The donor history questionnaire has been developed with psychological principles designed to increase donor comprehension of questions and recall of relevant risk activities. For example:
- Questions are grouped into similar time frames, beginning with "today", and progressing further into the past, eventually arriving at "Have you ever..." type questions. This format takes the donor through time in a way that they are more likely to accurately recall activities.
- Each questionnaire item asks only one question that requires only one answer. Compound questions (e.g., "Have you ever been exposed to hepatitis or experienced a needlestick injury?") that may require separate responses are intentionally not used.
- The process also aims to minimize the number of questions the donor has to answer, with topics broad enough for the donor historian to ask additional follow-up questions only if the donor's response requires further expansion.