The effect of programme testimonials on registrations for an online cognitive behaviour therapy intervention: a randomised trial

Objective: Suboptimal visit-to-registration rates limit the reach and potential impact of online health interventions. In this study, we examined whether testimonials presented during a new-user registration process could increase the uptake rates of MoodGYM, an open-access automated intervention designed to reduce the symptoms of depression. Methods: We conducted a three-armed parallel randomised controlled trial on the MoodGYM website involving variations of the first page of the registration process. Spontaneous visitors saw either the current pre-registration content, the current content supplemented by a first-person past user testimonial or the current content accompanied by a testimonial from a third-party health professional. The primary outcome measure was the proportion of visitors seeing each version who completed registration. Results: A total of 14,267 visits were recorded across the three conditions. The past user, health professional and control condition registration rates were 45.6%, 45.5% and 45.5% respectively, indicating that there was no effect of registration content on registration rate. (p>0.05) Conclusions: There may be limited use for testimonials in well-established interventions that have programme benefits clearly stated and presented in other forms. However, we cannot exclude the possibility that testimonial effects might be moderated by positioning or other elements within the registration flow or by visitor source. Further research is required to examine these factors and, more broadly, assess whether modifications to other aspects of the registration process can improve visit-to-registration rates.