The purpose of this paper was to examine the relationship of sex and pain-related fear in pain intensity reports to thermal stimuli and whether sex differences in reported pain intensity were mediated by pain-related fear. 177 participants, 124 female (23.5 ± 4.5 years old), filled out a demographic and fear of pain questionnaire (FPQ-III). Experimental pain testing was performed using thermal stimuli applied to the lower extremity. Participants rated the intensity of pain using the numerical pain rating scale (NPRS). Independent t-tests, Sobel’s test, and linear regression models were performed to examine the relationships between sex, fear of pain, and pain sensitivity. We found significant sex differences for thermal pain threshold temperatures ( ) and suprathreshold pain ratings for 49°C ( ) and 51°C ( ). FPQ-severe score mediated the effect of suprathreshold pain ratings of 49° ( ), 51° ( ), and pain threshold temperatures ( ). There are differences in the pain sensitivity between sexes, but this difference may be mediated by baseline psychosocial factors such as fear of pain. 1. Introduction Pain is a prevalent, debilitating condition that has serious health and economic consequences. Approximately 116 million Americans suffer from chronic pain conditions and the costs of pain range from $560 billion to $635 billion annually; this amount is equal to approximately 2,000 dollars for everyone living in the United States [1]. The prevalence of pain in primary care settings is estimated at approximately 30%, with nearly two-thirds of those pain reports attributed to musculoskeletal pain [2]. Evidence suggests men and women experience and report pain differently [3–6]. Clinically this is relevant because research has demonstrated that a greater percentage of chronic pain sufferers are women [4, 7]. Women also report more areas of bodily pain [8, 9] and more pain-related disability compared to men [10]. Given that pain is such a prevalent and debilitating condition with serious health and economic consequences, the Institute of Medicine has stressed the need to improve healthcare delivery of pain management, including individualized treatment approaches [1]. Although an individualized approach to the treatment of pain is recommended, should healthcare providers tailor their treatments based on the sex of the patient or are there other factors that could be important as well? The etiology of sex differences in pain reports is still not clear. Evidence suggests that different biological [11–14] and psychosocial factors [15–17] may account for these
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