COVID-19 Negative Control Outcomes

For 29 outcomes, relevant SNOMED and ICD-10-CM codes were identified, descendants were added, and the concept table was string searched to identify codes of interest. For 10 outcomes, existing concept sets from prior studies were applied. The full concept set includes diagnoses, drugs, procedures, lab measurements and immunizations. The concept set was used to identify negative control outcomes expected to have a null association with COVID-19, to be used when calibrating effect estimates of the primary outcomes examined in the cohort. Negative control outcomes included in the concept set are: acne, ankle sprain, appendectomy, appendicitis, astigmatism, autism, chemotherapy drugs, congenital cleft lip or palate surgery, closed fracture distal end of radius, concussion, congenital cardiac surgery, contact dermatitis, falls, foot pain, foreign body in ear, fracture, impacted cerumen, impetigo, influenza or pneumococcal vaccination, inguinal hernia, injury of free lower limb, insect bite, lead labs, lipid panel labs, myopia, orthopedic procedures, penicillin, plagiocephaly, scoliosis, seizure and epilepsy, speech and language disorders, tinea capitis, tinea corporis, tongue tie, transcranial doppler procedures, umbilical hernia, visual testing abnormal, well visits, and wrist pain. While a clinician reviewed the general list of outcome categories and confirmed they were likely to be unassociated with COVID-19, the full concept set was constructed rapidly and was not vetted by a clinician for accuracy.