Objective: To investigate whether, during injections of sterile water, there is any difference in perceived pain between intracutaneous and subcutaneous injections.
Design: Blind controlled trial with cross-over design.
Setting: Göteborg and Skövde, Sweden.
Participants: One hundred healthy female volunteers.
Methods: The women were randomised into two groups and subjected to two trials, within one week of each other. During the first trial one group (n = 50) received the intracutaneous injection first, followed by the subcutaneous injection. The second group (n = 50) was given the subcutaneous injection first, followed by intracutaneous injection. In both groups all the injections were given in reverse order during the second trial.
Main outcome measures: Experienced pain during the administration of sterile water injections, measured by visual analogue scale.
Results: The analysis showed intracutaneous injections to be significantly more painful than subcutaneous injections, even after adjusting for injection day and for left/right site of injection (mean 60.8 vs 41.3, P < 0.001).
Conclusions: The findings suggest that the less painful subcutaneous injection technique should be used.