Scheduled and urgent inguinal hernia repair in Ontario, Canada between 2010 and 2022: Population-based cross sectional analysis of trends and outcomes

Abstract

Introduction: We examine trends in inguinal hernia repairs with respect to the COVID-19 pandemic and secular trends in Ontario, Canada.

Methods: This was a retrospective cohort study. Hernia repairs performed January 1, 2010-December 31, 2022 were captured from health administrative inpatient and outpatient databases. Patients managed in three clinical settings were examined: public hospital in-patient, semi-private hospital in-patient (Shouldice Hospital), and public hospital out-patient. We examined the effect of the COVID-19 pandemic on surgical volumes, clinical setting, patient characteristics by setting, time from diagnosis until surgery, hospital length-of-stay, and patient outcomes (90-day readmissions, 1-year reoperations). We used multivariable logistic regression to examine whether patient outcomes were comparable between the COVID-19 period and the pre-pandemic period, adjusted sociodemographic and clinical factors. Shouldice Hospital is the only semi-private hospital in Ontario specializing in hernia repair (patients pay for the mandated admission, but not for the procedure).

Results: During the pandemic (March 2020-December 2022), there were 8,162 fewer (15%) scheduled inguinal hernia repairs than expected, but the age-sex standardized rate of urgent repairs remained unchanged. Shouldice Hospital performed more surgeries in the COVID-19 era than pre-pandemic and had a shorter average LOS by 24 hours, despite treating more patients with older age, higher ASA score [adjusted odds ratio (aOR) 2.13 (1.93-2.35) III vs I-II] and greater comorbidity [aOR 1.36 (1.08-1.70) for 2 vs none] than pre-pandemic. Patients treated in the COVID-19 era experienced a longer time until surgery, being the longest in 2022 (median 133 days). Ninety-day readmissions and 1-year reoperations were lower in the COVID-19 era and lower for patients receiving surgery at Shouldice Hospital.

Conclusion: During the COVID-19 pandemic, there were 8,162 fewer scheduled hernia repairs than expected, longer wait-times until surgery, shorter length-of-stay, and more patients with comorbidities, but outcomes were not worse compared with the pre-pandemic period.

Fig 1. Hernia repair by setting.

Number (A) and age-sex standardized rate (B) of scheduled (e.g. elective) and urgent inguinal hernia repairs over time. The 2019 Ontario census counts were used for standardization. Age groups were 18–29 years, 30–44 years, 45–59 years, and 60+ years for males and 18–44 years, 45–59 years, and 60+ years for females).

Fig 2. Weekly scheduled inguinal hernia repair volumes over time.

Comparison of observed versus expected number of elective (scheduled) inguinal hernia repairs over time. The solid black line is the expected number of repairs per week. The pink shaded region below the line of expectation represents the total number of repairs in that was lower than expected (observed < expected). The blue shaded region above the line of expectation represents the total number of repairs that was greater than expected (observed > expected).

Fig 3. Scheduled hernia repair by setting.

Percent of hernia repairs over time performed in the outpatient or inpatient setting.

Fig 4. Regional variability in the use of outpatient hernia repair for scheduled inguinal hernia repair (excluding Shouldice Hospital).

Funnel plot showing proportion of scheduled inguinal hernia repairs by hospital performed in the outpatient setting in relation to hernia repair volumes during the study period.