Comparison of Health Outcomes in Adolescent and Young Adults (AYA) Oncology Patients Treated at a Pediatric Versus Adult Institute
Authors: Moskop Amy , Yan Ke , Dobrozsi Sarah K. , Panepinto Julie 
Published: November 2019

BACKGROUND
Overall survival for adolescent and young adult (AYA) cancer population, ages 15 to 39 years, demonstrated minimal improvement during the last several decades. Potential factors influencing inferior outcomes within this group include the complex biology of AYA cancers, lower rates of clinical trial enrollment, the significant toxicities caused by therapies, and unmet psychosocial needs. AYA patients can often be treated in either pediatric or adult institutions. The type of institution where they receive treatment is influenced by age, type of cancer, and distance from a pediatric oncology center.
There are concerns that differences in care between pediatric and adult treatment settings are influencing the slow progress in improving outcomes. Acute care utilization might reflect the burden of toxicities and access to care, which might vary based on treatment setting. There is limited research suggesting that AYAs treated at pediatric institutes are more likely to be enrolled in clinical trials. The AYA population also has challenging psychosocial needs and it is unknown if there is a difference in how those needs are addressed in different treatment settings. The objective of this study was to examine whether there are differences in clinical trial enrollment, acute care utilization, and psychosocial support between AYA oncology patients treated at a pediatric versus an adult facility. Our hypothesis was that AYAs treated at a pediatric facility will have increased enrollment in clinical trials, less acute care utilization, and more psychosocial referrals compared to AYAs treated at an adult facility.
METHODS
We conducted a retrospective cohort study of patients ages of 15 to 39 years who were diagnosed with a hematologic malignancy (acute lymphoblastic leukemia (ALL), acute myelocytic leukemia (AML), Hodgkin lymphoma (HL) and Non-Hodgkin Lymphoma (NHL)) and were cared for at a pediatric or adult facility during the years 2013-2017. The primary health outcomes examined were acute care utilization and psychosocial resources utilized, based on a patient's exposure time (defined as one year from diagnosis or 1 month after completion of therapy, whichever came first). Data were analyzed using SAS 9.4. To compare the health outcomes between patients treated at the two facilities, the Chi-square test or Fisher's exact test was used for categorical variables. For continuous variables, due to the skewness of the data, a log transformation was applied to the length of stay (LOS) variable, and then the Student's t-test was used. The Mann-Whitney test was used for the other continuous variables. This study was approved by the Children's Hospital of Wisconsin Institutional Review Board.
RESULTS
A total of 196 patients were treated as either newly diagnosed or relapse/progressive patients who received care at the pediatric or adult treatment facilities. Leukemia patients treated at a pediatric facility were more likely to be enrolled on a clinical trial than patients treated at an adult facility (84% vs 22%, p<0.0001). There was no statistically significant difference in enrollment in clinical trials for lymphoma patients at both treatment facilities (4% vs 8%, p=0.68) as shown in Table 1.
There was no significant difference in acute care utilization for ED visits or inpatient hospitalizations for all diagnoses for the pediatric and adult facilities. Both ALL and HL patients had more ICU admissions per month at the pediatric facility compared to the adult facility (ALL: mean 0.25 vs 0.05, p=0.021; HL: mean 0.03 vs 0, p=0.0027). ALL and HL patients had longer hospitalization LOS at the adult facility (ALL p=0.020, HL p=0.014)
There were more referrals for psychology, social work or case management and palliative care in the pediatric versus adult facility (p<0.0001, p=0.011, p<0.0001, respectively).
CONCLUSION
For AYA patients treated at a pediatric institute, leukemia patients have higher rates of clinical trial enrollment and all patients receive more psychosocial support compared to AYA patients treated at an adult institute. There was no difference in acute care utilization for ED visits or hospitalizations between patients treated at a pediatric or an adult facility. Patients with ALL and HL have more ICU admissions but overall shorter hospital LOS at the pediatric institution. Further work to determine the impact of these findings on the long-term outcomes and survival of AYA patients is needed.

Disclosures
Panepinto: NIH: Research Funding.