Dyadic coping after cancer diagnosis - a longitudinal cluster analysis.

Background and purpose: Dyadic coping (DC) considers the perception of both the individual and their partner's coping behavior and influences various health outcomes. Given the paucity of research investigating the course of DC after a cancer diagnosis, we explored longitudinal data to find statistically distinct trajectories of DC and to characterize and predict those based on medical, psychological and sociodemographic characteristics.

Materials and methods: In this prospective, multicenter study, we assessed patients with primary solid tumors at four measurement points using validated self-report questionnaires: first within 8 weeks of diagnosis, then at 6-month intervals. We measured DC using the Dyadic Coping Inventory (DCI). Clusters were identified via a feature-based clustering approach, characterized with t-tests and chi-squared tests and predicted with multinomial logistic regression.

Results and interpretation: We analyzed data from 418 patients in a partnership (mean age 61 years, 55.3% men, 84.8% married). Most prevalent cancers were prostate cancer (25.6%), skin cancer (17.5%) and breast cancer (16.3%). One cluster (33.5%) reported a stable high trajectory of coping behavior, indicating good coping behavior. It had the following characteristics: male (62.9%), regularly employed (57.9%), prostate cancer (34.3%) and childless (27.1%). The remaining sample contained a cluster with increasing coping behavior (34.7%) and another with decreasing coping behavior (31.8%). Lack of regular employment, having children and generalized anxiety are significantly associated with worsening coping behavior. This study is one of the first to examine DC trajectories in a large sample of cancer patients in the early phase after diagnosis. It is essential to understand markers such as psychological stress or family and work-related issues to optimize clinical and psycho-oncological outcomes and facilitate the support or maintenance of couple-related disease management in the long term.