April 2019

  • The Science behind the IDDSI Testing Methods
  • Hot Off the Press
  • Updates on Syringe Codes
  • IDDSI Congress
  • The #IDDSIchallenge is almost here
  • University of Michigan recordings available
  • Resources update
  • IDDSI Translations
  • IDDSI on the Move
The Real News on IDDSI Testing Methods
The IDDSI Board of Directors is aware of some information that has been shared suggesting that IDDSI testing methods do not have any scientific basis.  The IDDSI framework is founded upon many peer-reviewed scientific publications and details of framework development process can be found in the article: 

This publication along with the IDDSI systematic review are some of the highest downloaded and highest cited papers in the history of the journal Dysphagia.   

The IDDSI Testing methods were developed using the following criteria:
  • Based on best scientific evidence available, published in our systematic review; Steele, C.M., Alsanei, W.A., Ayanikalath, S. et al. Dysphagia (2015) 30: 2. https://doi.org/10.1007/s00455-014-9578-x
  • Able to be used at the point of serving
  • Simple, practical and accessible to EVERYONE globally
  • Provide a more objective way to ensuring consistency and accuracy than currently exists.

Even in scientific labs there is not one standard test which can be used to define consistency for all foods & drinks. There are machines which can be used to measure specific aspects of drink thickness and food texture, but the equipment is expensive and not available to clinicians, food services and consumers. 

The IDDSI framework does not use viscosity values for identifying texture modified products for the following reasons:
  • It’s not scientifically correct: Viscosity is used to describe Newtonian liquids (e.g. water, oil) however almost all thick drinks have shear-thinning non-Newtonian behavior. Their “apparent viscosity” depends on how they are tested. 
  • It’s not specific enough: Two different liquid types(e.g. gum- vs starch-thickened) with exactly the same measured viscosity at any given shear rate (e.g. 50 /s) will not have the same measured viscosity at any other different shear rate. Nor will they necessarily appear the same or behave the same way when swallowed. 
  • It is not practical: specialised, expensive equipment is required (e.g. rheometer / viscometer with cone-plate attachment) which is not available in health and community care settings. It is not reliable to measure a drink in a lab and assume it will have the same consistency at the bedside. 

The IDDSI Flow Test is based on the Posthumus funnel concept which has been used for many decades in the dairy industry to audit the thickness of milk, cream, yoghurt & custard.Thegeometry of the syringe allows for both shear and elongation flow types which represent flow conditions within the oral cavity and pharynx, consistent with the most current research.  We adapted this concept to use a commonly-available, inexpensive 10 ml syringe and set a time limit of 10 seconds and volume of 10 ml to minimize time and wastage. The resulting test gives a scale from 0-10 which maps the full range of consistency from watery liquids to semi-solids.

In tests performed by the research community and international medical products industries, the IDDSI flow test has been demonstrated to be accurate and reliable. 

Testing foods is more complex as there are many important characteristics such as moistness, stickiness, hardness and toughness which are not straightforward to assess even in a laboratory.  Research also suggests that in healthy adults, foods will be chewed into small particles and mixed with saliva until there is sufficient moisture to lubricate the bolus for swallowing.  Further research on particle size of chewed boluses has also found that hard foods such as nuts and raw carrots will be chewed to smaller size particles(~2mm) before swallowing, than softer foods. 
IDDSI considered all this evidence in developing simple testing methods which could address the complexities of different food properties: 

The concept of “fork mash-able” has been used in the past, but this depends on individual hand strength and judgement. We introduced the concept of thumbnail blanching pressure to provide a more-consistent definition of pressure without having to resort to mechanical tools or motors. This thumbnail blanching pressure corresponds to systolic blood pressure and has been measured to be equivalent to a low tongue compression pressure. 

The spoon-tilt and fork-drip tests are practical measures of adhesiveness and cohesiveness respectively, designed to be used at the point of serving and can be performed very quickly with minimal training required. There is no standard industrial or scientific test to define these quantities relating to swallowing. 

Particle size:
For Level 6 soft and bite sized:  Research on tracheal size and choking was reviewed in determining the particle size recommendation for Level 6 soft and bite-sized for both children and adults. The recommended sizes of no larger than 1.5 cm x1.5 cm for adults and no larger than .8 cm x .8 cm for children was determined as being small enough to not fully obstruct an average adult or child’s airway.  
For Level 5 minced and moist:  Research into food particles size of chewed boluses in healthy adults suggests averages of 2-4 mm depending on the type of food being chewed.  However food particles in a chewed bolus are not necessarily all uniform in size and particles need to be considered in dimensions of width, depth and length. 
Level 5 minced and moist particle size for an adult has been outlined as no larger than 4mmx4mm x15 mm*.  4 mm is the space between the tines of an ordinary dinner fork.  In consideration of the smaller anatomy of young children, the recommendation is for no larger than 2mm x2mm x8mm* is recommended for pediatric populations. (2 mm is half the distance of the space between the tines of a regular dinner fork.)
*15 mm for adults and 8 mm for children are considered small enough to not obstruct the airway. 

Clinical assessment should always be used to determine if an individual has the ability to safely manage the particle size outlined in Level 5 minced and moist and Level 6 Soft and Bite-sized.

We also strongly recommend using the IDDSI testing methods, rather than relying on the less accurate methods of pictures, descriptions or lists of food and drinks, to ensure those with swallowing or choking risk are provided with the required food or drinks.
Click below for additional details on the evidence used to develop the IDDSI testing methods:
Hot Off the Press
Check out more IDDSI related research. Dr. Catriona Steele and colleagues have just published their paper on VFSS reference values for healthy swallowing across the range from IDDSI level 0 to IDDSI level 4 in the Journal of Speech-Language Hearing Research. The manuscript is available open access and can be accessed as follows:
Steele, C. M., Peladeau-Pigeon, M., Barbon, C. E. A., Guida, B. T., Namasivayam-MacDonald, A. M., Nascimento, W. V., Smaoui, S., Tapson, M. S., Valenzano, T. J., Waito, A. A., Wolkin, T. S. (2019). Reference values for healthy swallowing across the range from thin to extremely thick liquids. Journal of Speech-Language Hearing Research.  https://doi.org/10.1044/2019_JSLHR-S-18-0448
An accompanying webinar describing the study, can be accessed for free at:  https://youtu.be/Kg9aL72LJQQ
Syringe Codes
North America

It has come to our attention that some IDDSI documentation had outdated code number as some changes were made by BD .  303134 is the correct code number for North America syringes that meet the requirements to perform the IDDSI flow test.   The 0-10 ml markings measure 61.5 mm.  

Update on the Syringe Code for Australia
The BD codes differ depending on the part of the world you are ordering from.  In Australia the correct syringe code is  BD REF 302143.
Resources Update
Just a reminder we are working on updating our various resources and making minor changes and clarifications based on feedback received. Currently we are reviewing our audit tools.

Updating our website:
Just a reminder, we are working on updating our current Framework, Descriptor and Testing Method documents on the IDDSI website to align with some of our new resources and the new  Level 7 Regular Easy to Chew .  

We will keep you posted in our e-bites about the status of these updates.   Resource development and updates are completed by the volunteer members of the IDDSI Board of Directors so we appreciate your patience. 
IDDSI Congress

Both the UK and Belgium have held IDDSI congresses which have received overwhelmingly positive responses from participants. The Academy of Nutrition and Dietetics (AND) is currently planning an IDDSI Congress in the USA. Stay tuned for more details…  

If you are interested in organizing and hosting an IDDSI congress for your region, please contact us. We’ll be glad to guide you through the process and share our experiences in setting an Agenda
The Second IDDSI Challenge

JUNE is Dysphagia Awareness Month – just around the corner…

Stay tuned as plans are underway for the second IDDSI challenge, jointly organized with the National Foundation of Swallowing Disorders and IDDSI.    
If you missed the very popular webinar ( Implementation in an Academic Hospital setting:University of Michigan, presented by Kit Warner RD and Sarah Russell SLP ),  you can still watch the recorded version here.

Stay tuned for upcoming webinars.
IDDSI Translations
Hebrew Translation is ready for Peer Reviews! Please help us spread the word.

Catalán translation will be up for review soon.

We now have an easier online-based translation feedback form.

Check out our Translations tab.
Looking for a translated version of the IDDSI Framework, Descriptors or Testing Methods?
Check our completed translations tab on the IDDSI website for the following:
Chinese (simplified), Farsi, French (Canada), French (France), Italian, Norwegian, Portuguese (Brazil), Spanish and Swahili.

Languages currently up for review include:     
Arabic, German, Greek, Japanese, Russian, Slovenian and Vietnamese.  Are you fluent in any of these languages?  If so, please consider reviewing these documents and adding any comments or suggestions for the translation before final posting.
Languages in progress:
Thai, Turkish, Hindi, Urdu, Zulu, Portuguese (Portugal), and Marathi.

Do you speak a language not currently under translation? Would you be willing to provide a translation? We want to hear from you.
IDDSI on the Move
  • May 2019 - Canadian Society of Nutrition Management Conference, Calgary, AB, Canada
  • June 2019 - Dietitians of Canada Conference, Ottawa, ON, Canada
  • June 2019 - Association of Nutrition & Foodservice Professionals Conference, St. Louis, MO, USA
  • June 2019 - Speech Pathology Australia and New Zealand Speech-Language Therapists’ Association Joint Conference, Brisbane, Australia
  • July 2019 - ASHA Connect Conference, Chicago, USA
  • June 2019 - First Latin American Congress on Deglutition, Buenos Aires, Argentina: http://www.congresodisfagia.com

Please let us know what you are doing in your part of the world. We would be happy to share it with the rest of the world.
Connect with us on social media & let us know your thoughts!