Garrison, Michelle M.Taylor, Mallory2020-08-142020-08-142020Taylor_washington_0250O_21389.pdfhttp://hdl.handle.net/1773/46053Thesis (Master's)--University of Washington, 2020Background: Psychological distress is prevalent during adolescent development, and adolescents and young adults (AYAs) with serious illness like cancer experience even higher rates of depression, post-traumatic stress, and suicide. Recent large meta-analyses link depression and stress with cancer incidence and survival across a variety of malignancies. Identifying the mechanisms underlying these biobehavioral connections is a growing focus of epidemiologic and laboratory investigation, and evidence points to autonomic nervous system (ANS) dysregulation as an important component of this relationship. Heart rate variability (HRV), which is the fluctuation between successive heartbeats, is a measure of ANS regulation and has been widely applied in both social science and biomedical settings. The objective of this study was to examine associations between HRV and patient-reported psychosocial outcomes in AYAs with cancer. Methods: This was a secondary analysis of a completed randomized controlled trial (RCT) testing a resilience intervention in AYAs with cancer. Heart rate variability was our predictor of interest, and patient-reported psychosocial measures served as our outcomes. HRV was derived from baseline electrocardiograms (ECGs) found in the medical record. Eligible patients were English speaking, aged 12-25 years, and diagnosed with a new cancer within 10 weeks of enrollment, or diagnosed with relapsed or refractory cancer. To test associations between HRV and PRO scores, we performed linear regression. In our adjusted models, we controlled for factors known or hypothesized to affect both ANS regulation (and thus HRV) and psychological constructs represented by our PROs. Results: There were a total of n=76 patients with both ECGs and surveys at baseline. Just under half of participants were female, and the mean age at study entry was 16 years with a range of 12 to 25 years. The most common cancer diagnosis was leukemia or lymphoma, and most participants self-identified as White. The median values (IQR) for SDNN and RMSSD were 30.9 (12.7-50.3) and 31.2 (20.4-38.6), respectively. Newly-diagnosed patients had higher median HRV values [SDNN=33.0 (13.2-50.4), RMSSD = 29.5 (11.6-47.6)] compared to those patients who enrolled in the trial at the time of relapse [SDNN = 23.6 (10.2-50.2), RMSSD = 20.8 (10.0-43.1)]. There was no statistically significant association between PRO measures and SDNN or RMSSD in either an unadjusted or adjusted linear regression model. Conclusion: In this secondary analysis, we did not find evidence of an association between HRV measures and patient-reported psychosocial outcomes. However, this study is the first to report normative values for two commonly-used measures of HRV in AYA patients with cancer. This baseline data provides an important framework for future study in this field.application/pdfen-USnonePsychobiologyHealth servicesThesis