Response to “Premature and Incomplete Overview of Health Technology Assessments for Flash Glucose Monitoring Leads to Misleading Conclusions”

In response to the letter to the editor by Hellmund et al ¹ regarding our article “Health Technology Assessments for Flash Glucose Monitoring and How to Use Them in Everyday Clinical Practice,” ² we wish to raise a number of rebuttals. First, we regard the title of the letter as fundamentally untrue; our article was neither premature nor incomplete, and the conclusions presented in our article for flash glucose monitoring are those made by the health technology assessment (HTA) agencies that have assessed the technology.

The aim of our article was to present the structure and content of HTAs to non-expert readers and to also underline that HTA processes differ between countries.

The authors state that we have used a narrow definition of an HTA within our article, and that conclusions can only be drawn from a broader cross-section of agencies; however, one of the central points of our article is that different processes and methods are used by different HTA agencies, and that presenting recommendation from all HTA as having equal weight can mislead the reader. Where we used definitions for HTAs (full or limited), this was necessary to show where HTAs could not be considered to conform to the usual process in that country, for example, the UK HTA cannot be considered a full HTA as it does not follow standard NICE Single Technology Appraisal (STA), Multiple Technology Appraisal (MTA), or Medical Technologies Evaluation Programme (MTEP) processes. This is an important point and is one of the central considerations of our article.

The authors also state that our article relegates some HTAs in importance despite being based on a thorough review of the evidence, citing the French HTA as an example. It is true that we gave different weight to the conclusions from different agencies, however, the primary objective of our research was to critically evaluate the different processes used by HTA agencies according to criteria defined within the article. Based on these criteria, the French HTA was considered less rigorous than other HTAs (eg, the Norwegian HTA) as evidence quality assessment and an economic evaluation were not carried out, and it was unclear if a systematic literature review was conducted. In our view, the recommendations from this HTA are therefore of lesser importance than those from HTAs which met all of our criteria. As far as we are aware, our article is the first attempt in the literature to critically evaluate HTAs according to defined criteria. We acknowledge that it may be possible to refine and improve our criteria, and would welcome suggestions that could help achieve this.

Several other minor points are noted by Hellmund et al in their letter. The assumption that an evidence quality assessment was not conducted if an assessment tool was not used was challenged, stating that other methods may have been used to assess quality. While we agree that study quality can be assessed by other means, one cannot assume that this was performed if it is not clearly stated in the HTA report. Analytical issues regarding the use of a meta-analysis in the Norwegian HTA were also noted. However, examining the validity of a meta-analysis is a highly technical task and was outside of the scope of our research, which sought only to report the recommendations from the available HTAs and compare the processes and methods used to generate these recommendations. Finally, the Canary Islands HTA was stated to be based on insufficient evidence due to the date of publication; we cannot comment further on this but note that the dates of each HTA are clearly stated within our article. However, if this is true the same conclusion likely also applies to the French HTA, which was published 3 months later than the Canary Islands HTA.

To conclude their letter, Hellmund et al state that the conclusions of our article are “selective, premature, and do not reflect the range of HTAs for the flash glucose monitoring system.” We strongly disagree with this assertion. Our conclusions reflect the full range of available HTAs for flash glucose monitoring and are presented based on a critical appraisal of these HTAs. According to the defined criteria, we concluded that certain HTAs (and their recommendations) were more rigorous; indeed, a key aim of the article was to demonstrate to non-experts the characteristics of HTAs and that HTA processes differ between countries. From a scientific point of view, not all recommendations can be considered to have equal weight.