Objectives: This study assesses whether pegylated interferon and ribavirin is cost-effective compared with no antiviral treatment provided in routine clinical practice, for different patient subgroups. Methods: The cost-effectiveness analysis (CEA) uses a Markov decision model to estimate the lifetime cost per quality-adjusted life-year (QALY) of antiviral treatment compared with no treatment. The model is populated with data on sustained virological responses, costs, and transition probabilities all taken from a large representative sample of UK cases and centers (Trent HCV database). Results: The CEA found that pegylated interferon and ribavirin was cost-effective for most patient subgroups. The CEA found that for patients with genotype non-1, the intervention led to cost reductions and gains of at least 0.5 QALYs. For genotype 1 cases with mild or moderate disease, and younger cirrhotic patients (aged 40 or less), costs per QALY remained below £20,000 ($40,000 or €29,000). For genotype 1 cases with cirrhosis aged 50, the mean cost per QALY rose to over £60,000 ($120,000 or €87,000). Conclusions:The study concludes that, based on cost and effectiveness data collected from routine clinical practice, treatment with pegylated interferon and ribavirin is generally cost-effective. The study shows that there are variations according to patient subgroup and for older (aged 50 or over) genotype 1 patients with cirrhosis, antiviral treatment appears less cost-effective.

The choice of instrument (e.g. EQ-5D vs. SF-6D) can lead to different health-related utility scores, but it is unclear why these differences arise and whether they change cost utility analysis (CUA) results. This paper addresses these issues using a case study where using SF-6D rather EQ-5D led to greater utility gain and a lower cost per QALY for treatment. The paper examines reasons for this difference. This paper finds that an important factor was the inclusion in the SF-6D descriptive system of separate items for "vitality" and "social functioning", not explicitly included in EQ-5D. Further studies are required that examine the impact of the choice of instrument on cost-utility.

The model suggests that memantine delays the need for FTC and decreases cost. It can be regarded as a cost-effective choice in the management of moderate and severe AD.

The model suggests that memantine prolongs time to FTC for no additional cost to the healthcare system and society. It can be regarded as a cost-effective choice in the management of moderate and severe Alzheimer's disease.

The model simulates and predicts progression of pre-FTC AD patients until the need for FTC based on assessments for cognitive, functional and behavioural domains. The main application of the model is to assess the cost effectiveness of AD therapies as potential adjuncts to a background AD treatment including disease-modifying treatments. The applicability of the predictive model to a specific setting should be carefully assessed, i.e. the patient population being examined should have similar characteristics as patients in the LASER-AD cohort.