The National Syndromic Surveillance Program (NSSP), in collaboration with the syndromic surveillance community, has assigned priority levels to data elements within syndromic HL7 messages. Data elements are described in detail in the PHIN Messaging Guide for Syndromic Surveillance 2.0pdf icon. Processing details for each element can be found in the NSSP Data Dictionaryexcel icon. Priority levels help guarantee data quality in the production environment and are used when onboarding new facilities or re-onboarding existing facilities. Priority levels are included in the NSSP New Site Onboardingpdf icon and New Facility Onboardingpdf icon guides.

Priority 1 data elements are the minimum required to perform surveillance activities. Shown below are the required fields for maintaining a minimum level of completeness and validity so that a facility can achieve and maintain production status.

Priority 1 Data Elements
Processed Column Priority Required HL7
Admit_Date_Time 1 R PV1-44.1
Admit_Reason_Description 1 RE PV2-3.2, PV2-3
C_Chief_Complaint 1 CRE OBX or PV2-3
C_Death 1 CRE PID.30.1
C_Facility_ID 1 CR EVN-7.2, MSH-4.2 or MSH-4.1
C_FacType_Patient_Class 1 CR OBX-2,3,5
C_Patient_Age 1 CRE OBX-2,3,5
C_Patient_Age_Years 1 CRE OBX-2,3,5
C_Patient_Class 1 CR PV1.2.1 or calculate
C_Unique_Patient_ID 1 CR PID.3.1
Chief_Complaint_Text 1 RE OBX-2,3,5
Diagnosis_Code 1 RE DG1-3.1, DG1-3.4
Diagnosis_Description 1 RE DG1-3.2, DG1-3.5
Facility_Type_Code 1 R OBX-2,3,5
Patient_Class_Code 1 R PV1.2.1
Patient_Zip 1 RE PID.11.5
Processing_ID 1 R MSH.11.1
Sending_Facility_ID 1 R MSH-4.2 or MSH-4.1
Treating_Facility_ID 1 R EVN.7.2
Trigger_Event 1 R MSH.9.2
Visit_ID 1 R PV1.19.1

Priority 2 data elements are also useful for surveillance activities and may be required by sites before a facility can move to production. NSSP requires these data elements meet minimum standards of completeness and validity within 12 months of a facility achieving production status.

Priority 2 Data Elements
Processed Column Priority Required HL7
First_Patient_ID 2 R PID-3.1
Medical_Record_Number 2 R PID-3.1
Sending_Facility_ID_Source 2 R MSH-4.1
Message_Date_Time 2 R MSH.7.1
Recorded_Date_Time 2 R EVN.2.1
Discharge_Disposition 2 RE PV1.36.1
Discharge_Date_Time 2 RE PV1.45.1
Administrative_Sex 2 RE PID.8.1
Age_Reported 2 RE OBX.5.1
Age_Units_Reported 2 RE OBX.6.2
C_Patient_Age_Units 2 C OBX.6.2
Race_Code 2 RE PID-10.1
Ethnicity_Code 2 RE PID-22.1
Ethnicity_Description 2 RE PID-22.2
Patient_City 2 RE PID.11.3
Patient_State 2 RE PID.11.4
C_Patient_County 2 CRE PID-11.9
Patient_Country 2 RE PID.11.6
Admit_Reason_Code 2 RE PV2-3.1, PV2-3
Chief_Complaint_Code 2 RE OBX-2,3,5
Diagnosis_Type 2 RE DG1.6.1
Version_ID 2 R MSH.12.1

Priority 3 data elements are mostly Optional data elements; still useful for surveillance activities, but not required by most sites. Currently, the NSSP does not require that these fields be populated in incoming data

Priority 3 Data Elements
Processed Column Priority Required HL7
First_Patient_ID_Type_Code 3 O PID-3.5
First_Patient_ID_Assigning_Authority 3 O PID-3.4
First_Patient_ID_Assigning_Facility 3 O PID-3.6
Medical_Record_Number_Assigning_Authority 3 O PID.3.1
Medical_Record_Number_Assigning_Facility 3 O PID.3.1
Visit_ID_Assigning_Authority 3 O PV1.19.4
Visit_ID_Assigning_Facility 3 O PV1.19.6
Patient_Account_Number 3 O PID.18.1
Alternate_Visit_ID 3 O PV1.50
Facility_Type_Description 3 O OBX-2,3,5
Receiving_Facility 3 O MSH.6.1
Diagnosis_Date_Time 3 O DG1.5.1
Procedure_Date_Time 3 O PR1.5
Observation_Date_Time 3 O OBX.14.1
Onset_Date 3 O OBX.5.1
Patient_Death_Indicator 3 O PID.30.1
Death_Date_Time 3 O PID.29.1
Admission_Type 3 O PV1.4
Admit_Source 3 O PV1.14
Ambulatory_Status 3 O PV1.15
Hospital_Service 3 O PV1.10
Insurance_Company_ID 3 O IN1-3
Insurance_Coverage 3 O IN1-15
Previous_Hospital_Unit 3 O PV1-6
Provider_Type_Code 3 O OBX-2,3,5
Provider_Type_Combo 3 O OBX-2,3,5
Provider_Type_Description 3 O OBX-2,3,5
Unique_Physician_Identifier 3 O PV1-7.1
Unique_Physician_Identifier_Assigning_Authority 3 O PV1-7.9
Hospital_Unit_Code 3 O OBX-2,3,5
Hospital_Unit_Description 3 O OBX-2,3,5
Age_Calculated 3 RE OBX.5.1
Age_Units_Calculated 3 RE OBX.6.2
Birth_Date_Time 3 O PID.7.1
Race_Description 3 O PID-10.2
Triage_Notes 3 O OBX.5.1
Diagnosis_Priority 3 O DG1.15
Event_Type_Code 3 O EVN.1.1
Procedure_Code 3 O PR1.3.3
Procedure_Description 3 O PR1.3.2
Clinical_Impression 3 O OBX-2,3,5
Initial_Acuity_Code 3 O OBX.5.1
Initial_Acuity_Description 3 O OBX.5.1
Initial_Evaluation_Note 3 O OBX-2,3,5
Medication_Code 3 O OBX.5.1
Medication_Description 3 O OBX.5.1
Medication_List 3 O OBX.5.1
Problem_List_Code 3 O OBX.5.1
Problem_List_Description 3 O OBX.5.1
Travel_History 3 O OBX-2,3,5
Initial_Temp 3 O OBX-5
Initial_Temp_Units 3 O OBX-6
Initial_Pulse_Oximetry 3 O OBX-5
Initial_Pulse_Oximetry_Units 3 O OBX-6
Diastolic_Blood_Pressure 3 O OBX-5
Diastolic_Blood_Pressure_Units 3 O OBX-6
Str_Diastolic_Blood_Pressure 3 O OBX-5
Systolic_Diastolic_Blood_Pressure 3 O OBX-5
Systolic_Diastolic_Blood_Pressure_Units 3 O OBX-6
Systolic_Blood_Pressure 3 O OBX-5
Systolic_Blood_Pressure_Units 3 O OBX-6
Pregnancy_Status_Code 3 O OBX-2,3,5
Pregnancy_Status_Description 3 O OBX-2,3,5
Smoking_Status_Code 3 RE OBX-2,3,5
Smoking_Status_Description 3 RE OBX-2,3,5
Body_Mass_Index 3 O OBX-5
Height 3 RE OBX-5
Height_Units 3 RE OBX-6
Weight 3 RE OBX-5
Weight_Units 3 RE OBX-6
Assigned_Patient_Location 3 O PV1-3
Time_Zone 3 O MSH-7.1
Page last reviewed: September 22, 2021