Trial reportBMC medicine2022
Prednisolone does not improve olfactory function after COVID-19: a randomized, double-blind, placebo-controlled trial.
Trial report in BMC medicine, 2022. The graph could read no effect estimate from its abstract, so it casts no vote on the map. An erratum has been issued. Cited by 15 papers, 4 of them syntheses that pooled it.
What it found
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The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
15 citing papers in PubMed, 4 syntheses or guidelines pooled it, 21 citations in OpenAlex.
- Effect of glucocorticoids on smell sensation in patients with non-traumatic olfactory disorders: a systematic review and meta-analysis.European journal of clinical pharmacology · 2026Pooled it
- Treatment of COVID-19 Associated Olfactory Dysfunction: A Systematic Review.Current allergy and asthma reports · 2024Pooled it
- The effectiveness of olfactory training for chronic olfactory disorder following COVID-19: a systematic review.Frontiers in human neuroscience · 2024Pooled it
- Pooled it
- Impacts of different treatment methods on patients with COVID-related olfactory dysfunction: a systematic review and network meta-analysis.Clinics (Sao Paulo, Brazil) · 2026Article
- Olfactory Training for Post-COVID-19 Olfactory Dysfunction: A Meta-Analysis of Efficacy and Combination Therapies.Journal of clinical medicine · 2025Review
- The efficacy and safety of corticosteroids in treating severe COVID-19 patients: A meta-analysis with trial sequential analysis.Pakistan journal of medical sciences · 2025Review
- Treatments for Olfactory Dysfunction in COVID-19: A Systematic Review.International archives of otorhinolaryngology · 2024Review
- Long-term olfactory loss post-COVID-19: Pathobiology and potential therapeutic strategies.World journal of otorhinolaryngology - head and neck surgery · 2024Review
- Diagnostic accuracy of the screenings Sniffin' Sticks Test (SST-12) in COVID-19 induced olfactory disorders.PloS one · 2024Article
- One-year psychophysical evaluation of COVID-19-induced olfactory disorders: a prospective cohort study.BMC medicine · 2023Article
- Review
- Correction: Prednisolone does not improve olfactory function after COVID-19: a randomized, double-blind, placebo-controlled trial.BMC medicine · 2023Article
- Assessment of COVID-19-related olfactory dysfunction and its association with psychological, neuropsychiatric, and cognitive symptoms.Frontiers in neuroscience · 2023Review
- Post-viral olfactory loss and parosmia.BMJ medicine · 2023Review
Corrections and comments
- Erratum issued
Authors and funding
7 authors at 3 institutions in 1 country.
Funding
No grant is acknowledged in the PubMed record.
Abstract
backgroundPrednisolone has been suggested as a treatment for olfactory disorders after COVID-19, but evidence is scarce. Hence, we aimed to determine the efficacy of a short oral prednisolone treatment on patients with persistent olfactory disorders after COVID-19.
methodsWe performed a randomized, double-blind, placebo-controlled, single-centered trial in the Netherlands. Patients were included if they were > 18 years old and if they had persistent (> 4 weeks) olfactory disorders within 12 weeks after a confirmed COVID-19 test. The treatment group received oral prednisolone 40 mg once daily for 10 days and the placebo group received matching placebo. In addition, all patients performed olfactory training. The primary outcome was the objective olfactory function on Sniffin' Sticks Test (SST) 12 weeks after the start of treatment, measured in Threshold-Discrimination-Identification (TDI) score. Secondary outcomes were objective gustatory function assessed by the Taste Strip Test (TST) and subjective self-reported outcomes on questionnaires about olfactory, gustatory and trigeminal function, quality of life, and nasal symptoms. The CONSORT 2010 guideline was performed.
resultsBetween November 2021 and February 2022, we included 115 eligible patients, randomly assigned to the treatment (n = 58) or placebo group (n = 57). No difference in olfactory function between groups was obtained after 12 weeks. Median TDI score on SST was 26.8 (IQR 23.6-29.3) in the placebo group and 28.8 (IQR 24.0-30.9) in the prednisolone group, with a median difference of 2.0 (95% CI 0.75 to 1.5). There was similar improvement on olfactory function in both groups after 12 weeks. Furthermore, on secondary outcomes, we obtained no differences between groups.
conclusionsThis trial shows that prednisolone does not improve olfactory function after COVID-19. Therefore, we recommend not prescribing prednisolone for patients with persistent olfactory disorders after COVID-19.
trial registrationThis trial is registered on the ISRCTN registry with trial ID ISRCTN70794078.
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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.