Psychosocial Outcomes of Youth with Chronic Physical Illness and Siblings

Abstract

Youth with chronic physical illness (YwCPI) are more vulnerable to developing psychopathology than their healthy counterparts. Prospective studies show that psychopathology in youth remains stable over time and extends into adulthood. Ongoing symptoms, treatment, and worry about disease progression increase the risk for worsened mental health. Given that health status often impacts physical, mental, and psychosocial health outcomes, health-related quality of life (HRQL) has been a focus in health research. The functional limitations resulting from disability caused by chronic physical illness (CPI) disrupt school participation, peer support, and family relationships, contributing to lower HRQL compared to healthy peers. Existing research on CPI continuity and HRQL is constrained by infrequent assessments and disease-specific approaches, limiting understanding of psychosocial outcomes in YwCPI. CPI in youth also affects siblings. This is consistent with family systems theory, which posits that emotional functioning results from interactions between an individual and their family members, and the family unit and its contextual circumstances. Research finds that CPI negatively impacts sibling mental, physical, and psychosocial health. Siblings of YwCPI are also at higher risk for internalizing and externalizing symptoms compared to controls. However, studies on sibling mental health and HRQL are limited. Few studies use longitudinal methods, limiting the ability to assess the long-term impact of CPI.

The aim of this research is to assess psychosocial outcomes in YwCPI and siblings. To address the aforementioned literature gaps, the objectives of this dissertation were to:

1) compare the homotypic and heterotypic continuity of psychopathology in YwCPI and siblings over 48 months, 2) model 48-month trajectories and assess predictors of HRQL in YwCPI and siblings, and 3) assess the mediating effect of sibling psychopathology on the association between YwCPI disability and sibling HRQL.

Data come from the Multimorbidity in Children and Youth Across the Life Course Study; data were collected at baseline, 6, 12, 24, and 48 months.

Study 1 utilized cross-lagged panel modelling to assess internalizing and externalizing symptom continuity in YwCPI and siblings. Auto-regressive pathways assessed homotypic continuity and cross-lagged pathways assessed heterotypic continuity. Separate models were computed for YwCPI and siblings. The method of variance estimates recovery (MOVER) assessed how patterns of continuity in YwCPI differed from siblings. Significant (p<0.05) autoregressive pathways were detected between all time points for internalizing and externalizing symptoms in YwCPI and siblings. Few cross-lagged paths were significant in either model. The MOVER showed no significant differences in the magnitude of any path estimates between YwCPI and siblings.

Study 2 delineated trajectories of change for each domain of HRQL (physical well-being, psychological-being, autonomy and parent relations, peer and social support, school environment) using latent class growth analysis. Models were computed for YwCPI and siblings independently. Backward stepwise regression assessed predictors of trajectory group membership. The number of trajectory groups ranged from two to four, and class size ranged from 5% to 80%. Over half of the models included an increasing, no change, and decreasing group, with most changes occurring at earlier time points. The proportion of siblings having no change in HRQL was greater than YwCPI. Group membership predictors were age, income, and parenting stress.

In Study 3, linear mixed-effect models assessed the mediating effect of sibling psychopathology on the association between YwCPI disability and sibling HRQL. YwCPI disability predicted increased sibling psychopathology, which was associated with lower sibling HRQL on all domains. Mediation effects were statistically significant in all models.

Given the homotypic continuity of symptoms of psychopathology, health services should promote early and routine mental health screening for YwCPI and siblings. Early changes in YwCPI and sibling HRQL trajectories highlight critical opportunities for family-centred approaches to pediatric care. The mediating effect of sibling psychopathology in the association between YwCPI disability and sibling HRQL underscores the importance of integrating siblings into family-centred care, with targeted mental health screening and interventions that aim to mitigate negative psychosocial outcomes.