Sequence generation
milder difficulties, cognitive impairments, cognitive complaints, cognitive deficits
SECONDARY
Given our small sample size, and because individuals with more severe cognitive impairments might respond differently to the intervention than those with milder difficulties, we will use randomization by minimization. Although severity and interval since COVID episode are probably important prognostic factors in outcomes, we decided to achieve trial arm balance only on age, education level, gender, Centre, and severity of cognitive deficits and complaints. For cognitive deficits, scores will first be Z-scored based on normative data, and next a global Z-score calculated on all variables will be considered (sum of Z-scores divided by number of measures). A Z-score will also be calculated for both tools assessing cognitive complaints. For both these objective and subjective indices, balance will be done by Z-score range of 0.5 (e.g., Z-score from 0 to -0.50; -0.51 to -1, etc.). For age we will use 18–29; 30–39; 40–49; 50–59; 60–70. For education, we will use 4 levels: 1. primary or professional education; 2. secondary education; 3. bachelor; 4. master. In the calculation of the imbalance each arm and each prognostic factor will have the same weight. The imbalance score is calculated based on all previous allocations as well as the current participant's hypothetical allocation to each treatment. The distance measure used to calculate the imbalance score is the marginal balance. If there is no imbalance, the allocation will be completely random. If there is an imbalance, the treatment with the lowest imbalance score is chosen with a 75% probability.