Long COVID: Potential Risk Factors Identified via Analysis of Documented Care

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Researchers evaluated patients with documented care for long COVID to determine factors associated with its occurrence.

Factors associated with an increased risk for long COVID include older age, a higher comorbidity burden, disease severity at the time of diagnosis, and unvaccinated status at initial onset of infection. These study findings were published in JAMA Network Open.

Using data from the Veterans Affairs Corporate Data Warehouse and the COVID-19 Shared Data Resource, researchers conducted a retrospective cohort study among patients who tested positive for COVID-19 infection between February 2020 and April 2021. Excluded patients were those who died within 3 months of testing positive. Patient with a second positive result after 3 or more months also were excluded to avoid confounding from reinfection treatment. The primary outcome was the documentation of care for long COVID for 3 months or more after the initial onset of infection. Multivariable logistic regression was used to assess potential associations between patient characteristics and outcomes of long COVID care, with adjustments for age, sex, race/ethnicity, rural vs urban residence, time of infection, and the number of health care visits in the 2 years prior to the onset of infection.

A total of 198,601 patients were included in the analysis, of whom the mean age was 60.4±17.7 years, 89.1% were men, 67.4% were White, and 69.6% resided in urban areas.

During a mean follow-up period of 13.5±3.6 months, long COVID care was documented in 13.5% of patients overall. Analysis between these patients vs those without documented care showed several factors associated with an increased risk for long COVID. These factors included older age (18-49 years vs 50-84 years; adjusted odds ratio [aOR], 1.38; 95% CI, 1.28-1.48), hospitalization (aOR, 2.60; 95% CI, 2.51- 2.69), a need for mechanical ventilation (aOR, 2.46; 95% CI, 2.26-2.69), and an increased number of symptoms within the acute phase of infection (aOR, 1.71; 95% CI, 1.65-1.78).

Compared with patients who were White, those who were Black (aOR, 1.10; 95% CI, 1.09-1.21), Asian (aOR, 1.12; 95% CI, 0.98-1.29), and American Indian/Alaska Native (aOR, 1.18; 95% CI, 1.03-1.35) were significantly more likely to documented care for long COVID. Documented care for long COVID also more frequently occurred among patients who were Hispanic vs non-Hispanic (aOR, 1.15; 95% CI, 1.10-1.21), and in those who resided in urban vs rural areas (aOR, 1.14; 95% CI, 1.10-1.19).

The researchers found a linear association between patients’ Charlson comorbidity index scores and documented care for long COVID, with documented care significantly more likely among those with scores of 9 or higher (aOR, 2.19; 95% CI, 1.98-2.41). Comorbid conditions significantly associated with documented long COVID care included chronic obstruction pulmonary disease, asthma, congestive heart failure, prior myocardial infarction, cerebrovascular disease, chronic kidney disease, and diabetes.

Patients receiving opioids (aOR, 1.24; 95% CI, 1.17-1.30) or calcium channel blockers (aOR, 1.24; 95% CI, 1.20-1.27) were more likely to have documented care for long COVID.

No significant associations were found between the number of primary care visits within the past 2 years and documented long COVID care. However, patients with a higher number of visits to a mental health (≥20 visits; aOR, 1.16; 95% CI, 1.11-1.21) or specialty care (≥19 visits; aOR, 1.90; 95% CI, 1.65-2.18) clinic within the past 2 years were significantly more likely to have documented care for Long COVID.

This study was limited by the lack of standardized diagnostic criteria for long COVID.

These findings “provide support and guidance for health care systems to develop systematic approaches to the evaluation and management of patients who may be experiencing long COVID,” the researchers concluded.

Disclosure: One study author declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of disclosures. 


Ioannou GN, Baraff A, Fox A, et al. Rates and factors associated with documentation of diagnostic codes for long COVID in the national veterans affairs health care system. JAMA Netw Open. 2022;5(7):e2224359. doi:10.1001/jamanetworkopen.2022.24359

This article originally appeared on Infectious Disease Advisor