Parental Support Intervention in an Advanced Oncological Context

Frequency of parental communication with their children about cancer or its consequences

In the weekly assessment, participants are asked how many moments of communication they had with their child(ren) about cancer, treatments, or their consequences during the past week. This item measures the frequency of communication.

Quality of parental communication with their children about cancer or its consequences

A composite communication quality score will be computed for each communication moment reported in the weekly assessments. The score will be based on several dimensions: 1. Initiative, indicating whether the communication was initiated by the parent (yes/no); 2. Duration of the communication moment, reported in minutes; 3. Parental self-efficacy, defined as the perceived ability to inform, listen, answer questions, and reassure, each rated on a 0-10 Likert scale (0 = not at all capable; 10 = completely capable); 4. Comfort during the communication, assessed separately for the parent and the child using a 0-10 Likert scale (0 = not at all comfortable; 10 = extremely comfortable); 5. Disease-related topics discussed (yes/no); 6. Emotional expression, assessed using two yes/no items indicating whether the parent expressed their emotional experience and/or addressed the child's emotional experience related to the disease. Higher scores reflect better communication quality.

Parental communication difficulties

The level of perceived difficulties to communicate is assessed through one item 10-point Likert scale (0 = not at all certain; 10 = absolutely certain).

Parental self-efficacy regarding the communication with their children about cancer or its consequences

The level of self-efficacy to communicate is assessed through 27 items covering a list of disease-related communication topics (3 subscales of 9 items each : "I know how to communicate", "I am able to communicate" and "I am comfortable to communicate") 10-point Likert scale (0 = not at all certain; 10 = absolutely certain). The total score is obtained by summing the responses to all 27 items (maximum score = 270), and subscale scores are calculated by summing the 9 corresponding items (maximum score = 90).

Perceived children's communication behaviors

Perceived children's communication behaviors are assessed through a 12-item, 4-point Likert scale (0 = no; 1 = rather no; 2 = rather yes; 3 = yes). This questionnaire explores disease-related topics the child spontaneously brought up during conversations. The total score, obtained by summing the responses to all items, reflects the breadth of the child's spontaneous communication repertoire regarding the disease.

Parental self-efficacy in general

The level of parental self-efficacy in general is assessed through one validated item (Moore et al., 2015) rated on a 10-point Likert scale (0 = not at all certain; 10 = absolutely certain).

Children's academic performance

The authors developed a questionnaire to assess the academic performance of participants' children. This questionnaire explores the child's current level of education (i.e., current school grade if the child is still enrolled), as well as retrospective information about the previous school year, including the jury's decision (pass with or without conditions, or failure), the child's overall grade point average, and the number of subjects in which the child failed. Additionally, the questionnaire collects information on the total number of grade retentions since the beginning of the child's schooling.

Participant's perception of their AYA's global quality of life (KIDSCREEN)

Children's global quality of life is assessed using the KIDSCREEN questionnaire. The KIDSCREEN is available in both self-reported and hetero-reported versions; the latter is used to gather parents' perspectives on their children's quality of life. We used a 36-item version, rated on a 5-point Likert scale (with response options varying across items). In addition to a total score-calculated by summing responses across all 36 items-the questionnaire provides results on seven subscales: (1) Physical activities and health (5 items), (2) Child's feelings (3 items), (3) General mood (7 items), (4) Child's free time (4 items), (5) At home (6 items), (6) Friends (5 items), and (7) At school/university (6 items). For the last subscale, a "not applicable" option is available if the child is no longer enrolled in school.

Communication about cancer or its consequences in the family from the AYA perspective

Communication about cancer or its consequences in the family from the AYA perspective is assessed through 10 items 10-point Likert scale (0 = not at all true; 10 = absolutely true).

AYA's communication wishes

AYA communication wishes are assessed through 10 items 10-point Likert scale (0 = not at all true; 10 = absolutely true).

AYA's future expectations of parental disease and treatments

AYA's future expectations regarding parental disease and treatments are assessed using a 10-item measure. For each item, participants are asked to (1) choose between two proposed outcomes for a given situation-one optimistic and one pessimistic-and (2) indicate their level of certainty that this outcome will occur, selecting from three options: might, probably, or definitely. Among the 10 situations presented, 6 are neutral and realistic, while 4 are specifically related to the disease. Scoring is based on both the valence of the choice and the level of certainty. If the optimistic outcome is chosen, the score is assigned a positive sign; if the pessimistic outcome is chosen, the score is negative. The level of certainty determines the absolute value of the score: might = 1, probably = 2, and definitely = 3. Scores are summed separately for the two subscales.

Participant's future expectations of disease and treatments

This questionnaire should only be completed by the parent if one of his or her children is participating in the study. Participant's future expectations of disease and treatments are assessed using a 10-item measure. For each item, participants are asked to (1) choose between two proposed outcomes for a given situation-one optimistic and one pessimistic - and (2) indicate their level of certainty that this outcome will occur, selecting from three options : might, probably, or definitely. Among the 10 situations presented, 6 are neutral and realistic, while 4 are specifically related to the disease. Scoring is based on both the valence of the choice and the level of certainty. If the optimistic outcome is chosen, the score is assigned a positive sign; if the pessimistic outcome is chosen, the score is negative. The level of certainty determines the absolute value of the score: might = 1, probably = 2, and definitely = 3. Scores are summed separately for the two subscales.