Monitoring development of children with cerebral palsy: the On Track study. Protocol of a longitudinal study of development and services.

BACKGROUND The purpose of the On Track study is to determine how children with cerebral palsy (CP) progress in their physical development and participation in daily life. Study aims are to create longitudinal trajectories and percentile graphs for physical development and participation to help health care professionals and parents monitor development and track if children are progressing ‘as expected,’ ‘more than expected,’ or ‘less than expected.’ Services received will be explored in children within each developmental category.

METHODS On Track used a prospective cohort design, in which 708 children with CP were followed; 656 were assessed at least twice (baseline, 12-month) over 1 year and 424 were assessed up to 5 times (baseline, 6-, 12-, 18-, 24-months) over 2 years. Children, aged 1.5-11.9 years, and their families were from Canada and the United States. Children were assessed on standardized measures of body functions and structures, health conditions, activity, and participation. Trained physical and occupational therapists measured balance, range of motion, strength, endurance, and physical activity using valid and reliable tests. Parents completed questionnaires about their family demographics and about their children’s endurance, health, participation in recreation and self-care, and health care services. Therapists and parents collaborated to classify children within five functional levels for gross motor, manual, and communication functions. Body function and participation data from all visits will be analyzed by linear and nonlinear mixed-effects modeling to create longitudinal trajectories by functional classification levels. Data from baseline, 12-month, and 24-month visits will be analyzed via quantile regression to construct cross-sectional reference percentile graphs for each measure by functional classification levels. Using separate multinomial models, service amount, focus, and family-centeredness, controlling for country, will be explored to understand how services relate to children’s development.

DISCUSSION Developmental results including longitudinal trajectories and percentile ranks on children with CP by functional classification levels and exploration of services will assist health care professionals and families to monitor development and collaborate on service planning. These results will facilitate conversations to improve family-centered care in order to provide the most efficient and effective interventions for children with CP and their families.

Trial registration: Identifier: NCT02391948

Keywords: Cerebral palsy, longitudinal development, percentiles, prognosis, rehabilitation services, parent researchers