vs. S/Sx only, and whether unknown is documented. Leave blank if not present. Hit Resolve when done.
COLUMN PRIORITY: 1 — Unknown (MD) 2 — Code Stroke Form 3 — LKW / Normal 4 — S/Sx Only
Source Row
Priority
Priority 4
S/Sx Only
symptom onset,
no explicit LKW
Priority 3
LKW / Normal
explicitly last
known well
Priority 1
Unknown
unknown / uncertain
/ unclear
Priority 2
Code Stroke Form
RN-completed;
not MD priority
MD
Physician / APN / PA
1
See RN row
RN
Nursing / EMS
2
Context Flags
Abstraction Result
Last Known Well (Y/N)
Date LKW
Time LKW
Rule Applied
Guided Workflow

Answer each question to determine your LKW abstraction values step by step.

Step 1 — Stroke Timing
Did LKW / stroke signs first occur after hospital arrival?
Quick Reference

v2026B · STK-4 / ASR-IP-1 / ASR-OP-1

LKW Documentation Priority Matrix
ℹ️
Column priority determines what type of documentation wins. Row priority determines who wins when the same column has multiple entries. The hierarchy shown here (1=Unknown, 2=CSF, 3=LKW/Normal, 4=S/Sx) is the spec-derived hierarchy.
SourceRow Priority4 S/Sx Only3 LKW/Normal1 Unknown2 Code Stroke Form
MD1Date / Time/sDate / Time/sYes / No
YES = cancels ALL
See RN row
RN2Date / Time/sDate / Time/s✕ irrelevantDate / Time/s
Not MD-level priority — but beats all other positive sources
🚨
Time LKW — Multiple timesMultiple S/Sx episodes → most recent. Multiple MD times → earliest. MD unknown → cancels ALL. No CSF + multiple times → MD first.
⚠️
Date LKW — Multiple datesAlways use the earliest date when multiple are documented.

Last Known Well (Y/N)

Select YES whenBOTH date AND time present
NO — MD says unknownCancels all
NO — in-house strokePost-arrival LKW
NO — time >2h, no specific timeUTD
"Just prior to arrival"YES → use arrival time
RN unknown, MD has timeYES
MD unknown, RN has timeNO

Date Last Known Well

FormatMM-DD-YYYY
Invalid date (03-42)UTD
"This evening," arr 00:30Day before arrival
Midnight → advance date00:00 next calendar day
Multiple datesEarliest
CSF dateTakes precedence

Time Last Known Well

FormatHH:MM military
Invalid time (3300)UTD
With seconds (15:00:35)Drop seconds → 15:00
Hours ago ("2 hrs ago")Arrival − 2h
Range ("2–3 hrs ago")MAX → Arrival − 3h
"Less than X hrs ago"Use X → Arrival − X
"Just prior to arrival"Use arrival time

⏱ Calculators

MILITARY TIME CONVERTER
HOURS-AGO SUBTRACTOR
− hrs:
Always use MAX for ranges
Top Abstractor Pitfalls
🚨
Pitfall #1 — Using S/Sx when explicit LKW is documented"Patient normal at 8 PM" + "symptoms at 8:30 PM" → LKW = 20:00, not 20:30. Explicit LKW always beats symptom onset.
🚨
Pitfall #2 — Ignoring MD "unknown" because nursing has a timeMD Unknown (Priority 1) cancels everything. One MD saying unknown = NO. RN unknown = irrelevant.
⚠️
Pitfall #3 — Forgetting to advance date at midnight24:00 on 11-24 → 00:00 on 11-25. Always change the Date LKW when converting midnight.
⚠️
Pitfall #4 — Assuming wake-up stroke = unknownIf the physician documents a bedtime as LKW — use it. Only "unknown" if MD explicitly states it.
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Pitfall #5 — Stroke Education Form ≠ Code Stroke FormStroke Education Form and Core Measure Form are excluded. Only acute stroke response forms qualify as CSF.
💡
Pitfall #6 — Using first episode instead of lastSymptoms → resolved → recurred = use most recent episode before arrival. Grid note: "symptom onset/resolved → closest to arrival."
Practice Quiz

10 scenario-based questions covering every major LKW rule.

Question 1 of 10Score: 0 / 0
Case Walkthroughs

Step-by-step cases that explain the abstraction reasoning at every decision point.

🩺
How to useSelect a case, then work through each step. The trainer's reasoning appears at each decision point.
Educational use only. AbstractionDeskQA is a reference aid to support abstractor training and workflow. It does not constitute compliance advice and is not a substitute for the official TJC or CMS Specifications Manual. Always verify abstraction decisions against the current specifications.