Modeling the economic outcomes of immuno-oncology drugs: alternative model frameworks to capture clinical outcomes.

BACKGROUND: Economic models in oncology are commonly based on the three-state partitioned survival model (PSM) distinguishing between progression-free and progressive states. However, the heterogeneity of responses observed in immuno-oncology (I-O) suggests that new approaches may be appropriate to reflect disease dynamics meaningfully. MATERIALS AND METHODS: This study explored the impact of incorporating immune-specific health states into economic models of I-O therapy. Two variants of the PSM and a Markov model were populated with data from one clinical trial in metastatic melanoma patients. Short-term modeled outcomes were benchmarked to the clinical trial data and a lifetime model horizon provided estimates of life years and quality adjusted life years (QALYs). RESULTS: The PSM-based models produced short-term outcomes closely matching the trial outcomes. Adding health states generated increased QALYs while providing a more granular representation of outcomes for decision making. The Markov model gave the greatest level of detail on outcomes but gave short-term results which diverged from those of the trial (overstating year 1 progression-free survival by around 60%). CONCLUSION: Increased sophistication in the representation of disease dynamics in economic models is desirable when attempting to model treatment response in I-O. However, the assumptions underlying different model structures and the availability of data for health state mapping may be important limiting factors.

Assessing the economic value of maintained improvements in Type 1 diabetes management, in terms of HbA1c , weight and hypoglycaemic event incidence.

AIMS: Insulin therapy is indicated for people with Type 1 diabetes mellitus; however, treatment-related weight gain and hypoglycaemia represent barriers to optimal glycaemic management. This study assessed the health economic value of maintained reductions in HbA1c , BMI and hypoglycaemia incidence among the UK Type 1 diabetes population. METHODS: The Cardiff Type 1 Diabetes Model was used to estimate lifetime costs, life-years and quality-adjusted life-years (QALYs) for individuals with Type 1 diabetes at different baseline HbA1c , BMI and hypoglycaemic event rates. Results were discounted at 3.5%, and the net monetary benefit associated with improving Type 1 diabetes management was derived at £20 000/QALY gained. Per-person outputs were inflated to national levels using UK Type 1 diabetes prevalence estimates. RESULTS: Modelled subjects with an HbA1c of 86 mmol/mol (10.0%) were associated with discounted lifetime per-person costs of £23 795; £12 649 of which may be avoided by maintaining an HbA1c of 42 mmol/mol (6.0%). Combined with estimated QALY gains of 2.80, an HbA1c of 42 mmol/mol (6.0%) vs. 86 mmol/mol (10.0%) was associated with a £68 621 per-person net monetary benefit. Over 1 year, unit reductions in BMI produced £120 per-person net monetary benefit, and up to £197 for the avoidance of one non-severe hypoglyceamic event. CONCLUSIONS: Maintained reductions in HbA1c significantly alleviate the burden associated with Type 1 diabetes in the UK. Given the influence of weight and hypoglycaemia on health economic outcomes, they must also be key considerations when assessing the value of Type 1 diabetes technologies in clinical practice.

Tackling the burden of the hepatitis C virus in the UK: characterizing and assessing the clinical and economic consequences.

OBJECTIVES: The hepatitis C virus (HCV) remains a significant public health issue. This study aimed to quantify the clinical and economic burden of chronic hepatitis C in the UK, stratified by disease severity, age and awareness of infection, with concurrent assessment of the impact of implementing a treatment prioritization approach. STUDY DESIGN AND METHODS: A previously published back projection, natural history and cost-effectiveness HCV model was adapted to a UK setting to estimate the disease burden of chronic hepatitis C and end-stage liver disease (ESLD) between 1980 and 2035. A published meta-regression analysis informed disease progression, and UK-specific data informed other model inputs. RESULTS: At 2015, prevalence of chronic hepatitis C is estimated to be 241,487 with 22.20%, 33.72%, 17.22%, 16.67% and 10.19% of patients in METAVIR stages F0, F1, F2, F3 and F4, respectively, but is estimated to fall to 193,999 by 2035. ESLD incidence is predicted to peak in 2031. Assuming all patients are diagnosed and treatment is prioritized in F3 and F4 using highly efficacious direct-acting antiviral (DAA) regimens, a 69.85% reduction in ESLD incidence is predicted between 2015 and 2035, and the cumulative discounted medical expenditure associated with the lifetime management of incident ESLD events is estimated to be £1,202,827,444. CONCLUSIONS: The prevalence of chronic hepatitis C is expected to fall in coming decades; however, the ongoing financial burden is expected to be high due to an increase in ESLD incidence. This study highlights the significant costs of managing ESLD that are likely to be incurred without the employment of effective treatment approaches.

The cost-effectiveness of exenatide twice daily (BID) vs insulin lispro three times daily (TID) as add-on therapy to titrated insulin glargine in patients with type 2 diabetes.

OBJECTIVE: To evaluate the cost-effectiveness of exenatide twice daily (BID) vs bolus insulin lispro three times daily (TID) as add-on therapy when glycemic control is sub-optimal with titrated basal insulin glargine and metformin. METHODS: The analysis was based on the recent 4B Study, which compared exenatide BID and lispro TID as add-on therapies in subjects with type 2 diabetes insufficiently controlled, despite titrated insulin glargine. The Cardiff Diabetes Model was used to simulate patient costs and health benefits beyond the 4B Study. The Swedish healthcare perspective was adopted for this analysis; costs are reported in €EUR to aid interpretation. The main outcome measure was the cost per quality-adjusted life-year (QALY) gained with exenatide BID compared to lispro TID. RESULTS: Exenatide BID was associated with an incremental cost of €1,270 and a QALY increase of +0.64 compared with lispro TID over 40 years. The cost per QALY gained with exenatide BID compared with lispro TID was €1,971, which is within conventional limits of cost-effectiveness. Cost-effectiveness results were generally robust to alternative assumptions and values for key model parameters. LIMITATIONS: Extrapolation of trial data over the longer term can be influenced by modeling and parameter uncertainty. Cost-effectiveness results were generally insensitive to alternative values of key model input parameters and across scenarios. CONCLUSIONS: The addition of exenatide BID rather than insulin lispro to basal insulin is associated with similar or better clinical outcomes. Illustrated from the Swedish healthcare perspective, analysis with the Cardiff Diabetes Model demonstrated that exenatide BID represents a cost-effective treatment alternative to lispro TID as add-on therapy in type 2 diabetes patients insufficiently controlled on basal insulin.

Methods applied in cost-effectiveness models for treatment strategies in type 2 diabetes mellitus and their use in Health Technology Assessments: a systematic review of the literature from 2008 to 2013.

OBJECTIVE: To identify and compare health-economic models that were developed to evaluate the cost-effectiveness of treatments for type 2 diabetes mellitus (T2DM), and their use within Health Technology Assessments (HTAs). METHODS: In total, six commonly used databases were searched for articles published between October 2008 and January 2013, using a protocolized search strategy and inclusion criteria. The websites of HTA organizations in nine countries, and proceedings from five relevant conferences, were also reviewed. The identified new health-economic models were qualitatively assessed using six criteria that were developed based on technical components, and characteristics related to the disease or the treatments being assessed. Finally, the number of times the models were applied within HTA reports, published literature, and/or major conferences was determined. RESULTS: Thirteen new models were identified and reviewed in depth. Most of these were based on identical key data sources, and applied a similar model structure, either using Markov modeling or microsimulation techniques. The UKPDS equations and panel regressions were frequently used to estimate the occurrence of diabetes-related complications and the probability of developing risk factors in the long term. The qualitative assessment demonstrated that the CARDIFF, Sheffield T2DM and ECHO T2DM models seem technically equipped to appropriately assess the long-term health-economic consequences of chronic treatments for patients with T2DM. It was observed that the CORE model is the most widely described in literature and conferences, and the most often applied model within HTA submissions, followed by the CARDIFF and UKPDS models. CONCLUSION: This research provides an overview of T2DM models that were developed between 2008 and January 2013. The outcomes of the qualitative assessments, combined with frequent use in local reimbursement decisions, prove the applicability of the CORE, CARDIFF and UKPDS models to address decision problems related to the long-term clinical and economic consequences of new and existing T2DM treatments.

Cost-effectiveness of dapagliflozin versus DPP-4 inhibitors as an add-on to Metformin in the Treatment of Type 2 Diabetes Mellitus from a UK Healthcare System Perspective.

BACKGROUND: Type 2 diabetes mellitus (T2DM) is a chronic, progressive condition where the primary treatment goal is to maintain control of glycated haemoglobin (HbA1c). In order for healthcare decision makers to ensure patients receive the highest standard of care within the available budget, the clinical benefits of each treatment option must be balanced against the economic consequences. The aim of this study was to assess the cost-effectiveness of dapagliflozin, the first-in-class sodium-glucose co-transporter 2 (SGLT2) inhibitor, compared with a dipeptidyl peptidase-4 inhibitor (DPP-4i), when added to metformin for the treatment of patients with T2DM inadequately controlled on metformin alone. METHODS: The previously published and validated Cardiff diabetes model was used as the basis for this economic evaluation, with treatment effect parameters sourced from a systematic review and network meta-analysis. Costs, derived from a UK healthcare system perspective, and quality-adjusted life years (QALYs), were used to present the final outcome as an incremental cost-effectiveness ratio (ICER) over a lifetime horizon. Univariate and probabilistic sensitivity analyses (PSA) were carried out to assess uncertainty in the model results. RESULTS: Compared with DPP-4i, dapagliflozin was associated with a mean incremental benefit of 0.032 QALYs (95% confidence interval [CI]: -0.022, 0.140) and with an incremental cost of £216 (95% CI: £-258, £795). This resulted in an ICER point estimate of £6,761 per QALY gained. Sensitivity analysis determined incremental costs to be insensitive to variation in most parameters, with only the treatment effect on weight having a notable impact on the incremental QALYs; however, there were no scenarios which raised the ICER above £15,000 per QALY. The PSA estimated that dapagliflozin had an 85% probability of being cost-effective at a willingness-to-pay threshold of £20,000 per QALY gained. CONCLUSIONS: Dapagliflozin in combination with metformin was shown to be a cost-effective treatment option from a UK healthcare system perspective for patients with T2DM who are inadequately controlled on metformin alone.

The cost-effectiveness of dapagliflozin versus sulfonylurea as an add-on to metformin in the treatment of Type 2 diabetes mellitus.

AIMS: To assess the cost-effectiveness of dapagliflozin, a sodium-glucose co-transporter-2 (SGLT-2) inhibitor, compared with a sulfonylurea, when added to metformin for treatment of UK people with Type 2 diabetes mellitus inadequately controlled on metformin alone. METHODS: Clinical inputs sourced from a head-to-head randomized controlled trial (RCT) informed the Cardiff diabetes decision model. Risk equations developed from the United Kingdom Prospective Diabetes Study (UKPDS) were used in conjunction with the clinical inputs to predict disease progression and the incidence of micro- and macrovascular complications over a lifetime horizon. Cost and utility data were generated to present the incremental cost-effectiveness ratio (ICER) for both treatment arms, and sensitivity and scenario analyses were conducted to assess the impact of uncertainty on the final model results. RESULTS: The dapagliflozin treatment arm was associated with a mean incremental benefit of 0.467 quality-adjusted life years (QALYs) [95% confidence interval (CI): 0.420; 0.665], with an incremental cost of £1246 (95% CI: £613; £1637). This resulted in an ICER point estimate of £2671 per QALY gained. Incremental costs were shown to be insensitive to parameter variation, with only treatment-related weight change having a significant impact on the incremental QALYs. Probabilistic sensitivity analysis determined that dapagliflozin had a 100% probability of being cost-effective at a willingness-to-pay threshold of £20,000 per QALY. CONCLUSIONS: Dapagliflozin in combination with metformin was shown to be a cost-effective treatment option compared with sulfonylurea from a UK healthcare perspective for people with Type 2 diabetes mellitus who are inadequately controlled on metformin monotherapy.

Refitting of the UKPDS 68 risk equations to contemporary routine clinical practice data in the UK.

OBJECTIVE: Economic evaluations of new diabetes therapies rely heavily upon the UK Prospective Diabetes Study (UKPDS) equations for prediction of cardiovascular events; however, concerns persist regarding their relevance to current clinical practice and appropriate use in populations other than newly diagnosed patients. This study refits the UKPDS 68 event equations, using contemporary data describing low- and intermediate-risk patients. RESEARCH DESIGN AND METHODS: Anonymized patient data describing demographics, risk factors and incidence of cardiovascular and microvascular events were extracted from The Health Improvement Network (THIN) database over the 10-year period from 1 January 2000 to 31 December 2009. Following multiple imputation of missing values, accelerated failure-time Weibull regression equations were refitted to produce new coefficients for each risk group. Discriminatory performance was assessed and compared with both UKPDS 68 and UKPDS 82 risk equations, and the implication of coefficient choice within an economic evaluation was assessed using the Cardiff type 2 diabetes model. RESULTS: When applied to patient-level data, the three sets of coefficients (UKPDS, THIN low-risk and intermediate-risk) lead to fairly consistent predictions of the 5-year risk of events. Exceptions include lower predicted rates of myocardial infarction and higher rates of ischaemic heart disease, congestive heart failure and end-stage renal disease with both sets of revised THIN coefficients compared with UKPDS. Over a modelled lifetime, the coefficients derived from the low-risk data predict fewer total cardiovascular events compared with UKPDS, while those from the intermediate-risk data predict a greater number. The areas under the receiver-operating characteristic curves demonstrated a marginal improvement in the discriminatory performance of the refitted equations. The incremental cost-effectiveness ratio associated with dapagliflozin versus sulphonylurea in addition to metformin changed from £7,708 to £7,519 and £6,906 per QALY gained, using the THIN intermediate- and low-risk coefficients, respectively. CONCLUSION: The results suggest that while the UKPDS equations perform best in newly diagnosed patients, they may overpredict the lifetime risk in this group and underpredict it in patients with more advanced diabetes. Implementation of the revised coefficients will result in different absolute numbers of predicted diabetes-related events; however, they are not expected to significantly affect the conclusions of economic modelling.

A comparison of intermediate and long-acting insulins in people with type 2 diabetes starting insulin: an observational database study.

AIMS: Insulin is normally added to oral glucose-lowering drugs in people with type 2 diabetes when glycaemic control becomes suboptimal. We evaluated outcomes in people starting insulin therapy with neutral protamine Hagedorn (NPH), detemir, glargine or premixed insulins. METHODS: Insulin-naïve people with type 2 diabetes (n = 8009), ≥ 35 years old, HbA(1c) ≥ 6.5% and begun on NPH (n = 1463), detemir (n = 357), glargine (n = 2197) or premix (n = 3992), were identified from a UK database of primary care records (The Health Improvement Network). Unadjusted and multivariate-adjusted analyses were conducted, with persistence of insulin therapy assessed by survival analysis. RESULTS: In the study population (n = 4337), baseline HbA(1c) was 9.5 ± 1.6%, falling to 8.4 ± 1.5% over 12 months (change -1.1 ± 1.8%, p < 0.001). Compared with NPH, people taking detemir, glargine and premix had an adjusted reduction in HbA(1c) from baseline, of 0.00% (p = 0.99), 0.19% (p < 0.001) and 0.03% (p = 0.51). Body weight increased by 2.8 kg overall (p < 0.001), and by 2.3, 1.7, 1.9, and 3.3 kg on NPH, detemir, glargine and premix (p < 0.001 for all groups); insulin dose at 12 months was 0.70 (overall), 0.64, 0.61, 0.56 and 0.76 U/kg/day. After 36 months, 57% of people on NPH, 67% on glargine and 83% on premix remained on their initially prescribed insulin. DISCUSSION AND CONCLUSION: In routine clinical practice, people with type 2 diabetes commenced on NPH experienced a modest disadvantage in glycaemic control after 12 months compared with other insulins. When comparing the insulins, glargine achieved best HbA(1c) reduction, while premix showed greatest weight gain and the highest dose requirement, but had the best persistence of therapy.