Daniel Pollard

A cluster randomised trial, cost-effectiveness analysis and psychosocial evaluation of insulin pump therapy compared with multiple injections during flexible intensive insulin therapy for type 1 diabetes: the REPOSE Trial

BACKGROUND Insulin is generally administered to people with type 1 diabetes mellitus (T1DM) using multiple daily injections (MDIs), but can also be delivered using infusion pumps. In the UK, pumps are recommended for patients with the greatest need and adult use is less than in comparable countries. Previous trials have been small, of short duration and have failed to control for training in insulin adjustment. OBJECTIVE To assess the clinical effectiveness and cost-effectiveness of pump therapy compared with MDI for adults with T1DM, with both groups receiving equivalent structured training in flexible insulin therapy. DESIGN Pragmatic, multicentre, open-label, parallel-group cluster randomised controlled trial, including economic and psychosocial evaluations. After participants were assigned a group training course, courses were randomly allocated in pairs to either pump or MDI. SETTING Eight secondary care diabetes centres in the UK. PARTICIPANTS Adults with T1DM for > 12 months, willing to undertake intensive insulin therapy, with no preference for pump or MDI, or a clinical indication for pumps. INTERVENTIONS Pump or MDI structured training in flexible insulin therapy, followed up for 2 years. MDI participants used insulin analogues. Pump participants used a Medtronic Paradigm® VeoTM (Medtronic, Watford, UK) with insulin aspart (NovoRapid, Novo Nordisk, Gatwick, UK). MAIN OUTCOME MEASURES Primary outcome - change in glycated haemoglobin (HbA1c) at 2 years in participants whose baseline HbA1c was ≥ 7.5% (58 mmol/mol). Key secondary outcome - proportion of participants with HbA1c ≤ 7.5% at 2 years. Other outcomes at 6, 12 and 24 months - moderate and severe hypoglycaemia; insulin dose; body weight; proteinuria; diabetic ketoacidosis; quality of life (QoL); fear of hypoglycaemia; treatment satisfaction; emotional well-being; qualitative interviews with participants and staff (2 weeks), and participants (6 months); and ICERs in trial and modelled estimates of cost-effectiveness. RESULTS We randomised 46 courses comprising 317 participants: 267 attended a Dose Adjustment For Normal Eating course (132 pump; 135 MDI); 260 were included in the intention-to-treat analysis, of which 235 (119 pump; 116 MDI) had baseline HbA1c of ≥ 7.5%. HbA1c and severe hypoglycaemia improved in both groups. The drop in HbA1c% at 2 years was 0.85 on pump and 0.42 on MDI. The mean difference (MD) in HbA1c change at 2 years, at which the baseline HbA1c was ≥ 7.5%, was -0.24% [95% confidence interval (CI) -0.53% to 0.05%] in favour of the pump (p = 0.098). The per-protocol analysis showed a MD in change of -0.36% (95% CI -0.64% to -0.07%) favouring pumps (p = 0.015). Pumps were not cost-effective in the base case and all of the sensitivity analyses. The pump group had greater improvement in diabetes-specific QoL diet restrictions, daily hassle plus treatment satisfaction, statistically significant at 12 and 24 months and supported by qualitative interviews. LIMITATION Blinding of pump therapy was not possible, although an objective primary outcome was used. CONCLUSION Adding pump therapy to structured training in flexible insulin therapy did not significantly enhance glycaemic control or psychosocial outcomes in adults with T1DM. RESEARCH PRIORITY To understand why few patients achieve a HbA1c of < 7.5%, particularly as glycaemic control is worse in the UK than in other European countries. TRIAL REGISTRATION Current Controlled Trials ISRCTN61215213. 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. 21, No. 20. See the NIHR Journals Library website for further project information.

Incorporating Psychological Predictors of Treatment Response into Health Economic Simulation Models: A Case Study in Type 1 Diabetes

Background. Health economic modeling has paid limited attention to the effects that patients’ psychological characteristics have on the effectiveness of treatments. This case study tests 1) the feasibility of incorporating psychological prediction models of treatment response within an economic model of type 1 diabetes, 2) the potential value of providing treatment to a subgroup of patients, and 3) the cost-effectiveness of providing treatment to a subgroup of responders defined using 5 different algorithms. Methods. Multiple linear regressions were used to investigate relationships between patients’ psychological characteristics and treatment effectiveness. Two psychological prediction models were integrated with a patient-level simulation model of type 1 diabetes. Expected value of individualized care analysis was undertaken. Five different algorithms were used to provide treatment to a subgroup of predicted responders. A cost-effectiveness analysis compared using the algorithms to providing treatment to all patients. Results. The psychological prediction models had low predictive power for treatment effectiveness. Expected value of individualized care results suggested that targeting education at responders could be of value. The cost-effectiveness analysis suggested, for all 5 algorithms, that providing structured education to a subgroup of predicted responders would not be cost-effective. Limitations. The psychological prediction models tested did not have sufficient predictive power to make targeting treatment cost-effective. The psychological prediction models are simple linear models of psychological behavior. Collection of data on additional covariates could potentially increase statistical power. Conclusions. By collecting data on psychological variables before an intervention, we can construct predictive models of treatment response to interventions. These predictive models can be incorporated into health economic models to investigate more complex service delivery and reimbursement strategies.

Computer modeling of diabetes and its transparency: A report on the Eighth Mount Hood Challenge

Objectives: The Eighth Mount Hood Challenge (held in St. Gallen, Switzerland, in September 2016) evaluated the transparency of model input documentation from two published health economics studies and developed guidelines for improving transparency in the reporting of input data underlying model-based economic analyses in diabetes. Methods: Participating modeling groups were asked to reproduce the results of two published studies using the input data described in those articles. Gaps in input data were filled with assumptions reported by the modeling groups. Goodness of fit between the results reported in the target studies and the groups’ replicated outputs was evaluated using the slope of linear regression line and the coefficient of determination (R2). After a general discussion of the results, a diabetes-specific checklist for the transparency of model input was developed. Results: Seven groups participated in the transparency challenge. The reporting of key model input parameters in the two studies, including the baseline characteristics of simulated patients, treatment effect and treatment intensification threshold assumptions, treatment effect evolution, prediction of complications and costs data, was inadequately transparent (and often missing altogether).Not surprisingly, goodness of fit was better for the study that reported its input data with more transparency. To improve the transparency in diabetes modeling, the Diabetes Modeling Input Checklist listing the minimal input data required for reproducibility in most diabetes modeling applications was developed. Conclusions: Transparency of diabetes model inputs is important to the reproducibility and credibility of simulation results. In the Eighth Mount Hood Challenge, the Diabetes Modeling Input Checklist was developed with the goal of improving the transparency of input data reporting and reproducibility of diabetes simulation model results.

Ibrutinib for Treating Relapsed or Refractory Mantle Cell Lymphoma: An Evidence Review Group Perspective of a NICE Single Technology Appraisal

As part of its Single Technology Appraisal process, the UK National Institute for Health and Care Excellence (NICE) invited the manufacturer of ibrutinib (Janssen) to submit evidence on the clinical effectiveness and cost effectiveness of ibrutinib for the treatment of relapsed or refractory (R/R) mantle cell lymphoma (MCL). The School of Health and Related Research Technology Assessment Group at the University of Sheffield was commissioned to act as the independent Evidence Review Group (ERG). The ERG produced a critical review of the evidence contained within the company’s submission to NICE. The clinical effectiveness evidence for ibrutinib included one randomised controlled trial comparing ibrutinib and temsirolimus and two single-arm studies. The company’s indirect comparison of ibrutinib versus rituximab plus chemotherapy (R-chemo) produced a hazard ratio (HR) for progression-free survival (PFS) of 0.28. The ERG’s random effects network meta-analysis (NMA) indicated that the treatment effect on PFS was highly uncertain (HR 0.27; 95% credible interval (CrI) 0.06–1.26). The company’s Markov model assessed the cost effectiveness of ibrutinib versus R-chemo for the treatment of R/R MCL from the perspective of the National Health Service (NHS) and Personal Social Services over a lifetime horizon. Based on a re-run of the company’s model by the ERG, the incremental cost-effectiveness ratio (ICER) for ibrutinib versus R-chemo [including the company’s original patient access scheme (PAS)] was expected to be £76,014 per quality-adjusted life-year (QALY) gained. The ERG had several concerns regarding the company’s model structure and the evidence used to inform its parameters. The ERG’s preferred analysis, which used the ERG’s NMA and the observed Kaplan–Meier curve for time to ibrutinib discontinuation and excluded long-term disutilities for R-chemo, produced ICERs of £63,340 per QALY gained for the overall R/R MCL population and of £44,711 per QALY gained for patients with one prior treatment. Following an updated PAS and consideration of evidence from a later data-cut of the RAY trial, the appraisal committee concluded that the most plausible ICER for the one prior treatment subgroup was likely to be lower than the company’s estimate of £49,848 per QALY gained. The company’s ICER for the overall R/R MCL population was higher, at £62,650 per QALY gained. The committee recommended ibrutinib as an option for treating R/R MCL in adults only if they have received only one previous line of therapy and the company provides ibrutinib with the discount agreed in the commercial access agreement with NHS England.

Selecting pregnant or postpartum women with suspected pulmonary embolism for diagnostic imaging: the DiPEP diagnostic study with decision-analysis modelling

BACKGROUND Pulmonary embolism (PE) is a leading cause of death in pregnancy and post partum, but the symptoms of PE are common in normal pregnancy. Simple diagnostic tests are needed to select women for diagnostic imaging. OBJECTIVE To estimate the accuracy, effectiveness and cost-effectiveness of clinical features, decision rules and biomarkers for selecting pregnant or postpartum women with a suspected PE for imaging. DESIGN An expert consensus study to develop new clinical decision rules, a case-control study of women with a diagnosed PE or a suspected PE, a biomarker study of women with a suspected PE or diagnosed deep-vein thrombosis (DVT) and decision-analysis modelling. SETTING Emergency departments and consultant-led maternity units. PARTICIPANTS Pregnant/postpartum women with a diagnosed PE from any hospital reporting to the UK Obstetric Surveillance System research platform and pregnant/postpartum women with a suspected PE or diagnosed DVT at 11 prospectively recruiting sites. INTERVENTIONS Clinical features, decision rules and biomarkers. MAIN OUTCOME MEASURES Sensitivity, specificity, area under receiver operating characteristic (AUROC) curve, quality-adjusted life-years (QALYs) and health-care costs. RESULTS The primary analysis involved 181 women with PE and 259 women without PE in the case-control study and 18 women with DVT, 18 with PE and 247 women without either in the biomarker study. Most clinical features showed no association with PE. The AUROC curves for the clinical decision rules were as follows: primary consensus, 0.626; sensitive consensus, 0.620; specific consensus, 0.589; PE rule-out criteria, 0.621; simplified Geneva score, 0.579; Wellss PE criteria (permissive), 0.577; and Wellss PE criteria (strict), 0.732. The sensitivities and specificities of the D-dimer measurement were 88.4% and 8.8%, respectively, using a standard threshold, and 69.8% and 32.8%, respectively, using a pregnancy-specific threshold. Previous venous thromboembolism, long-haul travel, multiple pregnancy, oxygen saturation, recent surgery, temperature and PE-related chest radiograph abnormality were predictors of PE on multivariable analysis. We were unable to derive a rule through multivariable analysis or recursive partitioning with adequate accuracy. The AUROC curves for the biomarkers were as follows: activated partial thromboplastin time - 0.669, B-type natriuretic peptide - 0.549, C-reactive protein - 0.542, Clauss fibrinogen - 0.589, enzyme-linked immunosorbent assay D-dimer - 0.668, Innovance D-dimer (Siemens Healthcare Diagnostics Products GmbH, distributed by Sysmex UK Ltd, Milton Keynes, UK) - 0.651, mid-regional pro-atrial natriuretic peptide (MRproANP) - 0.524, prothrombin fragment 1 + 2 - 0.562, plasmin-antiplasmin - 0.639, Prothombin time - 0.613, thrombin generation lag time - 0.702, thrombin generation endogenous potential - 0.559, thrombin generation peak - 0.596, thrombin generation time to peak - 0.655, tissue factor - 0.531 and troponin - 0.597. The repeat analysis excluding women who had received anticoagulation was limited by the small number of women with PE (n = 4). The health economic analysis showed that a strategy of scanning all women with a suspected PE accrued more QALYs and incurred fewer costs than any selective strategy based on a clinical decision rule and was therefore the dominant strategy. LIMITATIONS The findings apply specifically to the diagnostic assessment of women with a suspected PE in secondary care. CONCLUSIONS Clinical features, decision rules and biomarkers do not accurately, effectively or cost-effectively select pregnant or postpartum women with a suspected PE for diagnostic imaging. FUTURE WORK New diagnostic technologies need to be developed to detect PE in pregnancy. TRIAL REGISTRATION Current Controlled Trials ISRCTN21245595. FUNDING DETAILS 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. 22, No. 47. See the NIHR Journals Library website for further project information.

Cost-effectiveness of insulin pumps compared with multiple daily injections both provided with structured education for adults with type 1 diabetes: A health economic analysis of the relative effectiveness of pumps over structured education (REPOSE) randomised controlled trial

Objectives To assess the long-term cost-effectiveness of insulin pumps and Dose Adjustment for Normal Eating (pumps+DAFNE) compared with multiple daily insulin injections and DAFNE (MDI+DAFNE) for adults with type 1 diabetes mellitus (T1DM) in the UK. Methods We undertook a cost–utility analysis using the Sheffield Type 1 Diabetes Policy Model and data from the Relative Effectiveness of Pumps over Structured Education (REPOSE) trial to estimate the lifetime incidence of diabetic complications, intervention-based resource use and associated effects on costs and quality-adjusted life years (QALYs). All economic analyses took a National Health Service and personal social services perspective and discounted costs and QALYs at 3.5% per annum. A probabilistic sensitivity analysis was performed on the base case. Further uncertainties in the cost of pumps and the evidence used to inform the model were explored using scenario analyses. Setting Eight diabetes centres in England and Scotland. Participants Adults with T1DM who were eligible to receive a structured education course and did not have a strong clinical indication or a preference for a pump. Intervention Pumps+DAFNE. Comparator MDI+DAFNE. Main outcome measures Incremental costs, incremental QALYs gained and incremental cost-effectiveness ratios (ICERs). Results Compared with MDI+DAFNE, pumps+DAFNE was associated with an incremental discounted lifetime cost of +£18 853 (95% CI £6175 to £31 645) and a gain in discounted lifetime QALYs of +0.13 (95% CI −0.70 to +0.96). The base case mean ICER was £142 195 per QALY gained. The probability of pump+DAFNE being cost-effective using a cost-effectiveness threshold of £20 000 per QALY gained was 14.0%. All scenario and subgroup analyses examined indicated that the ICER was unlikely to fall below £30 000 per QALY gained. Conclusions Our analysis of the REPOSE data suggests that routine use of pumps in adults without an immediate clinical need for a pump, as identified by National Institute for Health and Care Excellence, would not be cost-effective. Trial registration number ISRCTN61215213.

10 Decision analysis modelling of diagnostic strategies for suspected pulmonary embolism in pregnancy: the DiPEP economic evaluation

Background Using diagnostic imaging for suspected pulmonary embolism (PE) in pregnancy involves weighing the benefits, harms and costs of different approaches to selecting women for imaging. Objectives To estimate the effectiveness of diagnostic strategies for PE in pregnancy and postpartum, in terms of adverse outcomes from venous thromboembolism, bleeding and radiation exposure, and cost effectiveness, measured as the incremental cost per quality-adjusted life year (QALY). Methods Decision-analysis modelling was used to estimate costs incurred and expected outcomes from thromboembolism, bleeding and radiation exposure if a hypothetical cohort of pregnant or postpartum women based on the Diagnosis of PE in Pregnancy (DiPEP) study population were investigated for suspected PE using different strategies, including no imaging, selective imaging based on a clinical decision rule and imaging for all. Outcomes were modelled to estimate the quality-adjusted life years (QALYs) accrued by each strategy and the incremental cost per QALY gained by each strategy compared to the next most effective alternative. Threshold analysis explored the parameters required for a hypothetical clinical decision rule to be cost-effective. Results Decision analysis showed that a nonselective strategy of scanning all women with suspected PE accrued more QALYs and incurred fewer costs than any selective strategy based on a clinical decision rule and was therefore the dominant strategy. This finding was robust in sensitivity analysis and scenario analysis exploring assumptions in the model. Threshold analysis showed that a clinical decision rule to select women for imaging would need to have sensitivity exceeding 97.5% to be cost-effective compared to nonselective use of scanning. Figure 1 Conclusion There is little potential for selective imaging based on a clinical decision rule to be cost-effective compared to a strategy of nonselective imaging for all women with suspected PE in pregnancy and postpartum.