Psychological factors associated with chronic postoperative inguinal pain: a qualitative systematic review

Chronic postoperative inguinal pain (CPIP) may affect up to 12% of patients undergoing inguinal hernia repair (IHR) and has surpassed recurrence as the most important patient-centered outcome of this procedure. Although psychological factors have been associated with chronic postsurgical pain, no consistent prognostic association has been established for CPIP, largely due to heterogeneity in psychometric instruments, outcome definitions, and assessment timing. This review aims to synthesize evidence and evaluate the methodological quality of studies on psychological factors associated with CPIP.

A systematic review was conducted in accordance with PRISMA guidelines, searching PubMed, EMBASE, and Web of Science. Studies of adults undergoing IHR that evaluated psychological factors in association with chronic pain development were included. Data extraction focused on baseline characteristics, protective and risk factors for CPIP, perioperative psychometric instruments, psychological constructs and domains, methodological heterogeneity across study designs and statistical models, and terminology consistency. The primary endpoint was to identify psychological factors associated with CPIP development across study populations.

Nine studies of 1,519 participants were identified. Among the studies that reported gender, 74 women were included (6.0%). In prospective studies, 78 patients (12.3%) developed CPIP. Eight psychometric instruments were identified; none was used in more than three studies. Anxiety was the most frequently assessed construct, present in 8 studies (88.9%), followed by depression in 6 (66.7%), pain catastrophizing and history of chronic pain each in 3 (33.3%), and optimism in 2 (22.2%). Significant associations between at least one psychological factor and chronic pain were reported in 5 studies (55.6%), of which 3 retained significances after multivariable adjustment (33.3%). Preoperative state anxiety independently predicted CPIP in two studies using the STAI. Dispositional optimism was the only protective factor identified in one study, while low optimism was associated with increased risk in the same study. CPIP definitions, assessment timing, and psychometric instruments varied substantially across studies.

Preoperative state anxiety showed the most replicated association with CPIP, and dispositional optimism was identified as protective in one study. Substantial heterogeneity in psychometric assessment and highly variable perioperative factors restrict these findings to a hypothesis-generating role and highlight the need for methodological standardization in future CPIP research.