3-week recruitment period of portuguese medical students wanting to attend the 28-hour online course

The control group was recruited in order to match the age, gender, academic year and teaching faculty variables with the intervention group and people with these characteristics were invited to participate.

The online self-knowledge and communication course, created for the purpose of this clinical trial and taught by professionals with certified training in the area by the Shalom Enneagram Institute (https://iesh.pt/), consisted of providing volunteers with mechanisms for self-knowledge using the enneagram. Three modules were carried out between October and December 2020, spaced in time to allow participants to consolidate knowledge: there was 1 month between the first and second module, and between the second and third, 3 weeks.

Perceived Stress Scale (PSS-10: Perceived Stress Scale; Cohen, Kamarck & Mermelstein, 1983 (Cohen et al., 1983); Portuguese version by Trigo et al, 2010) (Trigo et al., 2010). Composed of 10 items, it allows to understand how the unpredictability, uncontrollability or excessiveness of life events are perceived as generators of stress by the individual. Each item is assigned a rating between 0 ("never") and 4 ("very often"). To calculate the final score, it is necessary to reverse the rating of items referring to positive situations (items 4, 5, 7 and 8). Thus, a result between 0 and 40 points is obtained, with values between 0 and 13 being defined as low levels of stress, 14 to 26 medium levels and 27 to 40 high levels. In the Portuguese population, the PSS-10 version has good internal consistency (α=0.87)

Maslach Burnout Scale for Portuguese students: Its original version is, to date, the most used burnout rating scale. The version adapted for students (MBI - Student Survey), focusing on feelings and emotions in a school context, comprises 3 subscales, which assess the dimensions Emotional Exhaustion, Disbelief and Professional Effectiveness with 5, 4 and 6 items, respectively. Respondents must rate each of the 15 items between 0 ("never/never") to 6 ("always/everyday"). The final scores are interpreted in the 3 subscales, after the sum of their items, allowing the diagnosis of burnout syndrome when the respondent is simultaneously above the 66th percentile of the Emotional Exhaustion and Disbelief scores and below the 33rd percentile of the Professional Efficacy score, relative to the studied group.

Visual Analogue Scale for Perceived Quality of Life (EQ-VAS: European Quality of Life - Visual Analogue Scale; EuroQol Group, 1990; Portuguese version by Ferreira, Ferreira & Pereira, 2014) (Ferreira et al., 2013). It is an integral part of the EuroQoL-5Dimension scale (EQ-5D), which comprises two components: a descriptive system, subdivided into 5 dimensions, and a numerical system, achieved through a visual analogue scale - the EQ-VAS thermometer. This offers the possibility for the respondent to quantify their health status on a scale from 0 ("worst imaginable health status") to 100 ("best imaginable health status"), at that moment. In the Portuguese version, the EQ-VAS showed good internal consistency (α=0.862)

Compassion Scale (CS: Compassion Scale; Pommier, 2011 (Pommier, 2011); Portuguese version by Vieira, Castilho & Duarte) (Vieira CS, 2013). Bringing together the six factors of compassion (Kindness vs. Indifference, Common Humanity vs. Disconnectedness, Mindfulness vs. Non-involvement), this scale aims to measure how each individual behaves towards others. Each subject must identify their level of agreement regarding the 24 items of the long version, on a scale from 0 ("almost never") to 5 ("almost always"). Items 1, 2, 3, 5, 7, 10 , 12, 14, 18, 19, 22 and 23, corresponding to subscales with negative connotations (Indifference, Disconnected and Non-Involvement) must be recoded to access the total compassion score. Higher scores translate to a higher level of compassion.