Background
Between 25 and 75% of people with persistent post-acute sequelae of SARS-CoV-2 infection (PASC) experience cognitive difficulties, compromising functional ability, quality of life, and activities of daily living, including work. Despite this significant morbidity, there is a paucity of interventions for this disorder that have undergone evaluation within a formal trial setting. Therefore, we have developed a cognitive rehabilitation programme, specifically designed to address the cognitive symptoms of PASC, notably impaired attention and processing speed, while also accounting for other PASC symptoms (fatigue, post-exertional malaise) that may aggravate the cognitive impairment. This study protocol outlines a randomised controlled trial (RCT) designed to evaluate the effectiveness of this programme compared to standard clinical care.

Methods
This is a multi-centre, parallel-group, individually randomised controlled trial, comparing standard clinical care with and without cognitive rehabilitation. We will recruit 120 non-hospitalised adults (aged 30–60 years) from three NHS sites in England with a history of COVID-19 infection and cognitive impairment persisting more than 3 months after the acute infection. Participants will be randomised (1:1) to the intervention or control groups, with the latter represented as a provision of standard clinical care without cognitive rehabilitation. The cognitive rehabilitation programme consists of ten 1-hour sessions, delivered weekly. Outcomes will be collected at baseline, 3, and 6 months, with participant-defined goal-attainment scores, relating to functional goals, at 3 months as the primary outcome measure. Secondary outcomes will be cognitive function, measures of quality of life, social functioning, mental health, fatigue, sleep, post-exertional malaise, and social and health care service use. We will also evaluate the health-economic benefits of cognitive rehabilitation in this population.

Discussion
Cognitive impairment in PASC is a major cause of functional disability with no effective treatment. Accordingly, we will undertake an RCT of cognitive rehabilitation, the protocol of which is published here. If this trial is successful in delivering improvements in trial outcomes, it will address a major unmet need relating to this emergent disorder, with a significant impact on affected individuals and the wider health economy.

Trial registration
ClinicalTrials.gov NCT05731570. Registered on February 16, 2023