Phase III

INTERVAL Phase III – why now?

INTERVAL Phase III has emerged out of a growing interest, among blood donation services and researchers, in factors that influence the recovery of iron stores following repeated donation. The INTERVAL study provides an ideal opportunity to explore these factors – especially as it will be possible to look at patterns of iron recovery at different donation frequencies.

INTERVAL Phase III – why have I been invited?

We want to recruit about 4,000 INTERVAL participants to INTERVAL Phase III. We are inviting donors who:

  • Do not have an existing donation deferral at the time of joining Phase III
  • Have enough time remaining on the study to give a minimum of 2 consecutive research samples at their allocated donation frequency

To take part, it is important that you i) have no known reasons (e.g. extended holidays) which will prevent you from giving blood between the time of your invite and your last donation as part of the INTERVAL study, and ii) are willing to give a small, research sample at each donation attended as part of the INTERVAL study.

What will be involved?

If you choose to join INTERVAL Phase III the following will happen:

  • A flag will be placed on your donor record indicating to staff at your Donor Centre that you are happy to provide a small research blood samples at each of your next donations attended as part of the INTERVAL study.
  • If you meet NHSBT’s usual criteria for blood donation when you attend an appointment you will be able to give your routine blood donation plus your research blood samples.
  • If you do not meet NHSBT’s usual criteria for blood donation when you attend an appointment, a research blood sample only will be taken.
  • The INTERVAL study team will send reminders, similar to those you are already receiving, to remind you to book and/or attend study donation appointments when they are due.
What should I do if I want to take part?

If you are eligible to join, you will receive an email invite from the INTERVAL study team – this will contain a web-link to Phase III study information and an online consent form. If you would like to join INTERVAL Phase III then all you need to do is complete the online consent form and give your consent.

What happens immediately after I enroll in the study?

A few days after enrolling we will send you a welcome email which will include contact details for your future appointments and for any further questions you have about the study.

What standards are in place to protect me and the samples I provide?

Phase III will maintain the same standards to protect you and your data and samples that were set out at the time of you enrolment to the study.

I don’t want to consent online, can you send me a copy in the post?

Unfortunately, no. Due to practical considerations, the consenting process has been designed to be completed online only.

Who do I contact if I have any further questions or concerns?

If you have any more questions or concerns about INTERVAL Phase III please contact the Helpdesk on 0800 064 0089 or email