Cost effectiveness of ranibizumab vs aflibercept vs bevacizumab for the treatment of macular oedema due to central retinal vein occlusion: the LEAVO study

Background We aimed to assess the cost effectiveness of intravitreal ranibizumab (Lucentis), aflibercept (Eylea) and bevacizumab (Avastin) for the treatment of macular oedema due to central retinal vein occlusion. Methods We calculated costs and quality-adjusted life-years from the UK National Health Service and Personal Social Services perspective. We performed a within-trial analysis using the efficacy, safety, resource use and health utility data from a randomised controlled trial (LEAVO) over 100 weeks. We built a discrete event simulation to model long-term outcomes. We estimated utilities using the Visual-Functioning Questionnaire-Utility Index, EQ-5D and EQ-5D with an additional vision question. We used standard UK costs sources for 2018/19 and a cost of £28 per bevacizumab injection. We discounted costs and quality-adjusted life-years at 3.5% annually. Results Bevacizumab was the least costly intervention followed by ranibizumab and aflibercept in both the within-trial analysis (bevacizumab: £6292, ranibizumab: £13,014, aflibercept: £14,328) and long-term model (bevacizumab: £18,353, ranibizumab: £30,226, aflibercept: £35,026). Although LEAVO did not demonstrate bevacizumab to be non-inferior for the visual acuity primary outcome, the three interventions generated similar quality-adjusted life-years in both analyses. Bevacizumab was always the most cost-effective intervention at a threshold of £30,000 per quality-adjusted life-year, even using the list price of £243 per injection. Conclusions Wider adoption of bevacizumab for the treatment of macular oedema due to central retinal vein occlusion could result in substantial savings to healthcare systems and deliver similar health-related quality of life. However, patients, funders and ophthalmologists should be fully aware that LEAVO could not demonstrate that bevacizumab is non-inferior to the licensed agents

Intravitreal ranibizumab versus aflibercept versus bevacizumab for macular oedema due to central retinal vein occlusion: the LEAVO non-inferiority three-arm RCT

Background Licensed ranibizumab (0.5 mg/0.05 ml Lucentis®; Novartis International AG, Basel, Switzerland) and aflibercept (2 mg/0.05 ml Eylea®; Bayer AG, Leverkusen, Germany) and unlicensed bevacizumab (1.25 mg/0.05 ml Avastin®; F. Hoffmann-La Roche AG, Basel, Switzerland) are used to treat macula oedema due to central retinal vein occlusion, but their relative clinical effectiveness, cost-effectiveness and impact on the UK NHS and Personal Social Services have never been directly compared over the typical disease treatment period. Objective The objective was to compare the clinical effectiveness and cost-effectiveness of three intravitreal antivascular endothelial growth factor agents for the management of macula oedema due to central retinal vein occlusion. Design This was a three-arm, double-masked, randomised controlled non-inferiority trial. Setting The trial was set in 44 UK NHS ophthalmology departments, between 2014 and 2018. Participants A total of 463 patients with visual impairment due to macula oedema secondary to central retinal vein occlusion were included in the trial. Interventions The participants were treated with repeated intravitreal injections of ranibizumab (n = 155), aflibercept (n = 154) or bevacizumab (n = 154). Main outcome measures The primary outcome was an increase in the best corrected visual acuity letter score from baseline to 100 weeks in the trial eye. The null hypothesis that aflibercept and bevacizumab are each inferior to ranibizumab was tested with a non-inferiority margin of –5 visual acuity letters over 100 weeks. Secondary outcomes included additional visual acuity, and imaging outcomes, Visual Function Questionnaire-25, EuroQol-5 Dimensions with and without a vision bolt-on, and drug side effects. Cost-effectiveness was estimated using treatment costs and Visual Function Questionnaire-Utility Index to measure quality-adjusted life-years. Results The adjusted mean changes at 100 weeks in the best corrected visual acuity letter scores were as follows – ranibizumab, 12.5 letters (standard deviation 21.1 letters); aflibercept, 15.1 letters (standard deviation 18.7 letters); and bevacizumab, 9.8 letters (standard deviation 21.4 letters). Aflibercept was non-inferior to ranibizumab in the intention-to-treat population (adjusted mean best corrected visual acuity difference 2.23 letters, 95% confidence interval –2.17 to 6.63 letters; p = 0.0006), but not superior. The study was unable to demonstrate that bevacizumab was non-inferior to ranibizumab in the intention-to-treat population (adjusted mean best corrected visual acuity difference –1.73 letters, 95% confidence interval –6.12 to 2.67 letters; p = 0.071). A post hoc analysis was unable to demonstrate that bevacizumab was non-inferior to aflibercept in the intention-to-treat population (adjusted mean best corrected visual acuity difference was –3.96 letters, 95% confidence interval –8.34 to 0.42 letters; p = 0.32). All per-protocol population results were the same. Fewer injections were required with aflibercept (10.0) than with ranibizumab (11.8) (difference in means –1.8, 95% confidence interval –2.9 to –0.8). A post hoc analysis showed that more bevacizumab than aflibercept injections were required (difference in means 1.6, 95% confidence interval 0.5 to 2.7). There were no new safety concerns. The model- and trial-based cost-effectiveness analyses estimated that bevacizumab was the most cost-effective treatment at a threshold of £20,000–30,000 per quality-adjusted life-year. Limitations The comparison of aflibercept and bevacizumab was a post hoc analysis. Conclusion The study showed aflibercept to be non-inferior to ranibizumab. However, the possibility that bevacizumab is worse than ranibizumab and aflibercept by 5 visual acuity letters cannot be ruled out. Bevacizumab is an economically attractive treatment alternative and would lead to substantial cost savings to the NHS and other health-care systems. However, uncertainty about its relative effectiveness should be discussed comprehensively with patients, their representatives and funders before treatment is considered. Future work To obtain extensive patient feedback and discuss with all stakeholders future bevacizumab NHS use. Trial registration Current Controlled Trials ISRCTN13623634. Funding This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 25, No. 38. See the NIHR Journals Library website for further project information

Multilevel modelling of child mortality Gibbs sampling versus other approaches

SIGLEAvailable from British Library Document Supply Centre-DSC:DXN017144 / BLDSC - British Library Document Supply CentreGBUnited Kingdo

Perceptions of absolute versus relative differences between personal and comparison health risk

OBJECTIVE: To explain inconsistent results in previous attempts to determine whether, when presented with health risk information, people focus primarily on information about their own risk status or on a comparison with others. DESIGN: A randomized between-groups experiment in which participants were presented with hypothetical cardiac risk information. We examined whether affective responses were primarily sensitive to the relative difference between personal and comparison risk, rather than the absolute difference. MAIN OUTCOME MEASURES: Participants' negative affective response to the risk information. RESULTS: When relative differences were held constant, participants' responses were independently influenced by both personal risk and comparative standing, effects that were greatly attenuated when absolute differences were held constant. When maintaining constant absolute differences, personal and comparison risk information appeared to interact. CONCLUSION: Previous studies tended to maintain constant absolute risk differences and so may have underestimated the impact of personal risk information. Participants' responses were sensitive to the way the risk difference was constructed. Basing experimental design decisions on assumptions about the information participants will respond to can lead to misinterpretations of the basis of risk judgments

Psychological impact of screening for type 2 diabetes: controlled trial and comparative study embedded in the ADDITION (cambridge) randomised controlled trial

Objective To quantify the psychological impact of primary care based stepwise screening for type 2 diabetes. Design Controlled trial and comparative study embedded in a randomised controlled trial. Setting 15 practices (10 screening, five control) in the ADDITION (Cambridge) trial in the east of England. Participants 7380 adults (aged 40-69) in the top fourth for risk of having undiagnosed type 2 diabetes (6416 invited for screening, 964 controls). Interventions Invited for screening for type 2 diabetes or not invited (controls), incorporating a comparative study of subgroups of screening attenders. Attenders completed questionnaires after a random blood glucose test and at 3-6 months and 12-15 months later. Controls were sent questionnaires at corresponding time points. Non-attenders were sent questionnaires at 3-6 months and 12-15 months. Main outcome measures State anxiety (Spielberger state anxiety inventory), anxiety and depression (hospital anxiety and depression scale), worry about diabetes, and self rated health. Results No significant differences were found between the screening and control participants at any time—for example, difference in means (95% confidence intervals) for state anxiety after the initial blood glucose test was −0.53, −2.60 to 1.54, at 3-6 months was 1.51 (−0.17 to 3.20), and at 12-15 months was 0.57, −1.11 to 2.24. After the initial test, compared with participants who screened negative, those who screened positive reported significantly poorer general health (difference in means −0.19, −0.25 to −0.13), higher state anxiety (0.93, −0.02 to 1.88), higher depression (0.32, 0.08 to 0.56), and higher worry about diabetes (0.25, 0.09 to 0.41), although effect sizes were small. Small but significant trends were found for self rated health across the screening subgroups at 3-6 months (P=0.047) and for worry about diabetes across the screen negative groups at 3-6 months and 12-15 months (P=0.001). Conclusions Screening for type 2 diabetes has limited psychological impact on patients. Implementing a national screening programme based on the stepwise screening procedure used in the ADDITION (Cambridge) trial is unlikely to have significant consequences for patients' psychological health. Trial registration Current Controlled Trials ISRCTN99175498

Researchers’ experiences of the design and conduct challenges associated with parallel-group cluster-randomised trials and views on a novel open-cohort design

Background: Two accepted designs exist for parallel-group cluster-randomised trials (CRTs). Closed-cohort designs follow the same individuals over time with a single recruitment period before randomisation, but face challenges in settings with high attrition. (Repeated) cross-sectional designs recruit at one or more timepoints before and/or after randomisation, collecting data from different individuals present in the cluster at these timepoints, but are unsuitable for assessment of individual change over time. An ‘open-cohort’ design allows individual follow-up with recruitment before and after cluster-randomisation, but little literature exists on acceptability to inform their use in CRTs. Aim: To document the views and experiences of expert trialists to identify: a) Design and conduct challenges with established parallel-group CRT designs, b) Perceptions of potential benefits and barriers to implementation of open-cohort CRTs, c) Methods for minimising, and investigating the impact of, bias in open-cohort CRTs. Methods: Qualitative consultation via two expert workshops including triallists (n = 24) who had worked on CRTs over a range of settings. Workshop transcripts were analysed using Descriptive Thematic Analysis utilising inductive and deductive coding. Results: Two central organising concepts were developed. Design and conduct challenges with established CRT designs confirmed that current CRT designs are unable to deal with many of the complex research and intervention circumstances found in some trial settings (e.g. care homes). Perceptions of potential benefits and barriers of open cohort designs included themes on: approaches to recruitment; data collection; analysis; minimising/investigating the impact of bias; and how open-cohort designs might address or present CRT design challenges. Open-cohort designs were felt to provide a solution for some of the challenges current CRT designs present in some settings. Conclusions: Open-cohort CRT designs hold promise for addressing the challenges associated with standard CRT designs. Research is needed to provide clarity around definition and guidance on application

Researchers’ experiences of the design and conduct challenges associated with parallel-group cluster-randomised trials and views on a novel open-cohort design

Background: Two accepted designs exist for parallel-group cluster-randomised trials (CRTs). Closed-cohort designs follow the same individuals over time with a single recruitment period before randomisation, but face challenges in settings with high attrition. (Repeated) cross-sectional designs recruit at one or more timepoints before and/or after randomisation, collecting data from different individuals present in the cluster at these timepoints, but are unsuitable for assessment of individual change over time. An ‘open-cohort’ design allows individual follow-up with recruitment before and after cluster-randomisation, but little literature exists on acceptability to inform their use in CRTs. Aim: To document the views and experiences of expert trialists to identify: a) Design and conduct challenges with established parallel-group CRT designs, b) Perceptions of potential benefits and barriers to implementation of open-cohort CRTs, c) Methods for minimising, and investigating the impact of, bias in open-cohort CRTs. Methods: Qualitative consultation via two expert workshops including triallists (n = 24) who had worked on CRTs over a range of settings. Workshop transcripts were analysed using Descriptive Thematic Analysis utilising inductive and deductive coding. Results: Two central organising concepts were developed. Design and conduct challenges with established CRT designs confirmed that current CRT designs are unable to deal with many of the complex research and intervention circumstances found in some trial settings (e.g. care homes). Perceptions of potential benefits and barriers of open cohort designs included themes on: approaches to recruitment; data collection; analysis; minimising/investigating the impact of bias; and how open-cohort designs might address or present CRT design challenges. Open-cohort designs were felt to provide a solution for some of the challenges current CRT designs present in some settings. Conclusions: Open-cohort CRT designs hold promise for addressing the challenges associated with standard CRT designs. Research is needed to provide clarity around definition and guidance on application

The fitting of parameter-constrained demographic models

It is common to have knowledge about the unknown parameters of a demographic model which restricts the values of the parameters. With such knowledge, it is reasonable to require that our parameter estimates satisfy the parameter constraints and one should use a constrained estimation procedure. We briefly review existing approaches to fitting parameter-constrained models. We describe a Bayesian approach for the fitting of parameter-constrained demographic models, which is the main focus of the paper. We illustrate the Bayesian approach by fitting a parameter-constrained proportional hazards model based on current-status data and a parameter-constrained log-linear regression model for standardized mortality ratios