Table 2 Primary and secondary outcomes by allocated study arm and time point

Primary outcome: Unengaged participants

Retinal screening uptake since baseline

Baseline

4 weeks

Knowledge of: Diabetes/vision link (range 0–2)

Baseline

1.97 (.17)

1.96 (.21)

4 weeks

1.97 (.17)

1.98 (.15)

Change

0.00 (0.24)

0.02 (0.15)

 Diabetic retinopathy (DR) (range 0–11)

Baseline

6.43 (2.38)

6.78 (2.00)

4 weeks

7.64 (1.97)^b*

6.86 (2.10)

Change

1.21 (2.58)^a*

0.08 (2.07)

 Retinal screening (range 0–3)

Baseline

1.45 (.55)

1.42 (.70)

4 weeks

1.70 (.72)^b*

1.72 (.70)^b*

Change

0.25 (0.78)

0.30 (0.68)

Attitudes: Retinal screening (range 11–55)

Baseline

46.29 (4.99)

46.28 (6.17)

4 weeks

46.61 (5.70)

45.85 (5.4)

Change

0.32 (4.36)

−0.43 (4.14)

 Risk perception (range 4–28)

Baseline

13.49 (4.24)

12.30 (4.08)

4 weeks

13.64 (3.91)

12.17 (3.57)

Change

0.15 (3.18)

−0.13 (3.35)

 Anticipated regret (range 6–42)

Baseline

24.62 (5.96)

24.79 (5.55)

4 weeks

30.67 (5.85)^b*

29.40 (7.16)^b*

Change

6.05 (5.53)

4.62 (5.75)

Normative beliefs (range 2–14)

Baseline

13.26 (2.28)

13.43 (1.44)

4 weeks

13.10 (2.34)

13.02 (2.66)

Change

−0.15 (2.38)

−0.40 (2.21)

Intention (range 3–21)

Baseline

18.51 (4.61)

18.72 (5.22)

4 weeks

18.46 (4.01)

18.83 (4.36)

Change

−0.05 (4.38)

0.11 (2.12)

Behavioural skills: Perceived control (range 6–30)

Baseline

24.72 (4.10)

24.50 (4.38)

4 weeks

25.28 (4.24)

24.11 (4.97)

Change

0.56 (3.48)

−0.39 (4.22)

 Overcoming barriers (range 5–25)

Baseline

20.21 (3.27)

19.91 (4.08)

4 weeks

20.08 (3.43)

19.15 (4.17)

Change

−0.13 (3.26)

−0.77 (3.44)

Depressive symptoms (PHQ-2, range 0–6)

Baseline

2.38 (2.42)

1.94 (1.96)

4 weeks

2.05 (2.04)

2.00 (2.01)

Change

−0.33 (1.78)

0.06 (1.68)