chart-review-cohort

name	chart-review-cohort
description	Analyzes a cohort of completed chart reviews under a locked guideline to detect drift, surface override patterns, and generate Role-C-style feedback. Use when the user says "what's drifting", "any patterns in recent overrides", "Role C analysis", "cohort feedback", "is the guideline still working", "agent quality over time", "run cohort QA", or asks for a periodic or quality-assurance review of how a locked guideline is performing in production. Outputs a feedback report with detected drift, clustered override patterns, and pointers to issues that warrant a chart-review-improve proposal. Does not propose edits itself — surfaces findings only. Composes with chart-review-improve to act on the findings.
metadata	{"author":"chart-review-platform","version":"0.2.0"}

Cohort Feedback (Role C)

Continuous-quality monitoring for a locked guideline in production. This skill walks all completed reviews under a locked guideline, computes per-criterion override rates over two sliding time windows, detects drift where the recent rate exceeds the baseline by more than the threshold, clusters recent overrides by pattern, and writes a feedback report. It surfaces findings — it does not propose edits. Editing is chart-review-improve's job.

When to use

• User says "what's drifting", "any patterns in recent overrides", "Role C analysis", "cohort feedback", "is the guideline still working", "agent quality over time", or "run cohort QA"
• Periodically on a production locked guideline to check if override rates are increasing
• After a corpus shift (new reviewers, new patient cohort, EHR migration) to detect whether the shift broke the guideline's performance

Do not use on draft guidelines — drift analysis requires a sufficient production baseline.

Inputs

• guideline_path: the locked guideline (guidelines/<id>/)
• reviews_root: typically reviews/ — contains reviews/<patient>/<guideline-id>/review_state.json
• window (optional): how recent counts as "recent". Default: 30 days or last 50 reviews, whichever is smaller
• drift_threshold (optional): percentage-point delta in override rate vs baseline. Default: 10 pp
• min_window_fill (optional): minimum reviews per window for drift computation. Default: 25 each side

Procedure

1. Read the guideline. <guideline_path>/meta.yaml and <guideline_path>/criteria/*.yaml for criterion ids and time_window tags.

2. Enumerate completed reviews. For each reviews/<patient>/<guideline-id>/review_state.json:

   • Skip if review_status is not in ["reviewer_validated", "locked"] — unfinished reviews must not contaminate override stats.
   • For each field_assessments[i]: if source == "reviewer" and original_agent_snapshot exists, this was an override. Capture {patient_id, criterion, agent_answer, reviewer_answer, edit_reason, edit_note, ts}.

3. Compute per-criterion override rate.

   • total_reviewer_writes = # reviewer assessments touching this field.
   • overrides = subset where status == "overridden".
   • rate = overrides / total_reviewer_writes.

4. Detect drift — for each criterion, compute two windowed rates:

   • current: most recent N reviewer writes (default N = 50).
   • baseline: the N reviewer writes preceding current.
   • Need >= min_window_fill in each window. If either is too small, skip drift for this criterion and note it in the report.
   • delta_pp = (current_rate - baseline_rate) × 100.
   • If |delta_pp| >= drift_threshold AND no recent drift_alert in the audit log for this (criterion, window), flag drift.

5. Cluster recent overrides. For each criterion with elevated current override rate, cluster by:

   • edit_reason: missed_evidence, misinterpreted, wrong_rule, criterion_ambiguous, other. A spike in one category suggests a specific failure mode.
   • Evidence pattern: recurring quote, code, or structural finding in reviewer evidence → likely a missing edge case, code, or keyword.
   • Temporality: did drift coincide with a corpus shift?

Universal references

• See skills/chart-review/references/lifecycle.md for the production monitoring phase this skill covers.
• See skills/chart-review/references/reliability-metrics.md for the override rate interpretation context.

Hard rules (with reasons)

• Output goes ONLY to cohorts/<guideline-id>/. Cohort feedback reports are QA artifacts — writing to guideline or review paths would corrupt the data model.
• Don't include unfinished reviews in stats. Unfinished reviews have incomplete override counts; including them would make override rates appear lower than reality and mask drift.
• Don't propose edits. This skill surfaces findings; chart-review-improve makes proposals. Conflating the two roles undermines the methodologist's oversight of guideline changes.
• Drift requires both windows to have ≥ min_window_fill reviews. A delta computed from 3 reviews vs 50 is statistically meaningless and would generate false alerts; the fill requirement prevents this.
• Honor cooldown — don't re-flag the same drift signal more than once per cooldown period (default 30 minutes). Repeated alerts for the same signal fatigue the methodologist and obscure new signals.

Troubleshooting

Only one window's worth of data (new guideline): Report "insufficient data for drift analysis." Emit current override rates without a baseline comparison. This is the expected state for a new guideline in its first production weeks.

Override rate is high but stable (no drift): Baseline 30%, current 32% — delta below threshold. Don't flag as drift; note in summary that the criterion is "chronically high override" and may warrant a chart-review-improve pass even though it's not drifting.

One reviewer dominates the cohort: If 80% of reviews are by one person, "override patterns" may reflect that person's preferences rather than protocol issues. Stratify by reviewer in the cluster analysis and flag: "override patterns concentrate in <reviewer_id> (X of Y); consider whether this is reviewer style vs protocol issue."