PERsonalised Knowledge to reduce the risk of Stroke (PERKS-International): a randomised controlled trial testing the efficacy of an mHealth application to reduce risk factors for the primary prevention of stroke

Background and aimsWe evaluated the efficacy of the Stroke Riskometer mobile phone App to change the Lifes Simple 7(R) (LS7(R)) risk factor score at 6 months post-randomisation. Methods and designThis Phase III, prospective, outcome assessor-blinded, 2-arm randomised controlled trial (RCT) in Australia and New Zealand recruited participants from August 2021 to January 2024. Inclusion criteria: age [≥]35 and [≤]75 years; [≥]2 risk factors; smartphone ownership; no cardiovascular disease history. The intervention group was given access to the App; the usual care group received one e-mail with generic risk factor information. The primary outcome was the mean between group difference in LS7(R) (score 0 [poor] to 14 [ideal] comprising blood pressure, cholesterol, glucose, body mass index, smoking, physical activity and diet) from baseline to 6 months post-randomisation. Secondary outcomes were between group changes in individual LS7 items. Analyses were performed using intention to treat (ITT) principles with ANCOVA and linear mixed models to examine differences between groups, with pre-specified per protocol and subgroup analyses. ResultsWe randomised 862 participants (mean {+/-} SD age 58{+/-}11 years; 63% women; 74% Caucasian). At 6 months post-randomisation in ITT analyses, the mean difference between usual care (n=433) and intervention (n=429) groups in the change in LS7(R) score from baseline was 0.03 (95% CI -0.19, 0.25, p=0.79). Per protocol analyses (n=320 usual care; n=276 intervention) were similar (mean difference in change 0.11 95% CI -0.12, 0.34, p=0.34). Compared to usual care in ITT analyses, the intervention group had a borderline increase in metabolic equivalent of task (MET) minutes/week of physical activity (313.42 95% CI -2.80, 629.65, p=0.05), with no differences in other LS7(R) items. DiscussionAmong a general population aged 35 to 75 years with [≥]2 stroke risk factors, there was no evidence that having access to the App changed overall LS7(R) scores at 6-month follow-up. Participants in the intervention group did have a small increase in physical activity, compared to the usual care group after 6 months, but not other individual risk factors.