Pain and hospital admissions were the most important factors that were negatively associated with HRQoL in nonambulatory children with CP between five to 18 years.

The CPCHILD-DV has sufficient reliability and validity as a proxy measure of health status and well-being of non-ambulatory children with CP.

Health-related quality of life (HRQoL) is defined as an individual's perception of how an illness and its treatment affect the physical, mental and social aspects of his or her life. HRQoL is seen as a multidimensional construct, which can be measured indirectly using multiple items in several domains (Vet et al., 2011). These domains encompass aspects of physical, psychological and social functioning. The domains of HRQoL are a subset of the eight-core quality of life (QoL) domains that have been identified and which cover all aspects of life: emotional well-being, interpersonal relationships, material well-being, personal development, physical well-being, self-determination, social inclusions and rights (Schalock et al., 2005) (Gómez et al., 2015. QoL is, therefore, broader than HRQoL because it includes evaluation of non-health-related features of life, whereas HRQoL is connected to an individual's health or disease status. As QoL is important to everyone (with or without disabilities), HRQoL focuses on the impact health status has on quality of life. HRQoL is especially important for people with chronic illness or disabilities since the consequences of their conditions play a prominent role in almost every aspect of their lives and are lifelong. Most interventions for these people have a common goal, not to cure but to preserve or enhance their health-related quality of

Background: The purpose of this study was to evaluate the longitudinal validity of the Dutch version of the Caregiver Priorities and Child Health Index of Life with Disabilities (CPCHILD), a health-related quality of life instrument for nonambulatory children with severe motor disabilities and accompanying disorders. Methods: The effect of two interventions, Botox injections in the hip region and percutaneous endoscopic gastrostomy, was followed over time. Caregivers (n = 38) of nonambulatory children (26 boys, 12 girls; mean age: 9 years, 5 months [4 years, 9 months]) with severe disabilities completed the questionnaire prior to the intervention, at 3 months and 6 months follow up. Seven a priori hypotheses were formulated. Longitudinal validity was analysed by a paired t test of the pre-post scores and correlation analysis between the change-scores and two external criteria: a caregivers' perceived change in health-related quality of life of the child questionnaire and a general health-related quality of life instrument. Results:The results reported here follow completely the pattern we hypothesized for four analyses and partially in the remaining three. In the Botox group, the mean change-score at 3 months was 6.9 points (p < 0.05), which exceeds the minimal clinically important difference of 5.8 points. At 6 months, the effect was diminished to 4.5 points, in line with the temporary effect of Botox. There were moderate positive correlations between the change-scores and an external criterion (Spearman's rho: 0.46-0.58). Conclusions: This study indicates that the CPCHILD Dutch version has sufficient longitudinal validity statistically and clinically in nonambulatory children with severe disabilities.