DISCUSSION
We examined potential racial disparities in QoL two or more years
post-HSCT in a regional cohort of pediatric patients. Our results
demonstrate no significant racial disparities in QoL across a variety of
functioning scales during this post-transplant window. Socioeconomic
factors did not appear to have any significant impact on this
relationship between race and QoL in our patient cohort. However,
transplant -related factors did impact certain QoL metrics, even after
accounting for certain socioeconomic factors. These findings can provide
critical information to providers and patient families concerning
potential avenues for growth in managing long-term patient wellbeing
following HSCT.
Given multiple reports of racial disparities affecting clinical outcomes
related to HSCT.19-22, the current findings of no
effect of patient race in long-term QoL scores were surprising. Prior
published studies that draw upon much larger databases or registries and
include participants from varied socioeconomic backgrounds have found
racial and socioeconomic disparities in access to fully-matched
unrelated donors for HSCT and in overall completion of HSCT for
malignancy.18,27,28 There are numerous explanations
for the lack of racial disparities in QoL scores post-HSCT within the
current study. As a single institution evaluation in a moderately-sized
pediatric hospital, the absence of racial disparities in readjustment
rates at least two years post-HSCT may not necessarily indicate a lack
of racial disparities in transplant outcomes within the United States.
For example, it was noted in this study that a significant majority of
patients (74.1%) came from estimated annual income bracket of above
$50,000; this indicates a patient population with a higher
socioeconomic status than that of the general population, which had a
median income of $55,000 in 2015.26 Such higher
income levels could allow patients and families to better handle
post-HSCT life and afford resources to improve their physical and
emotional health.29-31
These findings are potentially attributable to a very organized
supportive care program present throughout the transplant process within
this institution. During both the immediate and later post-transplant
periods, we utilize dedicated mental health specialists, hospital-based
schoolteachers, social worker services, inpatient and outpatient pain
services, multidisciplinary survivor clinics, and post-HSCT community
engagement programs to optimize patient wellbeing; such programs may
identify and resolve early declines in physical, emotional, social, and
school/work functioning following treatment.32-35Findings from our institution may be able to provide insight to other
transplant centers regarding global changes that can be made to ensure
patients from marginalized groups experience optimal outcomes. This
includes educating transplant center leadership and staff about racial
disparities that may be present in transplant referral, ensuring racial
and ethnic minorities have adequate psychosocial support from community
and hospital services, and implementing multidisciplinary survivor
clinics into other transplant centers to monitor all patients years
after transplant.36,37
The results from this study can be contrasted with other work evaluating
QoL in healthy controls, cancer patients, and transplant patients via
the PedsQL TM 4.0 questionnaire (Table 5). While the QoL scores of
patients in this study were still slightly below those of healthy
controls,23 their post-transplant QoL scores were
greater than those of pediatric cancer patients across all the
categories of readjustment,38 and were higher than
cited transplant QoL scores for emotional and work/school
functioning.39 The report comprised of healthy
controls evaluated a group of patients from California with similar
racial and ethnic demographics to the transplant population at our
institution, making this a reasonable comparison.23,24The study sample’s QoL scores were also comparable to that of pediatric
liver transplant recipients 10 years post-transplant39as well as pediatric HSCT recipients in other published studies
.40,41 These non-statistical comparisons indicate that
patients undergoing HSCT at our institution are adaptive, on average
exhibiting nearly healthy functioning two years post-transplant. Further
research should examine the role of institution-specific influences,
such as effective long-term monitoring of possible complications
including heart failure and endocrinopathies and an emphasis on
psychosocial readjustment and transition to adult care.
When pediatric patients were divided based on their diagnosis of
malignant or non-malignant conditions, regardless of race, patients with
malignant conditions reported significantly lower physical and
work/school functioning in preliminary analyses. Patients with malignant
conditions likely face more physical limitations due to their cancer
diagnosis; the physical side effects of cancer therapies and
myeloablative conditioning regimens also likely persist for years
following transplant, inhibiting long-term improvements in QoL. Those
with malignant conditions necessitating HSCT also likely spend a greater
amount of time away from school or work due to hospitalizations or
treatments related to their diagnosis, impacting their work/school
functioning.42 The significant relationship between
type of diagnosis and physical functioning seen in multivariate
regression analysis persisted when estimated household income was
factored into the analysis, suggesting that even those with higher
income experience lasting physical challenges. Conversely, relationships
of diagnosis and school functioning were not present in multivariate
analyses. These differences in outcomes highlight a need for provider
intervention and follow-up to optimize wellbeing in patients with
malignancies. Outside of racial and ethnic groups, particular care and
focus should be given to patients with malignant conditions within
institutions and transplant centers to improve physical and academic
outcomes.
Limitations of this study include retrospective data collection, which
precludes inferring causal relationships between covariates. The
relationships we describe are based upon the inclusion of self-reported
QoL from pediatric patients and estimates of socioeconomic status based
upon medical records; it is possible that the nature of these metrics
biased subsequent analyses. While there is no gold standard for
measuring pediatric QoL, the PedsQL not only has strong psychometric
properties,23,24 but is also appropriate for use in
our population of interest.38 Nonetheless, there is
the potential for differences in self-reporting across race and
ethnicity that impact metrics like the PedsQL.43 We
have no means of quantifying potential reporting bias, but rely on
previous research suggesting the strength of parent-reported health
status of children.23,44 Lastly, the results of our
study should be interpreted in the context of a small sample size (n =
86) as a single center experience. While we had a diverse sample,
subsequent work would benefit from exploring the relationships described
herein using larger samples sizes and multi-center approaches.