General cognition
The Montreal Cognitive Assessment (MoCA) will be used for general cognitive screening for all patients at baseline measurement and after the intervention.
The MoCA is designed as a rapid screening instrument for cognitive dysfunction. It assesses different cognitive domains: attention and concentration, executive functions, memory, language, visioconstructional skills, conceptual thinking, calculations, and orientation. The possible score is 30 points; a score of ≥ 26 is considered as normal, 18-25 indicates mild cognitive impairment, 10-17 moderate cognitive impairment and < 10 severe cognitive impairment.
Attention
Change in visual selective attention, processing speed and concentration is measured in all patients with the D2 test at baseline measurement, after the intervention and at 3 months follow-up. Change in visual attention, executive function (divided attention) and processing speed is measured with the Trail Making Test (TMT A & B) at baseline measurement, after the intervention and at 3 months follow up. The Stroop Test measures mental speed, executive attention and response inhibition in all participants of the study at baseline measurement, after the intervention and at 3 months follow-up.
Working memory
Working memory is measured in all patients at baseline measurement, after the intervention and at 3 months follow-up with the use of the Digit Span Forward (DSF) and Digit Span Backward (DSB) test (part of the Wechsler adult intelligence scale). It involves the oral presentation of spans of digits. The measure has both a 7-item digits forward task and a 7-item digits backward task, each one with its own individual score.
Together with 'calculation' (also a part of the Wechsler adult intelligence scale), an index for working memory can be calculated.
Subjective cognitive complaints
The Cognitive Failures Test (CFQ) is used for all participants at baseline measurement, after the intervention and at 3 months follow-up to assess the frequency with which people experience cognitive failures in everyday life, such as absent-mindedness, slips and errors of perception, memory, and motor functioning. The total score of the scale is the sum of the ratings of the 25 individual items, yielding a score from 0-100. The CFQ has 3 sub-scales: forgetfulness, distractibility, and false triggering.
Anxiety and depression
The Dutch Hospital Anxiety and Depression Scale (HADS) is used for all participants at baseline measurement, after the intervention and at 3 months follow-up as a general measure of emotional distress and contains two sub-scales: anxiety and depression. Each sub-scale consists of 7 items, which are rated on a 0 to 3 point rating scale. Sub-scale scores ≥ 8 might indicate the presence of a depressive disorder or an anxiety disorder. Reliability and validity are adequate for several clinical populations, including multiple sclerosis and acquired brain injury.
Health-related quality of life (HR-QoL)
The EQ-5D-5L is used for all participants at baseline measurement, after the intervention and at 3 months follow-up as a measurement for HR-QoL. The EQ-5D-5L consists of the 5-item EQ-5D index (mobility, self-care, usual activities, pain/discomfort and anxiety/depression) and a visual analogue scale (EQ VAS). Psychometric properties of the Dutch version showed to be good. The five EQ-5D index items are summarized into one weighted overall score, which runs from 0 for the value of death to 1.00 for full health. The EQ VAS ranges from 0 to 100 (worst to best imaginable health state). For the general Dutch population average EQ-5D index = 0.843 and average EQ VAS = 81.36.
Fatigue
The Fatigue Assessment Scale (FAS) is used for all participants at baseline measurement, after the intervention and at 3 months follow-up as a measurement for fatigue. The FAS is a simple and short self-administered questionnaire to assess chronic fatigue. Patients' agreement with 10 statements is rated on a 5 points Likert-scale, ranging from 1 ("never") to 5 ("always"). Total scores can range from 10, indicating the lowest level of fatigue, to 50, denoting the highest.
Coping
The Coping Inventory for Stressful Situations (CISS-Short Form) is used at baseline measurement to measure coping styles of all participants.
The short version of the CISS is used as a measure of coping with stressful situations. It has 21 items which are rated on a 1 to 5 point rating scale. It contains 3 subscales: task-oriented, emotion-oriented, and avoidance-oriented coping.
Personality traits neuroticism and extraversion
The Eysenck Personality Questionnaire Brief Version (EPQ-BV) is used at baseline measurement to measure level of neuroticism and level of extraversion of all participants.
The EPQ-BV is a revised version of the EPQ-S to measure individuals on two primary personality traits in Eysenck's personality theory (1990). It consists of two measures, one for extraversion (12 items) and one for neuroticism (12 items).