JCPSLP Vol 22 No 2 2020

accuracy of each audit method and the prescribed norms for each audit method. Reduced levels of compliance on each low technology audit method likely additionally reflects that viscosity of thickened fluids is influenced by numerous complex rheological factors (Cichero et al., 2017; Hadde, 2017; Hanson, 2016; O’Leary et al., 2015 and O’Leary et al., 2010) and further reflects the numerous challenges involved in viscosity measurement (Cichero et al., 2017; Hadde et al., 2016; Hadde, 2017; Hanson, 2016; O’Leary et al., 2015; O’Leary et al., 2010). Therefore, it is suggested that the results from low technology audit methods found in this study should be interpreted with caution which is supported by other findings in the available literature with reference to the Bostwick and the LST (Adeleye & Rachal, 2007; Budke et al., 2008; Germain, Dufresne & Ramaswamy, 2006; Nicosia & Robbins, 2007; O’Leary et al., 2010). This study found low levels of agreement between the three audit methods as to which samples were compliant with no agreement across all three audit methods as to the samples which were non-compliant with prescribed norms. This suggests that it is possible that all of the low technology devices used in this study may not be able to reliably measure the viscosity of all types of thickened fluids at therapeutically significant levels. This is speculative though, given results in the study were unable to be directly compared to rheometry/viscometry data. In our study, due to the low levels of agreement and variability in compliance results, it can also not be excluded that one of the low technology methods used in this study may be more accurate than the other two auditing methods. This would additionally warrant further study utilising a rheometer to determine accuracy of compliance results for each audit method. It is acknowledged that differences between the audit methods including different norms and differences in how each of the audit methods precisely measure flow rate are likely contributing to the limited agreement between the audit methods. The low level of agreement between the audit methods in this study is not consistent with the results of a recent study by Garcia, Chambers and Cook (2018) which found high correlation between measurements obtained with the Bostwick and the LST. However, there were significant differences in the samples audited between the two studies and in the Garcia and colleagues study (2018), only hand thickened water at two levels of thickness was assessed. Regardless of the accuracy of each of the examined audit methods, the high rate of non-compliant thickened fluid samples as part of this small pilot study needs to be considered against a requirement of patient safety. Health care sites expect that pre-packaged thickened fluid products provided by suppliers are compliant with prescribed norms. As majority of hospital and health care sites will not have access to a rheometer/viscometer or access to specific knowledge and expertise pertaining to the operation of these devices, it is imperative that hospital and health care sites work collaboratively with suppliers and manufacturers of pre-packaged thickened fluid products who will have access to high technology devices and who will conduct rigorous quality control assessments with thickened fluid products. It would be highly advantageous if information from these quality control assessments could be made available to health care sites utilising pre- packaged thickened fluids. Pre-packaged thickened fluids should be optimally assessed with high technology devices such as a rheometer to ensure that products are at an appropriate level.

90% 80% 70% 60% 50% 40% 30& 20% 10% 0%

Bostwick

LST

Flow test

% compliant with norms % non-compliant with norms Missing information

Bostwick, the LST and the Flow Test) as to the items which were assessed as non-compliant with viscosity norms. When the agreement levels between two auditing methods as to the assessment of the samples as compliant was analysed, on 7 occasions there was agreement between the Flow Test and the LST, on 5 occasions there was agreement between the Flow Test and the Bostwick, and on 2 occasions there was agreement between the LST and the Bostwick. When agreement levels between two auditing methods as to the assessment of thickened fluid samples as non-compliant was analysed, on 12 occasions there was agreement between the LST and the Bostwick as to non-compliance. There was no agreement between the Flow Test and the LST and additionally the Flow Test and the Bostwick as to samples which were assessed as non-compliant. Discussion This small pilot study examined the use of three commonly used low technology measuring devices in an audit of pre-packaged thickened fluids against prescribed norms (Queensland Health, 2013; IDDSI, 2017). Results must be interpreted in light of several acknowledged study limitations. The samples assessed as non-compliant by the three low technology audit methods were from a range of different flavour categories and from a range of thickness levels; however, the sample size of fluids audited was small, consisted of products only from the one manufacturer with several other methodological limitations acknowledged in the auditing process. Many of the thickened fluids audited as part of this study were assessed as non-compliant with prescribed norms. The majority of the non-compliant thickened fluid samples were assessed as too thick as opposed to too thin. All samples assessed as non-compliant because they were too thin were from the mildly thick fluids category. When data was aggregated across the three audit methods, there was an increased number of refrigerated samples assessed as non-compliant (62%) compared to non-compliant samples from room temperature (38%). As pre-packaged thickened fluids are subject to rigorous testing using high technology devices (such as a rheometer) prior to product distribution, these results are possibly more likely a reflection of the potential limitations relating to both the

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JCPSLP Volume 22, Number 2 2020

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