Singapore COVID-19 Chemosensory Tracking (SCCT) Study
Condition: Covid19
MeSH terms: COVID-19
Study type: Observational

Summary: 
      The study aims to longitudinally track the onset, severity and recovery of changes in
      chemosensory acuity (smell and/or taste loss) among those suspected of COVID-19 infection.
      Using standardised questionnaire and testing approaches, the investigators aim to objectively
      characterise and measure temporal changes in taste and smell to confirm the prevalence of
      these symptoms as an early marker of infection. Information on symptoms experience, changes
      in appetite and food-related quality of life will be also be assessed via questionnaire.

      The results of the study will help individuals who experience a loss of smell and/or taste to
      self-isolate and/or self-refer to a medical professional, if an association between smell
      and/or taste and COVID-19 infection is found.
    

Detailed description: 
      The study will be a retrospective-prospective, longitudinal case-control observational study
      using a convenience sample drawn from patients presenting for COVID-19 screening, and will
      recruit both males and females above the age of 21 years who consent to provide anonymised
      data online on recent changes to their taste and smell. There will be no intervention
      (medication or foods) as part of this study. Potential participants will be screened to
      ensure they meet the study inclusion and exclusion criteria and all participants will sign an
      informed consent.

      During their first recruitment session at the hospital/clinic, participants will be required
      to complete a series of questionnaires to record recent changes in taste and smell
      sensitivity. The series of questionnaires will include: Singapore Smell and Taste
      Questionnaire (SSTQ), Sino-nasal Outcome Test-22 (SNOT-22) and optionally, the Global
      Consortium of Chemosensory Research Questionnaire (GCCRQ). The purpose of administering the
      different questionnaires is to cover wide range of complementary questions that capture
      information related to changes in taste and smell function associated with COVID-19
      infection. Thereafter participants will be briefed on how to complete the home-use
      standardized smell and taste test (Home-use Test). The Home-use Test (HUT) will be completed
      daily over a 28 day period at participants place of residence, to enable self-monitoring of
      changes to smell and taste abilities. During the HUT, participants will rate their sense of
      smell using the two standardised odour pens they are provided on the first day of their
      session at the hospital/ clinic. For each pen, participants will be asked to identify the
      odour and rate the perceived intensity. This will then be followed a taste test where
      participants will take a small quantity of a powder representing each of the four
      prototypical basic tastes sweet (sugar), salt (table salt), bitter (coffee powder or tea) and
      sour (lime powder), to the tip end of their tongue with a small spoon to taste. Participant
      are asked to self-report that they confirm that can identify the taste quality and to rate
      the perceived intensity on line scales provided in an online questionnaire. All measures are
      self-administered and completed independently by the participant, with responses captured
      using unique identifier code for each participant through an online software (CompuSense,
      Guelph, Ontario). During the 28-day home use test period, once a week participants will be
      asked to complete a 'Follow-up Questionnaire' which will assess how the symptoms experienced
      have impacted their enjoyment of food, appetite and food-related quality of life.
    

Intervention name(s): Home-use Test and Follow-up Questionnaire
Intervention type(s): Other
Intervention description(s): Prospective tracking of changes in taste and smell acuity, and related changes in appetite, enjoyment of food and food-related quality of life will be assessed using the Home-use Tests and Follow-up questionnaire over a period of 28 days.
Observational model: Case-Control
Time perspective: Other
Sampling method: Non-Probability Sample
Study population: 
        Patients present for COVID 19 screening
      
Keywords: Olfactory dysfunction; Gustatory dysfunction; Anosmia; Ageusia; SARS-CoV-2; COVID-19