Personal growth initiative and posttraumatic stress among survivors of transportation accidents: Mixture modeling indicating changes in group membership over time: Mixture modeling indicating changes in group membership over time

The current study explored subgroups in reported personal growth initiative (PGI) and posttraumatic stress symptoms (PTSS) and examined the changes in class memberships among survivors of a transportation accident. Participants at Time 1 were 602 adults who reported directly experiencing a transportation accident within the past year (M_months = 6.36; SD_months = 3.20). Of these participants, 171 adults completed the follow-up survey after 3 months (Time 2). Finite mixture modeling was conducted to identify the heterogeneity of PTSS in relation with PGI at each time point. At Time 1, a four-class model was the best-fitting model, and at Time 2, a three-class model was the best-fitting model. As hypothesized, when examined cross-sectionally, various subgroups were identified at each time point, finding subgroups with moderate to high levels of PGI but differing in their PTSS. However, when examining the longitudinal changes in class membership from Time 1 to Time 2, members of subgroups with higher PGI skills at Time 1 were more likely to be assigned to subgroups with lower PTSS at Time 2. The current study suggests a potential application of PGI skills in alleviating PTSS after a transportation accident and having a critical role in adjustment after hardship.