Changes in surgical mortality during COVID-19 pandemic by patients’ race, ethnicity and socioeconomic status among US older adults: a quasi-experimental event study model

ObjectivesTo examine changes in the 30-day surgical mortality rate after common surgical procedures during the COVID-19 pandemic and investigate whether its impact varies by urgency of surgery or patient race, ethnicity and socioeconomic status.DesignWe used a quasi-experimental event study design to examine the effect of the COVID-19 pandemic on surgical mortality rate, using patients who received the same procedure in the prepandemic years (2016–2019) as the control, adjusting for patient characteristics and hospital fixed effects (effectively comparing patients treated at the same hospital). We conducted stratified analyses by procedure urgency, patient race, ethnicity and socioeconomic status (dual-Medicaid status and median household income).SettingAcute care hospitals in the USA.ParticipantsMedicare fee-for-service beneficiaries aged 65–99 years who underwent one of 14 common surgical procedures from 1 January 2016 to 31 December 2020.Main outcome measures30-day postoperative mortality rate.ResultsOur sample included 3 620 689 patients. Surgical mortality was higher during the pandemic, with peak mortality observed in April 2020 (adjusted risk difference (aRD) +0.95 percentage points (pp); 95% CI +0.76 to +1.26 pp; p