Abstract
Chemosensory scientists have been skeptical that reports of COVID-19 taste loss are genuine, in part because before COVID-19 taste loss was rare and often confused with smell loss. Therefore, to establish the predicted prevalence rate of taste loss in COVID-19 patients, we conducted a systematic review and meta-analysis of 376 papers published in 2020–2021, with 241 meeting all inclusion criteria. Drawing on previous studies and guided by early meta-analyses, we explored how methodological differences (direct vs. self-report measures) may affect these estimates. We hypothesized that direct measures of taste are at least as sensitive as those obtained by self-report and that the preponderance of evidence confirms taste loss is a symptom of COVID-19. The meta-analysis showed that, among 138,897 COVID-19-positive patients, 39.2% reported taste dysfunction (95% confidence interval: 35.34%–43.12%), and the prevalence estimates were slightly but not significantly higher from studies using direct (n = 18) versus self-report (n = 223) methodologies (Q = 0.57, df = 1, P = 0.45). Generally, males reported lower rates of taste loss than did females, and taste loss was highest among middle-aged adults. Thus, taste loss is likely a bona fide symptom of COVID-19, meriting further research into the most appropriate direct methods to measure it and its underlying mechanisms.
This is a retraction and replacement of: Mackenzie E Hannum, Riley J Koch, Vicente A Ramirez, Sarah S Marks, Aurora K Toskala, Riley D Herriman, Cailu Lin, Paule V Joseph, Danielle R Reed, Taste loss as a distinct symptom of COVID-19: a systematic review and meta-analysis, Chemical Senses, Volume 47, 2022, bjac001, https://doi.org/10.1093/chemse/bjac001
Readers raised concerns about this meta-analysis in November 2022, and an Expression of Concern1 was posted in June 2023. Following an investigation, the authors have acknowledged the concerns, revised the text, and agreed to retract and replace the original version. The new revised version of the meta-analysis has been reviewed and approved by the editors and is available at: https://doi.org/10.1093/chemse/bjad043.
1 Expression of concern: Taste loss as a distinct symptom of COVID-19: a systematic review and meta-analysis, Chemical Senses, Volume 48, 2023, bjad019, https://doi.org/10.1093/chemse/bjad019