5.1
The company identified 7 studies that incorporated a cost-effectiveness analysis. It did not rely on these economic studies for its model, but the structure of the de novo model is similar to that described in Gadler et al. (2016). The external assessment centre (EAC) judged the company's search strategy and inclusion/exclusion criteria reasonable, but noted that it could be improved with access to more databases and a more thorough strategy. The EAC considered that the population used by the company in its selection of economic evidence – 'patients implanted with cardiac resynchronisation therapy-defibrillators (CRT‑Ds)' – differed from the population specified in the scope. The company's population is broader and the EAC acknowledged that this probably reflects the lack of detail in the published evidence on the specific criteria used to define heart failure and CRT‑D use from the NICE's technology appraisal guidance on implantable cardioverter defibrillators and cardiac resynchronisation therapy for arrhythmias and heart failure.