The study attempts to quantify the relative risks for chronic postoperative inguinal pain (CPIP) after Lichtenstein repair of groin hernia, depending on mesh type and fixation suture material.

For this purpose the investigators will analyze data from the Swedish Hernia Registry (SHR).

This is an open cohort study design where the investigators will analyze existing data that have been prospectively collected in SHR, which covers > 95% of all groin hernia repairs in Sweden. The large database enables assessment of the relative risks for CPIP depending on in particular mesh and mesh fixation, adjusted for other plausible risk factors.

Each participant was entered at the date of surgery, when demographic and intraoperative data were registered. One year postop, each patient was sent a questionnaire focusing on present pain.

Inclusion Criteria:

All Lichtenstein and similar open mesh repairs that have been registered in the SHR from September 1, 2012, until December 31, 2018.

Exclusion Criteria:

• Laparoscopic repairs.
• Preperitoneal open repairs.
• Pure suture repairs
• Patients not having a 10-digit state-assigned Patient Identification Number.

An unselected, consecutive nationwide cohort during 7 years, with a 1-year follow-up