Table 2

Validity and reliability of study questionnaires

Self-efficacy (Self-Efficacy for Diabetes Self-Management Measure)Participants will rate their degree of certainty in their ability to correctly carry out 10 diabetes management tasks on a 10-point Likert scale ranging from ‘not sure at all’ to ‘completely sure’.The test-retest intraclass correlation for the measure was 0.89. The Cronbach’s alpha coefficient 0.90.
Diabetes knowledge (L'Aide aux Jeunes Diabétiques Diabetes Knowledge and Skills questionnaire)A validated scale composed of 50 true-false questionsConstruct validity:
scores differed by haemoglobin A1c (p<0.001) and by age (p<0.001).
Transition readiness (Am I ON TRAC? For Adult Care questionnaire)The questionnaire is a 25-item validated scale consisting of: (1) knowledge scale with a 4-point Likert scale ranging from ‘strongly disagree’ to ‘strongly agree’ and a (2) behaviour index with a 5-point ordinal scale, ‘never’ to ‘always’ and asks youth to report how frequently they engage in several health-related behavioursCronbach’s alpha coefficient 0.93
Diabetes distress (Diabetes Distress Scale for Adults with Type 1 Diabetes)A validated 28-item self-report scaleAlpha coefficient 0.91. The test-retest reliability was 0.74.
Quality of life (Paediatric Quality of Life Inventory Generic Core Scale and Diabetes Module)A 23-item and 33-item questionnaire, age-specific for 13- to 18-year-olds will be usedCronbach’s alpha coefficient 0.88