1. A Discrete Choice Experiment Reveals Physician Bias in Management of Desmoid Tumors Simianu VV, Cizik AM, Flum DR, Mann GN, Davidson DJ University of Washington Department of Surgery, Department of Orthopaedics and Sports Medicine

2. Desmoid Tumors Which approach is best?  Resection: morbid, 70% recurrence-free survival  Systemic therapy: still morbid, 70% symptom improvement  Observational results: no progression in 65% When available evidence is controversial…  Individualized decision Patient characteristics Physician preference ? ?

3. Research Question Can we quantify physician preference in treating desmoid tumors? Patient characteristics Physician preference X% Y%

4. Discrete Choice Experiments: measure preferences in healthcare decisions  simultaneously assess multiple attributes of therapy  mimicking complex clinical decisions 3 Components:  Treatment attributes  Scenarios with paired choices  Conditional model analytics Methods: DCE

5. Abdominal desmoid: 37yo female, 6cm mass Extremity desmoid: 29yo male, 6cm mass Attributes:  Outcome: probability of 2-year PFS  Morbidity: immediate and/or long-term Vary attribute levels, size and symptoms Methods: DCE DC#1 AttributeTreatment ATreatment B outcomelowhigh morbiditylowhigh Which treatment do you prefer?  A  B

6. 2 weeks later: unblinded treatment names  Resection (high probability PFS, high morbidity)  Systemic (med probability PFS, med morbidity)  Observation (low probability PFS, low morbidity) Methods: DCE DC#1 AttributeObserveResection outcomelowhigh morbiditylowhigh Which treatment do you prefer?  Observe  Resection DC#2 AttributeSystemic therapyResection outcomemediumlow morbiditymediumlow Which treatment do you prefer?  Systemic therapy  Observe

7. Surgical Specialty (n=7) Nonsurgical Specialty (n=6) How often do you treat desmoid tumors? Participants

8. Results Lower Morbidity Higher Morbidity Lower PFS Higher PFS

9. Results Lower Morbidity Higher Morbidity Lower PFS Higher PFS Abdominal Blind Unblind Extremity Blind Unblind

10. Results: Non-surgeons Lower Morbidity Higher morbidity Lower PFS Higher PFS Abdominal Blind Unblind Extremity Blind Unblind

11. Results: Surgeons Lower Morbidity Higher Morbidity Lower PFS Higher PFS Abdominal Blind Unblind Extremity Blind Unblind

12. Assumptions of treatment attributes Simplification of clinical decision Generalizability to other physicians Limitations

13. Outcome is preferred attribute Similar in both surgeons and non-surgeons  For both tumor locations DCE is new and complementary methodology to study preferences Conclusions

14. FUNDINGT32DK070555 COLLABORATIONSurgery, Orthopaedics, Oncology CERTAIN CHOICES MENTORSHIPAmy M. Cizik Darin J. Davidson David R. Flum Gary N. Mann Karen D. Horvath Brandt K. Oelschlager Carlos A. Pellegrini Acknowledgment University of Washington Departments of Surgery and Orthopaedics and Sports Medicine

15. Preferences in Soft-Tissue Sarcoma: http://washington.co1.qualtrics.com/SE/?SID=SV_a9mQKpmkVtNTHYp Acknowledgment University of Washington Departments of Surgery and Orthopaedics and Sports Medicine