On Track

Developmental Trajectories of Children with CP

The On Track Study (2012-2017) was a large multi-site collaboration involving researchers, therapists, families, and children with cerebral palsy (CP) from across Canada and the United States. The aim of the Canadian Institutes of Health Research (CIHR) funded study was to describe the changes in balance (a primary impairment), range of motion limitations, strength, and endurance (secondary impairments), number and impact of health conditions, and participation in self-care, recreation, and leisure activities over a one-year period in young children with CP aged 18 months through 11 years. We aimed to recruit 175 children with CP, aged 18 months to 10 years, in each of the 5 levels of the Gross Motor Function Classification System (GMFCS) for a total sample of 875 families. The On Track Study recruited some families involved in our previous Move & PLAY study, and also welcomed some new children and their families to the project. Trained therapist assessors measured primary and secondary impairments (i.e. balance, range of motion limitations, and strength) on 2 occasions (12-months apart). Parents completed questionnaires to track changes in the child's endurance, health conditions, and participation in self-care and recreation activities, at the same data collection points. We used these data collection points to develop reference percentiles and to present the data so that therapists can assist families to determine if children with CP are progressing as expected, more than expected, or less than expected, depending on their functional ability levels.

In 2013, our team was awarded additional funding from the Patient-Centered Outcomes Research Institute (PCORI) to complement the original On Track Study by increasing data collection in a subsample of 600 children with cerebral palsy across all 5 GMFCS levels. Rather than having two observations across one year, this subsample had up to five observations (6-months apart) across two years. With these data the first additional study aim was to create longitudinal developmental curves for impairments, health conditions, and participation variables by estimating the average pattern of change, important individual variations in the pattern of change between children, and the degree of consistency over time within children. Establishment of longitudinal developmental curves provides easily understood and useful tools for families and service providers to discuss questions about how well their children are doing in relationship to other children with CP of similar functional ability levels. The second study aim was to utilize service data collected from parents and children's progress on the longitudinal developmental curves to develop recommendations for rehabilitation service provision for children with CP across functional ability levels. Having this information can assist with collaborative decision-making among family members and service providers that efficiently utilizes rehabilitation services to meet families' goals. To date this information did not exist, rather, many different types and intensities of services are recommended based primarily on convention, clinicians' past experiences, and education rather than on evidence of children's potentials to achieve goals. An additional sub-study under the PCORI funding collected direct physical activity measurements from a subset of the children in the larger study. These data were examined in relationship to other measures of endurance and participation.