Doctor of Philosophy in Experimental Medicine (PhD)
Communicating the Safety Benefit of Booster Seats
My research focuses on understanding injuries in children and youth, and measuring the physical, psychosocial and financial impacts of injuries on children, their families and the health care system. I also investigate the importance of outdoor risky play for children’s healthy development, and how built outdoor environment impacts children’s play.
In Canada, unintentional injuries are a leading cause of hospitalization for children aged 5-19 years old. The need for longitudinal studies examining the impact of non-fatal childhood injuries across age groups and injury types has been identified internationally. Health related quality of life (HRQoL) measures assess functional limitations in multiple health domains making HRQoL an interesting and appropriate outcome to measure the impact of injury. The overarching goal of this dissertation was to advance the understanding of HRQoL among children following injury and the appropriate analysis of longitudinal HRQoL data. A systematic review was performed to summarize the findings of research on HRQoL following pediatric injury, and to examine the methods used to measure and analyze HRQoL data in the childhood injury context. In addition, primary research was conducted with 365 children 0-16 years old and their parents who presented with an injury at a tertiary care pediatric hospital in Vancouver, British Columbia. Children aged between 5-16 years old and all parents completed questionnaire measures at the time of presentation for the injury and again at one-, four- and 12-months post-injury. How childhood injury and the process of recovery impacts children’s HRQoL from both the child’s and parent’s perspective was investigated. Four different longitudinal models were explored to determine the model that best fit the data.Analyses revealed that injuries among older children, children requiring hospitalization and children with lower extremity fractures had more significant impact on HRQoL at one-month post-injury. By four-months post-injury differences in HRQoL were minimal. On average, parents rated their children’s HRQoL lower at one-month post-injury relative to the children’s self-perceived HRQoL. Most injured children regained HRQoL baseline status by four-months post-injury. Non-linear quantile regression provided the best fitting model as it is robust to skewness and outliers and free from any assumptions regarding the distribution of errors. Older children, those hospitalized, and children with lower extremity fractures were at higher risk of having lower HRQoL in the early part of recovery relative to younger children, those seen in the ED and children with other types of injuries.
Traumatic knee injuries are among the most common sport-related injuries sustained by youth and are associated with significant personal and societal burden, including increased risk of post-traumatic osteoarthritis (PTOA). Despite the key role of physical activity (PA) in prevention of disease, disability, and death, there is a paucity of knowledge surrounding PA participation, and other health-related outcomes for these individuals. The overarching aim of this dissertation was to understand the attitudes and beliefs, health-related outcomes, and PA participation of youth and young adults after recovery from acute knee injury, yet before onset of symptomatic joint disease. This dissertation is comprised of four studies. First, qualitative interviews were conducted with youth and young adults 3-10 years following intra-articular knee injury examining the influence of their injury on attitudes and beliefs about PA and PTOA. Four main themes were: acceptance of the injury impact; high determination and resiliency; lack of knee confidence; and evolving sense of athletic identity.Second, knee confidence was quantitatively examined in youth and young adults 3-10 years after intra-articular knee injury and age-and sport-matched uninjured controls. Individuals with a previous knee injury had over seven times greater odds of being troubled by knee confidence than controls. Third, the Swedish Knee Self-Efficacy scale (K-SES) was translated and cross-culturally adapted into English for individuals with an intra-articular knee injury in the previous five years. Measurement properties were evaluated and revealed high internal consistency, acceptable validity, and very good reliability. Fourth, objectively measured PA and other health-related outcomes were examined in female youth and young adults, 1-2 years after anterior cruciate ligament reconstruction (ACLR), as well as in age-and-sport-matched uninjured female controls. Participants with previous ACLR had less vigorous PA; increased knee pain and symptoms; reduced function in sports; lower quality of life; as well as poorer neuromuscular control than controls. Taken together, these studies highlight specific longer-term physical and psychological health-related outcomes that should be addressed in youth and young adults with previous knee injury. They support that these individuals deserve intervention beyond the traditional injury recovery period with the ultimate goal of preventing PTOA.
Children’s independent mobility (IM), their freedom to move about their neighbourhood without supervision by adults, has been in steady decline in recent decades. Previous research has linked perceptions of the environment with various measures of IM, but recently concerns have been raised regarding inconsistency in measuring IM. This study used various measures of IM and aimed to address how parental perceptions of the neighbourhood environment are associated with children’s territorial range – their actual spatial mobility – as well as how this relationship is mediated by IM parenting practices. Territorial range was derived from GPS, accelerometer, and activity diary data and IM parenting practices measured by license for independent mobility (LIM), roaming allowance, and parental boundaries. Path analysis was used to investigate the direct and indirect effects of these relationships. Some parental perceptions of the neighbourhood environment were significantly associated with IM parenting practices (LIM and roaming allowance). IM parenting practices were significantly associated with children’s territorial range. Direct effects of parental perceptions of the neighbourhood environment on children’s territorial range were variable, and only roaming allowance was found to mediate this relationship. Results indicate that IM parenting practices directly affect children’s territorial range to varying degrees. Parental perceptions of the neighbourhood environment have mixed effects on IM parenting practices and children’s territorial range. These findings suggest that future interventions to increase children’s IM should focus primarily on behavior change among parents since they are setting restrictions or allowances for children’s IM.