Construct | Measures | No. of items | Questionnaire* |
---|---|---|---|
Primary outcomes | Â | Â | Â |
   Knowledge | Knowledge questionnaire based on information provided in the decision aid | 20 Statements (True/false/don't know) | 2 |
Secondary outcomes | Â | Â | Â |
   Attitude | Marteau [26] | 4 | 1,2 |
   Ambivalence | Felt ambivalence [24] | 3 | 1,2 |
   Follow-up behaviour | Uptake of self-tests, visiting a doctor, changing lifestyle. | 7 | 3 |
   Intention | Intention towards self-testing, seeing a doctor. | 2 | 1,2,3 |
 | Intention towards changing lifestyle | 1 | 2,3 |
 | Stages of change [27] | 1 | 1,2,3 |
   Psychosocial determinants | Perceived benefits and barriers | 14 | 2 |
 | Self-efficacy | 3 | 2 |
 | Response-efficacy | 4 | 2 |
 | Perceived susceptibility/risk perception [28] | 3 | 1,2,3 |
 | Cues to action | 1 | 2 |
 | Perceived severity | 1 | 2 |
 | Anticipated regret | 1 | 2 |
 | Moral obligation | 2 | 2 |
 | Subjective norm | 1 | 2 |