Development of a text message intervention designed to promote safe contact lens wear.

Introduction: Some contact lens wearers demonstrate poor compliance with hygiene behaviours which increase their risk of corneal infection. Text message interventions for behaviour change can provide support and education in healthcare domains. This study reports on the co-design of a text message intervention to target hygiene compliance, user satisfaction and discontinuation in contact lens wear.

Methods: In phase 1, draft messages were composed using contact lens compliance advice from peak bodies, which was then optimised for persuasion using behaviour change theory. Phase 2 involved consultation with Patient Advocates (3), Health Psychology Experts (5) and Eyecare Practitioners (11), who rated messages (Likert 1-6) on readability, appropriateness, behaviour change and provided comments. Lay contact lens wearers participated in focus groups (2-4 per group) and provided feedback on relevance, comprehension and likely behaviour change. Phase 3 assessed messages and modified for readability (Flesh-Kincaid). Phase 4 created and pilot tested (n = 5 users) text message sequences.

Results: Phase 1 created 95 messages. In Phase 2, ratings (1-6) of readability (M = 5.4, SD = 0.5), appropriateness (M = 5.3 SD = 0.6) and likelihood to change behaviour (M = 5.0, SD = 0.6) combined with free text comments led to the modification of 59/95 (62%) messages, including the deletion of five messages. Focus group participants (5 groups, n = 14) suggested engagement, educational content and simplification. Most (62/90, 69%) messages were modified, four removed and two new messages proposed. In Phase 3, 88% were assessed as fairly easy or better. Post-modification, all messages were fairly easy, mean readability 82.1 (range: 73.7-91.8, SD = 5.8). Phase 4 created 17 sequences of text messages and pilot testing established the process for replies, opt-outs and modified time-zone delivery.

Conclusion: Co-designing and evaluating text messages was feasible, resulting in a library of 88 optimised text messages formed into semi-personalised sequences.