Performance of the UK Prospective Diabetes Study Outcomes Model 2 in a Contemporary UK Type 2 Diabetes Trial Cohort

Bariatric Surgery for Adults With Class I Obesity and Difficult-to-Manage Type 2 Diabetes: A Health Technology Assessment

Background

Many individuals with type 2 diabetes are classified as either overweight or obese. A patient may be described as having difficult-to-manage type 2 diabetes if their HbA1c levels remain above recommended target levels, despite efforts to treat it with lifestyle changes and pharmacotherapy. Bariatric surgery refers to procedures that modify the gastrointestinal tract. In patients with class II or III obesity, bariatric surgery has resulted in substantial weight loss, improved quality of life, reduced mortality risk, and resolution of type 2 diabetes. There is some evidence suggesting these outcomes may also be possible for patients with class I obesity as well. We conducted a health technology assessment of bariatric surgery for adults with class I obesity and difficult-to-manage type 2 diabetes, which included an evaluation of effectiveness, safety, cost-effectiveness, the budget impact of publicly funding bariatric surgery, and patient preferences and values.

Methods

We performed a systematic clinical literature review. We assessed the risk of bias of each included study, using the Cochrane Risk of Bias tool for randomized controlled trials, the Risk of Bias in Non-randomized Studies - of Interventions (ROBINS-I) tool for cohort studies, and the Risk of Bias in Systematic Reviews (ROBIS) tool for systematic reviews; we assessed the quality of the body of evidence according to the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) Working Group criteria. We performed a systematic economic literature review and conducted a cost-utility analysis of bariatric surgery in comparison with nonsurgical usual care over a lifetime horizon from a public payer perspective. We also analyzed the budget impact of publicly funding bariatric surgery for adults with class I obesity and difficult-to-manage type 2 diabetes in Ontario. To contextualize the potential value of bariatric surgery, we spoke with people with obesity and type 2 diabetes who had undergone or were considering this procedure.

Results

We included 14 studies in the clinical evidence review. There were large increases in diabetes remission rates (GRADE: Low to Very low) and large reductions in body mass index (GRADE: Low to Very low) with bariatric surgery than with medical management. Bariatric surgery may also reduce the use of medications for type 2 diabetes (GRADE: Low) and may improve quality of life for people with class I obesity and difficult-to-manage type 2 diabetes compared with medical management. (GRADE: Low)Our economic evidence review included 5 cost-effectiveness studies; none were conducted in a Canadian setting, and 4 were considered partially applicable to our research question. Most studies found bariatric surgery to be cost-effective compared to standard care for patients with class I obesity and type 2 diabetes; however, the applicability of these results to the Ontario context is uncertain due to potential differences in clinical practice, resource utilization, and unit costs.Our primary economic evaluation found that over a lifetime horizon, bariatric surgery was more costly (incremental cost: $8,151 per person) but also more effective than current usual care (led to a 0.339 quality-adjusted life-year [QALY] gain per person). The cost increase was driven by costs associated with surgery (before, after, and during surgery), and the QALY gain was due to life-years gained. Results were sensitive to the bariatric surgery cost and assumptions regarding its long-term benefits with respect to weight loss and diabetes remission.Publicly funding 50 bariatric surgeries in year 1, and gradually increasing to 250 surgeries in year 5, for people with class I obesity and difficult-to-manage type 2 diabetes would lead to budget increases of $0.55 million in year 1 to $2.45 million in year 5, for a total of $7.63 million over 5 years.The people with obesity and type 2 diabetes with whom we spoke reported that bariatric surgery was generally seen as a positive treatment option, and those who had undergone the procedure reported positively on its value as a treatment to manage their weight and diabetes.

Conclusions

For adults with class I obesity and difficult-to-manage type 2 diabetes, bariatric surgery may be more clinically effective and cost-effective than medical management. Compared with medical management in people with class I obesity and difficult-to-manage type 2 diabetes, bariatric surgery may result in large increases in diabetes remission rates, large reductions in BMI, and reduced medication use for type 2 diabetes, improved quality of life. Over a lifetime horizon, bariatric surgery led to a cost increase and QALY gain. Bariatric surgery can result in postsurgical complications that are not faced by those receiving medical management. The cost-effectiveness of bariatric surgery depends on its long-term impacts on obesity-related and diabetes-related complications, which could be uncertain.Our budget impact analysis suggests that publicly funding bariatric surgery in Ontario for people with class I obesity and difficult-to-manage type 2 diabetes would lead to a budget increase of $7.63 million over 5 years.For people with obesity and type 2 diabetes, bariatric surgery was seen as a potential positive treatment option to manage their weight and diabetes.

Prognostic models for heart failure in patients with type 2 diabetes: a systematic review and meta-analysis

OBJECTIVE

To provide a systematic review, critical appraisal, assessment of performance and generalisability of all the reported prognostic models for heart failure (HF) in patients with type 2 diabetes (T2D).

METHODS

We performed a literature search in Medline, Embase, Central Register of Controlled Trials, Cochrane Database of Systematic Reviews and Scopus (from inception to July 2022) and grey literature to identify any study developing and/or validating models predicting HF applicable to patients with T2D. We extracted data on study characteristics, modelling methods and measures of performance, and we performed a random-effects meta-analysis to pool discrimination in models with multiple validation studies. We also performed a descriptive synthesis of calibration and we assessed the risk of bias and certainty of evidence (high, moderate, low).

RESULTS

Fifty-five studies reporting on 58 models were identified: (1) models developed in patients with T2D for HF prediction (n=43), (2) models predicting HF developed in non-diabetic cohorts and externally validated in patients with T2D (n=3), and (3) models originally predicting a different outcome and externally validated for HF (n=12). RECODe (C-statistic=0.75 95% CI (0.72, 0.78), 95% prediction interval (PI) (0.68, 0.81); high certainty), TRS-HFDM (C-statistic=0.75 95% CI (0.69, 0.81), 95% PI (0.58, 0.87); low certainty) and WATCH-DM (C-statistic=0.70 95% CI (0.67, 0.73), 95% PI (0.63, 0.76); moderate certainty) showed the best performance. QDiabetes-HF demonstrated also good discrimination but was externally validated only once and not meta-analysed.

CONCLUSIONS

Among the prognostic models identified, four models showed promising performance and, thus, could be implemented in current clinical practice.

The challenges and pitfalls of incorporating evidence from cardiovascular outcomes trials in health economic modelling of type 2 diabetes

The clinical evidence base for evaluating modern type 2 diabetes interventions has expanded greatly in recent years, with numerous efficacious treatment options available (including dipeptidyl peptidase-4 inhibitors, glucagon-like peptide-1 receptor agonists and sodium-glucose cotransporter-2 inhibitors). The cardiovascular safety of these interventions has been assessed individually versus placebo in numerous cardiovascular outcomes trials (CVOTs), statistically powered to detect differences in a composite endpoint of major adverse cardiovascular events. There have been growing calls to incorporate these data in the long-term modelling of type 2 diabetes interventions because current diabetes models were developed prior to the conduct of the CVOTs and therefore rely on risk equations developed in the absence of these data. However, there are numerous challenges and pitfalls to avoid when using data from CVOTs. The primary concerns are around the heterogeneity of the trials, which have different study durations, inclusion criteria, rescue medication protocols and endpoint definitions; this results in significant uncertainty when comparing two or more interventions evaluated in separate CVOTs, as robust adjustment for these differences is difficult. Analyses using CVOT data inappropriately can dilute clear evidence from head-to-head clinical trials, and blur healthcare decision making. Calibration of existing models may represent an approach to incorporating CVOT data into diabetes modelling, but this can only offer a valid comparison of one intervention versus placebo based on a single CVOT. Ideally, model development should utilize patient-level data from CVOTs to prepare novel risk equations that can better model modern therapies for type 2 diabetes.

The WISDOM self-management intervention: A cost-effectiveness analysis to support the transformation of type 2 diabetes care in England

OBJECTIVES

To assess the cost-effectiveness of the WISDOM self-management intervention for type 2 diabetes compared with care as usual.

DESIGN

We performed a difference-in-differences analysis to estimate differences in risk factors for diabetes complications between people in the WISDOM group (n = 25, 276) and a control group (n = 15, 272) using GP records. A decision analytic model was then used to extrapolate differences in risk factors into costs and outcomes in the long term.

SETTING

Participating GP practices in West Hampshire and Southampton, UK.

PARTICIPANTS

All people diagnosed with type 2 diabetes between January 1990 and March 2020 (n = 40,548).

OUTCOMES

Diabetes-related complications, quality-adjusted life years (QALYs) and costs to the English National Health Service at 5 years and lifetime.

INTERVENTIONS

The WISDOM intervention included risk stratification, self-management education programme to professionals and people with type 2 diabetes, and monitoring of key treatment targets.

RESULTS

WISDOM was associated with less atrial fibrillation [p = 0.001], albuminuria [p = 0.002] and blood pressure [p = 0.098]. Among all people in the intervention group, WISDOM led to 51 [95%CI: 25; 76] QALYs gained and saved £278,036 [95%CI: -631,900; 176,392] in the first 5 years after its implementation compared with care as usual. During those people' lifetime, WISDOM led to 253 [95%CI: 75; 404] QALYs gained and cost saving of £126,380 [95%CI: -1,466,008; 1,339,628]. The gains in QALYs were a result of reduced diabetes-related complications through improved management of the associated risk factors.

CONCLUSIONS

The WISDOM risk-stratification and education intervention for type 2 diabetes appear to be cost-effective compared to usual care by reducing diabetes complications.

Insulin degludec/liraglutide versus its monotherapy on T2D patients: A lifetime cost-utility analysis in China

Introduction: IDegLira (brand name Xultophy) is a novel fixed ratio combination of insulin degludec and liraglutide for type 2 diabetes (T2D) patients. This study aimed to investigate the lifetime cost-effective value of IDegLira compared with its single component (Degludec or Liraglutide) and to explore the suitable annual cost of IDegLira if necessary. Methods: UKPDS OM2 was applied to determine the long-term quality-adjusted life years (QALYs) and total costs. The efficacy data that were inputted into the model were synthesized from 6 randomized clinical trials (RCTs) that directly assessed the clinical benefit of IDegLira and its components in the treatment of uncontrolled T2D patients. The economic results were examined by one-way sensitivity analysis (OSA) and probabilistic sensitivity analysis (PSA). Further price reduction of IDegLira was investigated by binary search. Results: The IDegLira, IDeg, and Lira yielded 11.79 QALYs, 11.62 QALYs, and 11.73 QALYs and total cost of $20281.61, $3726.76, and $11941.26, respectively. The incremental cost-utility ratio (ICUR) of IDegLira versus IDeg was $99464.12/QALYs, and the ICUR of IDegLira versus Lira was $143348.26/QALYs, which indicated that IDegLira was not a cost-effective therapy for T2D patients compared with its components at the current price from a Chinese national healthcare system perspective. Base case results were robust to OSA and PSA. A further binary search showed that IDegLira appears to only be cost-effective if the annual cost of IDegLira is decreased by 58% when IDeg is considered as a reference, or by 30.57% when Lira is considered as a reference. Conclusion: In conclusion, IDegLira appears to not be cost-effective when compared with the current prices of IDeg or Lira for T2D patients in China. However, after the binary search, IDegLira appears to only be cost-effective if the annual cost of IDegLira is decreased 58% when IDeg is considered as a reference, or by 30.57% when Lira is considered as a reference.