Impact of the COVID-19 Pandemic on the Incidence and Composition of Urolithiasis in New Brunswick, Canada.

Introduction: The COVID-19 pandemic affected the presentation and management of many diseases. Lifestyle and dietary habit changes caused by social limitations and quarantine may alter the incidence of chronic diseases such as urolithiasis. This epidemiology study aimed to investigate the impact of the COVID-19 pandemic on the incidence of kidney stones in the Canadian province of New Brunswick.

Methods: Reports of 3253 kidney stone analysis from 1 January 2021, to 31 December 2023, were retrospectively reviewed from the laboratory information system. All stone compositions were analysed by Fourier transforminfrared spectrometry technology. Incident rates were compared with 3838 urolithiasis reports from 1 October 2016, to 30 September 2019, stratified by different ages, sexes and the geographic regional health authority (RHA) zones.

Results: The overall incidence of urolithiasis in New Brunswick significantly dropped from 148 (95% confidence interval (CI) 139-157) per 100,000 person-years in 2016-2019 to 115 (95% CI 110-120) per 100,000 person-years in the period of 2021-2023 (χ²: 94.167, p < 0.01, risk ratio: 0.78). The decrease occurred in both sexes, most age groups and the most densely populated RHA zones (Zones 1 and 2; p < 0.01). However, geographic differences on the impact of COVID-19 on prevalence were observed. Similar to that of the pre-COVID-19 period, calcium oxalate monohydrate remained as the predominant (61.27%) kidney stone type in 2021-2023. Struvite stone decreased from 2.19% to 0.86%.

Conclusions: The incidence rate of urolithiasis in New Brunswick was significantly lower in the COVID-19 pandemic than in the pre-COVID-19 period. However, we found no significant change in kidney stone compositions.