Admission Diagnosis Section

Template ID: 2.16.840.1.113883.10.20.22.2.43 Version: R2.1 (2015-08-01) Badge: Hospital Section

Overview

The Admission Diagnosis Section contains a narrative description of the problems or diagnoses identified by the clinician at the time of the patient's admission to a hospital facility. This section documents the clinical reasoning for admission and may contain coded entries representing the admitting diagnoses.

Clinical Purpose and Context

Admission diagnoses documented in this section represent: - The primary reason(s) for hospital admission - Clinical conditions identified at admission that require inpatient management - Suspected diagnoses that warrant hospital-level observation or treatment - Problems that necessitate the level of care provided in a hospital setting

Common examples include acute myocardial infarction, pneumonia, acute exacerbation of chronic conditions, or traumatic injuries requiring immediate hospital care.

When to Include

The Admission Diagnosis Section is typically included in: - Discharge Summaries (primary use case) - Transfer Summaries - Hospital Course Documentation

This section provides important context for understanding why the patient required hospitalization and helps establish the baseline clinical picture at the time of admission.

Template Details

Official OID

• Root: 2.16.840.1.113883.10.20.22.2.43
• Extension: 2015-08-01 (R2.1)

Conformance Level

• Conformance: SHOULD (Recommended in Discharge Summary documents)
• Section Code: 46241-6 (LOINC - "Hospital Admission diagnosis")
• Translation Code: 42347-5 (LOINC - "Admission Diagnosis")

Cardinality

• Section: 0..1 (Optional but recommended)
• Entries: 0..* (Hospital Admission Diagnosis entries)

Related Templates

• Hospital Admission Diagnosis (V3): 2.16.840.1.113883.10.20.22.4.34:2015-08-01
• Problem Observation (V3): 2.16.840.1.113883.10.20.22.4.4:2015-08-01

Protocol Requirements

The AdmissionDiagnosisProtocol defines the data contract for admission diagnosis entries. Each diagnosis must provide:

Required Properties

Property	Type	Description
name	str	Human-readable diagnosis name
code	str	SNOMED CT or ICD-10 diagnosis code
code_system	str	Code system: 'SNOMED' or 'ICD-10'

Optional Properties

Property	Type	Description
admission_date	Optional[date]	Date of hospital admission
diagnosis_date	Optional[date]	Date diagnosis was identified
persistent_id	Optional[PersistentIDProtocol]	Persistent ID across document versions

Data Types and Constraints

• name: Clear, clinical description of the admission diagnosis
• code: Must be a valid SNOMED CT or ICD-10 code
• code_system: 'SNOMED' (preferred) or 'ICD-10'
• admission_date: Date patient was admitted to hospital (YYYYMMDD format)
• diagnosis_date: Date this specific diagnosis was identified (may differ from admission date)

Code Example

Here's a complete working example using ccdakit to create an Admission Diagnosis Section:

from datetime import date
from ccdakit.builders.sections.admission_diagnosis import AdmissionDiagnosisSection
from ccdakit.core.base import CDAVersion

# Define admission diagnoses using a class that implements AdmissionDiagnosisProtocol
class AdmissionDiagnosis:
    def __init__(self, name, code, code_system, admission_date=None, diagnosis_date=None):
        self._name = name
        self._code = code
        self._code_system = code_system
        self._admission_date = admission_date
        self._diagnosis_date = diagnosis_date
        self._persistent_id = None

    @property
    def name(self):
        return self._name

    @property
    def code(self):
        return self._code

    @property
    def code_system(self):
        return self._code_system

    @property
    def admission_date(self):
        return self._admission_date

    @property
    def diagnosis_date(self):
        return self._diagnosis_date

    @property
    def persistent_id(self):
        return self._persistent_id

# Create admission diagnosis instances
diagnoses = [
    AdmissionDiagnosis(
        name="Acute Myocardial Infarction",
        code="57054005",
        code_system="SNOMED",
        admission_date=date(2024, 10, 15),
        diagnosis_date=date(2024, 10, 15)
    ),
    AdmissionDiagnosis(
        name="Type 2 Diabetes Mellitus",
        code="44054006",
        code_system="SNOMED",
        admission_date=date(2024, 10, 15),
        diagnosis_date=date(2024, 10, 15)
    )
]

# Build the Admission Diagnosis Section
section_builder = AdmissionDiagnosisSection(
    diagnoses=diagnoses,
    title="Hospital Admission Diagnosis",
    version=CDAVersion.R2_1
)

# Generate XML element
section_element = section_builder.build()

# Convert to XML string (for demonstration)
from lxml import etree
xml_string = etree.tostring(section_element, pretty_print=True, encoding='unicode')
print(xml_string)

Official Reference

For complete specification details, refer to the official HL7 C-CDA R2.1 documentation: - HL7 C-CDA R2.1 Implementation Guide - Section: Admission Diagnosis Section (V3) - Conformance IDs: CONF:1198-9930 through CONF:1198-32750

Best Practices

Common Patterns

1. Use Standard Vocabularies
2. Prefer SNOMED CT codes for better semantic interoperability
3. ICD-10 codes are acceptable and commonly used for billing-related documentation

4. Use the most specific code available that accurately represents the diagnosis

5. Document Admission Context

6. Include the admission date to provide temporal context
7. The diagnosis date may be the same as or earlier than the admission date

8. Document suspected diagnoses that warranted admission even if later ruled out

9. Distinguish from Discharge Diagnoses

10. Admission diagnoses represent what was known/suspected at admission
11. May differ from discharge diagnoses based on findings during hospitalization

12. Both sections may be present in the same Discharge Summary document

13. Handle Multiple Diagnoses

14. List primary admission diagnosis first if multiple diagnoses are present
15. Include all significant conditions that contributed to the admission decision
16. Each diagnosis becomes a separate Problem Observation within the entry

Validation Tips

1. Section Code Validation
2. Ensure section code is 46241-6 (LOINC "Hospital Admission diagnosis")
3. Must include translation code 42347-5 (LOINC "Admission Diagnosis")

4. Both codes are automatically set by the builder

5. Template ID Validation

6. Verify template ID includes extension="2015-08-01" for R2.1

7. Multiple template IDs may be present for backward compatibility

8. Entry Structure Validation

9. Each entry contains a Hospital Admission Diagnosis Act (classCode="ACT")
10. Act contains Problem Observations via entryRelationship

11. Problem Observations use standard Problem Observation (V3) template

12. Code System Mapping

13. 'SNOMED' maps to OID 2.16.840.1.113883.6.96
14. 'ICD-10' maps to OID 2.16.840.1.113883.6.90
15. Builder handles OID mapping automatically

Common Pitfalls

1. Confusing with Discharge Diagnosis
2. Don't use this section for final/discharge diagnoses
3. Admission diagnoses may be tentative or rule-out diagnoses

4. Use Discharge Diagnosis Section (2.16.840.1.113883.10.20.22.2.24) for discharge

5. Missing Admission Date

6. While optional, admission date provides critical context
7. Include whenever available for complete documentation

8. Helps establish timeline of care

9. Inconsistent Dates

10. Diagnosis date should not be after admission date
11. If diagnosis was made prior to admission, use the actual diagnosis date

12. Admission date should match the hospital admission timestamp

13. Code System Format

14. Use 'SNOMED' or 'ICD-10' as string values
15. Don't use OIDs directly (builder converts them)

16. Ensure codes are valid for the specified system

17. Empty Section Handling

18. If no admission diagnosis is documented, consider omitting the section
19. Alternatively, include narrative text stating "No admission diagnosis documented"

20. Empty entries may fail validation in some contexts

21. Problem vs. Diagnosis Terminology

22. C-CDA uses Problem Observation template for diagnoses
23. This is standard and correct per the specification
24. Don't be confused by "problem" terminology - it includes diagnoses

Related Sections

• Discharge Diagnosis Section: Documents final diagnoses at discharge
• Problems Section: Documents ongoing/chronic problems
• Hospital Course Section: Narrative describing the hospitalization
• Chief Complaint and Reason for Visit: Documents presenting symptoms

Code Systems and Terminologies

Diagnosis Codes

• SNOMED CT (Preferred): OID 2.16.840.1.113883.6.96
• Provides detailed clinical terminology

• Better for interoperability and clinical decision support

• ICD-10-CM: OID 2.16.840.1.113883.6.90

• Commonly used for billing and administrative purposes
• May be required by some systems

Section Codes

• Primary: 46241-6 - "Hospital Admission diagnosis" (LOINC)
• Translation: 42347-5 - "Admission Diagnosis" (LOINC)

Status Codes

• Admission diagnoses are typically documented as "active" at time of admission
• Use Problem Status value set (2.16.840.1.113883.3.88.12.80.68) for status values

Implementation Notes

Narrative Generation

The builder automatically generates an HTML table in the narrative section with: - Diagnosis name (with content ID for referencing) - Code and code system - Admission date - Diagnosis date

Multiple Diagnoses

Multiple admission diagnoses are common and fully supported: - Each diagnosis becomes a separate entry - Each entry contains a Hospital Admission Diagnosis Act - Acts contain Problem Observations representing the specific diagnoses

Persistent IDs

While optional, persistent IDs are valuable for: - Tracking diagnoses across multiple documents - Reconciling admission vs discharge diagnoses - Supporting continuity of care across episodes

Integration with Other Sections

Consider coordinating with: - Problems Section: May include same diagnoses as ongoing problems - Discharge Diagnosis Section: Compare admission vs discharge diagnoses - Hospital Course: Narrative explanation of how diagnoses evolved