AbstractBackgroundPersistent pain after hernia repair is widely recognised as a considerable problem, although the natural course of postoperative pain is not fully understood. The aim of the present study was to explore the natural course of persistent pain after hernia repair in a population-based cohort and identify risk factors for prolonged pain duration.MethodsThe study cohort was assembled from the Swedish Hernia Register (SHR), which has compiled detailed information on more than 140 000 groin hernia repairs since 1992. All patients operated on for groin hernia in the County of Uppsala, Sweden, 1998–2004 were identified in the SHR. Those who were still alive in 2005 received the Inguinal Pain Questionnaire, a validated questionnaire with 18 items developed with the aim of assessing postherniorrhaphy pain, by mail. Reminders were sent to non-responders 5 months after the first mail. The halving time was estimated from a linear regression of the logarithmic transformation of the prevalence of pain each year after surgery. A multivariate analysis with pain persisting more than 1 month with a retrospective question regarding time to pain cessation as dependent variable was performed.ResultsAltogether 2834 repairs in 2583 patients were recorded, 162 of who had died until 2005. Of the remaining patients, 1763 (68%) responded to the questionnaire. In 6.7 years the prevalence of persistent pain had decreased by half for the item “pain right now” and in 6.8 years for the item “worst pain last week”. The corresponding figures if laparoscopic repair was excluded were 6.4 years for “pain right now” and 6.4 years for “worst pain past week”. In a multivariate analysis, low age, postoperative complication and open method of repair were found to predict an increased risk for pain persistence exceeding 1 month.ConclusionPersistent postoperative pain is a common problem following hernia surgery, although it often recedes with time. It is more protracted in young patients, following open repair and after repairs with postoperative complications. Whereas efforts to treat persistent postoperative pain, in particular neuropathic pain, are often fruitless, this group can at least rely on the hope that the pain, for some of the patients, gradually decreases with time. On the other hand, 14% still reported a pain problem 7 years after hernia surgery. We do not know the course after that.Although no mathematical model can provide a full understanding of such a complex process as the natural course of postoperative pain, assuming an exponential course may help to analyse the course the first years after surgery, enable comparisons with other studies and give a base for exploring factors that influence the duration of the postoperative pain. Halving times close to those found in our study could also be extrapolated from other studies, assuming an exponential course.
A Population-Based Multivariate Analysis of the Association of County Demographic and Medical System Factors with Per Capita Pediatric Trauma Death Rates in North Carolina
