Table 3.
Outcome measures of the primary and secondary endpoints of the BOOST pACP program
| Outcomes | Measurement instrument | No. of items | Unit of analysis | Timepoint | ||
|---|---|---|---|---|---|---|
| T0 | T1 | T2 | ||||
| Primary endpoint | ||||||
| 1. Quality of Parent-Adolescent Communication | Parent-Adolescent Communication Scale (PACS) [32] | 20 items | Adolescent | x | ||
| Secondary endpoints | ||||||
| 2. Quality of Parent-Adolescent Communication | PACS | 20 items | Adolescent | x | x | |
| 3. Attitude on talking with the other (parent(s)/ their child) about what the adolescent finds important regarding his/her care and treatment | Created by the research teama | 8 items | Adolescent | x | x | x |
| 7 items | Parent(s) | x | x | x | ||
| 4. Self-efficacy towards talking with the other (parent(s)/ their child) about different ACP themes | Created by the research teama | 9 items | Adolescent | x | x | x |
| 4a. if the child initiates the conversation | Created by the research teama | 9 items | Parent(s) | x | x | x |
| 4b. to initiate the conversation his/herself | Created by the research teama | 9 items | Parent(s) | x | x | x |
| 5. Self-efficacy towards talking with their child and letting their child talk in different situations | Created by the research teama | 6 items | Parent(s) | x | x | x |
| 6. Behaviour: talking with the other (parent(s)/ their child) about different ACP themes | Created by the research teama | 9 items | Adolescent | x | x | x |
| 9 items | Parent(s) | x | x | x | ||
| 7. Intention to talk with the other (parent(s)/ their child) parent(s) about different ACP themes | Created by the research teama | 9 items | Adolescent | x | x | x |
| 9 items | Parent(s) | x | x | x | ||
| 8. Behaviour: talking with paediatric oncologist about different ACP themes | Created by the research teama | 9 items | Adolescent | x | x | x |
| 9. Intention to talk with paediatric oncologist about different ACP themes | Created by the research teama | 9 items | Adolescent | x | x | x |
| 10. Anxiety | PROMIS Anxiety 8a Short version [33]b | 8 items | Adolescent | x | x | x |
| PROMIS 7a Short version [34]b | 7 items | Parent(s) | x | x | x | |
| 11. Level of shared decision making | CollaboRATE Scale [35, 36]c | 3 items | Parent(s) | x | x | x |
| 12. Satisfaction items for the intervention group | Created by the research team | 14 items | Adolescent and parent(s) | x | x | |
| 13. Behaviour & intention to discuss ACP with the family | Created by the research team | 3 items | Oncologist | x | x | x |
| 14. Quality of Life | EQ-5D-Y [37] | 6 items | Adolescent | x | x | x |
| Background characteristics | ||||||
| 15. Demographic and background information | Created by the research team | 3 items | Adolescent | x | ||
| 14 items | Parent(s) | x | ||||
| 16. Disease & treatment information about adolescent | Created by the research team | 7–10 items | Oncologist | x | x | x |
aThe following procedure was followed: 1) The Theory of Planned Behaviour instructed ways items were formulated regarding the four key constructs operationalizing ACP as a health behaviour: attitude, self-efficacy, intention and actual behaviour; 2) the prototype instrument was linguistically improved and made age appropriate by a literacy expert agency; 3) cognitive interviews with adolescents who were diagnosed with cancer (n = 4) and parents (n = 6) were then performed; 4) feedback using thematic analysis and discussions with the researchers informed refinements. Response categories: ‘Strongly Disagree’, ‘Disagree’, ‘Neither Agree Nor Disagree’, ‘Agree’ or ‘Strongly Agree’
bResponse categories: ‘Never’, ‘Rarely’, ‘Sometimes’, ‘Often’, or ‘Always’.
cResponse categories: 10 – point Likert scale, ranging from ‘No effort was made’ (=0) to ‘Every effort was made’ (=10)