A Meta-Analysis of Sex Differences in Pain Threshold, Tolerance, and Intensity

Over the past 70 years, substantial research investigating sex differences in pain sensitivity has suggested that males may have higher pain thresholds and tolerances than females. However, no meta-analytic review has been conducted in over 20 years.

A meta-analysis of cross-sectional studies examining sex differences in pain threshold, tolerance, and intensity.

PubMed, Cumulative Index to Nursing and Allied Health Literature, Scopus, Embase, and PsycInfo.

Effect size of sex was assessed across studies for threshold, tolerance, and intensity, with moderation testing for sample type (clinical vs. healthy) and pain stimulus type. Sources were assessed to determine the extent of sex and gender conflation.

Ninety studies (7,464 participants for pain threshold, 4,935 for tolerance, and 4,911 for intensity) were included and assessed for bias. Sex and gender were conflated in 91.7% of threshold studies, 81.6% of tolerance studies, and 81.6% of intensity studies. Males had significantly higher pain thresholds (d = 0.66), higher pain tolerance (d = 0.79), and lower pain intensity (d = -0.58) than females. Publication bias was identified for all outcomes. Pain stimulus type significantly moderated sex differences in pain threshold, with electrical stimuli producing the largest difference. Clinical samples exhibited smaller sex differences in pain tolerance than healthy samples.

Although sex differences in pain sensitivity seem to be robust, effect size varies depending on stimulus and sample type. It remains unclear whether sex or gender contributes to the identified effects given the extent to which these constructs have been conflated.

Clinical implications and future directions are discussed. © 20XX by the American Society for Pain Management Nursing.