Applied tension may help retain donors who are ambivalent about needles

Vasovagal symptoms can discourage people who might otherwise give blood on many occasions. However, the effects of symptoms on donor retention as well as the effects of treatments to reduce vasovagal symptoms on donor retention are probably moderated by a person's confidence that they can tolerate the procedure.

Data from a study on the effects of the muscle tensing technique applied tension (AT) on donor retention were examined to determine if (1) the degree of donor ambivalence about needles influenced the impact of vasovagal symptoms on subsequent return and (2) ambivalence about needles moderated the effect of learning AT on donor return. One-year follow-up data on 614 people who had previously given blood and were randomly assigned to either a no treatment, donation-as-usual condition or one of two conditions involving AT were obtained. Self-reported degree of needle ambivalence and vasovagal symptoms were assessed during the initial blood donation.

Among participants in the no treatment group, increases in vasovagal symptoms were associated with decreases in donor return but only among people who expressed some fear of blood draws. Similarly, among people who expressed no fear of needles, learning AT had no effect on post-donation estimate of the likelihood they would give blood again or return rate. However, among people with some fear of blood draws learning AT led to both a higher estimate that they would give blood again as well as actual return rate.

The experience of vasovagal symptoms may not deter people who are generally confident in their ability to tolerate blood donation. However, among people who are ambivalent about needles, symptoms may 'confirm' pre-existing doubts about their suitability for blood donation and lead to drop-out. Targeted interventions that give the uncertain volunteer a sense of confidence that they might be able to realize their goal and become a regular blood donor may be useful.