Statistical Analyses
depression, anxiety
Analyses included all caregivers randomized, with the completed questionnaire at baseline, and all data available were considered at each timepoint. Only descriptive analyses per group were conducted.Socio-demographic, clinical patient characteristics, and caregiver characteristics were described in the global population and in each group. Categorical variables were expressed using number and frequency (n,%), and continuous variables used median (min-max). Mean (standard deviation)/median (min-max) scores were described at each timepoint in both groups. No statistical comparisons between randomization groups were done due to the limited sample size.Reliability of the questionnaires was evaluated with the assessment of the internal consistency using a Cronbach’s alpha coefficient for each dimension of the SF-36, HADS, and ZBI at baseline. A Cronbach’s alpha of at least 0.70 was expected [To assess potential attrition bias, baseline characteristics of caregivers with early discontinuation at M12 and at M24 were compared to those continuing the study. Mean changes in SF-36, HADS, and ZBI scores from baseline to M12 and M24 are presented per group with a paired Mixed models for repeated measures were used for longitudinal analysis including all timepoints up to M24 and including the following effects: randomization group, time, allocation-by-time interaction, adjustment on baseline score, and baseline score-by-time interaction. Random effects on intercept and time were used in order to reflect individual variations. Adjusted mean changes at M12 and M24 were reported with 95% confidence interval for SF-36-PCS and MCS scores, HADS anxiety and depression, and burden, per group. Statistical and MID clinical significances were indicated.Analyses were performed using SAS version 9.4 software (SAS Institute Inc., Cary, NC, USA).