Objective: Venous blood sampling is one of the most common diagnostic medical procedures performed in clinical practice. It has been shown that negatively loaded words may result in negative affective reactions and, consequently, in an increased perception of pain. We aimed to evaluate whether common warnings before venous blood sampling might induce unnecessary pain.
Methods: We included 100 healthy participants (50 females, 50 males) who were randomized to one of the 2 study groups ("sting" vs. "beware"). Directly before insertion of the needle, the participants were warned with either the word "sting" or "beware." Venous blood sampling was performed according to a standardized protocol. Preinterventional and postinterventional blood pressure and heart rate, as well as pain scores after venous blood sampling, were evaluated.
Results: There were 98 participants, 26.2 ± 3.2 years of age, who were included into the analysis. Participants experienced significantly more pain after having been warned with the word "sting" compared with the word "beware." The numeric rating scale results were 2.7 ± 1.2 versus 1.9 ± 1.1, respectively (P=0.001).
Discussion: Words associated with pain increase the perception of pain during venous blood sampling. Omitting these words may be a simple and essential method by which to avoid unnecessary pain.