Differences in Medical Decision Making in Adult and Pediatric Hematopoietic Stem Cell Transplantation (HCT).
Authors: Lee Stephanie , Joffe Steven , Artz Andrew , Champlin Richard , Davies Stella , Jagasia Madan , Kernan Nancy A. , Soiffer Robert J. , Eapen Mary 
Published: April 2020

Abstract
There are no studies investigating individual physician practice variation in HCT. We conducted an international Internet-based survey of transplant physicians to explore the spectrum of medical decision making in adult and pediatric HCT practice. The questions were constructed separately for adult and pediatric physicians and where appropriate, questions were identical for the two groups. Eight questions presented clinical scenarios and elicited treatment recommendations. Adult transplant physicians were also asked 6 questions about choice of myeloablative vs. reduced intensity conditioning in specified situations. Response options were closed-ended offering several management approaches. The response rate was 526/627 (84%) of eligible physicians who confirmed receipt of the invitation or 526/1823 (29%) of all invitations. The sample was predominantly male (74%), practiced in an academic center (73%) and was very clinically involved with a median of 2.5 days in clinic and 4 months on the inpatient ward. The median age was 47 years, and 57% practiced in the U.S.; 27% performed pediatric and 73%, adult transplants. Pediatricians spent less time in direct patient care, practiced at smaller centers (median annual transplant center volume 40 vs. 80, p&lt;0.0001), were more likely to practice in the United States (68% vs. 52%, p=0.0015) and be female (38% vs. 18%, p&lt;0.0001). Pediatric and adult transplant physicians differed in their management strategies for chronic myeloid leukemia, acute and chronic graft versus host disease (GVHD), and choice of graft source for patients with aplastic anemia. Specifically, pediatric transplant physicians were more likely to recommend allogeneic HCT over a trial of imatinib for an 18 year old man with chronic phase CML (69.6% vs. 34.9%, p&lt;0.0001) and bone marrow over peripheral blood for aplastic anemia (89.7% vs. 68%, p&lt;0.0001) compared to adult transplant physicians. Pediatricians favored higher dose steroids &gt;2 mg/kg, daclizumab and infliximab for steroid-refractory acute GVHD whereas adult transplant physicians endorsed mycophenolate mofetil and rabbit anti-thymocyte globulin. Although half of both groups would use mycophenolate mofetil for steroid-refractory chronic GVHD, pediatric transplant physicians also used higher dose steroids and pentostatin, whereas adult transplant phyisicians would use sirolimus and extracorporeal photopheresis. Among adult transplant physicians, there was little consensus on the patient factors for recommending reduced intensity conditioning as opposed to myeloablative conditioning. When presented with a 30 year old man with multiple myeloma in a minimal disease state after conventional chemotherapy who has an HLA-identical sibling, 41.4% recommended autologous HCT followed by non-myeloablative HCT, 25.9% a single autologous HCT, 17.7% an allogeneic HCT, and 15% a tandem autologous HCT. These results emphasize the heterogeneity of worldwide transplant practices and the recognition that local preferences or biases likely result in similar patients being offered different transplant and related treatment procedures. The degree of practice variation also highlights the need for clinical trials, where feasible, to clarify areas of controversy.