A Pediatric Illness Trajectory Framework for Chronic Disease Transition

Thesis Abstract

This study addresses the persistent fragmentation in pediatric chronic disease care by proposing a comprehensive Illness Trajectory Framework to model transitions across pediatric–adult care, family adaptation, and developmental milestones. The core problem is that existing trajectories are ill-suited to acute-to-chur complex transitions and fail to integrate biological, psychosocial, and system-level factors that influence long-term outcomes. The aim is to develop and validate a theory-driven framework that links illness progression, care transitions, and family-centered outcomes to guide cohesive pediatric chronic disease management. Specific objectives are (1) to synthesize constructs from transition theory, trajectory analysis, and chronic illness management; (2) to articulate a multidimensional Illness Trajectory Model (ITM) with operational indicators across pre-diagnosis, stabilization, transition, and adulthood phases; (3) to assess the predictive value of ITM constructs on health-related quality of life, adherence, and healthcare utilization; (4) to evaluate contextual moderators such as family functioning, health literacy, and social determinants; and (5) to propose a policy- and practice-oriented implementation strategy for healthcare teams. A mixed-methods design will be employed. The quantitative strand will recruit a cohort of 480 pediatric patients with diagnosed chronic conditions (e.g., type 1 diabetes, pediatric-onset rheumatic disease, cystic fibrosis) from five tertiary centers and follow them for 24 months, with data points at baseline, 12 months, and 24 months. Instrumentation will include validated scales Pediatric Quality of Life Inventory (PedsQL), Medication Adherence Report Scale (MARS-5), and the Transition Readiness Assessment Questionnaire (TRAQ-12), along with objective data from electronic health records (ECG, HbA1c, pulmonary function tests, hospitalization frequency). Structural equation modeling (SEM) will test the ITM’s latent constructs and their relationships with outcomes. The qualitative strand will use purposive sampling of 40 families and 20 healthcare providers for semi-structured interviews at two timepoints, analyzed via thematic analysis to elicit narratives of trajectory shifts, transition experiences, and system interactions. Triangulation will synthesize quantitative results with qualitative insights to refine the ITM. Analytical techniques will include regression analyses to identify predictors of quality of life and adherence, ANOVA to compare trajectory stages across disease groups, and SEM to evaluate the network of relationships posited by the ITM. Theoretical grounding will draw on Aristotelian developmental theory of telos to frame goal-directed transitions, Meleis’ Transition Theory to conceptualize health-related transitions, and the Cumulative Risk and Resilience framework to account for contextual modifiers. Data collection instruments will be validated for the study population with pilot testing (n=30) and cross-cultural reliability checks. Expected findings include (a) a validated ITM comprising core domains—biomedical trajectory, patient/family self-management capacity, transition readiness, healthcare system navigation, and psychosocial well-being; (b) evidence that higher transition readiness and family functioning predict better adherence, lower hospitalization rates, and improved quality of life; (c) identification of critical transition points where targeted support (e.g., transition clinics, care coordinators, telehealth check-ins) yields measurable improvements; and (d) differential effects of socio-economic factors on trajectory progression across disease groups. The study anticipates that the ITM will account for up to 62% of variance in quality of life and 48% of variance in adherence trajectories in the SEM analyses, after controlling for disease severity and age. The study contributes to knowledge by providing a theoretically informed, empirically tested framework that integrates biomedical trajectories, developmental considerations, and health-system interfaces to guide pediatric chronic disease management and transition planning. It offers concrete indicators for surveillance, a blueprint for transition-centric interventions, and implications for policy, education, and the design of pediatric-to-adult care pathways. Practical recommendations include embedding transition coordinators in pediatric clinics, implementing standardized transition readiness assessments at age 12–14, and developing family-centered education modules aligned with ITM domains to optimize long-term outcomes.