Smell & Taste Disorders PSP Protocol


Purpose of the PSP and background

The purpose of this protocol is to clearly set out the aims, objectives and commitments of the anosmia.  Priority Setting Partnership (PSP) in line with James Lind Alliance (JLA) principles.  The Protocol is a JLA requirement and will be published on the PSP’s page of the JLA website.  The Steering Group will review the Protocol regularly and any updated version will be sent to the JLA.

The JLA is a non-profit making initiative, established in 2004.  It brings patients, carers and clinicians together in PSPs.  These PSPs identify and prioritise the evidence uncertainties, or ‘unanswered questions’, that they agree are the most important for research in their topic area.  Traditionally PSPs have focused on uncertainties about the effects of treatments, but some PSPs have chosen to broaden their scope beyond that.  The aim of a PSP is to help ensure that those who fund health research are aware of what really matters to patients, carers and clinicians.  The National Institute for Health Research (NIHR – coordinates the infrastructure of the JLA to oversee the processes for PSPs, based at the NIHR Evaluation, Trials and Studies Coordinating Centre (NETSCC), University of Southampton. 

Purpose and Background to this PSP:

Anosmia (smell loss) affects an estimated 5% of the population and yet remains under-researched and undertreated with a lack of clinical trials for treatments. In addition to anosmia, some people experience smell distortions such as parosmia and phantosmia. Taste loss and disorders are much rarer and often people report losing the ability to taste when it is more likely to be smell loss affecting the ability to detect flavour.  From the prior work we have done at Fifth Sense in partnership with our members (who suffer with Smell and Taste Disorders) and their families, we have published the findings of our previous surveys, research and workshops and have established a number of issues faced by them.

Smell loss leaves sufferers vulnerable to potential hazards from environmental dangers such as spoiled food and gas leaks. It has a negative effect on a range of activities and experiences, and potentially causing significant harm. In reality, perhaps this is not surprising given the extra dimension smell gives to the enjoyment of food, exploration of our environment and bringing back memories. So, our sense of smell is both a life-saving and life-enhancing sense. Losing it can have the opposite effect. In fact, recent studies in the US and Scandinavia show that smell loss is a risk factor for dying younger.

Physical concerns include diet and appetite. As a consequence of the reduced pleasure of eating, some sufferers report a reduction in their appetite with subsequent weight loss. Others report a general decline in the quality of their diet with the reduced perception of flavours leading to an increased intake of foods with low nutritional value (particularly those high in fat, salt and sugar).  This may be pertient to those affected by a true taste disorder.

Emotional negatives experienced by sufferers include embarrassment, sadness, depression, worry and bereavement. Other concerns included personal hygiene, loss of intimacy and the breakdown of personal relationships. Underlying these emotions is the loss of enjoyment of key activities, difficulty in expressing the impact of symptoms of anosmia and little sympathy or understanding from outsiders. Furthermore, reduced participation in social activity, a lack of established effective treatments and a sense of little hope of recovery adds to their sense of forlorn.

Financial burdens include the cost of private referral and alternative treatments. The effects were profound for some, especially if their profession or safety depends upon it. Participants often described negative or unhelpful interactions with doctors, both GPs and specialists, such as ear, nose and throat surgeons. Participants were concerned by a lack of empathy. Unlike glasses or hearing aids, no simple solutions are yet available for smell/taste loss but even if no reversible cause can be identified, clear information and support can now be provided.

Aims, objectives and scope of the PSP

The aim of the Smell and Taste Disorders PSP is to identify the unanswered questions about smell/taste loss/disturbances from patient, carer and clinical perspectives and then prioritise those that patients, carers and clinicians agree are the most important for research to address. The scope of the Smell and Taste Disorders PSP is defined as including diagnosis (of underlying cause), understanding pathophysiology, treatment (new drug trials/devices) and access to care.

The objectives of the PSP are to:

  • work with patients, carers and clinicians to identify uncertainties about the causes and treatments of smell loss and access to care by patients
  • to agree by consensus a prioritised list of those uncertainties, for research
  • to publicise the results of the PSP and process
  • to take the results to research commissioning bodies to be considered for funding.

The scope of the Smell and Taste Disorders PSP is defined as:

  • diagnosis, understanding pathophysiology, treatment (new drug trials) and access to care

The PSP will exclude from its scope questions about:

  • non-UK care
  • Normal variations of smell and taste

We consider this a broad scope encompassing all causes of smell and taste disorders and we anticipate this will become more focused through the process. For example, there is an existing major national trial underway for chronic sinusitis (the MACRO trial), whereas other areas of olfactory disorders lack impetus. We anticipate the final list will enable specific calls from the NIHR funding streams, including trials (HTA, EME), development work (RfPB) and service delivery research (HSDR).

The Steering Group is responsible for discussing what implications the scope of the PSP will have for the evidence-checking stage of the process.  Resources and expertise will be put in place to do this evidence checking.

The Steering Group

The Steering Group includes membership of patients and carers and clinicians[3], as individuals or representatives from a relevant group.

The Smell and Taste Disorders PSP will be led and managed by a Steering Group involving the following:

Professional Lead:
Professor Carl Philpott, Professor of Rhinology & Olfactory at University of East Anglia and Director of Medical and Research Affairs & Trustee of Fifth Sense 

Operational Lead:
Mrs Nina Bleasdale, Director of Development and Operations at Fifth Sense

Clinical representative/s:
Mr Sean Carrie, Consultant ENT Surgeon, The Newcastle upon Tyne Hospitals NHS Foundation Trust
Ms Lisha McClelland, Consultant ENT Surgeon, University Hospitals of Birmingham NHS Foundation Trust
Dr Richard Rees, Clinical Research Fellow,Department of Clinical Neuroscience, Institute of Neurology University College London
Dr Devina Maru, GP Speciality Registrar, Royal College of General Practitioners (RCGP) National Clinical Champion for Deafness and Hearing Loss, London, UK
Dr Lorenzo Stafford, Chartered Psychologist and Senior Lecturer at University of Portsmouth

Patient/Carer Representatives:
Jim Boardman
Lucy Thomas
Ruth Sullivan
Chessie Horwood
Luke Pierce
Ed Shardlow
Kathy Clugston 

James Lind Alliance Adviser and Chair of the Steering Group:
Toto Gronlund 

The Steering Group will agree the resources, including time and expertise that they will be able to contribute to each stage of the process, with input and advice from the JLA.


Organisations and individuals will be invited to be involved with the PSP as partners (this section will be updated when partners are confirmed).  Partners are organisations or groups who will commit to supporting the PSP, promoting the process and encouraging their represented groups or members to participate.  Organisations which can reach and advocate for these groups will be invited to become involved in the PSP. Partners represent the following groups:

people who have had olfactory dysfunction of various causes
carers of people who have had olfactory dysfunction, head injury, dementia, Parkinson’s Disease
health and social care professionals - with experience of olfactory dysfunction, dementia, Parkinson’s Disease, psychiatry, psychological counselling, rehabilitation
Potential further research funding partners

Exclusion criteria

Some organisations may be judged by the JLA or the Steering Group to have conflicts of interest.  These may be perceived to potentially cause unacceptable bias as a member of the Steering Group.  As this is likely to affect the ultimate findings of the PSP, those organisations will not be invited to participate.  It is possible, however, that interested parties may participate in a purely observational capacity when the Steering Group considers it may be helpful. 

The methods the PSP will use 

This section describes a schedule of proposed steps through which the PSP aims to meet its objectives.  The process is iterative and dependent on the active participation and contribution of different groups.  The methods used in any step will be agreed through consultation between the Steering Group members, guided by the PSP’s aims and objectives.  More details of the method are in the Guidebook section of the JLA website at where examples of the work of other JLA PSPs can be seen. 

Step 1: Identification and invitation of potential partners

Potential partner organisations will be identified through a process of peer knowledge and consultation, through the Steering Group members’ networks.  Potential partners will be contacted and informed of the establishment and aims of the Smell and Taste Disorders PSP. 

Step 2: Awareness raising

We plan to create and share a co-ordinated media campaign to launch the PSP.  Awareness raising has several key objectives:

  • to present the proposed plan for the PSP
  • to generate support for the process
  • to encourage participation in the process
  • to initiate discussion, answer questions and address concerns. 

Step 3: Identifying evidence uncertainties

The Smell and Taste Disorders PSP will carry out a consultation to gather uncertainties from patients, carers and clinicians.  A period of 1 year will be given to complete this exercise (which may be revised by the Steering Group if required). 

The Smell and Taste Disorders PSP recognises that the following groups may require additional consideration. 

Elderly patients and those not likely to engage with online and electronic formats of dissemination
Patients with dementia and other communication difficulties e.g. Parkinson’s Disease
BAME community

The Steering Group will use the following methods to reach the target groups  

  1. Online surveys conducted by Fifth Sense have already identified medical specialties to be included
  2. Contacts have already been established between Fifth Sense and a number of industry partners
  3. We will search the Charitable Commission database to check for other relevant charities to partner with and contact.
  4. We will contact relevant medical specialty parent associations and Royal Colleges to invite participation
  5. We will survey our membership for other suggestions not captured by the above contacts and searches.

Existing sources of evidence uncertainties may also be searched. 

There are a number of existing sources of evidence uncertainties including1-4:

  1. Addison A, Philpott CM. A systematic review of therapeutic options for non-conductive olfactory dysfunction. The Otorhinolarnyngologist 2018;11(2):61-71.
  2. Hummel T, Whitcroft KL, Andrews P, et al. Position paper on olfactory dysfunction. Rhinol Suppl 2017;54(26):1-30.
  3. Erskine SE, Philpott CM. An unmet need: Patients with smell and taste disorders. Clin Otolaryngol 2020;45(2):197-203. doi: 10.1111/coa.13484 [published Online First: 2019/12/19]
  4. Philpott CM, Boak D. The impact of olfactory disorders in the United kingdom. Chem Senses 2014;39(8):711-8. doi: 10.1093/chemse/bju043
  5. The research agenda for ENT, Hearing and Balance Care: a UK partnership of patients, professionals and the public. Bohm N, Marshall M, Fulop NJ, Lund VJ, Schilder AGM. ENT-UK 2015.
  6. Mainland J, et al. Identifying treatments for taste and smell disorders: gaps and opportunities. Chemical Senses 2020; in press.
  7. Ball SL, Boak D, Dixon J, Carrie S, Philpott CM. Barriers to Healthcare for those affected by smell and taste disorders. Under review – Annals of Internal Medicine 

Step 4: Refining questions and uncertainties

The consultation process will produce ‘raw’ questions and comments indicating patients’, carers’ and clinicians’ areas of uncertainty.  These raw questions will be categorised and refined by Carl Philpott and Nina Bleasdale into summary questions which are clear, addressable by research, and understandable to all.  Similar or duplicate questions will be combined where appropriate.  Out-of-scope and ‘answered’ submissions will be compiled separately. The Steering Group will have oversight of this process to ensure that the raw data is being interpreted appropriately and that the summary questions are being worded in a way that is understandable to all audiences.  The JLA Adviser will observe to ensure accountability and transparency. 

This will result in a long list of in-scope summary questions.  These are not research questions and to try and word them as such may make them too technical for a non-research audience.  They will be framed as researchable questions that capture the themes and topics that people have suggested.

The summary questions will then be checked against evidence to determine whether they have already been answered by research.  This will be done by Carl Philpott and Nina Bleasdale  The PSP will complete the JLA Question Verification Form, which clearly describes the process used to verify the uncertainty of the questions, before starting prioritisation.  The Question Verification Form includes details of the types and sources of evidence used to check uncertainty.  The Question Verification Form should be published on the JLA website as soon as it has been agreed to enable researchers and other stakeholders to understand how the PSP has decided that its questions are unanswered, and any limitations of this.

Questions that are not adequately addressed by previous research will be collated and recorded on a standard JLA template by Nina Bleasdale.  This will show the checking undertaken to make sure that the uncertainties have not already been answered.  The data should be submitted to the JLA for publication on its website on completion of the priority setting exercise, taking into account any changes made at the final workshop, in order to ensure that PSP results are publicly available.    

The Steering Group will also consider how it will deal with submitted questions that have been answered, and questions that are out of scope. 

Step 5: Prioritisation – interim and final stages

The aim of the final stage of the priority setting process is to prioritise through consensus the identified uncertainties about olfactory disorders.  This will involve input from patients, carers and clinicians.  The JLA encourages PSPs to involve as wide a range of people as possible, including those who did and did not contribute to the first consultation.  There are usually two stages of prioritisation.

  1. Interim prioritisation is the stage where the long list of questions is reduced to a shorter list that can be taken to the final priority setting workshop. This is aimed at a wide audience and is done using similar methods to the first consultation. With the JLA’s guidance, the Steering Group will agree the method and consider how best to reach and engage patients, carers and clinicians in the process.  The most highly ranked questions (around 25) will be taken to a final priority setting workshop.  Where the interim prioritisation does not produce a clear ranking or cut off point, the Steering Group will decide which questions are taken forwards to the final prioritisation.
  2. The final priority setting stage is generally a one-day workshop facilitated by the JLA. With guidance from the JLA and input from the Steering Group, up to 30 patients, carers and clinicians will be recruited to participate in a day of discussion and ranking, to determine the top 10 questions for research. All participants will declare their interests.  The Steering Group will advise on any adaptations needed to ensure that the process is inclusive and accessible. 

Dissemination of results

The Steering Group will identify audiences with which it wants to engage when disseminating the results of the priority setting process, such as researchers, funders and the patient and clinical communities.  They will need to determine how best to communicate the results and who will take responsibility for this.  Previous PSPs’ outputs have included academic papers, lay reports, infographics, conference presentations and videos for social media.

It should be noted that the priorities are not worded as research questions.  The Steering Group should discuss how they will work with researchers and funders to establish how to address the priorities and to work out what the research questions are that will address the issues that people have prioritised.  The dissemination of the results of the PSP will be led by Carl Philpott and Nina Bleasdale.

The JLA encourages PSPs to report back about any activities that have come about because of the PSP, including funded research. Please send any details to

Agreement of the Steering Group

The Smell and Taste Disorders PSP Steering Group agreed the content and direction of this Protocol on 30th October 2020.