A Systematic Review and Critical Appraisal of Economic Evaluations of Pharmacological Interventions for People with Bipolar Disorder

Designing and testing of a health-economic Markov model to assess the cost-effectiveness of treatments for Bipolar disorder: TiBipoMod

BACKGROUND

Bipolar disorder is an often recurrent mood disorder that is associated with a significant economic and health-related burden. Increasing the availability of health-economic evidence may aid in reducing this burden. The aim of this study is to describe the design of an open-source health-economic Markov model for assessing the cost-effectiveness of interventions in the treatment of Bipolar Disorders type I and II, TiBipoMod.

METHODS

TiBipoMod is a decision-analytic Markov model that allows for user-defined incorporation of both pharmacological and non-pharmacological interventions for the treatment of BD. TiBipoMod includes the health states remission, depression, (hypo)mania and death. Costs and effects are modeled over a lifetime horizon from a societal and healthcare perspective, and results are presented as the total costs, Quality-Adjusted Life Years (QALY), Life Years (LY), and incremental costs per QALYs and LYs gained.

RESULTS

Functionalities of TiBipoMod are demonstrated by performing a cost-utility analysis of mindfulness-based cognitive therapy (MBCT) compared to the standard of care. Treatment with MBCT resulted in an increase of 0.18 QALYs per patient, and a dominant incremental cost-effectiveness ratio per QALY gained for MBCT at a probability of being cost-effective of 71% when assuming a €50,000 willingness-to-pay threshold.

CONCLUSION

TiBipoMod can easily be adapted and used to determine the cost-effectiveness of interventions in the treatment in Bipolar Disorder type I and II, and is freely available for academic purposes upon request at the authors.

Economic Evaluations of Child Nutrition Interventions in Low- and Middle-Income Countries: Systematic Review and Quality Appraisal

Economic evaluation is crucial for cost-effective resource allocation to improve child nutrition in low and middle-income countries (LMICs). However, the quality of published economic evaluations in these settings is not well understood. This systematic review aimed to assess the quality of existing economic evaluations of child nutrition interventions in LMICs and synthesize the study characteristics and economic evidence. We searched 9 electronic databases, including MEDLINE, with the following concepts: economic evaluation, children, nutrition, and LMICs. All types of interventions addressing malnutrition, including stunting, wasting, micronutrient deficiency, and overweight, were identified. We included economic evaluations that examined both costs and effects published in English peer-reviewed journals and used the Drummond checklist for quality appraisal. We present findings through a narrative synthesis. Sixty-nine studies with diverse settings, perspectives, time horizons, and outcome measures were included. Most studies used data from sub-Saharan Africa and South Asia and addressed undernutrition. The mortality rate, intervention effect, intervention coverage, cost, and discount rate were reported as predictors among studies that performed sensitivity analyses. Despite the heterogeneity of included studies and the possibility of publication bias, 81% of included studies concluded that nutrition interventions were cost-effective or cost-beneficial, mostly based on a country's cost-effectiveness thresholds. Regarding quality assessment, the studies published after 2016 met more criteria than studies published before 2016. Most studies had well-stated research questions, forms of economic evaluation, interventions, and conclusions. However, reporting the perspective of the analyses, justification of discount rates, and describing the role of funders and ethics approval were identified as areas needing improvement. The gaps in the quality of reporting could be improved by consolidated guidance on the publication of economic evaluations and the use of appropriate quality appraisal checklists. Strengthening the evidence base for child malnutrition across different regions is necessary to inform cost-effective investment in LMICs. Trial registration: PROSPERO CRD42020194445.

Appraisal of patient-level health economic models of severe mental illness: systematic review

BACKGROUND

Healthcare decision makers require accurate long-term economic models to evaluate the cost-effectiveness of new mental health interventions.

AIMS

To assess the suitability of current patient-level economic models to estimate long-term economic outcomes in severe mental illness.

METHOD

We undertook pre-specified systematic searches in MEDLINE, Embase and PsycINFO to identify reviews and stand-alone publications of economic models of interventions for schizophrenia, bipolar disorder and major depressive disorder (PROSPERO: CRD42020158243). We screened paper titles and abstracts to identify unique patient-level economic models. We conducted a structured extraction of identified models, recording the presence of key predefined model features. Model quality and validation were appraised using the 2014 ISPOR and 2016 AdViSHE model checklists.

RESULTS

We identified 15 unique patient-level models for psychosis and major depressive disorder from 1481 non-duplicate records. Models addressed schizophrenia (n = 6), bipolar disorder (n = 2) and major depressive disorder (n = 7). The predominant model type was discrete event simulation (n = 9). Model complexity and incorporation of patient heterogeneity varied considerably, and only five models extrapolated costs and outcomes over a lifetime horizon. Key model parameters were often based on low-quality evidence, and checklist quality assessment revealed weak model verification procedures.

CONCLUSIONS

Existing patient-level economic models of interventions for severe mental illness have considerable limitations. New modelling efforts must be supplemented by the generation of good-quality, contemporary evidence suitable for model building. Combined effort across the research community is required to build and validate economic extrapolation models suitable for accurately assessing the long-term value of new interventions from short-term clinical trial data.

Economic evaluations of non-pharmacological interventions and cost-of-illness studies in bipolar disorder: A systematic review

Background Bipolar disorder (BD) is associated with substantial societal burden. Therefore, economic studies in BD are becoming increasingly important. The goal of the current study is three-fold: (1) summarize the evidence regarding economic evaluations (EEs) of non-pharmacological interventions for BD, (2) summarize cost-of-illness studies (COIs) for BD published 2012 or later and (3) assess the quality of the identified studies. Methods A systematic search was conducted in MedLine, EMBASE and PsycINFO. For both EEs and COIs, quality assessments were conducted and general and methodological characteristics of the studies were extracted. Outcomes included incremental-cost-effectiveness ratios for EEs and direct and indirect costs for COIs. Results Eight EEs and ten COIs were identified. The included studies revealed high heterogeneity in general and methodological characteristics and study quality. All interventions resulted in improved clinical outcomes. Five studies additionally concluded decreased total costs. For COIs, we found a wide range of direct ($881-$27,617) and indirect cost estimates per capita per year ($1,568-$116,062). Limitations High heterogeneity in terms of interventions, study design and outcomes made it difficult to compare results across studies. Conclusions Interventions improved clinical outcomes in all studies and led to cost-savings in five studies. Findings suggest that non-pharmacological intervention for BD might be cost-effective. Studies on the costs of BD revealed that BD has a substantial economic burden. However, we also found that the number of EEs was relatively low and methodology was heterogenous and therefore encourage future research to widen the body of knowledge in this research field and use standardized methodology.

Cost–effectiveness of long-acting injectable aripiprazole once-monthly 400 mg in bipolar I disorder in the USA

Aim: To evaluate the cost–effectiveness of aripiprazole once-monthly 400/300 mg (AOM 400) in maintenance monotherapy treatment of bipolar I disorder (BP-I). Methods: A de novo lifetime Markov model was developed for BP-I using available data for AOM 400 and relevant comparators. Base-case analysis considered costs and outcomes from the US payer perspective. Results: The cost per quality-adjusted life year gained with AOM 400 versus comparators ranged from US$2007 versus oral asenapine to dominance (i.e., lower cost with quality-adjusted life gain) versus long-acting injectable risperidone, paliperidone palmitate, oral cariprazine and best supportive care. Patients treated with AOM 400 were estimated to have fewer mood episodes and hospitalizations per patient (5.37) than comparators (6.33, asenapine or cariprazine; 6.54, risperidone long-acting injectable; 7.64, paliperidone palmitate; and 8.93, best supportive care). Sensitivity analyses showed results were robust to parameter uncertainty. Conclusion: AOM 400 may be considered cost effective in the maintenance monotherapy treatment of BP-I in adults.

Vitamin D supplementation in bipolar depression: A double blind placebo controlled trial

OBJECTIVE

Bipolar depression is difficult to treat. Vitamin D supplementation is well tolerated and may improve mood via its neurotransmitter synthesis regulation, nerve growth factor enhancement and antioxidant properties. Vitamin D adjunct reduces unipolar depression, but has not been tried in bipolar depression.

METHODS

18-70yos with DSM IV bipolar depression and Vitamin D deficiency (<30 ng/ml) were randomized in a controlled double blind trial of 5000IU Vitamin D₃ po qday supplementation versus placebo for twelve weeks. Change in Montgomery-Åsberg Depression Rating Scale (MADRS), Hamilton Anxiety Rating Scale (HAM-A), Young Mania Rating Scale (YMRS), medication, and tolerance were assessed q2weeks.

RESULTS

16 VitD vs 17 placebo subjects did not differ in baseline characteristics (mean = 44 yo, SD = 13), VitD level (19.2 ± 65.8  g/ml vs 19.3 ± 5.5 ng/ml respectively) or mood ratings (MADRS 21.3 ± 6.4 vs 22.8 ± 6.9 respectively). At 12wks, the placebo group VitD levels remained unchanged, while the VitD group levels increased to 28 ng/ml. MADRS score decreased significantly in both placebo (mean = 6.42 (95% CI [2.28 to 10.56]) and VitD groups (mean = 9.54 (95% CI[3.51 to 15.56]) (p = 0.031), but there were no differences between treatment groups (time by treatment interaction estimate: 0.29, t₍₂₃₎ = 0.14, p = 0.89); VitD and placebo groups had similar reductions in YMRS and HAM-A. Vitamin D₃ was well tolerated.

CONCLUSIONS

In this small study, despite a greater rise in Vitamin D levels in the VitD supplementation group, there was no significant difference reduction in depressive symptoms. However both groups' VitD levels remained deficient. Vitamin D₃ supplementation vs placebo did not improve reduction in mood elevation or anxiety symptoms.