Box 2.

Priority areas and considerations for future research.

• Treatment options are currently limited as there is insufficient understanding of the mechanisms that underpin long COVID. Longer-term longitudinal observational studies are needed to fully understand the pathophysiology of the symptoms and complications associated with long COVID-19, its clinical course, symptom clusters and syndromes. This evidence will be crucial to understand the natural history of long COVID and the types of interventions that may be required. Qualitative research into the lived experiences of patients could provide the insight required for the planning of effective care pathways and lead to improved clinical outcomes. Clinical trials are urgently needed to evaluate interventions for long COVID that address the wide range of symptoms and complications identified in this review.

• Racial differences in the incidence of acute COVID-19 infections have been well documented. However, such differences have not been well researched in patients with long COVID and need further exploration.

• Most studies have focused on hospitalised patients and there is an urgent need for studies to investigate long COVID in non-hospitalised COVID-19 patients who have been underrepresented in the current research literature.