Digital Multimodal Rehabilitation for People With Post-acute COVID-19 Syndrome.

Global cognition was assessed with the Montreal Cognitive Assessment (MoCA) a screening tool designed to identify mild cognitive impairment (MCI) and other cognitive deficits. The MoCA takes around 10-15 minutes to complete and consists of 30 items (range=0-30). Higher scores mean a better outcome.

Selective attention, inhibition, and processing speed are measured with the Stroop Color and Word Test. Participants are asked to name the color of a series of color patches (Stroop Color Naming), read a series of color words (Stroop Word Reading), and name the color of a series of color words where the word and color do not match (e.g., the word "red" written in blue ink), Stroop Color-Word Interference. Higher scores mean a better outcome.

Visual scanning and processing speed are measured with the Trail-Making Test-A version. Participants are asked to connect a series of numbered circles on a page in numerical order. Higher scores mean a better outcome.

Executive functioning and cognitive flexibility are measured with the Trail-Making Test-B version. Participants are asked to connect a series of circles that contain both numbers and letters in alternating numerical and alphabetical order. Higher scores mean a better outcome.

Auditory attention is measured with Digit Span Forward from WAIS-IV. Participants are asked to repeat numbers in the same order as read aloud by the examiner. Higher scores mean a better outcome.

Working memory is measured with Digit Span Backward from WAIS-IV. Participants are asked to repeat the numbers in the reverse order of that presented by the examiner. Higher scores mean a better outcome.

Perceptual Reasoning is measured with Matrices from the WAIS-IV. Participants are presented with a pattern or design with one missing piece and are asked to select the correct piece from a set of options to complete the pattern. Higher scores on the Perceptual Reasoning Index mean a better outcome.

Conners Continuous Performance Test - 2nd edition (CPT-II) is task-oriented computerised assessment of attention-related problems. Participants are presented with a repetitive array of visual stimuli on a computer screen for 14 min. Participants are instructed to press the space bar every time a letter other than "X" appears and to not press the space bar when "X" appears. The rate of stimulus presentation varies according to 1, 2, and 4 s intervals throughout the task. Measures: Correct Detection (Higher rates indicate better outcome), Reaction times (Lower scores indicate better outcome), Omission errors (Lower rates indicate better outcome), and Commission errors (Lower rates indicate better outcome).

The Digit Symbol Coding subtest from the WAIS-III is a neuropsychological assessment instrument for the detection of brain dysfunction in children and adults. It consists of replacing symbols that lack verbal meaning with numbers based on a key. Higher scores indicate better outcomes.

Verbal memory and learning are measured with the Rey Auditory Verbal Learning Test (RAVLT). It is a word-learning test where five presentations of a 15-word list are given, each followed by an attempted recall. This is followed by a second 15-word interference list (list B), followed by a recall of list A. Delayed recall and recognition are also tested. Higher scores mean a better outcome.

Phonetic fluency is measured with the FAS test. It consists of saying words that start with a certain letter, as many words as possible must be mentioned during a specific time of 1 minute. The standard administration of the test provides three letters, the most used are the letters F, A, and S. Higher scores indicate better performance.

Semantic verbal fluency is measured with the ANIMAL test. It consists of generating the name of as many species of animals as possible within 1min. Higher scores indicate better performance.

Memory and everyday forgetfulness are measured with The Memory Failures of Everyday-MFE Questionnaire is a self-reported test that allows an assessment of memory and everyday forgetfulness. It is a unifactorial questionnaire and consists of 30 items. The total score results from the sum of the scores in each item, from 1 to 30. The MFE can assess the current situation of the patients and their evolution long-term or changes due to treatment. Scores <8 represent an optimal memory function. Lower scores indicate better outcomes.

Anxiety is measured with the 7-item Generalized Anxiety Disorder Scale (GAD-7), a Likert-type scale with questions ranging from "not at all" (0 points) to "nearly every day" (3 points). The maximum score is 24. Higher scores mean a worse outcome.

Depression is measured with the Patient Health Questionnaire-9 (PHQ-9) which scores each of the 9 DSM-IV criteria as "not at all" (0 points) to "nearly every day" (3 points). Higher scores mean a worse outcome.

Mindfulness levels are measured with The Mindful Attention Awareness Scale (MAAS) assesses an individual's level of mindfulness, including attention, awareness, and non-judgment. The 15-item self-report questionnaire uses a 6-point Likert scale to measure an individual's general tendency to be aware of and attentive to their current experience. Scores on the MAAS range from 15 to 90, with higher scores indicating greater levels of mindfulness. A higher score suggests better outcome.

Fatigue is measured with the Chalder Fatigue Scale, an 11-item questionnaire measuring the severity of physical and mental fatigue on two separate subscales. Seven items represent physical fatigue (items 1-7) and 4 represent mental fatigue (items 8-11). Each item " less than usual" (0) to " much more than usual" (3). The ratings of items are added together to calculate the total score (range=0-33). High scores represent high levels of fatigue.

Psychological flexibility is measured with the Acceptance and Action Questionnaire, a 7-point Likert scale, ranging from 1 ("never true") to 7 ("always true"), indicating how frequently they experience the described behavior or feeling in their daily lives. The scale has 9 items and the total score ranges from 9 to 63, with higher scores indicating greater levels of psychological flexibility (better outcome).

Functionality is measured with a 12-item World Health Organization Disability Assessment Schedule-II (WHODAS-II). Patients are asked to state the level of difficulty experienced, considering how they usually do the activity. The scale scores each item as "none" (1) to "cannot do" (5). The total score is calculated with an SPSS syntax, and the range varies from 0 to 100, with higher scores reflecting more significant disability.

Sleep Quality is measured with The Pittsburgh Sleep Quality Index (PSQI). This test presents 24 items, although only 19 are taken into account for the correction. This test is divided into 7 dimensions, namely, sleep quality, sleep onset latency, sleep duration, sleep efficiency, sleep disturbances, hypnotic drugs, and daytime dysfunction. Higher scores indicate worse sleep quality.

Quality of Life is measured with EuroQol a self-completion questionnaire, which consists of five questions: covering mobility, hygiene, activities, pain, and anxiety. The descriptive system divides each of the 5 dimensions into three levels of response: the absence of a problem, some problem, and extreme problem. Lower scores indicate better outcomes. In addition, the questionnaire has a plus scale where the participants rated their health state on a scale of 0-100. In this scale, higher scores indicate better outcome.

Performed physical activity is measured with The International Physical Activity Questionnaire (IPAQ) is a questionnaire composed of 7 questionsin order to assessthe frequency, duration, and intensity (vigorous or moderate) of the performed physical activity, walking, and sitting time during a business day for the last 7 days. Later, from the minutes obtained from the participant's answers, the METS (metabolic equivalent tasks) conversion is performed, allowing a classification, depending on the energy consumption obtained for each activity, into three categories (low, medium, high). Higher score indicate better outcome.

White matter integrity: tractography measured by MRI

Grey and white matter volume measured by MRI

Resting state brain activity using fMRI

Sirt-1 levels are measured with the Sirtuin-1 ELISA Kit

microRNAs are measured with TaqMan miRNA qRT-PCR