Exeter Test Group

ALT Results awaiting peer review, so interested on thoughts on approach at this stage. Could post-market surveillance provide credible evidence, particularly in the challenging area of demonstrating clinical utility where timely, practical and affordable options are currently so limited?

ALT From the initial two-gate study comparing the blood glucose measured on the newborn blood spot punches (Guthrie card) of babies with neonatal diabetes and normal controls. McDonald, T.J., Besser, R.E., Perry, M. et al. Screening for neonatal diabetes at day 5 of life using dried blood spot glucose measurement. Diabetologia 60, 2168–2173 (2017). https://doi.org/10.1007/s00125-017-4383-3

ALT Evidence linkage is the generic term used to describe bringing together evidence on test accuracy with evidence on the effectiveness of treatments that might be used if the test is positive or negative. We found that methods of linkage were rarely described, particularly where the linkage was achieved using modelling. Little is known about whether narrative linkage as a prelude to modelling results in better estimation of effectiveness and cost-effectiveness of tests than modelling alone. Given the frequency with which modelled evidence linkage is used, the lack of detail on method is particularly concerning. Absence of consideration of whether linking accuracy and effectiveness evidence is always appropriate and the strengths and weaknesses of different modelling approaches adds to the concern. The possibility of modelling cost-effectiveness from direct evidence was not mentioned by any HTA organisation.

ALT Illustrating different approaches to the incorporation of direct evidence of the effect of introducing a new test on patient health outcomes, most commonly achieved through an RCT. Most organisations although stating that they preferred the use of direct evidence defaulted to the use of indirect evidence, often by using evidence linkage. The most common view was that direct evidence is likely to be rare. The possibility of the growing need to consider both direct and indirect evidence (and reconcile different results from each) was not encountered. Our view is that direct evidence is increasingly available and should be consistently dealt with in HTAs. Direct evidence should not be assumed to be rare.

ALT Illustrating the various approaches to incorporating claims of tests in HTAs. Most HTA organisations consider test claims, but few follow this through into downstream parts of the HTA process. The best approach in our view is where test claims are systematically identified, categorised and then the implied outcomes identified and prioritised. These are then in turn transparently and clearly incorporated into evidence syntheses and health economic evaluations.