Table 3 Summary of self-report primary and secondary outcomes, respective assessment measures, and screening measures

Psychological distress

Depression Anxiety Stress Scales-21 (DASS-21 [100]; EP version by [101])

It is a public domain instrument that evaluates negative affective states, being one of the available measures to assess psychological distress [102, 103]. It is also used in RCTs of manualized MBIs in the oncological context [104]. It is an abbreviated version of the original version of 42 items and can be administered to people aged 18 or more. It comprises 21 items, 7 measuring depression, 7 measuring anxiety, and 7 measuring stress. Specifically, participants are required to rate each item on a 4-point Likert-type scale as reference to how they have been feeling during the last week. The rating scale varied between 0 and 3, in which 0 represents “did not apply to me at all” and 3 represents “applied to me very much or most of the time”. The score for each subscale is obtained by summing the respective 7 items, whose result range between 0 and 21. In this study, a total score will be used by summing all items, with higher scores being indicative of higher self-reported negative affective experiences. The EP version yielded satisfactory internal consistency and convergent and discriminant validity [101]).

Emotion suppression

Expressive Suppression scale of the Emotion Regulation Questionnaire (ERQ [105]; EP version by [106])

It evaluates strategies of emotional regulation, particularly cognitive reappraisal, and expressive suppression. It is a brief questionnaire including 10 items, 4 dedicated to expressive suppression and 6 to cognitive reappraisal, contributing to the 2-factor structure. Each item is rated on a 7-point Likert-type scale, wherein 1 represents strongly disagree and 7 strongly agree. Two scores are derived, one related to cognitive reappraisal (ranging from 6 to 42) and the other related to expressive suppression (ranging from 4 to 28). Higher scores indicate higher employment of the regulation strategy under evaluation. The original study demonstrated that ERQ has good psychometric properties of internal consistency, test-retest reliability, convergent, and discriminant validity. These good properties have been replicated in different samples such as community samples (e.g. [107]) and people diagnosed with cancer, including in the Portuguese context (e.g. [108]). In the current study, only the expressive suppression scale will be used as an outcome.

Fear of cancer recurrence

7-item Fear of Cancer Recurrence Questionnaire (FCR7 [109])

It is a unidimensional screening measure of FCR to be used in oncological contexts. It is composed of 7 items, most of them rated in a 5-point Likert-type scale ranging from 1 (not at all) to 5 (all the time) and one item rated in a 10-point scale ranging from 0 (not at all) to 10 (a great deal). Higher scores are indicative of higher reported levels of FCR. As a reference, a score of 17 corresponds to a moderate level of FCR and a score of 27 corresponds to a high level. Satisfactory psychometric properties have been documented in terms of internal consistency, test-retest reliability (1-month), content and convergent validity [110]. As FCR7 is a recent questionnaire, no EP version is yet available. Thus, the research version is being developed in the context of this study.

Mindfulness

Five-Facet Mindfulness Questionnaire (FFMQ [111, 112]; EP version by [113])

It was developed based on a comprehensive analysis of different mindfulness questionnaires, supporting the notion that mindfulness is a multifaceted construct. Specifically, this questionnaire assesses mindfulness and self-awareness states in everyday life, incorporating five facets/subscales: observing, describing, acting with awareness, nonreactivity to inner experience, and nonjudging of inner experience. It encompasses 39 items, each one rated on a 5-point Likert-type scale ranging from 1 (never or very rarely true) and 5 (very often or always true). A score is derived for each facet. This questionnaire has been widely used in intervention studies. In addition, it has been adapted to different cultures with good results [114]. In the case of the EP version, satisfactory psychometric properties for the five-dimension solution in terms of internal consistency, convergent and discriminant validity had been reported [113].

Nicotine dependence

Fagerström Test for Nicotine Dependence (FTND [115]; EP version by [116])

It is a widely used questionnaire to assess nicotine dependence. It is a brief measure composed of 6 items. Two of the items are scored between 0 and 3, and the remaining are scored between 0 and 1. Thus, the total score ranges between 0 and 10. The EP version has been tested for internal consistency and test-retest reliability with satisfactory results. Also, a two-factor structure emerged, one related to cigarette consumption and the other related to morning smoking [116].

Of note, to complement the data regarding the consumption of substances that may interfere with the biological markers under study, questions concerning the weekly consumption of alcohol, coffee, coffee-based beverages, and tea, as well as the type of diet and its self-perceived quality will be added.

Physical activity

International Physical Activity Questionnaire – Short Form (IPAQ – SF; [117])

It evaluates physical activity and sedentary behaviour (sitting). In this study, the short form will be used because it is faster and easier to administer while maintaining similar reliability and validity properties as compared to the extended version. It contains 9 items encompassing the frequency (days) and time spent on walking, moderate-intensity activities, vigorous-intensity activities, and sedentary activities. The reference period to be used in the current study will be the “usual week”. An estimation of time (minutes) per week dedicated to each type of intensity (vigorous, moderate, walking) and sitting can be obtained. From these data it is possible to estimate the total weekly physical activity in MET minutes per week. Also, it is possible to categorize the people into 3 possible levels of physical activity: low, moderate, or high (the following protocol can be used: https://sites.google.com/site/theipaq/scoring-protocol). Concerning the psychometric properties, acceptable results were described in the study of Craig and collaborators [117], considering test-retest reliability (around 1 week), criterion (based on accelerometer), and concurrent (based on short and long versions) validity. Although scarce, the evidence available for the EP adaption is also reasonable [118].

Posttraumatic growth

Posttraumatic Growth Inventory (PTGI [119]; EP version by [120])

It is a self-report questionnaire that assesses positive psychological change in people that faced traumatic experiences. It is composed of 21 items structured in a 5-factor model: new possibilities (5 items); relating to others (7 items); personal strength (4 items); spiritual change (2 items); appreciation of life (3 items). Each item is rated on 6-point Likert-type scale ranging from 0 (“I did not experience this change as a result of my crisis”) to 5 (“I experienced this change to a very great degree as a result of my crisis”). The total score varies between 0 and 105, with higher scores depicting a greater degree of posttraumatic growth. The original study revealed satisfactory internal consistency, test-retest reliability (2 months), construct, concurrent, and discriminant validity. The Portuguese adaptation including participants diagnosed with breast cancer and non-clinical participants yielded reasonable psychometric properties [120, 121].

Quality of life

World Health Organization Quality of Life – Bref (WHOQOL-Bref [122, 123]; EP version by [124])

It is the abbreviated version of the 100-item instrument (WHOQOL-100), suitable for epidemiological and clinical trials, which evaluates the quality of life following the WHO’s proposal (i.e. the perception of an individual regarding one’s position in life given the cultural and social environment, as well as expectations, preoccupations, and goals). It includes 26 items arranged in one general facet and four specific domains: physical health, psychological, social relationships, and environment. Each item is rated having the last 2 weeks as the time period of reference and using a 5-point Likert-type scale. The scoring procedures can be consulted here: https://www.who.int/mental_health/media/en/76.pdf. Higher scores indicate higher self-reported quality of life. The original studies showed satisfactory psychometric properties in terms of internal consistency, test-retest reliability, construct, discriminant, and criterion validity. Similarly, satisfactory psychometric properties of validity and reliability were documented for the Portuguese adaptation [124], being successfully used in several studies with Portuguese oncological groups (e.g. [125, 126]).

Sleep quality

Basic Scale on Insomnia complaints and Quality of Sleep (BaSIQS [127])

It is a brief easy to administer self-report questionnaire that evaluates sleep quality and difficulties related to fall asleep and to maintaining sleep, considering a typical week in the last month. It encompasses 7 items rated on a 5-point Likert-type scale, and each one scored between 0 and 4. The total score ranges between 0 and 28, with the highest values being indicative of poor sleep quality. This questionnaire was initially developed and tested with groups of Portuguese higher education students, yielding good internal consistency, test-retest reliability, and convergent validity. Normative scores for males and females were presented based on percentiles, 25, 50, and 75. These good psychometric properties were also extended to a Portuguese community sample, and BaSIQS was able to distinguish between people with clinical insomnia and people with sleep disturbance [128].

In the current study, additional questions available in the plus version of BaSIQS will be included, namely the number of hours usually slept per night during week and weekend, frequency of nights per week wherein the participant is able to sleep the number of needed hours, frequency and duration of naps, and perceived subjective sleep problems.

Social support

Social Support Satisfaction Scale (SSSS [129])

It is a self-report questionnaire that assesses perceived social support. It is composed of 15 items distributed in four factors: satisfaction with friendship (5 items), intimacy (4 items), satisfaction with family (3 items), and social activities (3 items). Each item is rated on a 5-point Likert-type scale, ranging from totally agree to totally disagree, and scored between 1 and 5. A score can be obtained for each subscale, but the total score will be considered in this study. The total score can be extracted by adding each subscale score, and it ranges between 15 and 75, with higher scores representing higher perceived social support. The original study conducted with a Portuguese sample revealed good internal consistency, discriminant, and concurrent validity. Reasonable psychometric properties of validity and reliability were also reported study with a Portuguese and Brazilian sample of university students [130].

Distress

Distress thermometer (DT [7])

It is a simple visual analogue scale with 11 points (from 0—no distress to 10—extreme distress) shaped like a thermometer and devised to screen the experience of distress during the last week in oncology populations. The higher the value selected, the higher the level of distress reported by the participant.

Global distress and mental health difficulties

Clinical Outcome Routine Evaluation – Outcome Measure (CORE-OM [131,132,133]; EP version by [134])

It is a self-report measure that incorporates 34 items organized in four different dimensions: well-being (4 items), symptoms (12 items), social and personal functioning (12 items), and risk behaviours (6 items). Each item is evaluated using a 5-point Likert-type scale that varies from 0 (not at all) to 4 (most or all the time). The time window of reference is the last week, and it takes about 5–10 min to complete. The original total score is obtained by averaging all the items. The mean score can be multiplied by 10 to facilitate interpretation, resulting in scores ranging between 0 and 40. Higher values denote a more severe level of global distress (see https://www.coresystemtrust.org.uk/instruments/core-om-information/). CORE-OM has been widely tested and demonstrates satisfactory concurrent and convergent validity, internal consistency, and test-retest reliability (1-week interval; [131,132,133]). Good internal consistency was also found in the EP adaption [134].

Sociodemographic and health-related information

It consists in information to be obtained directly from participants or clinical records: age; gender; years of formal education; nationality(ies); mother language(s); marital status; current regional location of residence; professional occupation and current occupational situation; average household income (mensal); children (number and ages); informal care provided to other persons; people living in the household; clinical history; familial cancer history, date and age of the cancer diagnosis, who detected the cancer, type of cancer and site, stage, cancer treatments (including start and end date); comorbidities (e.g. hypertension; diabetes mellitus; autoimmune diseases such as lupus, thyroiditis, rheumatoid arthritis); history of surgical interventions; pharmacological treatments and possible adjustments in the last 3 months; psychological intervention; psychiatric intervention; mindfulness meditative practices; menopause signs and symptoms in the case of female participants.