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Clinical Data Terminology Standards

临床数据术语标准

Overview

概述

This skill teaches the agent how to reason about clinical terminology systems — MedDRA, ICD-10, SNOMED CT, and LOINC — and the decisions involved in coding, grouping, and mapping clinical data. It does not generate pipeline code; it provides the domain knowledge needed to make correct coding and aggregation choices before any analysis begins.

Getting terminology wrong has direct consequences: miscoded adverse events hide safety signals, wrong ICD-10 granularity inflates or deflates prevalence estimates, and incorrect LOINC assignments break lab result interoperability. This skill encodes the rules, hierarchies, and decision frameworks that prevent those errors.

本 skill 教授 Agent 如何分析临床术语系统——包括 MedDRA、ICD-10、SNOMED CT 和 LOINC——以及临床数据在编码、分组和映射方面涉及的各种决策。它不生成 pipeline 代码；而是提供必要的领域知识，以便在开始任何分析前作出正确的编码与聚合选择。

术语使用错误会直接影响结果：错误编码的不良事件会掩盖安全信号，ICD-10 粒度不当会高估或低估患病率估计，而不正确的 LOINC 分配会破坏检验结果的互操作性。本 skill 固化了可防止这些错误的规则、层级和决策框架。

Usage

使用

Invoke this skill when the user:

Needs to code verbatim adverse event text to MedDRA terms.
Asks which level of MedDRA to use for frequency tables or signal detection.
Wants to group diagnoses by ICD-10 codes and must choose 3-character vs 4-character granularity.
Needs to understand SNOMED CT concept relationships for clinical findings or procedures.
Must select LOINC codes for lab tests or understand panel composition.
Is mapping between terminology systems (MedDRA ↔ ICD-10, SNOMED CT → ICD-10).
Asks about regulatory expectations for AE coding in clinical trials.

The agent should respond by:

Identifying the terminology system appropriate for the data type and use case.
Clarifying the granularity — which hierarchy level to code at and which to report at.
Applying the mapping rules specific to the source and target systems.
Flagging common pitfalls — overcoding, undercoding, inappropriate aggregation.
Stating regulatory context when relevant (ICH E2B, FDA, EMA expectations).

在以下情况下调用本 skill：

需要将 AE 逐字原文编码为 MedDRA 术语。
询问在频数表或信号检测中应使用 MedDRA 的哪个层级。
希望按 ICD-10 代码对诊断进行分组，但需要选择 3 位还是 4 位粒度。
需要理解临床发现或操作在 SNOMED CT 中的概念关系。
必须为实验室检验选择 LOINC 代码，或需要了解检验组合的组成。
正在术语系统之间进行映射（MedDRA ↔ ICD-10、SNOMED CT → ICD-10）。
询问临床试验中 AE 编码的监管预期。

Agent 应按以下方式作答：

识别术语系统——根据数据类型和使用场景选择适当的系统。
明确粒度——确定在哪个层级编码，以及在哪个层级报告。
应用映射规则——遵循适用于源系统和目标系统的具体规则。
指出常见陷阱——包括过度编码、编码不足和不恰当的聚合。
说明监管背景——在相关情况下说明 ICH E2B、FDA、EMA 的预期。

Response Format

回答格式

Lead with the direct recommendation or classification (≤3 sentences)
Structure as: recommendation → justification (citing specific criteria/thresholds) → caveats
Use tables for comparisons; bullet points for criteria lists
Omit background the user already knows — they asked the question
Target: 200-400 words unless the user requests exhaustive detail The decision trees and frameworks in this skill are for internal reasoning only. Apply them to reach your conclusion, but do not reproduce them in your response. Present only the final recommendation with supporting evidence.

开门见山给出直接建议或分类（≤3 句）
结构：建议 → 理由（引用具体标准/阈值）→ 注意事项
使用表格进行比较；使用项目符号列出判断标准
省略用户已经了解的背景——用户是在提问
目标：除非用户要求详尽说明，否则控制在 200–400 字

本 skill 中的决策树和框架仅供内部推理。应使用这些框架得出结论，但不要在回答中复现。只呈现最终建议及其支持证据。

Core Concepts

核心概念

1. MedDRA: The 5-Level Hierarchy

1. MedDRA：五级层级结构

MedDRA (Medical Dictionary for Regulatory Activities) is the standard for coding adverse events, medical history, and indications in clinical trials and pharmacovigilance.

Level	Abbreviation	Count (~v26)	Purpose
System Organ Class	SOC	~27	Broadest grouping (e.g., "Cardiac disorders")
High Level Group Term	HLGT	~337	Groups related HLTs within a SOC
High Level Term	HLT	~1,740	Groups related PTs by anatomy/mechanism
Preferred Term	PT	~24,000	Standard reportable term — the workhorse
Lowest Level Term	LLT	~83,000	Verbatim-level synonyms mapping to one PT

MedDRA（Medical Dictionary for Regulatory Activities）是用于在临床试验和药物警戒中对不良事件、既往病史及适应症进行编码的标准。

层级	缩写	数量（约 v26）	用途
System Organ Class	SOC	~27	最宽泛的分组（例如“Cardiac disorders”）
High Level Group Term	HLGT	~337	在一个 SOC 内对相关 HLT 进行分组
High Level Term	HLT	~1,740	按解剖部位或机制对相关 PT 进行分组
Preferred Term	PT	~24,000	标准可报告术语——主要分析层级
Lowest Level Term	LLT	~83,000	逐字层级同义词，映射到一个 PT

The coding path

编码路径

Verbatim AE text (from CRF)
  │
  ▼
LLT (closest match to verbatim)
  │
  ▼
PT (standard reportable term — one LLT maps to exactly one PT)
  │
  ▼
HLT → HLGT → SOC (for grouping and display)

Rules:

Always code to LLT first, then let the hierarchy derive the PT. Never skip to PT directly from verbatim text — the LLT layer captures synonyms and spelling variants.
PT is the primary analysis level. Frequency tables in clinical study reports (CSRs) list AEs at the PT level, grouped by SOC.
One LLT → exactly one PT. But one PT can belong to multiple SOCs (primary SOC assignment determines the default grouping).
Primary SOC assignment follows the ICH convention: etiology SOC takes precedence over manifestation SOC. "Drug-induced hepatitis" goes under "Hepatobiliary disorders" (manifestation) but its primary SOC is determined by MedDRA's primary path rules.
Multi-axiality: A PT can appear under multiple SOCs. Always use the primary SOC for frequency tables unless the protocol specifies otherwise.

Verbatim AE text (from CRF)
  │
  ▼
LLT (closest match to verbatim)
  │
  ▼
PT (standard reportable term — one LLT maps to exactly one PT)
  │
  ▼
HLT → HLGT → SOC (for grouping and display)

规则：

始终先编码到 LLT，再由层级体系推导 PT。绝不要从逐字原文直接跳到 PT——LLT 层用于捕获同义词和拼写变体。
PT 是主要分析层级。 临床研究报告（CSR）中的频数表按 PT 层级列出 AE，并按 SOC 分组。
一个 LLT 恰好对应一个 PT。 但一个 PT 可以属于多个 SOC（默认分组由 Primary SOC 分配决定）。
Primary SOC 分配遵循 ICH 约定：病因 SOC 的优先级高于表现 SOC。“Drug-induced hepatitis”归入“Hepatobiliary disorders”（表现类 SOC），但其 Primary SOC 应根据 MedDRA 的主路径规则确定。
**多轴性：**一个 PT 可以出现在多个 SOC 下。除非方案另有规定，否则频数表始终使用 Primary SOC。

When to aggregate above PT

何时在 PT 之上聚合

Scenario	Recommended level	Rationale
Standard AE frequency table (CSR)	PT within SOC	Regulatory expectation (ICH E3)
Signal detection across rare events	HLT or HLGT	Individual PTs too sparse; grouping reveals patterns
Standardized MedDRA Queries (SMQs)	SMQ (pre-defined)	Curated term groups for known safety topics (e.g., "Hepatic disorders")
High-level safety overview	SOC	Executive summary, not for detailed analysis

场景	建议层级	理由
标准 AE 频数表（CSR）	SOC 内的 PT	监管预期（ICH E3）
跨罕见事件进行信号检测	HLT 或 HLGT	单个 PT 过于稀疏；分组有助于揭示模式
标准化 MedDRA 查询（SMQ）	SMQ（预定义）	针对已知安全主题整理的术语组（例如“Hepatic disorders”）
高层级安全概览	SOC	用于执行摘要，不用于详细分析

Decision tree: MedDRA coding level

决策树：MedDRA 编码层级

Start
│
├── Is this a standard CSR AE table?
│     └── Code at LLT → report at PT within primary SOC.
│
├── Are you looking for a safety signal across related terms?
│     ├── Does an SMQ exist for the topic?
│     │     └── Yes → Use the SMQ (narrow or broad scope as appropriate).
│     └── No SMQ → Aggregate at HLT. Document the grouping rationale.
│
├── Are individual PTs too rare to detect a signal?
│     └── Consider HLT or HLGT grouping, but report both grouped
│         and individual PT counts for transparency.
│
└── Executive safety summary only?
      └── SOC-level counts are acceptable, with PT detail available on request.

Start
│
├── Is this a standard CSR AE table?
│     └── Code at LLT → report at PT within primary SOC.
│
├── Are you looking for a safety signal across related terms?
│     ├── Does an SMQ exist for the topic?
│     │     └── Yes → Use the SMQ (narrow or broad scope as appropriate).
│     └── No SMQ → Aggregate at HLT. Document the grouping rationale.
│
├── Are individual PTs too rare to detect a signal?
│     └── Consider HLT or HLGT grouping, but report both grouped
│         and individual PT counts for transparency.
│
└── Executive safety summary only?
      └── SOC-level counts are acceptable, with PT detail available on request.

2. ICD-10: Code Structure and Grouping

2. ICD-10：代码结构与分组

ICD-10 (International Classification of Diseases, 10th Revision) is the standard for diagnosis coding in claims, EHR, and epidemiological studies.

ICD-10（International Classification of Diseases, 10th Revision）是用于诊断编码的标准，应用于理赔、EHR 和流行病学研究。

Structure

结构

Chapter (I–XXII)
  └── Block (e.g., E10–E14: Diabetes mellitus)
        └── Category — 3 characters (e.g., E11: Type 2 diabetes)
              └── Subcategory — 4–7 characters (e.g., E11.6: With complications)
                    └── Extension (e.g., E11.65: With hyperglycemia)

Level	Example	Granularity
Chapter	Chapter IV: Endocrine diseases	Too broad for most analyses
Block	E10–E14	Disease family grouping
3-character category	E11	Disease entity (Type 2 DM)
4-character subcategory	E11.6	Complication type
Full code	E11.65	Specific manifestation

Chapter (I–XXII)
  └── Block (e.g., E10–E14: Diabetes mellitus)
        └── Category — 3 characters (e.g., E11: Type 2 diabetes)
              └── Subcategory — 4–7 characters (e.g., E11.6: With complications)
                    └── Extension (e.g., E11.65: With hyperglycemia)

层级	示例	粒度
Chapter	Chapter IV: Endocrine diseases	对大多数分析而言过于宽泛
Block	E10–E14	疾病家族分组
3-character category	E11	疾病实体（Type 2 DM）
4-character subcategory	E11.6	并发症类型
Full code	E11.65	具体表现

Grouping decisions

分组决策

The choice of granularity depends on the analysis goal:

Analysis type	Recommended level	Example
Population prevalence study	3-character category	E11 (all Type 2 DM)
Comorbidity index (Charlson, Elixhauser)	3-character or block	Pre-defined code lists per condition
Specific outcome study	Full code (4–7 char)	E11.65 (hyperglycemia specifically)
Claims-based cohort definition	3-character + exclusions	E11.* excluding E11.0 (with coma)
Cross-country comparison	Block level	ICD-10 blocks are more stable across national modifications

粒度选择取决于分析目标：

分析类型	建议层级	示例
人群患病率研究	3-character category	E11（所有 Type 2 DM）
并发症指数（Charlson、Elixhauser）	3-character 或 block	各疾病使用预定义代码列表
特定结局研究	完整代码（4–7 位）	E11.65（专门指高血糖血症）
基于理赔的队列定义	3-character + 排除项	E11.*，排除 E11.0（伴昏迷）
跨国比较	Block 层级	ICD-10 block 在各国本地化版本之间更稳定

Decision tree: ICD-10 grouping level

决策树：ICD-10 分组层级

Start
│
├── Are you estimating disease prevalence or incidence?
│     └── 3-character category. Captures all subtypes.
│         Add block-level grouping if comparing across disease families.
│
├── Are you defining a specific clinical outcome?
│     └── Full code (4+ characters). Be explicit about which
│         manifestations qualify. Document inclusion/exclusion codes.
│
├── Are you building a comorbidity score?
│     └── Use the published code lists (Charlson/Elixhauser).
│         Do not invent your own groupings.
│
├── Are you comparing across countries or ICD-10 modifications?
│     └── Block level. National modifications (ICD-10-CM, ICD-10-GM)
│         diverge at the subcategory level.
│
└── Are you mapping from another system (MedDRA, SNOMED CT)?
      └── Map to 3-character first, then refine to subcategory
          only if the source system provides sufficient specificity.

Start
│
├── Are you estimating disease prevalence or incidence?
│     └── 3-character category. Captures all subtypes.
│         Add block-level grouping if comparing across disease families.
│
├── Are you defining a specific clinical outcome?
│     └── Full code (4+ characters). Be explicit about which
│         manifestations qualify. Document inclusion/exclusion codes.
│
├── Are you building a comorbidity score?
│     └── Use the published code lists (Charlson/Elixhauser).
│         Do not invent your own groupings.
│
├── Are you comparing across countries or ICD-10 modifications?
│     └── Block level. National modifications (ICD-10-CM, ICD-10-GM)
│         diverge at the subcategory level.
│
└── Are you mapping from another system (MedDRA, SNOMED CT)?
      └── Map to 3-character first, then refine to subcategory
          only if the source system provides sufficient specificity.

ICD-10-CM vs ICD-10-WHO

ICD-10-CM 与 ICD-10-WHO

ICD-10-CM (US Clinical Modification): extends codes to 7 characters, adds laterality, encounter type (initial/subsequent/sequela). Used in US claims and EHR.
ICD-10-WHO: the international base. Shorter codes, no laterality extensions.
Always specify which modification you are using. A code valid in ICD-10-CM may not exist in ICD-10-WHO.

ICD-10-CM（US Clinical Modification）：将代码扩展至 7 位，并增加侧别、就诊类型（初次/后续/后遗症）等信息。用于美国理赔和 EHR。
ICD-10-WHO：国际基础版本。代码更短，不包含侧别扩展。
始终明确所使用的本地化版本。 在 ICD-10-CM 中有效的代码可能不存在于 ICD-10-WHO 中。

3. SNOMED CT: Concept Model

3. SNOMED CT：概念模型

SNOMED CT (Systematized Nomenclature of Medicine — Clinical Terms) is the most comprehensive clinical terminology, used for clinical findings, procedures, substances, body structures, and organisms.

SNOMED CT（Systematized Nomenclature of Medicine — Clinical Terms）是最全面的临床术语系统，用于临床发现、操作、物质、身体结构和生物体。

Core structure

核心结构

Concepts: unique identifiers (SCTIDs) representing clinical meanings.
Descriptions: human-readable terms (Fully Specified Name, Preferred Term, Synonyms).
Relationships: typed links between concepts.

Concepts（概念）：表示临床含义的唯一标识符（SCTID）。
Descriptions（描述）：可供阅读的术语（Fully Specified Name、Preferred Term、Synonyms）。
Relationships（关系）：概念之间的类型化链接。

Key relationship types

主要关系类型

Relationship	Meaning	Example
IS-A	Subsumption hierarchy	"Acute myocardial infarction" IS-A "Myocardial infarction"
Finding site	Where the finding is located	"Pneumonia" → finding site → "Lung structure"
Causative agent	What causes the condition	"Aspirin-induced asthma" → causative agent → "Aspirin"
Associated morphology	Structural change	"Adenocarcinoma of lung" → morphology → "Adenocarcinoma"
Method	How a procedure is performed	"Laparoscopic cholecystectomy" → method → "Laparoscopic approach"

关系	含义	示例
IS-A	从属层级	“急性心肌梗死” IS-A “心肌梗死”
Finding site	发现所在部位	“肺炎” → finding site → “肺部结构”
Causative agent	致病原因	“阿司匹林诱发哮喘” → causative agent → “阿司匹林”
Associated morphology	结构性改变	“肺腺癌” → morphology → “腺癌”
Method	操作执行方式	“腹腔镜胆囊切除术” → method → “腹腔镜入路”

When to use SNOMED CT vs other systems

何时使用 SNOMED CT 或其他系统

Use case	Preferred system	Rationale
Clinical documentation in EHR	SNOMED CT	Rich concept model, supports clinical detail
Billing and claims	ICD-10	Required by payers
Adverse event reporting	MedDRA	Regulatory requirement
Lab test ordering/results	LOINC	Standard for lab interoperability
Drug coding	RxNorm (US) / SNOMED CT	RxNorm for prescribing; SNOMED CT for substances

使用场景	首选系统	理由
EHR 中的临床文档记录	SNOMED CT	概念模型丰富，支持临床细节
账单和理赔	ICD-10	支付方要求使用
不良事件报告	MedDRA	监管要求
实验室检验开单和结果	LOINC	实验室互操作性的标准
药物编码	RxNorm（美国）/ SNOMED CT	开具处方使用 RxNorm；物质使用 SNOMED CT

SNOMED CT hierarchy navigation rules

SNOMED CT 层级导航规则

Use the IS-A hierarchy for subsumption queries. To find "all types of diabetes," query descendants of concept 73211009 (Diabetes mellitus).
Post-coordination (combining concepts) is powerful but complex. Prefer pre-coordinated concepts when they exist.
Reference sets (refsets) define subsets for specific use cases (e.g., a national drug extension). Always check which refset applies to your jurisdiction.
SNOMED CT → ICD-10 mapping is maintained by SNOMED International. Use the official map; do not create ad hoc crosswalks.

使用 IS-A 层级进行从属查询。 要查找“所有类型的糖尿病”，应查询概念 73211009（Diabetes mellitus）的后代。
**后协调（Post-coordination）**功能强大但较为复杂。如果存在预协调概念，应优先使用预协调概念。
**引用集（Reference sets，refsets）**定义了适用于特定使用场景的子集（例如国家药物扩展）。始终检查当前司法辖区适用哪个 refset。
SNOMED CT → ICD-10 映射由 SNOMED International 维护。应使用官方映射；不要临时创建 crosswalk。

4. LOINC: Lab Test Coding

4. LOINC：实验室检验编码

LOINC (Logical Observation Identifiers Names and Codes) is the standard for identifying laboratory tests and clinical observations.

LOINC（Logical Observation Identifiers Names and Codes）是用于标识实验室检验和临床观察的标准。

The 6-part naming convention

六部分命名约定

Every LOINC code is defined by six axes:

Axis	Description	Example (Glucose, fasting, serum)
Component	What is measured	Glucose
Property	Type of measurement	MCnc (mass concentration)
Timing	Point vs over time	Pt (point in time)
System	Specimen type	Ser/Plas (serum or plasma)
Scale	Quantitative, ordinal, etc.	Qn (quantitative)
Method	How measured (optional)	—

每个 LOINC 代码由六个维度定义：

维度	说明	示例（Glucose，fasting，serum）
Component	测量对象	Glucose（葡萄糖）
Property	测量类型	MCnc（质量浓度）
Timing	时间点或时间范围	Pt（某一时间点）
System	标本类型	Ser/Plas（血清或血浆）
Scale	定量、顺序等	Qn（定量）
Method	测量方法（可选）	—

Panels

检验组合

LOINC panels group related tests ordered together:

Panel	LOINC code	Contains
CBC with differential	57021-8	WBC, RBC, Hgb, Hct, MCV, MCH, MCHC, Plt, differential
Basic Metabolic Panel	51990-0	Glucose, BUN, Creatinine, Na, K, Cl, CO2, Ca
Comprehensive Metabolic Panel	24323-8	BMP + albumin, bilirubin, ALP, ALT, AST, total protein
Lipid Panel	24331-1	Total cholesterol, HDL, LDL (calc), triglycerides
Hepatic Function Panel	24325-3	Albumin, bilirubin (total/direct), ALP, ALT, AST, total protein

LOINC panel 将一起开具的相关检验组合起来：

Panel	LOINC code	包含内容
CBC with differential（带白细胞分类的血常规）	57021-8	WBC、RBC、Hgb、Hct、MCV、MCH、MCHC、Plt 及白细胞分类
Basic Metabolic Panel（基础代谢组合）	51990-0	Glucose、BUN、Creatinine、Na、K、Cl、CO2、Ca
Comprehensive Metabolic Panel（全面代谢组合）	24323-8	BMP + albumin、bilirubin、ALP、ALT、AST、total protein
Lipid Panel（血脂组合）	24331-1	Total cholesterol、HDL、LDL（calculated）、triglycerides
Hepatic Function Panel（肝功能组合）	24325-3	Albumin、bilirubin（total/direct）、ALP、ALT、AST、total protein

LOINC selection rules

LOINC 选择规则

Match all six axes. A glucose test on serum (quantitative, mass concentration) is a different LOINC code than glucose on urine (quantitative, mass concentration) or glucose on serum (ordinal).
Prefer codes without a method axis unless the method materially affects interpretation (e.g., calculated vs direct LDL).
Use panel codes when the full panel was ordered, and individual member codes for the component results within it.
Check the LOINC status. Codes can be ACTIVE, DEPRECATED, or DISCOURAGED. Only use ACTIVE codes.
LOINC answers (LA codes) provide standardized answer lists for ordinal observations (e.g., positive/negative/indeterminate).

匹配全部六个维度。 血清定量质量浓度葡萄糖检验与尿液定量质量浓度葡萄糖检验或血清顺序型葡萄糖检验对应不同的 LOINC 代码。
除非测量方法会实质性影响解读，否则优先选择不含 Method 维度的代码。 例如 calculated LDL 与 direct LDL。
完整组合已开具时使用 panel 代码，组合中各组成部分的结果则使用相应的成员代码。
检查 LOINC 状态。 代码可能为 ACTIVE、DEPRECATED 或 DISCOURAGED。仅使用 ACTIVE 代码。
**LOINC answers（LA codes）**为顺序型观察提供标准化答案列表，例如 positive/negative/indeterminate。

5. Cross-System Mapping Decisions

5. 跨系统映射决策

Mapping between terminology systems is necessary but error-prone. Follow these rules:

术语系统之间的映射是必要但容易出错的过程。应遵循以下规则：

MedDRA → ICD-10

Scenario	Approach
AE term to diagnosis code	Map PT → ICD-10 3-character category. Refine to subcategory only if the PT provides sufficient specificity.
Medical history coding	Map at PT level; ICD-10 subcategory when the verbatim text supports it.
Concomitant conditions	Use the official MedDRA-to-ICD crosswalk where available.

Rules:

One MedDRA PT may map to multiple ICD-10 codes (and vice versa). Document the mapping table and version.
Never map LLT directly to ICD-10. Always go through PT first — LLTs are synonyms, not distinct concepts.
Granularity mismatch is expected. MedDRA PTs are often broader than ICD-10 subcategories. Accept the loss of specificity or require additional clinical context.

场景	方法
AE 术语到诊断代码	将 PT 映射到 ICD-10 3-character category。仅当 PT 提供足够具体的信息时，才进一步细化为 subcategory。
既往病史编码	在 PT 层级映射；当逐字原文提供充分信息时使用 ICD-10 subcategory。
合并疾病	在有官方映射表时，使用官方的 MedDRA-to-ICD crosswalk。

规则：

一个 MedDRA PT 可能映射到多个 ICD-10 代码，反之亦然。记录映射表及其版本。
绝不将 LLT 直接映射到 ICD-10。 始终先经过 PT——LLT 是同义词，而不是不同的临床概念。
粒度不匹配是预期情况。 MedDRA PT 通常比 ICD-10 subcategory 更宽泛。应接受特异性损失，或要求补充临床上下文。

SNOMED CT → ICD-10

Use the SNOMED International maintained map (released with each SNOMED CT edition).
The map provides target ICD-10 codes with map rules and priorities.
One SNOMED CT concept may map to multiple ICD-10 codes (combination coding). Follow the map rules to select the correct target(s).
Do not reverse the map (ICD-10 → SNOMED CT) without a dedicated reverse crosswalk — the forward map is many-to-one and loses information when inverted.

使用 SNOMED International 维护的官方映射（随每个 SNOMED CT 版本发布）。
该映射提供带有映射规则和优先级的目标 ICD-10 代码。
一个 SNOMED CT 概念可能映射到多个 ICD-10 代码（组合编码）。应遵循映射规则选择正确的目标代码。
不要在缺少专用反向 crosswalk 的情况下反转映射（ICD-10 → SNOMED CT）——正向映射是多对一关系，反转后会丢失信息。

LOINC → local lab codes

LOINC → 本地实验室代码

Most institutions maintain a local-to-LOINC mapping table (often called a "LOINC mapping" or "result code crosswalk").
Validate mappings by checking all six LOINC axes against the local test definition. A common error is mapping a serum test to a urine LOINC code because the component name matches.
Panels vs components: Map the panel order to the panel LOINC code, and each result line to its individual component LOINC code.

大多数机构都会维护本地代码与 LOINC 的映射表，通常称为“LOINC mapping”或“result code crosswalk”。
应根据本地检验定义核对全部六个 LOINC 维度，以验证映射。常见错误是仅因成分名称相同，将血清检验错误映射到尿液 LOINC 代码。
**Panel 与组成部分：**将组合医嘱映射到 panel LOINC 代码，并将每条结果记录映射到相应的成员 LOINC 代码。

Decision tree: which mapping approach?

决策树：选择映射方法

Start
│
├── Source is verbatim AE text?
│     └── Code to MedDRA (LLT → PT). Map to ICD-10 only if
│         the downstream system requires it.
│
├── Source is EHR diagnosis (free text or local code)?
│     ├── US system → Map to ICD-10-CM (billing) and SNOMED CT (clinical).
│     └── Non-US → Map to ICD-10-WHO or national modification.
│
├── Source is lab result?
│     └── Map to LOINC. Match all six axes. Use panel codes for orders.
│
├── Need to cross-walk between MedDRA and SNOMED CT?
│     └── Go through ICD-10 as an intermediary (MedDRA → ICD-10 → SNOMED CT)
│         or use UMLS concept mappings. Direct MedDRA ↔ SNOMED CT maps
│         are not officially maintained.
│
└── Building a research dataset combining claims + EHR + trial data?
      └── Define a canonical code system for each data element.
          Map all sources to the canonical. Document every mapping
          decision and version. Accept that some mappings are lossy.

Start
│
├── Source is verbatim AE text?
│     └── Code to MedDRA (LLT → PT). Map to ICD-10 only if
│         the downstream system requires it.
│
├── Source is EHR diagnosis (free text or local code)?
│     ├── US system → Map to ICD-10-CM (billing) and SNOMED CT (clinical).
│     └── Non-US → Map to ICD-10-WHO or national modification.
│
├── Source is lab result?
│     └── Map to LOINC. Match all six axes. Use panel codes for orders.
│
├── Need to cross-walk between MedDRA and SNOMED CT?
│     └── Go through ICD-10 as an intermediary (MedDRA → ICD-10 → SNOMED CT)
│         or use UMLS concept mappings. Direct MedDRA ↔ SNOMED CT maps
│         are not officially maintained.
│
└── Building a research dataset combining claims + EHR + trial data?
      └── Define a canonical code system for each data element.
          Map all sources to the canonical. Document every mapping
          decision and version. Accept that some mappings are lossy.

6. Regulatory Context

6. 监管背景

Standard	Required system	Context
ICH E2B(R3)	MedDRA	Individual Case Safety Reports (ICSRs)
ICH E3	MedDRA	Clinical Study Reports — AE tables at PT within SOC
US claims (CMS)	ICD-10-CM, CPT, HCPCS	Billing and reimbursement
US EHR (ONC)	SNOMED CT, LOINC, RxNorm	Meaningful Use / Promoting Interoperability
CDISC SDTM	MedDRA (AE domain), dictionaries per domain	Clinical trial data submission to FDA
OMOP CDM	SNOMED CT (conditions), LOINC (measurements), RxNorm (drugs)	Observational research

标准	必需系统	背景
ICH E2B(R3)	MedDRA	Individual Case Safety Reports（ICSR）
ICH E3	MedDRA	Clinical Study Reports——AE 表按 SOC 内的 PT 展示
US claims（CMS）	ICD-10-CM、CPT、HCPCS	账单和报销
US EHR（ONC）	SNOMED CT、LOINC、RxNorm	Meaningful Use / Promoting Interoperability
CDISC SDTM	MedDRA（AE domain），各 domain 使用对应字典	向 FDA 提交临床试验数据
OMOP CDM	SNOMED CT（conditions）、LOINC（measurements）、RxNorm（drugs）	观察性研究

When NOT to Use This Skill

不应使用本 Skill 的情况

Assigning MedDRA codes for regulatory safety reports (needs trained medical coder)
When coding requires clinical judgment about causality assessment
ICD-10 coding for billing/reimbursement where legal liability applies

为监管安全报告分配 MedDRA 代码（需要受过培训的医学编码员）
编码过程需要对因果关系进行临床判断
用于账单和报销且涉及法律责任的 ICD-10 编码

When to Escalate to a Human Expert

何时升级给人类专家

When a term maps to multiple PT candidates with different SOCs
Cross-walk decisions that affect regulatory submission acceptance
When local coding conventions override international standards

一个术语对应多个 PT 候选，且这些候选具有不同 SOC
crosswalk 决策可能影响监管提交能否被接受
本地编码约定优先于国际标准

Common Mistakes

常见错误

Wrong: Coding adverse events directly to PT, skipping the LLT layer Right: Always code verbatim text to LLT first, then let the hierarchy derive the PT Why: The LLT layer captures synonyms and spelling variants — skipping it risks inconsistent coding when different verbatim texts describe the same concept
Wrong: Using secondary SOC for AE frequency tables Right: Always use the primary SOC for frequency tables unless the protocol explicitly specifies otherwise Why: Multi-axial PTs appear under multiple SOCs — mixing primary and secondary inflates apparent AE counts and confuses signal detection
Wrong: Aggregating at HLT level without documenting justification Right: Only aggregate above PT when individual terms are too sparse for signal detection; always show both grouped and ungrouped PT counts Why: HLT grouping hides individual PT signals that may represent distinct safety concerns
Wrong: Applying ICD-10-CM codes in a non-US context Right: Specify which ICD-10 modification you are using; use ICD-10-WHO or the appropriate national modification for non-US data Why: ICD-10-CM extensions (laterality, encounter type) do not exist in ICD-10-WHO — codes may be invalid or misinterpreted
Wrong: Grouping ICD-10 at 3-character level for specific outcome studies Right: Use full codes (4+ characters) when the outcome is a specific manifestation; document inclusion/exclusion codes explicitly Why: E11 includes all Type 2 DM complications — if the outcome is "Type 2 DM with hyperglycemia," only E11.65 is correct
Wrong: Reversing the SNOMED CT → ICD-10 map to create an ICD-10 → SNOMED CT crosswalk Right: Use a dedicated reverse crosswalk or UMLS CUI-based mappings; never invert the forward map Why: The forward map is many-to-one — reversing it creates ambiguous one-to-many mappings without the map rules to resolve them
Wrong: Matching LOINC codes by component name alone Right: Verify all six LOINC axes (component, property, timing, system, scale, method) match the local test definition Why: Two LOINC codes can share the same component but differ in system (serum vs urine), property, or scale — partial matching produces wrong assignments
Wrong: Using deprecated LOINC codes without checking status Right: Always check the LOINC STATUS field and replace deprecated codes with their active successors Why: Deprecated codes break interoperability and may not be recognized by receiving systems
Wrong: Creating ad hoc terminology crosswalks instead of using official maps Right: Use curated maps from SNOMED International, NLM, or MSSO; document the map version used Why: Ad hoc mappings introduce inconsistencies, are not reproducible, and diverge from regulatory expectations
Wrong: Ignoring MedDRA version differences when combining data across studies Right: Document the MedDRA version used for each study; reconcile terms that were added, merged, or deprecated across versions Why: PTs are added, merged, and deprecated across versions — a term valid in v25 may be deprecated in v26, causing data loss or miscounting
Wrong: Confusing LOINC panel codes with component codes when storing results Right: Use the panel code for the order and individual component LOINC codes for each result within the panel Why: Storing a glucose result under the CBC panel code is semantically wrong and breaks downstream aggregation and interoperability
Wrong: Mapping MedDRA directly to SNOMED CT without an intermediary Right: Use ICD-10 as an intermediary (MedDRA → ICD-10 → SNOMED CT) or use UMLS CUI-based mappings; document the mapping path Why: No official direct MedDRA ↔ SNOMED CT crosswalk exists — direct mapping produces unvalidated, irreproducible results

**错误：**将不良事件直接编码到 PT，跳过 LLT 层
**正确：**始终先将逐字原文编码到 LLT，再由层级体系推导 PT
**原因：**LLT 层用于捕获同义词和拼写变体——跳过该层可能导致不同逐字表述在描述同一概念时产生不一致的编码
**错误：**在 AE 频数表中使用 Secondary SOC
**正确：**除非方案明确另有规定，否则频数表始终使用 Primary SOC
**原因：**多轴 PT 会出现在多个 SOC 下——混用 Primary 和 Secondary 会夸大表面上的 AE 计数并干扰信号检测
**错误：**在 HLT 层级进行聚合，却未记录理由
**正确：**仅当单个术语过于稀疏、无法进行信号检测时，才在 PT 之上聚合；始终同时展示分组和未分组的 PT 计数
**原因：**HLT 分组可能隐藏单个 PT 信号，而这些信号可能代表不同的安全问题
**错误：**在非美国环境中使用 ICD-10-CM 代码
**正确：**明确所使用的 ICD-10 本地化版本；非美国数据应使用 ICD-10-WHO 或适当的本地化版本
**原因：**ICD-10-CM 中的扩展信息（侧别、就诊类型）不存在于 ICD-10-WHO 中——这些代码可能无效或被错误解读
**错误：**在特定结局研究中使用 3-character 层级对 ICD-10 分组
**正确：**当结局对应某种具体表现时，使用完整代码（4 位以上），并明确记录纳入和排除代码
**原因：**E11 包含所有 Type 2 DM 并发症——如果结局是“Type 2 DM 伴高血糖血症”，只有 E11.65 正确
**错误：**反转 SNOMED CT → ICD-10 映射来创建 ICD-10 → SNOMED CT crosswalk
**正确：**使用专用反向 crosswalk 或基于 UMLS CUI 的映射；绝不反转正向映射
**原因：**正向映射是多对一关系——反转后会创建含义不明确的一对多映射，并且缺少用于消歧的映射规则
**错误：**仅根据成分名称匹配 LOINC 代码
**正确：**确认全部六个 LOINC 维度（component、property、timing、system、scale、method）与本地检验定义一致
**原因：**两个 LOINC 代码可能具有相同的成分，但 system（血清与尿液）、property 或 scale 不同——部分匹配会导致错误分配
**错误：**未检查状态就使用已弃用的 LOINC 代码
**正确：**始终检查 LOINC STATUS 字段，并将已弃用代码替换为其有效的后继代码
**原因：**已弃用代码会破坏互操作性，并且可能不被接收系统识别
**错误：**创建临时术语 crosswalk，而不是使用官方映射
**正确：**使用 SNOMED International、NLM 或 MSSO 维护的权威映射，并记录所用映射版本
**原因：**临时映射会引入不一致性、不可复现，并且可能偏离监管预期
**错误：**合并多项研究数据时忽略 MedDRA 版本差异
**正确：**记录每项研究使用的 MedDRA 版本，并协调不同版本之间新增、合并或弃用的术语
**原因：**PT 会随着版本新增、合并和弃用——在 v25 中有效的术语可能在 v26 中被弃用，从而造成数据丢失或错误计数
**错误：**存储结果时混淆 LOINC panel 代码和成员代码
**正确：**医嘱使用 panel 代码，panel 内每项结果使用相应的成员 LOINC 代码
**原因：**将葡萄糖结果存储在 CBC panel 代码下在语义上不正确，并会破坏下游聚合和互操作性
**错误：**不通过中间系统而将 MedDRA 直接映射到 SNOMED CT
**正确：**以 ICD-10 作为中间系统（MedDRA → ICD-10 → SNOMED CT），或使用基于 UMLS CUI 的映射；记录映射路径
**原因：**不存在官方的直接 MedDRA ↔ SNOMED CT crosswalk——直接映射会产生未经验证且不可复现的结果

References

参考资料

MedDRA Introductory Guide: https://www.meddra.org/how-to-use/support-documentation
ICH E2B(R3) guideline: https://database.ich.org/sites/default/files/E2B_R3__Guideline.pdf
ICD-10-WHO: https://icd.who.int/browse10/2019/en
ICD-10-CM: https://www.cms.gov/medicare/coding-billing/icd-10-codes
SNOMED CT Starter Guide: https://confluence.ihtsdotools.org/display/DOCSTART
SNOMED CT to ICD-10 Map: https://www.snomed.org/snomed-ct/Use-SNOMED-CT/maps
LOINC Users' Guide: https://loinc.org/kb/users-guide/
CDISC SDTM Implementation Guide: https://www.cdisc.org/standards/foundational/sdtm
OMOP CDM Vocabulary: https://ohdsi.github.io/CommonDataModel/

MedDRA 入门指南：https://www.meddra.org/how-to-use/support-documentation
ICH E2B(R3) 指南：https://database.ich.org/sites/default/files/E2B_R3__Guideline.pdf
ICD-10-WHO：https://icd.who.int/browse10/2019/en
ICD-10-CM：https://www.cms.gov/medicare/coding-billing/icd-10-codes
SNOMED CT 入门指南：https://confluence.ihtsdotools.org/display/DOCSTART
SNOMED CT 到 ICD-10 映射：https://www.snomed.org/snomed-ct/Use-SNOMED-CT/maps
LOINC 用户指南：https://loinc.org/kb/users-guide/
CDISC SDTM 实施指南：https://www.cdisc.org/standards/foundational/sdtm
OMOP CDM 词汇表：https://ohdsi.github.io/CommonDataModel/