A study protocol for a retrospective cohort study and interrupted time series analysis to assess the effect of the COVID-19 pandemic on major trauma presentations and patient outcomes in English hospitals

A protocol for a retrospective cohort study and interrupted time series analysis to investigate the effect of successive COVID related “lockdown” restrictions on major trauma presentations and patient outcomes in English hospitals. The study specifically aims to assess: 1) The impact of successive “lockdowns” on the volume, demographics, injury mechanism, severity, treatment and outcomes of major trauma in England. 2) If the implementation of “lockdowns” affected major trauma related mortality.

A patient cohort will be derived from the Trauma and Audit Research Network (TARN) database, for all trauma receiving hospitals in England, between 1^stof January 2017 to 1^stof September 2021. This period encompasses two national “lockdown” periods (23^rdMarch 2020 to 29^thJune 2020 and 2^ndNov 2020 to 16^thMay 2021) in England. A time series will be used to illustrate changes in the volume and mechanism of injury associated with successive “lockdowns”. Demographic characteristics and features of the clinical care pathways will be compared during the “lockdown” and equivalent pre-COVID periods. To specifically assess if there were any changes in risk adjusted mortality associated with the “lockdowns” interrupted time series analysis will be conducted.