# Presentation: 110900

## Standardizing Clinical Condition Classifiers for Biosurveillance

**Standardizing ****Clinical Condition Classifiers for Biosurveillance**

- Craig Hales MD, MPH
- Carol Sniegoski MS
- Haobo Ma MD, MS
- Jacqueline Coberly PhD
- Jerome Tokars MD, MPH

- BioSense - CDC
- ESSENCE – JHU/APL
- BioSense – CDC
- ESSENCE – JHU/APL
- BioSense – CDC

- The findings and conclusions in this presentation are those of the author(s) and
- do not necessarily represent the views of the Centers for Disease Control and Prevention

## Topics

- Current state of clinical condition classifiers (“sub-syndromes”) in BioSense and ESSENCE
- Motivation and process for standardizing clinical condition classifiers
- Results
- Discussion / next steps

## Use of Clinical Condition Classifiers in Biosurveillance

- Collect diagnostic and pre-diagnostic data in electronic form
- ICD-9-CM diagnosis codes, chief complaint free text, others
- Aggregate data into groups (“bins”)
- Syndromes (e.g., gastrointestinal, respiratory)
- “Sub-syndromes” (e.g., diarrhea, cough)
- Analyze aggregated data counts for anomalies

## BioSense/ESSENCE Syndromes

**BioSense/ESSENCE Syndromes**

**Botulism-like**
**Hemorrhagic Illness**
**Lymphadenitis**
**Localized Cutaneous Lesion**
**Gastrointestinal**

**Respiratory**
**Neurological**
**Rash**
**Specific Infection**
**Fever**
**Severe Illness or Death**

## BioSense “Sub-syndromes”

- More granular than syndromes
- Cover a broader range of conditions then typical syndromic surveillance (e.g., injuries, chronic disease)
- Original set derived with input from EARS, ICD-9-CM classification, other systems

## BioSense Sub-syndrome to Syndrome Mapping

- Botulism-like
- Paralysis
- Speech disturbance
- Dysphagia
- Fever
- Fever
- Septicemia and bacteremia
- Viral infection, unspecified

- Gastrointestinal
- Abdominal pain
- Anorexia
- Diarrhea
- Food poisoning
- Intestinal infections, ill-defined
- Nausea and vomiting

## BioSense Sub-syndrome to Syndrome Mapping

- Hemorrhagic
- Coagulation defects
- Gastrointestinal hemorrhage
- Hemorrhage
- Purpura and petechia
- Cutaneous lesion
- Insect bites
- Skin infection
- Lymphadenitis
- Lymphadenopathy

- Neurological
- Alteration of consciousness
- CNS, inflammatory disease
- Convulsions
- Gait abnormality
- Headache
- Meningismus
- Photophobia

## BioSense Sub-syndrome to Syndrome Mapping

- Respiratory
- Asthma
- Bronchitis and bronchiolitis
- Chest pain
- Cough
- Cyanosis and hypoxemia
- Dyspnea
- Influenza-like illness
- Otitis media
- Pleurisy
- Pneumonia and lung abscess

- Respiratory (continued)
- Respiratory failure
- RSV
- Upper respiratory infections
- Hemoptysis
- Rash
- Rash
- Severe Illness and Death
- Coma
- Death
- Shock

## Other BioSense Sub-syndromes (Not Mapped to Syndromes)

**Injuries**
**Bites, animal**
**Burns**
**Carbon monoxide poisoning**
**Falls**
**Fractures and dislocation**
**Heat, excessive**
**Injury, NOS**
**Motor vehicle traffic accidents**
**Open wound**
**Poisoning by medicines**
**Sprains and strains**
**Chronic Disease**
**Cerebrovascular disease**
**COPD**
**Diabetes mellitus**
**Heart disease, ischemic**
**Hypertension**
**Neoplasms**

**Other**
**Allergy**
**Anemia**
**Cardiac dysrhythmias**
**Dehydration**
**Dizziness**
**Edema**
**Hypotension**
**Jaundice**
**Malaise and fatigue**
**Mental disorders**
**Migraine**
**Myalgia**
**Numbness**
**Pregnancy, childbirth complications**
**Syncope and collapse**
**Urinary tract infection**
**Visual impairment**

## BioSense Data Aggregation Using Clinical Condition Classifiers

**Chief Complaint Keywords**

**ICD-9-CM**

**Sub-syndrome**

**ICD-9-CM**

**BioSense Data Aggregation Using Clinical Condition Classifiers**

## BioSense: Diarrhea Sub-syndrome by Week and Data Source

**             ****Jan 05                                Jan 06                             Jan 07**

**     ****DoD diagnosis              VA diagnosis               Hospital ED CC**

## BioSense: Heat Injury Sub-syndrome by Week and Data Source

**             ****Jan 05                                Jan 06                             Jan 07**

**     ****DoD diagnosis              VA diagnosis               Hospital ED CC**

## BioSense: ILI Sub-syndrome by Week and Data Source

**             ****Jan 05                                Jan 06                             Jan 07**

**     ****DoD diagnosis              VA diagnosis               Hospital ED CC**

## Current Respiratory Syndrome

**Apnea**
**Asthma**
**Congestion**
**Cough**
**Croup**
**Difficulty breathing**
**Hypoxia**
**Otitis media**
**Pharyngitis**
**Pleurisy**
**Pneumonia**
**Respiratory distress**
**Respiratory failure**
**Sinusitis**
**Upper respiratory infection**
**Wheezing**

**Current Respiratory Syndrome**

**Syndromes are Constructed of Similar Clinical Conditions**

**ESSENCE D**

**Asthma**
**Bronchitis & Bronchiolitis**
**Chest pain**
**Cough**
**Dyspnea**
**Cyanosis & Hypoxemia**
**Hemoptysis**
**Influenza-like Illness**
**Otitis media**
**Pleurisy**
**Pneumonia & Lung Abscess**
**Respiratory failure**
**RSV**
**Upper respiratory infection**

**BioSense**

## Motivation for Standardizing Clinical Condition Classifiers

- Clinical condition classifiers (e.g., dyspnea) are more easily defined than syndromes (e.g., respiratory syndrome)
- Facilitate standardization of syndromes
- Facilitate creation of case definitions and ad hoc queries (e.g., headache OR stiff neck OR fever for a meningitis outbreak)
- BioSense and ESSENCE collaboration
- Federal systems, national scope
- Starting point

## Standardization Process

**Identify surveillance functions to support**
**Generate set of symptoms, signs, and illnesses**
**Aggregate conditions and assign SNOMED-CT term**
**Develop a text definition, keywords, and ICD-9-CM list for each clinical condition classifier**

## 1. Identify Surveillance Functions to Support

**Botulism-like**
**Hemorrhagic Illness**
**Lymphadenitis**
**Localized Cutaneous Lesion**
**Gastrointestinal**

**Respiratory**
**Neurological**
**Rash**
**Specific Infection**
**Fever**
**Severe Illness or Death**

## 1. Identify Surveillance Functions to Support

**1. Identify Surveillance Functions to Support**

_**http://www.bt.cdc.gov/agent/agentlist-category.asp**_

## 1. Identify Surveillance Functions to Support

_**http://www.cdc.gov/epo/dphsi/phs/infdis2007.htm **_

## 1. Identify Surveillance Functions to Support

## 2. Generate Set of Symptoms, Signs, Illnesses

**Syndrome**
**Anthrax **
**(inhalational)**
**Post-Disaster**
**Surveillance**

**Conditions of**
** ****Interest**

**2. Generate Set of Symptoms, Signs, Illnesses**

## 2. Generate Set of Symptoms, Signs, Illnesses

** ****Interest**

- cough
- stidor
- shortness of breath
- throat pain
- chest discomfort
- cough
- fatigue
- fever
- ILI
- malaise
- myalgia
- rhonchi
- shortness of breath
- sore throat
- acute respiratory infx
- conjunctitis

**Symptom/Sign/**
**Illness**

**Respiratory **
**Syndrome**
**Anthrax **
**(inhalational)**
**Post-Disaster**
**Surveillance**

**2. Generate Set of Symptoms, Signs, Illnesses**

## 3. Aggregate Conditions and Assign SNOMED-CT Term

**Principle: Utility as a distinct classifier**
**Appropriate level of granularity**
**Appropriate for chief complaint free text and ICD-9-CM diagnosis codes**

## 3. Aggregate Conditions and Assign SNOMED-CT Term

** ****Interest**

- cough
- stidor*
- shortness of breath*
- throat pain
- chest discomfort
- cough
- fatigue
- fever
- ILI
- malaise
- myalgia
- rhonchi*
- shortness of breath*
- sore throat
- acute respiratory sxs
- conjunctitis

**Symptom/Sign/**
**Illness**

**Respiratory **
**Syndrome**
**Anthrax **
**(inhalational)**
**Post-Disaster**
**Surveillance**

**Clinical Condition Classifier**

**Cough**
**Dyspnea***
**Sore Throat**
**Chest Pain**
**ILI**
**Malaise & **
**      ****Fatigue**
**Fever**
**Myalgia**
**Conjunctivitis**

**3. Aggregate Conditions and Assign SNOMED-CT Term**

## Respiratory Classifiers:

**Apnea**
**Asthma**
**Congestion**
**Cough**
**Croup**
**Difficulty breathing**
**Hypoxia**
**Otitis media**
**Pharyngitis**
**Pleurisy**
**Pneumonia**
**Respiratory distress**
**Respiratory failure**
**Sinusitis**
**Upper respiratory infection**
**Wheezing**

**Respiratory Classifiers:**

**ESSENCE D**

**Asthma**
**Bronchitis & Bronchiolitis**
**Chest pain**
**Cough**
**Dyspnea**
**Cyanosis & Hypoxemia**
**Hemoptysis**
**Influenza-like Illness**
**Otitis media**
**Pleurisy**
**Pneumonia & Lung Abscess**
**Respiratory failure**
**RSV**
**Upper respiratory infection**

**BioSense**

**Acute bronchitis**
**Asthma**
**Chest pain**
**Cough**
**Dyspnea**
**Hemoptysis**
**Influenza-like Illness**
**Pneumonia**
**Respiratory failure**
**Sore Throat**
**Upper respiratory infection**

## 4. Develop Text Definition, Key Words, ICD-9 List for Clinical Condition Classifiers

- Text definition for _respiratory failure_:
- Respiratory function fails to maintain adequate oxygen supply and carbon dioxide removal (UMLS)
- _Includes_: cyanosis, respiratory distress syndrome, respiratory insufficiency, hypoxemia, asphyxia, respiratory arrest, apnea, pulmonary edema
- _Does not include_: chronic respiratory failure, respiratory failure of newborn, respiratory failure due to surgery or trauma, sleep apnea, pulmonary edema related to heart failure

## Results:

- Developed criteria and process for selection of clinical condition classifers
- Applied criteria to generate:
- 73 conditions of interest
- 629 associated symptom/sign/illness
- 79 clinical condition classifiers

| Resp | 12 |
| --- | --- |
| GI | 7 |
| Neuro | 14 |
| Constitutional | 6 |
| Heme | 3 |

| Injury | 17 |
| --- | --- |
| Chronic | 3 |
| Derm | 6 |
| Mental | 4 |
| Other | 12 |

**N**

**N**

## Results:

- Current BioSense sub-syndromes not included:
- RSV, cardiac dysrhythmias, pleurisy
- New classifiers:
- Arthralgia, acute renal impairment, conjunctivitis
- Electric shock, drowning, abrasion/contusion/crushing injury
- Psychotic disorder, psychomotor agitation
- Re-named (SNOMED-CT) classifiers:
- Infectious enteritis ← gastroenteritis (ESSENCE), intestinal infections-ill defined (BioSense)
- Consolidated classifiers:
- Respiratory failure ← respiratory failure (E,B), respiratory distress (E), hypoxia (E), cyanosis and hypoxemia (B)

## Discussion:

- Knowledge-based approach, not data driven
- Appropriate for chief complaint and diagnosis data types
- Subjective “utility as a distinct classifier”
- Does not address specific infections
- Does not address exclusions

## Next Steps

- Participation in ISDS consultation in September
- Continue development of text definitions
- Continue development of suggested chief complaint keywords and ICD-9-CM codes
- BioSense and ESSENCE will move towards using a common set of clinical condition classifiers

## Slide 31