Outside-in: COVID-19 in a life-course perspective

Abstract

This thesis examines COVID-19 from a life-course perspective, focusing on how vulnerability and resilience are shaped over time through biological, psychological, and social processes. Using Swedish population registers, four cohort studies analyse how early-life characteristics, family structure in adulthood, and patterns of healthcare utilization influenced the risk of infection, severe disease, and diagnosis during and after the COVID-19 pandemic. The first study shows that higher cardiorespiratory fitness in late adolescence is associated with a lower risk of hospitalization and death due to COVID-19 several decades later. The second study finds that living with preschool-aged children was associated with lower risk of infection and severe disease, whereas living with adolescents was associated with increased infection risk. The third study demonstrates that low stress resilience assessed in adolescence is associated with a higher risk of severe COVID-19 and other serious respiratory infections later in life, independent of physical fitness. The fourth study shows that post-COVID diagnoses among women were strongly patterned by pre-pandemic symptom-based healthcare use. In conclusion, the thesis shows that the impact of COVID-19 was shaped by factors established long before the pandemic. A life course perspective is essential for understanding unequal vulnerability and recognition of illness.