UMIN000045185.

Study name	"Additional value" of nasal therapy in standard therapy for COVID‐19 patients with olfactory disorders: a preliminary randomized controlled clinical trial
Methods	Parallel‐group randomised controlled trial Study is reported as blinded to participants, but we note that no placebo is used
Participants	Confirmed COVID‐19 positive with mild or moderate symptoms Inclusion criteria: Confirmed SARS‐CoV‐2 PCR positive with mild or moderate symptoms  "Impaired Alcohol Swab test result"   Able to comply with the treatment protocol Aged 18 to 50 years Exclusion criteria: Cognitive and consciousness impairment Severe dyspnoea and unstable vital signs History of olfactory and taste disturbance before COVID History of chronic rhinosinusitis and severe head trauma History of routine use of intranasal steroid or decongestant before COVID‐19 History of skin and vascular problems Estimated sample size: 24 participants
Interventions	Intervention group: Nasal treatment (mometasone nasal spray, normal saline nasal irrigation both nostrils, oxymethazolin 0.5% nasal spray before bedtime, aromatic vapour rub on neck and chest before bedtime) for 2 weeks Comparator: No intervention Additional interventions used in both groups: Standard therapy for COVID‐19
Outcomes	Outcomes of interest in the review Primary outcomes: Presence of normal olfactory function Improvement of olfactory disorders both subjective (visual analogue score) and objective by alcohol sniff test and "intravenous olfaction test" results after treatment. Unclear how this will be assessed and reported.  Serious adverse effects Not reported Change in sense of smell Improvement of olfactory disorders both subjective (visual analogue score) and objective by alcohol sniff test and "intravenous olfaction test" results after treatment. Unclear how this will be assessed and reported.  Secondary outcomes: Prevalence of parosmia Not reported Change in sense of taste Not reported Disease‐related quality of life Not reported Other adverse effects (including nosebleeds/bloody discharge) Not reported Other outcomes reported by the study: No additional outcomes
Starting date	August 2020
Contact information	Indra Pamungkas Email: indraparmaditya@gmail.com
Notes	Estimated completion November 2020. Retrospectively registered.  Trial registered in Indonesia.

ALT: alanine aminotransferase; BiPAP bilevel positive airway pressure; BSIT Brief Smell Identification Test; CCCRC: Connecticut Chemosensory Clinical Research Center; CPAP continuous positive airway pressure; CRP: c‐reactive protein; LDH: lactate dehydrogenase; mQOD‐NS Modified Brief Questionnaire of Olfactory Dysfunction; MRI: magnetic resonance imaging; PCR polymerase chain reaction; RCT: randomised controlled trial; SNOT‐22 Sinonasal Outcomes Test; taVNS: transcutaneous auricular vagus nerve stimulation; UPSIT: University of Pennsylvania Smell Identification Test; VAS: visual analogue scale.