- Study design and population
This study incorporated a cross-sectional design performed at the multidisciplinary paediatric centre of a French public teaching hospital (La Timone, Marseille, France). Children and their parents were included. The inclusion criteria were as follows: 1) for children: child with a history of organ transplantion (liver, kidney, or heart) transplanted for more than 1 year and less than 10 years, born between 1998 and 2011, with parents or legal guardians authorizing participation in the study; and 2) for parents: parents of a predefined child. A medical database allowed the identification of eligible children according to the selection criteria. The study was proposed to consecutive parents and children during a planned routine visit between June and November 2015.
The protocol was approved by the ethics committee of Aix-Marseille University, France (reference number: 2014-08-04-03). According to French law (Article L1121-1, Law n°2011-2012 29 December 2011, art. 5), all children and parents were fully informed of the study. This study was conducted in accordance with the Declaration of Helsinki and French Good Clinical Practices. Written consent was collected for each included parent.
For the children, the following data were collected: 1. sociodemographic: sex and age of the child and school retardation ; 2. clinical data: the nature of the transplanted organ (liver, kidney, or heart), the age at transplantation, the time since transplantation, the occurrence of a transplant rejection (biopsy), post-transplantation radiointervention or surgery, background treatment, regular treatment (treatment other than the immunosuppressive therapy), immunosuppressive medication switch,test residual treatment level (satisfactory, unsatisfactory), and the number of hospitalizations after transplantation.
For the parents the following sociodemographic data were collected: age, gender (mother or father), marital status (single, couple), and professional status (worker, non-worker). The number of siblings was also recorded.
- Evaluation of quality of life
The QoL of the children and adolescents was assessed using a structured standardized questionnaire named the Vécu et Santé Perçue de l’Adolescent et de l’Enfant (VSP-A) (21, 22). The parent version, VSP-Ap, is designed to be answered by the parents of children or adolescents of all ages (from 4 to 18 years). The 37 items describe 10 dimensions : relations with parents (RPa), body image (BI), vitality (VIT), relations with friends (RFr), leisure activities (LEI), psychological well-being (PsWB), physical well-being (PhWB), school performance (SCH); relations with teachers (RT), and relations with medical staff (RMS). All scores range between 0 and 100, with higher scores indicating a better QoL. Two child versions (VSP-Ac for children aged 8 to 10 years and VSP-At for teenagers aged 11 to 17 years) and one parent version are available. In the two child versions, 7 dimensions were common (VSP-A): relations with parents/family (RFa), body image/self-esteem (BI), vitality (VIT), relations with friends (RFr), leisure activities (LEI), school performance (SCH), and relations with medical staff (RMS). The scores of children with chronic conditions associated with long-term consequences are also available from previous studies coordinated by our team: childhood leukaemia survivor children (23) and children with inborn errors of metabolism with restricted diet (24).
Parents’ QoL was assessed using the French version of the World Health Organization Quality of Life (WhoQoL-BREF) questionnaire, which is a generic questionnaire of 26 items used worldwide (25) that describes four domains: physical health, psychological health, social relationships, and environment. French norms are available only for three domains: physical health, psychological health, and social relationships (26). The scores of parents of children with inborn errors of metabolism with restricted diet are also available (24).
Continuous variables were expressed as the means and standard deviations or the medians and interquartile ranges (IQR). Qualitative variables were expressed as numbers and percentages. Nonparametric statistics were used. The VSPA-p scores were compared with the scores obtained from French parents of children suffering from inborn errors of metabolism with restricted diet (24) and French parents of childhood leukemia survivors (23). The VSP-A scores of the children and adolescents were compared to the scores obtained from French childhood leukaemia survivors (23). The WhoQoL scores of the parents were compared with the scores obtained from French parents of children suffering from of inborn errors of metabolism with restricted diet (24) and from French age-sex-crossed norms (26). Comparisons of mean QoL scores between different subgroups were performed using the Mann-Whitney tests for qualitative variables and Spearman’s correlation coefficients for quantitative variables. The statistical analyses were performed using the SPSS software package, version 20.0 (SPSS Inc., Chicago, IL, USA). All tests were two-sided. Statistical significance was defined as p<0.05.