An understanding of the impact of pediatric chronic illnesses on QoL is important for the health care workers who manage the relevant populations. We present one of the first studies to specifically assess children with IEMRD who are at risk of acute decompensation and their parents. Consistent with previous studies, our findings confirm that IEMRD impact the QoL of both parents and children affected by IEMRD [20, 33, 34]. One publication explored the QoL of children with maple syrup urine disease (MSUD), showing altered QoL scores compared with controls and similar QoL scores as children with cancer . Among the studies exploring the QoL of the parents, lower scores were found than for the parents of children affected by other chronic illnesses, such as sickle cell disease or Down syndrome, or for controls [20, 23, 34].
However, our results show that the ‘physical-like’ aspects of QoL are more impacted than the ‘psychological-like’ aspects, both for parents and for children. Indeed, the parents of these children reported lower scores on the physical dimension of the WHOQOL than the controls, and the children reported lower ‘physical’ scores than leukemia survivors. One explanation is the well-known phenomena of coping strategies and adjustment developed by patients and/or families . Relations with friends and leisure activities were also defined by the children as affected domains. We hypothesize that the dietary regime constraints are partly responsible for these affects, as shown in the comment that food preparation with minute weighting and logistics are problematic. Even if a parent stated always being prepared for potential decompensation, he or she also asserted that it can be hard to prepare for leisure and holidays. The limited diet was a complaint shared by the parents and the children. Alimentation plays a large cultural role; for example, parents complained that certain aliment cannot be shared, as these limitations are without exception. Moreover, in certain cases, it was noted that there are few pleasures in consuming food. These limits remain constant; indeed, in one study of approximately eight adults affected with MSUD and their parents, the dietary constraint was one of the major themes .
In contrast, the children reported better relationships with medical staff than did the leukemia survivors. In comparison with other chronic illnesses, such as cancer, IEMRD has specific features. The disease is lifelong, as opposed to cancer, for which the conventional treatment does not cure the disease. There is the lifelong strain of dietary management. Families and children face ongoing metabolic decompensation and a risk of death with decompensation and regularly visit hospitals and physicians throughout childhood. For all of the above reasons, we hypothesize that the parents and their children have faith in and rely on medical staff. Other authors did not report this phenomenon , which can be explained by the specifics of the health care system. The French free health care system most likely allows parents to not be worried by financial problems.
Interestingly, the presence of gastrostomy can have certain ‘protective effects’ on the self-reported QoL of parents, notably in the physical health and social relationship domains. A similar effect was previously shown , for children with inherited metabolic diseases  and cerebral palsy [37, 38]. Many explanations should be discussed. First, in case of enteral nutrition, gastrostomy removes the necessity of an enteral feeding tube, which is more apparent and less stable. Moreover, gastrostomy can be easily used in cases of difficulties in eating. Second, it has been previously reported that gastrostomy can decrease parents’ stress [34, 39]. Gastrostomy did not have an influence on children’s QoL, as found for children with cerebral palsy . In our cohort, the patients with urea cycle defects seemed to have a lower QoL, as reported by their parents. The influence of the nature of IEM was not explored in the previous studies . This finding could be related to the more severe natural course of the urea cycle defects, but we cannot exclude the effect of the size of the study population.
Two limitations of our study must be mentioned:
Moderate associations were possibly missed because of low statistical power due to the sample size, which was arguably too small. The sample size did not allow a multivariate approach that takes into account the potential confounding factors. A larger sample will allow the confirmation of these findings.
Cross-sectional studies examine individuals with heterogeneous disease durations. Longitudinal studies provide more valid information and are necessary to more accurately determine the weights of potential predictive factors of QoL. Future studies based on cohort studies should provide more robust findings, particularly regarding the childhood/adulthood transition, and should propose appropriate treatment strategies.