title: Factors predicting chronic pain after open mesh based inguinal hernia repair: ​A prospective cohort study.
abstract: BACKGROUND
  Chronic postherniorrhaphy pain is the foremost setback of today's inguinal hernia repair. Finding predictors for it affects implants, operative techniques and allows for preventive measures.
  
  
  METHODS
  Prospectively collected data from 932 outpatient open inguinal hernia operations between 2003 and 2010 were subjected to regression analysis. Visual analogue scale score (VAS) at least a year after operation and a measurement of chronic pain at one year were the target variables.
  
  
  RESULTS
  Chronic pain was present in 99 (11.5%) patients one year after operation. Independent predictors for the occurrence of chronic pain were positively recurrence (Odds ratio, OR 6.77 vs. no recurrence, P = 0.005), complication (OR 5.16 vs. no complication, P = 0.002), mid-density mesh (OR 2.28 vs. lightweight mesh, P = 0.012), higher preoperative VAS score (OR 1.15, P = 0.006) and negatively higher age (OR 0.98, P = 0.027). Predictors for a higher postoperative VAS score were recurrence (regression coefficient, RC, 1.49 vs. no recurrence, P = 0.001), complication (RC 0.76 vs. no complication, P = 0.016), heavyweight mesh (RC 0.50 vs. lightweight mesh, P = 0.046) and higher preoperative VAS level (RC 0.10, P < 0.001).
  
  
  CONCLUSIONS
  Recurrence, complication, mesh weight, preoperative VAS score and age are predictors for the occurrence chronic pain after open mesh based inguinal hernia repair. Recurrence, complication, mesh weight and preoperative VAS score are predictors of postherniorrhaphy VAS level.
authors.affiliation: Helsinki University Hospital, Töölö Hospital, P.O. Box 266, FIN-00029 HUS, Helsinki, Finland. Electronic address: georgios.pierides@fimnet.fi.
authors.forename: Georgios A
authors.initials: GA
authors.lastname: Pierides
authors.affiliation: Department of Surgery, Kuopio University Hospital, P.O Box 100, FIN-70029 KYS, Kuopio, Finland. Electronic address: hannu.paajanen@kuh.fi.
authors.forename: Hannu E
authors.initials: HE
authors.lastname: Paajanen
authors.affiliation: Helsinki University Hospital, Ambulatory Surgery Unit of Jorvi Hospital, P.O. BOX 700, FIN-00029 HUS, Espoo, Finland. Electronic address: jaana.vironen@hus.fi.
authors.forename: Jaana H
authors.initials: JH
authors.lastname: Vironen
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D059350:Chronic Pain / Q000209:etiology*; D005260:Female; D006552:Hernia, Inguinal / Q000601:surgery*; D059685:Herniorrhaphy / Q000009:adverse effects* / Q000379:methods; D006801:Humans; D008297:Male; D008875:Middle Aged; D010147:Pain Measurement; D010149:Postoperative Pain / Q000209:etiology*; D011446:Prospective Studies; D012008:Recurrence; D012307:Risk Factors; D013526:Surgical Mesh / Q000009:adverse effects*; D055815:Young Adult
keywords: Chronic pain; Factor; Inguinal hernia; Open surgery; Predictor