The impact of the South African Covid-19 lockdown on incidence and severity of traumatic brain injury at Tshepong hospital: A multivariate retrospective cohort study.

Background: Globally traumatic brain injuries (TBIs) are the leading cause of death in people under the age of 45. 2020 saw a series of social lockdowns as a response to the COVID-19 pandemic. We aimed to unveil the impact of the different levels of lockdown on TBI incidence at Tshepong Hospital.

Method: A retrospective review of patients with TBIs during the first 30 days of each of the 5 lockdown levels, between 1st of April -20th October 2020 was conducted. Each lockdown level was compared to a control of a similar period in 2019.

Results: Level 5 lockdown resulted in a 66% reduction in total incidence of TBI, with a decrease in the daily incidence median value to 0 when compared to its control group median of 1 (-value 0.004). However, Level 3 and 2 resulted in a significant 133% and 200% increase respectively in TBI incidence for similar period the year before.There was a 0,75% decrease in total trauma during the non-lockdown periods in relation to the lock down periods with a lockdown mean incidence of 53,4 (std Dev. 26.6) and non-lockdown mean of 53 (std Dev 20.8).

Conclusion: The cumulative effect of the lockdowns made miniscule changes in the overall TBI incidence but led to significant variation in TBI incidence in the comparative months. A "rebound trauma" phenomena is observed in transitioning from severe social restrictions to milder ones with unemployment and unbanning of alcohol as possible contributary factors. Further studies are needed to investigate these complex interactions.