aivanov_CIM/TASK_11_SUMMARY.md

Task 11 Summary: Vérificateur Implementation

Overview

Successfully implemented the Vérificateur class, which provides independent verification of coding proposals from the Codeur. The Vérificateur acts as a second opinion to detect DIM-sensitive errors and ensure coding quality.

Tasks Completed

Task 11.1: Créer la classe Verificateur avec prompt différent ✅

• Created src/pipeline_mco_pmsi/verifiers/verificateur.py
• Implemented Verificateur class with different prompt version from Codeur
  • Codeur uses: "codeur-1.0.0" (implied from tests)
  • Vérificateur uses: "verificateur-1.0.0" (DIFFERENT as required)
• Added validation to reject proposals if same prompt version is used
• Exigence 4.1: ✅ Verified - Vérificateur uses different prompt

Task 11.2: Implémenter detect_dim_errors() ✅

Implemented comprehensive DIM error detection for 5 types of errors:

1. Diagnostics niés codés comme affirmés (Exigence 4.2, 19.1)

   • Detects when negated facts are coded as affirmed
   • Severity: bloquant
   • Error type: negated_as_affirmed

2. Actes CCAM sans preuve explicite (Exigence 4.3, 19.3)

   • Detects CCAM codes without explicit act evidence
   • Checks that evidence comes from fact of type "acte"
   • Severity: bloquant
   • Error type: act_without_evidence

3. Antécédents codés comme épisode actuel (Exigence 4.4, 19.4)

   • Detects medical history coded as current episode (DP)
   • Checks temporality field
   • Severity: bloquant
   • Error type: history_as_current

4. Inversions DP/DAS (Exigence 19.5)

   • Detects when DAS has higher confidence than DP
   • Uses threshold of 0.1 margin
   • Severity: a_revoir (non-blocking)
   • Error type: dp_das_inversion

5. Suspicion transformée en certitude (Exigence 19.2)

   • Detects suspected diagnoses coded as certain DP
   • Checks qualifier certainty
   • Severity: bloquant
   • Error type: suspected_as_certain

Task 11.3: Implémenter la logique de veto et marquage ✅

Implemented decision logic with three outcomes:

1. VETO (Exigence 4.5)

   • Generated when blocking errors detected
   • Requires TIM arbitration
   • Blocks automatic validation

2. REVIEW (Exigence 4.6)

   • Generated for non-blocking errors or contradictions
   • Marks codes as "à_revoir"
   • Recommends TIM verification

3. ACCEPT (Exigence 4.8)

   • Generated when no errors detected
   • Confirms Codeur's proposal
   • Allows validation

Alternatives Generation (Exigence 4.6):

• Suggests alternative codes when DP has errors
• Uses highest-confidence DAS as alternative DP
• Provides reasoning for alternatives

Implementation Details

Key Features

1. Independent Analysis

   • Uses different prompt version than Codeur
   • Validates prompt difference at runtime
   • Raises error if same prompt used

2. Evidence Matching

   • Creates index of facts by evidence (document_id, span)
   • Matches code evidence to source facts
   • Detects mismatches and contradictions

3. Comprehensive Reasoning

   • Generates detailed reasoning for all decisions
   • Includes error details and affected codes
   • Provides actionable recommendations

4. Error Severity Levels

   • bloquant: Blocks validation, requires veto
   • a_revoir: Non-blocking, requires review
   • info: Informational only

Data Structures

DIMError:

{
    "error_type": str,  # Type of error
    "message": str,     # Detailed message
    "affected_codes": List[str],  # Codes with errors
    "severity": str     # bloquant/a_revoir/info
}

VerificationResult:

{
    "stay_id": str,
    "decision": str,    # accept/veto/review
    "dim_errors": List[DIMError],
    "contradictions": List[str],
    "alternatives": List[Code],
    "reasoning": str,
    "model_version": ModelVersion,
    "prompt_version": str  # MUST differ from Codeur
}

Test Coverage

Created comprehensive test suite with 16 tests:

Initialization Tests (2)

• ✅ test_verificateur_initialization
• ✅ test_verificateur_prompt_version_different_from_codeur

Verification Tests (2)

• ✅ test_verify_proposal_accepts_valid_proposal
• ✅ test_verify_proposal_rejects_same_prompt_version

DIM Error Detection Tests (6)

• ✅ test_detect_dim_errors_negated_diagnostic
• ✅ test_detect_dim_errors_suspected_as_dp
• ✅ test_detect_dim_errors_history_as_dp
• ✅ test_detect_dim_errors_ccam_without_evidence
• ✅ test_detect_dim_errors_ccam_with_valid_evidence
• ✅ test_detect_dim_errors_dp_das_inversion

Decision Tests (3)

• ✅ test_verify_proposal_veto_on_blocking_error
• ✅ test_verify_proposal_review_on_non_blocking_error
• ✅ test_verify_proposal_provides_alternatives

Complex Scenario Tests (3)

• ✅ test_verify_proposal_generates_reasoning
• ✅ test_verify_proposal_multiple_errors
• ✅ test_verify_proposal_no_errors_with_das_only

Test Results

16 passed in 7.29s
Code coverage: 91% for verificateur.py

Files Created

1. Implementation:

   • src/pipeline_mco_pmsi/verifiers/__init__.py
   • src/pipeline_mco_pmsi/verifiers/verificateur.py (138 lines)

2. Tests:

   • tests/test_verificateur.py (16 tests, comprehensive coverage)

Requirements Validated

Exigence 4: Vérification Indépendante

• ✅ 4.1: Vérificateur uses different prompt (validated at runtime)
• ✅ 4.2: Detects negated diagnostics coded as affirmed
• ✅ 4.3: Detects CCAM acts without explicit evidence
• ✅ 4.4: Detects medical history coded as current episode
• ✅ 4.5: Generates veto for blocking contradictions
• ✅ 4.6: Marks "à_revoir" for non-blocking contradictions
• ✅ 4.6: Provides alternatives
• ✅ 4.8: Accepts valid proposals

Exigence 19: Prévention des Erreurs Zéro-Tolérance

• ✅ 19.1: Prevents negated diagnostics from being coded
• ✅ 19.2: Prevents suspected diagnoses from becoming certain
• ✅ 19.3: Prevents CCAM acts without explicit evidence
• ✅ 19.4: Prevents medical history from being coded as current
• ✅ 19.5: Detects gross DP/DAS inversions

Usage Example

from pipeline_mco_pmsi.verifiers.verificateur import Verificateur
from pipeline_mco_pmsi.rag.rag_engine import RAGEngine

# Initialize
rag_engine = RAGEngine(...)
verificateur = Verificateur(
    rag_engine=rag_engine,
    model_name="mock-llm",
    model_version="1.0.0"
)

# Verify a proposal
result = verificateur.verify_proposal(
    proposal=coding_proposal,
    facts=clinical_facts,
    cim10_version="2026",
    ccam_version="2025"
)

# Check decision
if result.decision == "veto":
    print("REJECTED:", result.dim_errors)
elif result.decision == "review":
    print("NEEDS REVIEW:", result.contradictions)
else:
    print("ACCEPTED")

Key Design Decisions

1. Prompt Version Enforcement

   • Hard-coded different prompt version
   • Runtime validation to prevent accidental same-prompt usage
   • Raises ValueError if same prompt detected

2. Evidence Matching Strategy

   • Creates index by (document_id, start, end) for O(1) lookup
   • Matches code evidence to source facts
   • Detects orphaned evidence

3. Confidence-Based Inversion Detection

   • Uses 0.1 margin to avoid false positives
   • Only flags significant confidence differences
   • Marked as "a_revoir" not "bloquant"

4. Simple Alternative Generation

   • POC implementation suggests highest-confidence DAS as alternative DP
   • Full implementation would use RAG for more sophisticated alternatives
   • Provides reasoning for each alternative

Integration Points

The Vérificateur integrates with:

1. Codeur: Receives CodingProposal to verify
2. Clinical Facts Extractor: Uses ClinicalFact list for validation
3. RAG Engine: Can search for alternative codes (future enhancement)
4. Pipeline: Returns VerificationResult for downstream processing

Next Steps

The Vérificateur is now ready for integration into the main pipeline. Next tasks:

1. Task 12: Implement Groupage Validator
2. Task 14: Implement PMSI Validator and Question Generator
3. Task 16: Integrate all components into main Pipeline

Notes

• All 16 tests pass successfully
• 91% code coverage achieved
• Implementation follows conservative approach
• Ready for integration testing
• Meets all specified requirements (Exigences 4.1-4.8, 19.1-19.5)