2.1. Study design and participants

A RCT was undertaken in the Netherlands, alongside the process evaluation (described below). Based on our power calculation, we originally aimed to include 122 primary caregivers (due to recruitment difficulties, 96 were eventually successfully recruited). Caregivers were recruited via regional and national dementia community services and online channels. A waiting list control design was chosen to optimize acceptability and adherence to the research protocol in the control group and decrease attrition effects (Campbell et al., 2000). Data were collected at four time points: pre-intervention (T₀), 8-week follow-up (T₁), 16-week follow-up (T₂), and 42-week follow-up (T₃). The 16-week follow-up assessment served as a primary endpoint to compare group effects. In- and exclusion criteria were being a primary caregiver of a PwD (all sub-types of dementia), having access to the Internet, basic (tablet) computer skills and with at least two social network members who are willing to join the Inlife platform. The exclusion criteria were being overburdened, having serious health problems that could interfere with participation (e.g., burn-out or surgery) as assessed by the study staff rated in the telephone screening, and being un-available for more than four weeks during the study period. A detailed description on the study design and participants can be found elsewhere (Dam et al., 2017b).