Per protocol analyses on the primary and secondary outcome measures.

IRR: Incidence rate ratio; CI: Confidence interval; CES-D: Center for Epidemiologic Studies Depression Scale; HADS-A: Hospital Anxiety and Depression Scales; CRA: Caregiver reaction assessment scale; SF-12 Short Form 12 item version; CI: Confidence interval; R*T: Randomization-by-time interaction.
*intervention versus usual care group, adjusted for HADS-A baseline differences and clustering. An IRR >1 means that over a period of 12 months more caregivers in the intervention group developed a disorder than in the usual care group.
#The randomization-by-time interaction coefficient represents the estimated difference of the scores between the intervention and usual care group over 12 months. Scores were adjusted for HADS-A baseline differences and estimated with multilevel analysis.