[State of knowledge: classification of thickened liquids for dysphagia]

Raymond, MH
Record ID 32018002356
Original Title: État des connaissances - Classification des liquides épaissis pour la prise en charge de la dysphagie
Authors' objectives: A variety of systems for measuring and classifying the consistency of liquids exists around the world, and there is no consensus on this matter. For several years in Quebec, the Bostwick consistometer, a device used in the food industry, has been widely used in health care facilities to measure and classify thickened liquids. In 2015, a new international initiative was launched: The International Dysphagia Diet Standardization Initiative (IDDSI). This classification system measures the consistency of liquids by means of a vertical flow test in a syringe. The IDDSI is attracting increased interest among members of various professional groups and is being implemented in several countries around the world and elsewhere in Canada. However, its possible introduction in Quebec is not welcomed by everyone. The coexistence of the IDDSI and the classification system that uses the Bostwick consistometer appears to be a source of organizational confusion and raises concerns for the safety of users. In order to ensure excellence in practices and efficient use of resources, the MSSS has mandated INESSS to assess the value of the two classification systems for thickened liquids, i.e., the IDDSI and the classification using the Bostwick consistometer that is currently used in Quebec, in terms of clinical effectiveness, safety and organization of care and services, based on the information available in the scientific literature.
Authors' results and conclusions: RESULTS: 1. (Commonalities between the two classification systems) • Data on clinical impacts and cost-benefit ratios is virtually non-existent. • Although there is a good correlation between the measurements obtained using the IDDSI and those resulting from the classification using the Bostwick consistometer, the correspondence is not precise. These measurements are therefore not interchangeable, and no conversion is possible from one to the other. • Both systems have excellent intra-rater fidelity, i.e., a good stability of the results obtained by the same rater from the same sample. 2. (Summary of the strengths and limitations of the IDDSI): • In terms of content validity (i.e., the ability to adequately reflect the construct to be measured), the IDDSI stems from a well-documented development process. • A dozen studies generally report a good construct validity for the IDDSI, i.e., that the measurements obtained with this tool are generally consistent with the expected theoretical results. For example, relationships are observed between the results obtained with the IDDSI and other measurements of fluid consistency. • Inter-rater fidelity, i.e., the stability of the results obtained by two different raters, is high according to two studies. However, it is important to use a specific type of syringe to avoid measurement errors. • The IDDSI syringe test is better at discriminating among thin liquids than the Bostwick consistometer. This can be considered a strength since it seems to be more clinically advantageous to be able to differentiate among thin liquids than very thick liquids. Finally, since the IDDSI does not discriminate as well among very thick liquids, the IDDSI fork drip or spoon tilt test is more appropriate. 3. Summary of the strengths and limitations of the classification using the Bostwick consistometer currently practiced used in Quebec • With respect to content validity, the Bostwick consistometer is an instrument that is well recognized in the food industry for measuring the consistency of food and liquids. However, the theoretical basis and process leading to its use for people with dysphagia are not well documented in the scientific literature on dysphagia. • The construct validity of this classification system deserves further study since the measurements obtained with this tool are only partially consistent with the expected theoretical results, and relatively few studies have been carried out on this subject. • The inter-rater fidelity is unknown CONCLUSION: This review of the scientific literature identified the information available on two classifications of thickened liquids used for the management of dysphagia: the IDDSI and the classification using the Bostwick consistometer currently used in Quebec. The information collected on the IDDSI seems to give it certain advantages, particularly in terms of validity, alignment with international standards and research in dysphagia, accessibility of training materials and tools, as well as the possibility of being used where food is served, including at home. Nevertheless, both methods are still empirical, and neither is a clear standout in terms of demonstrating clinical benefits. Consideration must also be given to the fact that a change in the classification system could have organizational implications of unknown magnitude.
Authors' methods: INESSS carried out a review of the scientific literature in order to identify the available information for assessing the value of the IDDSI and the Bostwick consistometer with respect to measuring and classifying the thickened liquids used for people with dysphagia. The following were consulted for the period of 2010 to September 2021: Medline databases; Cochrane Database of Systematic Reviews; Database of Abstracts of Reviews of Effects; Health Technology Assessment; NHS Economic Evaluation Database, Embase, CINAHL (EBSCO). Based on the Framework for Assessing the Value of Health and Social Services Interventions [INESSS, 2021], the following dimensions were considered : clinical (efficacy, safety, metrological qualities, clinical applications), organizational (feasibility, implementation), population (accessibility), economic (costs) and sociocultural (acceptability, cultural aspect).
Project Status: Completed
Year Published: 2022
English language abstract: An English language summary is available
Publication Type: Other
Country: Canada
Province: Quebec
MeSH Terms
  • Deglutition Disorders
  • Viscosity
  • Food Additives
  • Enteral Nutrition
  • Nutritional Support
Organisation Name: Institut national d'excellence en sante et en services sociaux
Contact Address: L'Institut national d'excellence en sante et en services sociaux (INESSS) , 2021, avenue Union, bureau 10.083, Montreal, Quebec, Canada, H3A 2S9;Tel: 1+514-873-2563, Fax: 1+514-873-1369
Contact Name: demande@inesss.qc.ca
Contact Email: demande@inesss.qc.ca
Copyright: Gouvernement du Québec
This is a bibliographic record of a published health technology assessment from a member of INAHTA or other HTA producer. No evaluation of the quality of this assessment has been made for the HTA database.