This section below summarizes recent research evidence on the prevalence of “Long COVID”, describes care models, and summarizes the research on the effectiveness of rehabilitation interventions.

Note: The systematic reviews described in this note include preprints that have not been peer-reviewed. The research should not be used to guide clinical practice and should be evaluated with care.

Scientific Evidence

Prevalence of Long COVID

• A recent systematic review and meta-analysis (June 2021) on the prevalence of post-COVID-19 symptoms in hospitalized (N=15,244) and non-hospitalized (N=9,011) COVID-19 survivors reported that post-COVID-19 symptoms are present in more than 60% of patients infected by SARS-CoV‑2.
  • Prevalence: At least one post-COVID-19 symptom was exhibited at 30 days (63.2% of sample), 60 days (71.9%), or ≥90days (45.9%) after onset/hospitalization.
  • Symptoms: Fatigue and dyspnea (shortness of breath) were the most prevalent symptoms. Other post-COVID-19 symptoms included cough (20-25%), anosmia (loss of smell; 10-20%), ageusia (loss of taste; 15-20%), or joint pain (15-20%).

Rehabilitation Care Models for Long COVID

• A SPOR Evidence Alliance (EA) rapid systematic review (June 2021) identified recent international studies (N=12) describing care models for Long COVID that have been developed for COVID patients discharged following a hospitalization and patients who had lived with the infection in the community (United States [US], United Kingdom [UK], Germany, Spain, and Italy). See Table 2 for details.
  • Key Principles: Over half the studies included in the review reported on care model principles (22 care model principles were identified in the literature). The five most common were: 1) Multidisciplinary teams (92%); 2) Integrated care (67%); 3) Self-management (58%); 4) Coordination of care (58%); and, 5) Evidence-based care (58%). According to the review, the identified principles were not described in detail, nor were details of how they were implemented presented, limiting the evaluation of outcomes.
  • Care Model Components: The review identified 10 distinct care model components most frequently described in the research literature. The five most commonly named were: 1) Standardized symptom assessment (92%); 2) Referral system (83%); 3) Follow-up system (83%); 4) Telehealth / virtual care (83%); and, 5) Home-based care (58%). According to the SPOR EA review, the descriptions of the identified components did not describe how they were implemented, limiting the evaluation of outcomes.
  • Staffing: The models included access to specialized medical services. Thirty health care professions and medical specialties were proposed for staffing Long COVID services. The following 10 were most commonly named in the research literature: 1) Pulmonary/Respiratory (100%); 2) Cardiovascular (92%); 3) Psychiatry/Psychology (83%); 4) Physiotherapy (83%); 5) Occupational therapy (75%); 6) Social work (75%); 7) Neurology (75%); 8) Primary care (58%); 9) Nutrition (58%); and 10) Speech and language therapy team (50%).
  • Proposed Care Pathway: Based on the identified research findings on care models for Long COVID, and the frequency of their occurrence, the SPOR EA systematic review proposed a care pathway for people hospitalized with COVID and people who had COVID in the community. The pathway integrates: 1) Rehabilitation services; 2) Primary care; and, 3) Specialty care for medical assessment (e.g., investigation of organ impairment). The entry into a care pathway would be made possible through the use of a centralized referral system that facilitates post-COVID assessment and triage. For a detailed map of the pathway, see Figure 1.
  • Impact and Costs: The impact and costs of these identified rehabilitation care models for Long COVID have not yet been reported in the research literature.

Effectiveness of Long COVID Rehabilitation Programs

• This briefing note summarizes recent study results on Long COVID from a living systematic review; ne randomized controlled trial (RCT); and three observational studies. Details of the single studies are outlined in Table 3.

Feasibility of Rehabilitation Programs

• A Swiss study (2021) reported that a comprehensive outpatient pulmonary rehabilitation program is feasible and can confer benefits to patients recovering from COVID-19. The protocol included: Twice weekly (60- to 90-minute) interval-based aerobic cycle endurance and resistance training sessions at intensities of 50% peak work rate; education; and physical activity coaching.

Health Impacts of Rehabilitation Programs

• Four recent single studies (2021) assessed physical therapy and pulmonary rehabilitation (PR) programs that were delivered either in-person at outpatient clinics or virtually (United States [US], United Kingdom [UK], Switzerland, China). Overall, the studies reported that patients with Long COVID who received rehabilitation improved on exercise tests, quality of life, function (less fatigue and lower perceived limitations to daily activities due to COVID-19) from baseline to follow-up or compared with a control group.
  • Pulmonary PR Programs: Physiotherapy-led, comprehensive outpatient PR programs led to a reduction in the number of patients with perceived limitations in their performance of daily life activities due to COVID-19. In addition, studies demonstrated that PR programs led to improved strength and cardiopulmonary endurance among discharged COVID-19 patients. For example:
    • Overall Strength and Cardiopulmonary Endurance: A US-based strength and cardiopulmonary endurance rehabilitation program (30–60 mins. per session) improved sit-to-stand scores and step test results among COVID patients who engaged in virtual therapy and at-home physical therapy.
    • Strength/Walking: Two studies on at-home and virtual (‘RehabApp’) rehabilitation programs reported that aerobic exercises and strength training significantly improved performance on walking tests among discharged COVID-19 patients.
    • Fatigue: A single UK study (2021) that evaluated a rehabilitation program featuring exercise and education showed improvement in fatigue and other clinical outcomes, including symptoms of breathlessness (dyspnea), exercise capacity and cognition.
    • Mental Health: The single UK study (2021) that evaluated a rehabilitation program featuring exercise and education improved mental health outcomes (i.e., anxiety, depression) though results were not statistically significant.
  • Physical Therapy and Mobility: A single US-based study (2020) examined the impact of physical therapy (PT) visit frequency and duration on patients’ mobility status at hospital discharge:
    • Frequency: Increased PT visit frequency was associated with higher mobility scores and increased probability of discharging home;
    • Duration: Longer mean visit duration was associated with improved mobility, and greater probability of discharging home (effects were less pronounced).

International Scan

Definition of Long COVID

• While a World Health Organization (WHO) report (March, 2021) states there is no internationally agreed upon definition of Long COVID, it has been generally defined as the persistence of any COVID signs and symptoms that continue or develop between four and 12 weeks after acute COVID-19, including both ongoing symptomatic COVID-19 and post–COVID-19 syndrome.

Prevalence of Long COVID

• A WHO policy brief (February 2021) reported that approximately 25% of COVID-19-positive patients still experience symptoms beyond the acute phase of the disease (four to five weeks after a positive test), and approximately 10% experience debilitating symptoms 12 weeks after having COVID-19, which may last for several more months.

The COVID-19 Evidence Synthesis Network is comprised of groups specializing in evidence synthesis and knowledge translation. The group has committed to provide their expertise to provide high-quality, relevant, and timely synthesized research evidence about COVID-19 to inform decision makers as the pandemic continues. The following members of the Network provided an evidence synthesis product that were used to develop this Evidence Synthesis Briefing Note:

• Ontario Health. (June 23, 2021). Benefits of Rehabilitation for People with Long COVID: An Expedited Summary of the Evidence (Confidential Draft). Ontario Health; and
• Evidence Synthesis Unit, Research Analysis and Evaluation Branch, Ontario Ministry of Health.