The Event-Related Rumination Inventory: How Does Scale Validity Change with Time Instructions?

Two types of rumination following a traumatic event can be identified: intrusive and deliberate rumination. Intrusive rumination is defined as a series of intrusive and undesired thoughts, whereas deliberate rumination is characterized by voluntary repetitive thoughts that help make sense of the experience. The Event-Related Rumination Inventory (ERRI) is an instrument capable of assessing both types of rumination. This study aimed to define the best modality of administration for the ERRI, by comparing the two original time frame instructions (immediate vs recent) and examining its psychometric properties in an Italian sample. To achieve this goal, 601 participants who experienced a trauma at different times (subsample 1: 1 year maximum; subsample 2: more than 1 year) were recruited and asked to complete an online survey assessing the following constructs: rumination, post-traumatic growth, post-traumatic stress and depressive symptoms. ERRI's reliability and validity were evaluated using the exploratory structural equation modeling (ESEM) method, i.e. combining the power and flexibility of traditional confirmatory and exploratory factor analyses. The ESEM model for the "recent" time frame achieved the best indices in terms of goodness of fit. The correlation network revealed significant connections with related constructs, indicating the validity of intrusive and deliberate scores. Finally, the two dimensions of the scale demonstrated a significant ability to discriminate both intrusive and deliberate rumination as participants moved away from the time of the trauma. ERRI has shown very good psychometric properties and appears to be a good instrument to assess ruminative processing after a highly stressful event.