Informing Structural Assumptions for Three State Oncology Cost-Effectiveness Models through Model Efficiency and Fit.

The characteristics and relative strengths and weaknesses of partitioned survival models (PSMs) and state transition models (STMs) for three state oncology cost-effectiveness models have previously been studied. Despite clear and longstanding economic modeling guidelines, more than one structure is rarely presented, and the choice of structure appears correlated more with audience or precedent than disease, decision problem, or available data. One reason may be a lack of guidance and tools available to readily compare measures of internal validity such as the model fit and efficiency of different structures, or sensitivity of results to those choices. To address this gap, methods are presented to evaluate the fit and efficiency of three structures, with an accompanying R software package, psm3mkv. The methods are illustrated by analyzing interim and final analysis datasets of the KEYNOTE-826 randomized controlled trial. At both interim and final analyses, the STM Clock Reset structure provided the best and most efficient fit. Structural uncertainties had been reduced from interim to final analysis. Beyond measures of internal validity, guidelines highlight the importance of reflecting all available data, avoiding model selection purely on the basis of goodness of fit and strongly considering external validity. The method and software allow modelers to more easily evaluate and report model fit and efficiency, examine implicit assumptions, and reveal sensitivities to structural choices.

Modeling health outcomes associated with BRCA testing and treatment strategies for patients with metastatic pancreatic cancer.

BACKGROUND: Germline BRCA mutations (gBRCAm) occur in 4%-8% patients with metastatic pancreatic cancer (mPC); guidelines recommend platinum-based chemotherapies and olaparib maintenance in this population. We evaluated, through modeling, the role of treatments and gBRCA testing on health outcomes of mPC patients. METHODS: A decision tree/partitioned survival model was developed to assess lifetime health outcomes for four strategies: 1) no testing; 2) early testing/no olaparib maintenance; 3) early testing (i.e., before 1L treatment)/olaparib maintenance; and 4) late testing/olaparib maintenance. Treatment patterns were assumed to follow current practice in the United States. Overall survival and progression-free survival curves were extrapolated from pivotal trials, including POLO trial for outcomes from olaparib maintenance after at least 16 weeks of platinum-based chemotherapy. RESULTS: Among patients with gBRCAm, almost twice as many patients received platinum-based regimens in strategies involving early testing compared to when early testing was not employed (78.7 % vs 40.2 %). Health outcomes were highest in the strategy with early testing and available olaparib treatment whether considering progression-free life years (PF LYs, 1.27 vs 0.55-0.87), LYs (1.82 vs 0.95-1.27) or quality adjusted life years (QALYs, 1.15 vs 0.73-0.92 for others). Consistent patterns of results were observed in the overall cohort of mPC patients (i.e., irrespective of gBRCAm). CONCLUSION: Patients with mPC achieved longest health outcomes (as measured by mean PF LYs, LYs and QALYs) with a scenario of early gBRCA testing and availability of olaparib maintenance. The results were primarily driven by improved health outcomes associated with higher efficacy of platinum-based chemotherapies and olaparib used in gBRCAm patients.

Cost-Effectiveness Analysis of Biomarker Testing to Guide First-Line PARP Inhibitor Maintenance for Patients with Advanced Ovarian Cancer After Response to First-Line Platinum Chemotherapy in the USA.

BACKGROUND: Poly(ADP-ribose) polymerase inhibitor maintenance treatments are available for platinum-sensitive advanced ovarian cancer. Olaparib (O) is available for BRCA mutation patients or in combination with bevacizumab (O+B) for patients with homologous recombination deficiency (HRD+); niraparib (N) is available for all patients. OBJECTIVE: This study aimed to evaluate the cost effectiveness of biomarker testing and maintenance treatments (mTx) with poly(ADP-ribose) polymerase inhibitor in platinum-sensitive advanced ovarian cancer in the USA. PATIENTS AND METHODS: Ten strategies were evaluated (S1-S10), representing biomarker testing (none, BRCA or HRD), and mTx (O, O+B, N or B). PAOLA-1 data were used to build a model estimating progression-free survival (PFS), second PFS (PFS2) and overall survival for O+B. PFS was modelled through mixture cure models; PFS2 and overall survival were modelled by standard parametric models. Hazard ratios of PFS for O+B versus B, N and O were obtained from the literature to estimate PFS for B, N and O. PFS2 and OS for B, N and O were informed by PFS benefits. RESULTS: S2 (no testing, B) had the lowest cost while S10 (HRD testing, O+B for HRD+ and B for HRD-) had the highest quality-adjusted life-years (QALYs). All niraparib strategies were dominated. S2, S4 (BRCA testing, O for BRCA+ and B for BRCA-), S6 (BRCA testing, olaparib plus bevacizumab for BRCA+ and bevacizumab for BRCA-) and S10 were the non-dominated strategies with an incremental cost-effectiveness ratio of $29,095/QALY, $33,786/QALY and $52,948/QALY for S4 versus S2, S6 versus S4 and S10 versus S6, respectively. CONCLUSIONS: Homologous recombination deficiency testing followed by O+B for HRD+ and B for HRD- is a highly cost-effective strategy for patients with platinum-sensitive advanced ovarian cancer. A HRD biomarker-guided approach provides most QALYs with good economic value.

Cost-Effectiveness Analysis of Olaparib in Combination with Bevacizumab Compared with Bevacizumab Monotherapy for the First-Line Maintenance Treatment of Homologous Recombination Deficiency-Positive Advanced Ovarian Cancer.

BACKGROUND: In the PAOLA-1 trial, olaparib plus bevacizumab demonstrated significant clinical benefit following partial or complete response to platinum-based chemotherapy in homologous recombination deficiency (HRD)-positive ovarian cancer. Our study evaluated the cost effectiveness of olaparib plus bevacizumab compared with bevacizumab alone as a maintenance treatment for women in this population. METHODS: Our model was a cohort-level partitioned survival model with a lifetime horizon from a US healthcare system perspective. Its four health states were progression-free, post first progression, post second progression, and death, modeled using time to first progression (PFS1), second progression (PFS2), and overall survival (OS) from PAOLA-1. We modeled PFS1 through mixture survival modeling, and PFS2 and OS by fitting standard parametric models. Time-on-treatment was sourced directly from PAOLA-1, with treatment capped at 24 months for olaparib and 15 months for bevacizumab. Costs included drug acquisition and administration, adverse events, disease management, biomarker testing, and subsequent treatments. Deterministic and probabilistic sensitivity analyses tested the results. RESULTS: Compared with bevacizumab alone, olaparib plus bevacizumab increased quality-adjusted life-years (QALYs; +2.89) and life-years (LYs; +3.43) at an incremental cost of $164,209, leading to an incremental cost-effectiveness ratio of $56,863 per QALY. Olaparib plus bevacizumab had a 97.0% probability of being cost effective compared with bevacizumab alone at a willingness-to-pay threshold of $100,000 per QALY. CONCLUSION: The addition of olaparib to bevacizumab led to clinically significant increases in progression-free survival, resulting in substantial predicted LYs and QALYs gained, while being cost effective in the maintenance treatment of advanced ovarian cancer with HRD in the US.

Cost comparison of adverse event management among breast and ovarian cancer patients treated with poly (ADP-ribose) polymerase inhibitors: analysis based on phase 3 clinical trials.

Background: The economic impact of adverse events (AEs) for poly (ADP-ribose) polymerase inhibitors (PARPis) in ovarian or breast cancer has not been widely evaluated. Objective: Compare PARPi-related AE management costs from a US payer perspective. Methods: The frequency of treatment-related grade 3-4 AEs was obtained from published clinical trials of PARPis for the treatment of advanced ovarian cancer (AOC), platinum-sensitive recurrent ovarian cancer (PSROC), and metastatic breast cancer (MBC). AE management costs per patient (2020 USD) per treatment course were calculated by multiplying the AE unit costs by the frequency of AEs for each arm of each trial. Sensitivity analyses were conducted according to the lower and upper limits of the 95% confidence interval for AE rates and unit costs, respectively. Scenarios were also performed to explore the uncertainty of outcomes. Results: Total AE management costs in AOC were: $3,904, olaparib; $5,595, olaparib plus bevacizumab; and $12,215, niraparib. In PSROC, total costs were: $3,894, olaparib; $6,001, rucaparib; and $11,492, niraparib, and in MBC: $3,574, olaparib; and $9,489, talazoparib. Hematological toxicities were the key drivers of AE management costs for PARPis. Conclusions: The main AEs among PARPis were hematological. Olaparib was associated with lower AE costs compared to other PARPis.

Exploring the Impact of Treatment Switching on Overall Survival from the PROfound Study in Homologous Recombination Repair (HRR)-Mutated Metastatic Castration-Resistant Prostate Cancer (mCRPC).

BACKGROUND: In oncology trials, treatment switching from the comparator to the experimental regimen is often allowed but may lead to underestimating overall survival (OS) of an experimental therapy. OBJECTIVE: This study evaluates the impact of treatment switching from control to olaparib on OS using the final survival data from the PROfound study and compares validated adjustment methods to estimate the magnitude of OS benefit with olaparib. PATIENTS AND METHODS: The primary population from PROfound (Cohort A) was included, alongside two populations approved for treatment with olaparib by the European Medicines Agency and US Food and Drug Administration: BRCAm and Cohort A+B (excluding the PPP2R2A gene). Five methods were explored to adjust for switching: excluding or censoring patients in the control arm who receive subsequent olaparib, Rank Preserving Structural Failure Time Model (RPSFTM), Inverse Probability of Censoring Weights, and Two-Stage Estimation. RESULTS: The RPSFTM was considered the most appropriate approach for PROfound as the results were robust to sensitivity analysis testing of the common treatment effect assumption. For Cohort A, the final OS hazard ratio reduced from 0.69 (95% CI 0.5-0.97) to between 0.42 (0.18-0.90) and 0.52 (0.31-1.00) for olaparib versus control, depending on the RPSFTM selected. Median OS reduced from 14.7 months to between 11.73 and 12.63 months for control. CONCLUSIONS: The magnitude of the statistically significant (P < 0.05) survival benefit of olaparib versus control observed in Cohort A of PROfound is likely to be underestimated if adjustment for treatment switching from control to olaparib is not conducted. The RPSFTM was considered the most plausible method, although further development and validation of robust methods to estimate the magnitude of impact of treatment switching is needed.

Cost-effectiveness of olaparib as a maintenance treatment for women with newly diagnosed advanced ovarian cancer and BRCA1/2 mutations in the United States.

OBJECTIVE: This study evaluated the cost-effectiveness of olaparib monotherapy in the first-line maintenance setting vs. surveillance in women with newly diagnosed advanced ovarian cancer and a BRCA1/2 mutation from a US third-party payer perspective. METHODS: A three-state (progression free, progressed disease, and death) partitioned survival model over a 50-year lifetime horizon was developed. Piecewise models were applied to data from the phase III trial SOLO1 to extrapolate survival outcomes. Health state utilities and adverse event disutilities were obtained from literature and SOLO1. Treatment costs, adverse event costs, and medical costs associated with health states were obtained from publicly available databases, SOLO1, and real-world data. Time on treatment was estimated using the data from SOLO1. Incremental costs per quality-adjusted life year (QALY) and life year (LY) gained were estimated. One-way deterministic and probabilistic sensitivity analyses were conducted. RESULTS: Over a lifetime horizon, olaparib was associated with an additional 3.63 LYs and 2.93 QALYs, and an incremental total cost of $152,545 vs. surveillance. Incremental cost per LY gained and per QALY gained for olaparib were $42,032 and $51,986, respectively. The incremental cost-effectiveness ratios remained below $100,000 across a range of inputs and scenarios. In the PSA, the probability of olaparib being cost-effective at a $100,000 per QALY threshold was 99%. CONCLUSIONS: Compared to surveillance, olaparib increases both the LYs and QALYs of women with newly diagnosed advanced ovarian cancer and with a germline or somatic BRCA mutation. Olaparib offers a cost-effective maintenance option for these women from a US third-party payer perspective.

A Critical Appraisal and Recommendations for Cost-Effectiveness Studies of Poly(ADP-Ribose) Polymerase Inhibitors in Advanced Ovarian Cancer.

BACKGROUND: Ovarian cancer is the fifth leading cause of cancer death in women in the US. With poly(ADP-ribose) polymerase (PARP) inhibitors having shown promising results in ongoing trials, there is interest in better understanding their economic value. OBJECTIVE: This study aimed to review and evaluate the quality of published cost-effectiveness analyses (CEAs), and provide recommendations for CEAs in this setting. METHODS: A systematic literature review of the MEDLINE and EMBASE databases was conducted in June 2019 to identify CEAs of PARP inhibitors in treating advanced ovarian cancer from peer-reviewed journals and conferences. Key information from the identified publications were extracted and reviewed. The quality of full-text studies was assessed using the Quality of Health Economic Studies instrument. Recommendations for future CEAs were developed based on the findings from the literature review. RESULTS: Eighteen CEAs (five in full texts) met the inclusion criteria. Most adopted a US healthcare or societal perspective. The majority of the studies did not clearly display the economic model structure. No studies reported the validation of model projections based on internal or external data. Surrogate outcomes such as incremental costs per progression-free life-year gained were the most common outcomes reported. The majority of studies drew their conclusions based on surrogate outcomes, even with no theoretical or empirical threshold for cost effectiveness. All five full-text studies included some type of sensitivity or scenario analyses. The key drivers of the incremental cost-effectiveness ratio were treatment duration, effects, and costs, health utility, and prevalence of BRCA mutations. CONCLUSION: In the existing CEAs for PARP inhibitors, there were uncertainties and challenges leading to variation in quality. We provided recommendations to improve consistency and quality of CEAs in this setting, which will help to better understand the value of PARP inhibitors, improve decision making, and reduce potential misallocation of resources.

An efficacy comparison of anti-vascular growth factor agents and laser photocoagulation in diabetic macular edema: a network meta-analysis incorporating individual patient-level data.

BACKGROUND: This was an updated network meta-analysis (NMA) of anti-vascular endothelial growth factor (VEGF) agents and laser photocoagulation in patients with diabetic macular edema (DME). Unlike previous NMA that used meta-regression to account for potential confounding by systematic variation in treatment effect modifiers across studies, this update incorporated individual patient-level data (IPD) regression to provide more robust adjustment. METHODS: An updated review was conducted to identify randomised controlled trials for inclusion in a Bayesian NMA. The network included intravitreal aflibercept (IVT-AFL) 2 mg bimonthly (2q8) after 5 initial doses, ranibizumab 0.5 mg as-needed (PRN), ranibizumab 0.5 mg treat-and-extend (T&E), and laser photocoagulation. Outcomes included in the analysis were change in best-corrected visual acuity (BCVA), measured using an Early Treatment Diabetic Retinopathy Study (ETDRS) chart, and patients with ≥10 and ≥ 15 ETDRS letter gains/losses at 12 months. Analyses were performed using networks restricted to IPD-only and IPD and aggregate data with (i) no covariable adjustment, (ii) covariable adjustment for baseline BVCA assuming common interaction effects (against reference treatment), and (iii) covariable adjustments specific to each treatment comparison (restricted to IPD-only network). RESULTS: Thirteen trials were included in the analysis. IVT-AFL 2q8 was superior to laser in all analyses. IVT-AFL 2q8 showed strong evidence of superiority (95% credible interval [CrI] did not cross null) versus ranibizumab 0.5 mg PRN for mean change in BCVA (mean difference 5.20, 95% CrI 1.90-8.52 ETDRS letters), ≥15 ETDRS letter gain (odds ratio [OR] 2.30, 95% CrI 1.12-4.20), and ≥10 ETDRS letter loss (OR 0.25, 95% CrI 0.05-0.74) (IPD and aggregate random-effects model with baseline BCVA adjustment). IVT-AFL 2q8 was not superior to ranibizumab 0.5 mg T&E for mean change in BCVA (mean difference 5.15, 95% CrI -0.26-10.61 ETDRS letters) (IPD and aggregate random-effects model). CONCLUSIONS: This NMA, which incorporated IPD to improve analytic robustness, showed evidence of superiority of IVT-AFL 2q8 to laser and ranibizumab 0.5 mg PRN. These results were irrespective of adjustment for baseline BCVA.

A noninterventional study to monitor patients with diabetic macular oedema starting treatment with ranibizumab (POLARIS).

PURPOSE: Antivascular endothelial growth factor agents are increasingly used in diabetic macular oedema (DME); however, there are few studies exploring their use in DME in real-world settings. METHODS: POLARIS was a noninterventional, multicentre study to monitor 12-month outcomes in patients starting ranibizumab treatment in routine practices. The primary outcome was mean change in visual acuity (VA) from baseline to month 12 (last observation carried forward approach). Other outcomes included mean change in central retinal thickness (CRT) and resource utilization. Visual acuity (VA) outcomes were also stratified by country, baseline visual acuity score (VAS), sex, age and injection frequency. RESULTS: Outcomes were analysed from all treated patients (n = 804) and from first-year completers (patients who had a visual acuity assessment at 12 months; n = 568). The mean (SD) baseline VAS was 59.4 (15.9) letters, and the mean change in visual acuity was 4.4 letters (95% confidence interval: 3.3-5.4) at month 12 (study eye; first-year completers). The mean number of injections (study eye) was 4.9, and the mean number of all visits (any eye) was 10 (58% were injection visits) over 12 months (first-year completers). The mean (SD) baseline CRT was 410.6 (128.8) µm, and the mean change in CRT was -115.2 µm at month 12 (study eye; first-year completers). Visual acuity (VA) outcomes were generally comparable across most countries and subgroups and were greatest in patients with the lowest baseline VAS (≤60 letters). CONCLUSION: POLARIS showed that real-world outcomes in DME patients starting treatment with ranibizumab were lower than those observed in clinical studies, in spite of extensive monitoring.

Evaluating the Relationship Between Visual Acuity and Utilities in Patients With Diabetic Macular Edema Enrolled in Intravitreal Aflibercept Studies.

Purpose: The purpose of this study was to explore the relationship between visual acuity and utility (health-related quality of life) in diabetic macular edema (DME) using intravitreal aflibercept data. Methods: The relationship between visual acuity in the best-seeing eye (BSE) and worse-seeing eye (WSE) and utility was explored using ordinary least squares (OLS) and random-effects models adjusted for different covariates (age, age2, sex, body mass index, smoking status, glycated hemoglobin, diabetes severity, comorbidities, and geographic region). Utility was measured using the EuroQoL-five dimensions questionnaire (EQ-5D) and Visual Functioning Questionnaire-Utility Index (VFQ-UI). For each model, coefficients (R2) were reported, and WSE/BSE was expressed as the ratio of coefficients (OLS models). Models were independent of treatment effects, and outcomes from all time points (up to week 100) were included where available. Results: Data from 1320 patients with DME were analyzed. In all models, the association between visual acuity (BSE > WSE) was stronger with VFQ-UI- than EQ-5D-derived utilities. The estimated relationship between VFQ-UI and visual acuity in the BSE and WSE was robust, even with an increasing number of covariates. WSE/BSE coefficient ratios were similar across VFQ-UI OLS models (32%) compared with EQ-5D models (41%-48%). Actual (unadjusted) versus predicted data plots also showed a better fit with VFQ-UI- than EQ-5D-derived utilities. Conclusions: These analyses show that VFQ-UI was more sensitive than EQ-5D-derived utilities for measuring the impact of visual acuity in the BSE and WSE. Visual acuity in the BSE was a major contributor to utility, but WSE is also important though to a lesser degree as shown by the coefficient ratios. These new data will be useful for health technology assessments in DME, where utilities data are lacking.

Cost-effectiveness analysis of treatment of venous thromboembolism with rivaroxaban compared with combined low molecular weight heparin/vitamin K antagonist.

BACKGROUND: Venous thromboembolism (VTE) is a burden on healthcare systems. Standard treatment involves parenteral anticoagulation overlapping with a vitamin K antagonist, an approach that is effective but associated with limitations including the need for frequent coagulation monitoring. The direct oral anticoagulant rivaroxaban is similarly effective to standard therapy as a single-drug treatment for VTE and does not require routine coagulation monitoring. The objective of this economic evaluation was to estimate the cost-effectiveness of rivaroxaban compared with standard VTE treatment from a UK perspective. METHODS: A Markov model was constructed using data and probabilities derived from the EINSTEIN DVT and EINSTEIN PE studies of rivaroxaban and other published sources. Health outcomes included VTE rates, bleeding events avoided, quality-adjusted life-years (QALYs) and incremental cost-effectiveness ratios (ICERs). RESULTS: There was greater discounted quality-adjusted life expectancy with rivaroxaban than with standard therapy, irrespective of indication and treatment duration. Rivaroxaban was associated with per-patient cost savings for each treatment duration modelled (3, 6 and 12 months), and these were greatest with shorter durations. Rivaroxaban was found to be dominant (cheaper and more effective) and, therefore, cost-effective, in both patients with deep vein thrombosis and pulmonary embolism in all three treatment duration groups, and was also cost-effective in patients requiring lifelong anticoagulation (ICERs: £8677 per QALY and £7072 per QALY in patients with index deep vein thrombosis and pulmonary embolism, respectively). The cost-effectiveness of rivaroxaban was largely insensitive to variations in one-way sensitivity analysis. Probabilistic sensitivity analysis demonstrated that at a threshold of £20,000 per QALY, rivaroxaban had a consistent probability of being cost-effective, compared with LMWH/VKA treatment, of around 80% regardless of index VTE or duration of anticoagulation therapy (3, 6, 12 months or lifelong). CONCLUSIONS: This analysis suggests that rivaroxaban represents a cost-effective choice for acute treatment of deep vein thrombosis and pulmonary embolism and secondary prevention of VTE in the UK, compared with LMWH/VKA treatment, regardless of the required treatment duration.

Systematic review and mixed treatment comparison of intravitreal aflibercept with other therapies for diabetic macular edema (DME).

BACKGROUND: This was an indirect comparison of the effectiveness of intravitreal aflibercept (IVT-AFL) 2 mg every 8 weeks after 5 initial monthly doses (or if different periods, after an initial monthly dosing period) (2q8) and other diabetic macular edema (DME) therapies at doses licensed outside the USA. METHODS: A comprehensive search was undertaken to source relevant studies. Feasibility networks were prepared to identify viable comparisons of 12-month outcomes between IVT-AFL 2q8 and therapies licensed outside the USA, which were assessed for clinical and statistical homogeneity. Pooled effect sizes (mean difference [MD] and relative risk/risk ratio [RR]) were calculated using fixed- and random-effects models. Indirect comparisons were performed using Bucher analysis. If at least one 'head-to-head' study was found then a mixed treatment comparison (MTC) was performed using Bayesian methods. Two 12-month comparisons could be undertaken based on indirect analyses: IVT-AFL 2q8 versus intravitreal ranibizumab (IVR) 0.5 mg as needed (PRN) (10 studies) and IVT-AFL 2q8 versus dexamethasone 0.7 mg implants (three studies). RESULTS: There was an increase in mean best-corrected visual acuity (BCVA) with IVT-AFL 2q8 over IVR 0.5 mg PRN by 4.67 letters [95% credible interval (CrI): 2.45-6.87] in the fixed-effect MTC model (10 studies) and by 4.82 letters [95% confidence interval (CI): 2.52-7.11] in the Bucher indirect analysis (four studies). IVT-AFL 2q8 doubled the proportion of patients gaining ≥ 10 Early Treatment Diabetic Retinopathy Study letters at 12 months compared with dexamethasone 0.7 mg implants (RR = 2.10 [95% CI: 1.29-3.40]) in the fixed-effect model. There were no significant differences in safety outcomes between IVT-AFL 2q8 and IVR 0.5 mg PRN or dexamethasone 0.7 mg implants. CONCLUSIONS: Studies of IVT-AFL 2q8 showed improved 12-month visual acuity measures compared with studies of IVR 0.5 mg PRN and dexamethasone 0.7 mg implants based on indirect comparisons. These analyses are subject to a number of limitations which are inherent in indirect data comparisons.

Prevalence of gastrointestinal stromal tumour (GIST) in the United Kingdom at different therapeutic lines: an epidemiologic model.

BACKGROUND: The prevalence of patients with gastrointestinal stromal tumourgst (GIST) who fail currently available treatments imatinib and sunitinib (third-line treatment-eligible GIST) is unknown, but is expected to be below an ultra-orphan disease threshold of 2/100,000 population used in England and Wales. Our study was designed to estimate the prevalence and absolute number of UK patients with unresectable/metastatic GIST at first-, second- and eventually third-line treatment. METHODS: Our open population model estimates the probability that the prevalence of UK third-line treatment-eligible GIST patients will remain under the ultra-orphan disease threshold. Model parameters for incidence, proportion of unresectable/metastatic disease and survival estimates for GIST patients were obtained from a targeted literature review and a UK cancer register. The robustness of the results was checked through differing scenarios taking extreme values of the input parameters. RESULTS: The base-case scenario estimated a prevalence of third-line treatment-eligible GIST of 1/100,000 and a prevalence count of 598 with a 99.9% likelihood of being below the ultra-orphan disease threshold. The extreme scenarios, one-way and probabilistic sensitivity analyses and threshold analysis confirmed the robustness of these results. CONCLUSIONS: The prevalence of third-line treatment-eligible GIST is very low and highly likely below the ultra-orphan disease threshold.

Cost effectiveness of CT colonography for UK NHS colorectal cancer screening of asymptomatic adults aged 60-69 years.

BACKGROUND: Screening of populations at risk for colorectal cancer (CRC) allows the detection and successful treatment of tumours and their precursor polyps. The current UK CRC screening programme is faecal occult blood testing (FOBT), despite evidence from modelling studies to suggest that more cost-effective technologies exist. OBJECTIVE: To assess the cost effectiveness of CT colonography (CTC) for colorectal cancer screening from the perspective of the UK NHS. METHODS: A state-transition Markov model was constructed to estimate lifetime costs and health outcomes of a cohort of individuals screened at age 60-69 years using four different CRC screening technologies: FOBT, flexible sigmoidoscopy, optical colonoscopy and CTC. RESULTS: CTC screening offered every 10 years was cost saving compared with the current UK programme of biennial FOBT screening. This strategy also yielded greater health benefits (QALYs and life-years) than biennial FOBT screening. The model fit observed CRC epidemiology data well and was robust to changes in underlying parameter values. CTC remained cost effective under a range of assumptions in the univariate sensitivity analysis. However, in the probabilistic sensitivity analysis, CTC dominated FOBT in only 5.9% of simulations and was cost effective at a threshold of pound30,000 per QALY gained in 48% of simulations. CONCLUSIONS: CTC has the potential to provide a cost-effective option for CRC screening in the UK NHS and may be cost saving compared with the current programme of biennial FOBT. Further analysis is required to assess the impact of introducing CTC to the UK CRC screening programme on the NHS budget and capacity.

An economic evaluation of topical treatments for actinic keratosis.

Actinic keratoses (AK) commonly occur as lesions, in sun-exposed areas. Various treatment modalities exist for their removal. We assessed the cost-effectiveness in 2007 of topical treatments (5-fluorouracil, imiquimod) and photodynamic therapy with methyl aminolevulinate (MAL-PDT) for AK under the perspective of the UK National Health Service (NHS) in England and Wales over two lines of treatment. We used a decision tree analytical approach. Efficacy data were taken from published trial literature for two investigator-assessed outcomes: 'complete clinical response' and 'excellent cosmetic outcome'. MAL-PDT at first line followed by various second-line treatments provided the greatest probability of complete clinical response (91.7%), but MAL-PDT at first line followed by further MAL-PDT as the second-line treatment provided the greatest probability of excellent cosmetic outcome (73.6%). The cost of MAL-PDT was 437 pounds sterling after two lines of treatment if MAL-PDT was that second-line treatment or 418 pounds sterling if various treatments were offered at second line. The probabilistic analysis produced consistent results. Based on this model, the costs and effectiveness of MAL-PDT in the UK NHS compare well with other treatments for AK.

The effects of antimuscarinic treatments in overactive bladder: an update of a systematic review and meta-analysis.

CONTEXT: Antimuscarinic agents are currently the first-line pharmacotherapy for overactive bladder. OBJECTIVES: A systematic review published in 2005 was updated, including data on a newly licensed antimuscarinic (fesoterodine). The primary aim of this study was to systematically review evidence on the efficacy of licensed administration of antimuscarinic treatments in overactive bladder from randomised controlled trials. Secondary aims were to review evidence on tolerability and safety and health-related quality of life (HRQL). EVIDENCE ACQUISITION: All relevant data sources from randomised controlled trials were searched, and two independent reviewers considered publications for inclusion and extracted relevant data. Meta-analysis was used to pool efficacy, tolerability, safety, and HRQL outcomes by treatment. Efficacy was measured by continent days, mean voided volume, urgency episodes, and micturition frequency. Tolerability and safety were measured by means of adverse event and withdrawal rates. HRQL was measured by various instruments. EVIDENCE SYNTHESIS: An additional 1118 references were retrieved with data on 83 studies extracted. Antimuscarinics were found to be more effective than placebo. Tolerability was good; few of the antimuscarinics were found to have significantly higher withdrawal rates in comparison to placebo. No serious adverse event for any product was statistically significant compared to placebo. Dry mouth (mild, moderate, severe) was the most commonly reported adverse event (29.6% on treatment vs 7.9% on placebo), followed by pruritus (15.4% on treatment vs 5.2% on placebo). Improvements were seen in HRQL with treatment by darifenacin, fesoterodine, oxybutynin transdermal delivery system, propiverine extended release (ER), solifenacin, tolterodine ER and immediate release, and trospium. Limitations of the study include restrictions on the types of patients typically included in overactive bladder trials and topics that have not been adequately addressed in the current antimuscarinic literature. CONCLUSIONS: Antimuscarinics are efficacious, safe, and well-tolerated treatments that improve HRQL. Profiles of each drug and dosage differ and should be considered in making treatment choices.