Post-COVID-19 conditions identified by ICD-10-CM code in a cohort of U.S. primary care patients, 2021 - 2023

Describe patient characteristics, healthcare utilization, and Post-COVID-associated conditions among primary care patients with an ICD-10-CM diagnosis code for Post COVID-19 Condition (U09.9).

Using electronic health record (EHR) data from the American Family Cohort, a U.S. national primary care dataset, we identified patients with a U09.9 diagnosis documented October 1, 2021-June 1, 2023. Patient data were categorized into three periods: pre-pandemic (2016-2019), pandemic pre-index (2020 to the first U09.9 diagnosis, or 'index' date), and post-index (index date to the last observation). Post-COVID-associated conditions were aggregated a priori into 12 body systems.

We identified 10,265 patients with a U09.9 diagnosis code; 81.9% were ≥40 years, 63.3% female, 74.4% White, and 70.5% resided in metropolitan counties. Patients averaged 12.7 primary care encounters in the year before the index U09.9 diagnosis, compared to 9.2 encounters annually in the post-index period. Over 68% of patients who had ≥1 pre-pandemic encounters had ≥1 underlying medical conditions. The prevalence of conditions across 9 out of 12 body systems increased from the pre-pandemic to the pandemic pre-index period for patients who had ≥1 conditions. Prevalence of respiratory and musculoskeletal conditions had the largest decrease from the pandemic pre-index to the post-index period.

Compared to adults who self-report Long COVID in nationally representative population-based surveys, patient characteristics in this cohort highlight a potential diagnosis gap - particularly for patients with rural residence or high county-level socioeconomic deprivation. Given frequent healthcare utilization and clinical complexity, primary care may require additional resources to meet patient needs.