Using a data-driven approach to define post-COVID conditions in US electronic health record data.

OBJECTIVE: To create a data-driven definition of post-COVID conditions (PCC) by directly measure changes in symptomatology before and after a first COVID episode. MATERIALS AND METHODS: Retrospective cohort study using Optum® de-identified Electronic Health Record (EHR) dataset from the United States of persons of any age April 2020-September 2021. For each person with COVID (ICD-10-CM U07.1 "COVID-19" or positive test result), we selected up to 3 comparators. The final COVID symptom score was computed as the sum of new diagnoses weighted by each diagnosis' ratio of incidence in COVID group relative to comparator group. For the subset of COVID cases diagnosed in September 2021, we compared the incidence of PCC using our data-driven definition with ICD-10-CM code U09.9 "Post-COVID Conditions", first available in the US October 2021. RESULTS: The final cohort contained 588,611 people with COVID, with mean age of 48 years and 38% male. Our definition identified 20% of persons developed PCC in follow-up. PCC incidence increased with age: (7.8% of persons aged 0-17, 17.3% aged 18-64, and 33.3% aged 65+) and did not change over time (20.0% among persons diagnosed with COVID in 2020 versus 20.3% in 2021). For cases diagnosed in September 2021, our definition identified 19.0% with PCC in follow-up as compared to 2.9% with U09.9 code in follow-up. CONCLUSION: Symptom and U09.9 code-based definitions alone captured different populations. Maximal capture may consider a combined approach, particularly before the availability and routine utilization of specific ICD-10 codes and with the lack consensus-based definitions on the syndrome.

Proportion of Patients in the United States Who Fill Their Nirmatrelvir/Ritonavir Prescriptions.

INTRODUCTION: Although real-world studies demonstrate that those prescribed nirmatrelvir/ritonavir (and particularly within 5 days of symptom onset) are less likely to experience severe COVID-19 outcomes, prior studies show that only a small fraction of patients with COVID-19 who are eligible for nirmatrelvir/ritonavir receive a prescription. Studies calculating the proportion of nirmatrelvir/ritonavir prescriptions filled and identifying individual- and pharmacy-level correlates of filling nirmatrelvir/ritonavir are lacking. METHODS: This retrospective cohort study included individuals aged ≥ 12 years with a nirmatrelvir/ritonavir prescription ordered at a large national retail pharmacy (December 22, 2021-August 12, 2023). Those taking contraindicated medications were excluded. For those with only one nirmatrelvir/ritonavir prescription ordered, the outcome was whether the prescription was filled (yes/no). In a subanalysis of these individuals, the outcome was whether the prescription was filled within 5 days of symptom onset (yes/no). For those with multiple prescriptions ordered, the outcome was whether > 1 (vs. 0 or 1) prescriptions were filled. A log-binomial regression with generalized estimating equations was used to identify individual (clinical and demographic) and pharmacy-level (percentage of trade area that is non-Hispanic white, urbanicity, US Census region, and tract-level area deprivation index) correlates. RESULTS: A total of 2,103,570 unique nirmatrelvir/ritonavir prescriptions were ordered for 1,985,990 individuals. Among the 95% of individuals prescribed only one nirmatrelvir/ritonavir course, 88% filled their prescription. Among those with > 1 prescription ordered, 77% (82,993/108,411) filled one and 13% (13,662/108,411) filled > 1. Patients ≥ 50 years of age and those with documented high-risk conditions were slightly more likely to fill prescriptions, regardless of whether one or multiple courses were ordered. Individuals with cancer, asthma, or taking corticosteroids or immunosuppressive medications were more likely to fill multiple prescriptions. CONCLUSIONS: Most patients filled their nirmatrelvir/ritonavir prescriptions. Interventions to improve uptake should focus on increasing patient and provider awareness, reducing nirmatrelvir/ritonavir prescribing disparities, and ensuring treatment initiation within 5 days.