Matching males and females undergoing Shouldice repair using a prospective, longitudinal design

Marguerite Mainprize ¹, Anton Svendrovski ², Christoph Paasch ²

⁰From the Department of Surgery, Shouldice Hospital, Ont. (Mainprize, Paasch, Yilbas); the Department of General Surgery, University Hospital Brandenburg an der Havel, Brandenburg Medical School Theodor Fontane, Brandenburg, Germany (Mainprize, Paasch); UZIK Consulting Inc. Toronto, Ont. (Svendrovski); the Department of Psychology, York University, Ont. (Katz) mmainprize@shouldice.com.

Canadian Journal of Surgery. Journal Canadien De Chirurgie +

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August 8, 2025

View abstract on PubMed

Summary

Females report more frequent and severe postsurgical pain than males 3 months after Shouldice repair. However, these sex differences in chronic pain diminish by 1 year following surgery.

Area Of Science

Surgical outcomes
Pain research
Sex differences in health

Background

Chronic postsurgical pain incidence and severity differ between sexes.
Females generally report higher pain than males, but reasons are unclear.
This study investigated sex-based pain differences after Shouldice hernia repair.

Purpose Of The Study

To compare pain and psychological factors in matched male and female patients.
To assess pain at 3 months and 1 year post-Shouldice repair.
To identify potential factors contributing to sex differences in postsurgical pain.

Main Methods

Matched male-female pairs (1:1) undergoing Shouldice repair were compared.
Ten variables were matched: age, BMI, smoking, depression, anxiety, living status, ASA score, preoperative pain, and nerve handling.
Pain data collected via questionnaires at 3 months and 1 year postoperatively.

Main Results

At 3 months, females reported significantly higher pain incidence, frequency, duration, and severity than males.
Females showed higher "worst pain," "average pain," and "pain now" scores.
By 1 year postoperatively, no significant sex differences in pain were observed.

Conclusions

Sex differences in pain frequency, duration, incidence, and severity exist at 3 months after Shouldice repair.
These disparities are no longer significant by the 1-year mark.
Matching for key confounders highlighted transient sex-based pain variations.