Social inequalities in trajectories of contacts with the healthcare system in adolescence and young adulthood

Background: Understanding of healthcare utilization of different populations is useful for prevention and prioritization of healthcare resources. This study aims to identify populations following different trajectories of contacts with the healthcare system and to describe social inequalities between the groups.Methods: Individuals born 1980-2000 in Denmark were linked to national registers. Contacts with somatic hospitals, psychiatric hospitals, general practitioners, and redeemed prescriptions were counted for each year between 16 and 37 years of age. Trajectories of contacts with the four dimensions of healthcare use were identified using group-based multi-trajectory modeling.Results: Five trajectory groups were identified. One group had low healthcare utilization over time (12% in women; 27% in men). The largest group had low healthcare utilization but more contacts with especially GP (39% in women; 43% in men). A third group had more contacts with most dimensions of the healthcare system (33% in women; 21% in men). The fourth group had many contacts with especially somatic hospitals and GP (7% in women; 4% in men). The fifth group had many contacts especially to psychiatric hospitals (8% in women; 5% in men). Shorter parental education, parental unemployment, family income below the poverty line, and cohabitation with one or no parent was more frequent in the two high utilization groups compared to the lower utilization groups. Conclusion: The observed trajectories of health service use and the social inequalities between trajectory groups highlight that prevention and treatment targeting the entire population will benefit from a complementary focus on social inequalities in health.