The Role of SARS-CoV-2 Testing on Hospitalizations in California

TL;DR

This study analyzes how COVID-19 test positivity rates relate to hospitalization rates across California counties during three pandemic waves, highlighting demographic shifts and the importance of testing in managing hospital capacity.

Contribution

It provides a detailed county-level analysis of the association between test positivity and hospitalizations over time, considering demographic changes during the pandemic.

Findings

Test positivity rate is consistently linked to hospitalization rates across all waves.

Demographic factors influencing hospitalizations changed over time.

The study underscores the importance of testing in predicting healthcare system burden.

Abstract

The rapid spread of the new SARS-CoV-2 virus triggered a global health crisis disproportionately impacting people with pre-existing health conditions and particular demographic and socioeconomic characteristics. One of the main concerns of governments has been to avoid the overwhelm of health systems. For this reason, they have implemented a series of non-pharmaceutical measures to control the spread of the virus, with mass tests being one of the most effective control. To date, public health officials continue to promote some of these measures, mainly due to delays in mass vaccination and the emergence of new virus strains. In this study, we studied the association between COVID-19 positivity rate and hospitalization rates at the county level in California using a mixed linear model. The analysis was performed in the three waves of confirmed COVID-19 cases registered in the state to September 2021. Our findings suggest that test positivity rate is consistently associated with hospitalization rates at the county level for all waves of study. Demographic factors that seem to be related with higher hospitalization rates changed over time, as the profile of the pandemic impacted different fractions of the population in counties across California.