Primary care service use during adolescence and young adulthood: Tertiary care cohort affected by chronic health conditions.

Objective: To understand use of family physician services and emergency department visits by adolescents and young adults with chronic health conditions.

Design: Longitudinal retrospective observational cohort study using administrative health data.

Setting: Chronic care clinics at a tertiary care pediatric hospital in Calgary, Alta.

Participants: In total, 1326 adolescents who were between 12 and 15 years old in 2008, who were observed until 2016, and who received medical services for chronic conditions were enrolled in the study. Eligible participants had at least 4 visits to the same chronic disease clinic in any 2-year window before age 18.

Main Outcomes Measures: Group-based trajectory modeling was used to identify groups of adolescents with distinct patterns of health care use (for visits to emergency departments and to primary care practices), while tests explored trajectory group differences (eg, sex, location of residence).

Results: Median age was 14 years (range 12 to 17 years) at study entry, and 22 years (range 14 to 24 years) at study exit. Half were female and most (85.4%) lived in an urban area. Median observation period was 8.7 person-years (range 1.3 to 9.1 years). Group-based trajectory modeling identified 5 distinct trajectory groups of primary care use and 4 groups of emergency services use. Groups differed by sex and location of residence in each trajectory model.

Conclusion: Many adolescents increased their use of emergency services between the ages of 12 and 24 years, with distinct patterns of primary care use being observed. Association of additional patient- and system-level factors (eg, disease severity, distance to nearest family physician office) should be explored.