Activity disruption, illness intrusiveness, and life satisfaction in adults with type 1 diabetes: an ecological momentary assessment study

Illness intrusiveness is a psychological process reflecting the perceived impact of illness-related disruptions on daily life in chronic conditions. Type 1 diabetes (T1D) disrupts daily activities through symptoms, self-care demands, and device use, yet little is known about how these disruptions shape psychosocial well-being. This study examined activity disruptions in adults with T1D using ecological momentary assessment (EMA) and tested whether illness intrusiveness mediates the relationship between activity disruptions and life satisfaction. A total of 196 adults with T1D completed 14 days of momentary activity disruption assessments and follow-up surveys assessing illness intrusiveness and life satisfaction. On average, participants reported disruptions in 11% of momentary daily activities, with notable variation across activity types, racial/ethnic groups, and treatment regimens. Activity disruption significantly predicted greater illness intrusiveness (β = 0.33, p < 0.001), which in turn predicted lower life satisfaction (β = -0.51, p < 0.001). Mediation analysis revealed that illness intrusiveness fully mediated the relationship when adjusted for income. Subtype analyses showed that device-related (indirect effect: β = -0.12, p < 0.001) and symptom-related disruptions (indirect effect: β = -0.12, p = 0.01) were fully mediated, whereas self-care disruptions were not associated with life satisfaction. Findings highlight the value of capturing real-time activity disruptions and suggest that illness intrusiveness may be a key explanatory mechanism linking activity disruption and psychosocial outcomes. Device burden and socioeconomic context emerged as factors shaping these relationships.