Outpatient inguinal hernia repair in Spain: a population-based study of 1,163,039 patients-clinical and socioeconomic factors associated with the choice of day surgery

Reducing inpatient admissions and health care costs is a central aspiration of worldwide health systems. This study aimed to evaluate trends in outpatient surgery in inguinal hernia repair (IHR) and factors related to the outpatient setting in Spain. A retrospective cohort study (Record-Strobe compliant) of 1,163,039 patients who underwent IHR from January 2004 to December 2019 was conducted. Data were extracted from the public clinical administrative database CMBD ("Conjunto Minimo Basico de Datos"). The primary outcome was the outpatient surgery rate. Univariate and multivariable analyses were performed to identify clinical and socioeconomic factors related to the outpatient setting. The overall proportion of outpatient repairs was 30.7% in 2004 and 54.2% in 2019 (p < 0.001). Treatment in a public hospital was the most remarkable factor associated with the likelihood of receiving an outpatient procedure (OR 3.408; p < 0.001). There were also significant differences favouring outpatient procedures for patients with public insurance (OR 2.351; p < 0.001), unilateral hernia (OR 2.903; p < 0.001), primary hernia (OR 1.937; p < 0.0005), age < 65 years (OR 1.747; p < 0.001) and open surgery (OR 1.610; p < 0.001). Only 9% of patients who pay for their intervention privately or 15% of those covered by private insurance were treated as outpatients. Spain has significantly increased the rate of outpatient IHR over the last 16 years. However, the figures obtained still leave a significant margin for improvement. Important questions about the acceptance of outpatient settings remain to be answered.