Postdoctoral Scientist Eli Lilly and Company Indianapolis, United States
Background: Although previous research supported the validity of ICD-10-CM diagnosis code U07.1 for coronavirus disease 2019 (COVID-19) in inpatient settings, the accuracy of identifying patients with COVID-19 using outpatient claims for code U07.1 remains unstudied.
Objectives: The primary aim was to evaluate the positive predictive value (PPV) and sensitivity of using an outpatient claim record for U07.1 to identify patients with laboratory confirmed COVID-19 infection. The secondary aim was to replicate the accuracy of inpatient/emergency room (ER) U07.1 claims to identify COVID-19 patients using an additional claims database.
Methods: Patients with available administrative claims and laboratory results from Optum’s Clinformatics® Data Mart database (April, 2020 to December, 2020) were included to assess the PPV of one or two outpatient claims for U07.1 in identifying laboratory-confirmed positive COVID-19 infection. The sensitivity of code U07.1 assigned in the outpatient setting was also estimated. In support of the secondary aim, PPV and sensitivity of U07.1 in inpatient/ER settings were also assessed.
Results: The PPV of one outpatient claim for U07.1 in identifying patients with laboratory confirmed COVID-19 infection was 57.7% and improved to 74.8% when two outpatient claims for U07.1 were required, though 75% of individuals were eliminated from the cohort when two U07.1 claims were required. The sensitivity of at least one outpatient claim for U07.1 in identifying positive COVID-19 infection was low at 35.1%. Similar to previous research, the PPV of an inpatient/ER claim for U07.1 and the sensitivity of at least one inpatient/ER claim for U07.1 was high at 86.5% and 93.4%, respectively.
Conclusions: Outpatient claims for U07.1 do not favorably identify positive COVID-19 infections. Although suitable in inpatient/ER settings, researchers should be cautious when using outpatient claims for U07.1 if the goal is to identify patients with positive COVID-19 infections. Future studies are needed to develop alternative algorithms to more accurately identify outpatients with COVID-19, and to assess the validity of code U07.1 in a more recent time given the increased vaccination coverage and test kits availability, as well as the evolution of virus.
