Impact of COVID‐19 pandemic on mortality rate in memory clinic patients

Abstract

INTRODUCTIONWe investigated whether mortality in memory clinic patients changed due to coronavirus disease 2019 (COVID‐19) pandemic.METHODSWe included patients from the Amsterdam Dementia Cohort: (1) n = 923 pandemic patients (baseline visit: 2017–2018, follow‐up: until 2021), and (2) n = 830 historical control patients (baseline visit: 2015–2016, follow‐up: until 2019). Groups were well‐balanced. We compared mortality during pandemic with historical control patients using Cox regression. Differences in cause of death between groups were explored using Fisher's exact test.RESULTSPandemic patients had a higher risk of mortality than historical control patients (hazard ratio [HR] [95% confidence interval {CI}] = 1.34 [1.05–1.70]). Stratified for syndrome diagnosis, the effect remained significant in dementia patients (HR [95% CI] = 1.35 [1.03–1.78]). Excluding patients who died of COVID‐19‐infection, the higher mortality risk in pandemic patients attenuated (HR [95% CI] = 1.24 [0.97–1.58]). Only the difference in cause of death between pandemic patients and historical control patients for death to COVID‐19‐infection (p = 0.001) was observed.CONCLUSIONMemory clinic patients had increased mortality risk during COVID‐19 compared to historical control patients, attributable to dementia patients.Highlights We investigated if mortality rates in memory clinic patients changed due to COVID‐19 pandemic. We included patients along the cognitive continuum, including SCD, MCI, and dementia. We used a well‐balanced historical control group. Memory clinic patients had higher risk for mortality during COVID‐19 lockdown. Our results indicate that excess mortality is mainly caused by death to COVID‐19 infection.