A man who is exposed to physical pain feels less severe pain if he is subjected to pain by a woman compared with a man, according to new research from Lund University in Sweden. In addition, men experience less pain after surgery when asked about it by a woman than by a man.
"This was true despite the fact that the men and women involved in the study were dressed the same and used the same script", says Anna Sellgren Engskov, PhD student at Lund University and consultant in anesthesiology and intensive care.
Anna Sellgren Engskov will defend her dissertation at Lund University with her thesis Perception of nociceptive pain - perspectives on induction, evaluation and gender on November 17.
In the first study, healthy volunteers were stimulated with a short laser pulse in the arche of their feet. In addition to new knowledge about how different pain fibres are activated, a picture emerged that surprised the researchers: when it was a woman who induced pain in a male research subject, stronger pain stimulation was required to achieve the same pain threshold compared to if the performer was a man.
The results inspired to a follow-up study focusing solely on gender. Now the research subjects were given a small device in their hand, which when a button is pressed emits a weak electric current. The research subjects would release the button when they felt pain. The tests were conducted twice, once with a female examiner and once with a male. Both were neutrally and professionally dressed and stuck to a script to avoid any other interaction that could affect the situation.
"Just like in the first study, we saw that it required stronger stimulation to elicit the same estimated pain with a female examiner than with a male. Both female and male research subjects experienced this", says Anna Sellgren Engskov.
The results brought her on to a new group of subjects: postoperative patients. Could their pain experiences also be influenced by the gender of the examiner? A total of 245 patients in three different postoperative wards at Skåne University Hospital were surveyed. A female and a male investigator asked the patients about their pain shortly after surgery.
"We were able to partially confirm our previous results here as well. Men, but not women, were in less pain when asked by a woman. The differences were not that great, and probably has no significance at a group level. However, for the individual patient it can matter, especially given that the differences in pain were greatest when it hurt so much that the patients started asking for pain relief", says Anna Sellgren Engskov.
There is existing research that suggests a higher empathic ability in women, which in turn can be linked to silent communication - for example more smiles and more direct eye contact. But whether this explains the results is hard to say.
"This is the first confirmation of these results both experimentally in healthy individuals as well as clinically with newly operated patients. Including the gender perspective when pain is evaluated can hopefully contribute to patients receiving even better care and pain treatment in the future", concludes Professor Jonas Åkeson, main supervisor in the project and senior physician in anesthesiology and intensive care at SUS in Malmö.
