Adherence Intervention
OSA
The intervention comprised the delivery of personalized education and feedback aimed at increasing CPAP adherence in 2 ways.First, the participants received 2 educational brochures: one explaining OSA delivered in the sleep clinic on day 0 (and again by mail on day 2) and another explaining CPAP therapy delivered on day 7 by mail. The brochures provided general information and aimed to stimulate perceived importance, outcome expectations, self-efficacy, and motivation to adhere to CPAP therapy by covering 4 topics, namely potential risks of untreated OSA (perceived importance and motivation), potential benefits of CPAP (perceived importance and outcome expectations), tips for getting started on CPAP easily and confidently (self-efficacy), and common pitfalls with corresponding troubleshooting recommendations (self-efficacy and motivation). Four different versions of each of the 2 educational brochures were produced, each tailored to one of the 4 psychological profiles. The contents covered in the brochures were very similar; the only difference was the tailoring to the psychological profile. Textual or visual references to age, gender, and ethnicity within the brochures were adjusted for each individual.The second and biggest element of the intervention relied on digital technologies to compose 7 personalized CPAP reports delivered weekly by mail beginning on day 11 (refer to The contents of the brochures and CPAP reports were compiled into templates, each targeting one of the psychological profiles. As such, all intervention materials were digitally generated in a systematic, automated fashion. To increase the likelihood of measuring an effect of style tailoring, we maximized the tailoring difference between the PT and PN groups. The participants randomized to PT received the brochures and reports consistent with their profile, whereas those randomized to PN received materials consistent with their opposite profile. The opposite profile for each participant was determined based on the psychological profiling questionnaire.