Medications

This data contains patients whose EHR record included one of the displayed medications on any date included within the N3C Enclave.

• Patients may have taken other medications that are not shown here.
• Patient counts are per medication exposure. A patient may be simultaneously taking multiple medications and would be included in multiple medication groups shown here.
• Medications were aggregated based on ingredients included in the medication. The route of administration (oral, intravenous, etc.) and the dosage of the medication are variable within each medication group.
• The patient count for “Bamlanivimab + Etesevimab” is an aggregation of patients who were given both these medications.
  • Bamlanivimab and Etesevimab are two separate monoclonal antibodies sold as two separate medications. The FDA granted EUA for COVID-19 patients to be treated with Bamlanivimab and Etesevimab simultaneously. However, since these two medications are not sold as a mixture, EHR records will record each administration separately.
  • Patient counts for “Bamlanivimab + Etesevimab” were calculated by counting any patient who received Bamlanivimab and Etesevimab in the same month and year. They may not have received these medications at exactly the same time.
  • In contrast, Casirivimab and Imdevimab are sold as a mixture as well as separate medications. The counts shown for the Casirivimab + Imdevimab group are the number of patients who received the mixture of these two medications; therefore, they were given at exactly the same time.
• The data for “Molnupiravir”, “Nirmatrelvir + Ritonavir”, and “Tixagevimab + Celgavimab” is of lower confidence than the other drugs displayed here.
  • These drugs received FDA EUA in December of 2021. New drugs take time to be fully mapped to the OMOP Common Data Model, and each N3C site must then update their OMOP definitions to include any new drug mapping. Therefore, these three drugs were searched for by name across all N3C drug exposure data. This type of search may not capture all exposures to these drugs.

A medication exposure is defined as any occurrence of a medication name or related ICD-10 code within a patient's EHR.

• Medication exposures do not mean the patient was given the medication in order to treat COVID-19.
• Medication exposures do not mean the patient actually took the displayed medication.
  • Some records specify that a prescription for a medication was written, while others specify In-patient administration.

A COVID-positive patient is defined as any patient having one of the following within their EHR records:

1. Laboratory confirmed positive COVID-19 PCR or Antigen test
2. Laboratory confirmed positive COVID-19 Antibody test
3. Medical visit in which the ICD-10 code for COVID-19 (U07.1) was recorded
   • Condition diagnosis patients have no record of a positive PCR/Antigen or Antibody test within their EHR; however, they were diagnosed with COVID due to the symptoms they displayed.

The age of each patient is calculated as of the date of the last data update.

• If an age exceeds 89, it will be obscured using a date shift of +/- 10 years.
• As of 7/15/22, July 1st is used as a placeholder date of birth when there are 0s or nulls in the OMOP person table to avoid biasing towards older age.

General Enclave Limitations

• “Sicker” patients will likely be overrepresented within the N3C Data Enclave, as sicker patients will more often seek out and receive care at clinical centers.
• The N3C may have multiple contributors to data “missingness”. Clinical facts and events that occur in the real world may not be captured for reasons including:
  • The event was recorded at a clinical site that does not contribute data
  • Data is not yet linked across sites
  • Medical records are inherently incomplete
• Some of the external datasets that have been used for analysis cannot be fully mapped due to issues such as missing measurement units.
• All dates within the Enclave have been shifted between -3 to 45 days to ensure that reidentification is not possible.
• N3C data may not be representative of the entire US population
• N3C does NOT have a representative sample of any state, as data is contributed from only a few providers in each region (Region - includes multiple states).
• Cell sizes smaller than 20 people have been suppressed
• For COVID+ patients: A patient is only counted once in this data, even if they have multiple positive tests over time. Except in instances where dashboards focus on reinfection, only dates of first infection are utilized.