Treatment engagement
SD
Of the carers in the ITT analysis randomised to MS-BPD + Online, 20 (57.1%) completed treatment, while 12 (34.3%) did not attend any MS-BPD sessions. The carers spent a mean of 48.9 minutes (SD = 146.9) logged into the online intervention, visiting a mean of 0.7 (SD = 1.7) times. Carers were not logged out after periods of inactivity. Six (17.1%) carers used the online intervention for more than 45.2 minutes and 25 (71.4%) did not log in at all. The carers had a mean of 0.9 (SD = 1.9) and 0.4 (SD = 1.1) phone contacts and 1.4 (SD = 1.9) and 0.5 (SD = 1.0) face-to-face contacts with the HYPE family work clinician and family peer support worker, respectively.Of the carers in the ITT analysis randomised to Online, 17 (44.7%) completed treatment and 14 (36.8%) did not log in. Carers spent a mean total of 420.3 minutes (SD = 1594.6) logged into the online intervention, visiting a mean of 2.9 (SD = 3.8) times. They had a mean of 0.9 (SD = 1.9) and 0.3 (SD = 0.7) phone contacts and 0.6 (SD = 1.3) and 0.1 (SD = 0.4) face-to-face contacts with the HYPE family work clinician and family peer support worker, respectively.