JMIR Publications

ABSTRACT

Background:

To promote informed decision making and Maternal Pertussis Vaccination (MPV) uptake, we systematically developed an interactive, web-based decision aid for pregnant users. Intervention reach (the percentage of participants in the intervention group who used the intervention), use (how much and how long those participants used the intervention) and acceptability (how positively they evaluate the intervention) are essential for it to be effective, and should be reported to assess which intervention components may have been effective.

Objective:

This is a process evaluation aiming to evaluate (1) reach and (2) use of the intervention, and (3) the acceptability of the intervention.

Methods:

We analysed reach and use of the intervention among participants in the intervention group of a randomised controlled trial (RCT) that assessed the effects of the online tailored decision aid in the form of a web-app. Participants were recruited via social media and midwifery clinics and invited via e-mail to use the intervention at 18 weeks of pregnancy. Reach was measured objectively by assessing the number of participants that visited the intervention at least once. Use of the intervention was logged and included time spent on the decision aid, the number of times clicked, pages visited, and answers given in interactive components. Data of the baseline survey (at <18 weeks of pregnancy) was used to measure socio-demographics, informed decision making, MPV uptake and determinants of uptake. A post-test survey (20-22 weeks of pregnancy) was used to evaluate the acceptability of the decision aid. We report the findings descriptively, and assess baseline differences between those who used versus those who did not use the intervention.

Results:

Of the 586 participants in the intervention group, 463 (79.0%) reached the homepage of the intervention. Intervention reach appeared higher among those in their first pregnancy (8.35% difference, p=0.11), those recruited via their midwife rather than via social media (10.56% difference, p=.04), and those who completed a higher educational level (7.35% difference, p=.06). On average, participants spent 4.25 minutes on the decision aid (SD=4.39). Most participants used the decision aid once (56.2% of those who reached it, N=260) or twice (26.6%, N=123). The average number of clicks was 27.24 and varied widely (SD=25.08). Regarding acceptability, participants evaluated the decision aid positively with an overall grade of 8.0 out of 10 (SD=1.01). In total, 38.9% of participants indicated that the decision aid helped them with MPV decision-making.

Conclusions:

The reach of the decision aid was successful with 79.0%, and participants were very positive about the decision aid. Use of the intervention (e.g. time spent on the intervention) leaves room for improvement and should be improved to maximize intervention effects. Clinical Trial: Trial registration: https://onderzoekmetmensen.nl/en/trial/25018