Incidence of Inguinal Hernia Repairs in Olmsted County, MN A Population-Based Study

Objective: To determine age-and sex-specific incidence rates of inguinal hernia repairs (IHR) in a well-defined US population and examine trends over time. Background Data: IHR represent a substantial burden to the US healthcare system. An up-to-date appraisal will identify future healthcare needs. Methods: A retrospective review of all IHR performed on adult residents of Olmsted County, MN, from 1989 to 2008 was performed. Cases were ascertained through the Rochester Epidemiology Project, a record linkage system with more than 97% population coverage. Incidence rates were calculated by using incident cases as the numerator and population counts from the census as the denominator. Trends over time were evaluated using Poisson regression. Results: During the study period, a total of 4026 IHR were performed on 3599 unique adults. Incidence rates per 100,000 person-years were greater for men: 368 versus 44 for women, and increased with age: from 194 to 648 in men, and from 28 to 108 in women between 30 and 70 years of age. Initial, unilateral IHR comprised 74% of all IHR types. The lifelong cumulative incidence of an initial, unilateral or a bilateral IHR in adulthood was 42.5% in men and 5.8% in women. Over time (from 1989 to 2008), the incidence of initial, unilateral IHR in men decreased from 474 to 373 (relative reduction, RR = 21%). Bilateral IHR increased from 42 to 71 (relative increase = 70%), contralateral metachronous IHR decreased from 29 to 11 (RR = 62%), and recurrent IHR decreased from 66 to 26 (RR = 61%); for all changes P < 0.001. Conclusions: IHR are common, their incidence varies greatly by age and sex and has decreased substantially over time in Olmsted County, MN.