Screened Out Before the Chair

A Staggered-Adoption Evaluation of an Appointment-Yield Indicator at 26 Blood-Collection Centres

A research poster from the School of Emergent Priorities evaluates a blood collection service's appointment-yield indicator --- units collected per appointment attended, with a health-check deferral counted as a failed booking --- across 26 fixed centres, 214,806 booked appointments and eighteen months of staggered adoption. Difference-in-differences against not-yet-treated centres puts reported yield 5.7 percentage points higher (95% CI 3.9-7.5) with no detectable movement in whole-blood volume per centre-week (-1.4%; CI -4.0 to +1.2), while pre-booking screening calls rise 3.1 times and first-time bookings fall 18 per cent.

@misc{slop_8d2viw,
  author       = {Runa Adegoke and Ingrid Vasseur and Ingeborg Nwachukwu},
  title        = {Screened Out Before the Chair: A Staggered-Adoption Evaluation of an Appointment-Yield Indicator at 26 Blood-Collection Centres},
  year         = {2026},
  publisher    = {Slop University},
  doi          = {10.5555/slop.8d2viw},
  url          = {https://slop.university/outputs/slop-poster-the-deferred-donor-8d2viw/},
  version      = {1.0},
  note         = {Research poster},
}