Background:

Long COVID is characterized by persistent, new, or relapsing symptoms following severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. A standardized and reliable definition is needed to accurately identify patients with long COVID, and a number of models of care have been developed or proposed to provide the services needed to manage this complex condition.

Purpose:

The purpose of this Technical Brief is to summarize definitions of long COVID and describe what is known about long COVID models of care, including models currently in use, promising approaches, advantages and disadvantages of models in different populations and settings, barriers and facilitators to implementation, access and equity issues, and needed research.

Methods:

We performed searches in electronic databases from 2021 to November 2023, reviewed reference lists, searched grey literature sources, and interviewed Key Informants. We described key definitions of long COVID, identified components characterizing different long COVID models of care, developed a framework to categorize models based on these components, described representative practice- and systems-based models of care, and identified future research needs.

Findings:

We identified five definitions for long COVID based on clinical criteria and one proposed definition based on a summary symptom score. Clinical definitions varied with regard to requirement for documenting acute SARS-CoV-2 infection, timing of onset, and duration of symptoms. One newly proposed definition developed using data from people with symptoms for greater than 6 months is based on exceeding a threshold on a composite symptom score and requires further validation.

Based on 49 long COVID models of care described in the literature review or by Key Informants, we identified five key principles of long COVID care: (1) core “lead” team; (2) broad multidisciplinary expertise; (3) broad range of diagnostic and therapeutic services; (4) patient-centered, individualized, and equitable care; and (5) capacity to meet demand. Models of care varied with regard to how they addressed these principles. We developed a framework for describing and categorizing long COVID models of care based on seven key components that varied across models: (1) home department or clinical setting; (2) clinical lead; (3) co-location of other specialties; (4) role of primary care; (5) population managed; (6) use of teleservices; and (7) whether the model was practice- or system-based. Using this framework, we described 10 representative practice-based and 3 systems-based long COVID models of care. There was overlap between model components as well as variability within the same model. Across models, implementation strategies addressed multispecialty collaboration, use of systematic intake and assessment methods, care coordination, and education and training of clinic staff.

Research is needed to understand appropriate methods for measuring quality of care, approaches for providing access to underserved populations, strategies to ensure sustainability, provision of long COVID care in areas lacking multidisciplinary expertise, optimal education and training and care coordination methods, outcomes of long COVID models of care, and strategies for integrating long COVID management into primary care. Decisions about long COVID models of care may best be tailored to address the unique milieu of each implementation setting, leveraging the resources and expertise available.

Conclusions:

Definitions of long COVID vary and efforts are ongoing to develop a more standardized and reliable definition. A framework based on key model components may be useful to describe and categorize different long COVID models of care. Research is needed to clarify optimal long COVID models of care in different settings and to understand effective strategies for overcoming implementation barriers, including integration of long COVID management in primary care. The models of care presented in this Technical Brief may help inform the individualized implementation of long COVID models of care in different settings.