A FAIR intensive longitudinal data archive on prolonged grief in daily life.

The majority of grief research has assessed Prolonged Grief (PG) symptoms using cross-sectional surveys, which are limited in capturing within-person changes in daily grief reactions. These dynamic PG reactions can be more effectively assessed using Experience Sampling Methodology (ESM). Accordingly, this data note presents a Findable, Accessible, Interoperable, and Reusable (FAIR) archive comprising three existing ESM projects investigating PG reactions in daily life. Participants in this archive completed three data collection phases: baseline measures (including sociodemographic and loss characteristics, and psychopathology measures), a 14-day ESM phase (rating PG reactions and contextual factors up to five times daily), and follow-up psychopathology assessments. The participants provided explicit digital consent for the use and reuse of their data in scientific research. In total, 315 people are included in this archive, with a total of 22,050 ESM-measurement points. The majority of the participants were middle-aged, identified as women, and had completed higher education. Almost half of the sample (48.73%) experienced the loss of a partner or child, the majority of these losses were due to natural causes (70.06%), and happened less than a year ago (59.24%). The data are stored in a trusted repository. This archive demonstrates that it is feasible to develop a FAIR archive including existing data on PG reactions in daily life. Given the resource-intensive nature and richness of these data, we encourage researchers to reuse and/or share ESM-data through this archive, helping to deepen our understanding of grief in natural settings.