Background CIBMTR previously showed that centralized PRO collection from patients treated at multiple transplant centers (TC) was feasible; however, consenting by sites and the paper mode of collection were logistically challenging. CIBMTR built an electronic system (ePRO), and we report our initial experience. Methods This was a cross-sectional study of patients ≥55 years old with MDS who underwent allogeneic transplant. Additional inclusion criteria were: ≥6 months from transplant, English/Spanish speaking, an active email address. Lists of potentially eligible patients were sent to TCs to confirm eligibility and provide contact details. All further patient contact (email/phone) was then made by the CIBMTR Survey Research Group (SRG). SRG contacted patients by phone to describe the study, then obtained consent electronically. PRO measures were delivered using computerized adaptive testing (CAT). Results TCs provided contact information on 188/273 (69%) potentially eligible patients. The biggest reason for lack of confirmation of eligibility was an inability by the TC to contact the patient (Figure 1). Of the 188, SRG contacted and confirmed eligibility in 164 (87%). 90/164 (55%) enrolled, and 80 (89%) have completed PROs. A median time of 15 minutes (IQR 11.3-20.7) was required for PRO completion. 62 patients did not enroll: 28 lost to follow-up after initial contact and 34 actively declined to participate. Reasons for declining to participate included: lack of interest in research, technology issues, health reasons and study specific concerns. SRG made fewer contact attempts for those who participated (Table 1). Conclusions We show that while the ePRO system is an efficient mechanism to consent patients and collect PRO, many patients do not reach the enrollment stage. The biggest reason for this is lack of initial or subsequent contact, which was noted at every stage (both TC and SRG). It is unknown whether this is due to passive decline by the patient, or to incorrect contact details. Additionally, relying on the TC to provide contact details (engaging TCs as IRB approved-research sites) was time-consuming and inefficient. CIBMTR has moved to central IRB study approval, and begun to collect contact details proactively, achieving a truly centralized mechanism which should allow CIBMTR to establish contact with patients early in the transplant process. Maintaining engagement through the ePRO may help to address ongoing logistic challenges.