Modelling the cost-effectiveness of pregabalin versus usual care in daily practice in the treatment of refractory generalised anxiety disorder in Spain

Aligning the many definitions of treatment resistance in anxiety disorders: A systematic review

Anxiety Disorders often show a chronic course, even when treated with one of the various effective treatments available. Lack of treatment effect could be due to Treatment Resistance (TR). Consensus on a definition for TR Anxiety Disorders (TR-AD) is highly needed as currently many different operationalizations are in use. Therefore, generalizability in current TR-AD research is suboptimal, hampering improvement of clinical care. The objective of this review is to evaluate the currently used definitions of TR-AD by performing a systematic review of available literature. Out of a total of n = 13 042, 62 studies that operationalized TR-AD were included. The current review confirms a lack of consensus on TR-AD criteria. In 62.9% of the definitions, TR was deemed present after the first treatment failure. Most studies (93.0%) required pharmacological treatment failures, whereas few (29.0%) required psychological treatment failures. However, criteria for what constitutes "treatment failure" were not provided in the majority of studies (58.1%). Definitions for minimal treatment duration ranged from at least 4 weeks to at least 6 months. Almost half of the TR-AD definitions (46.8%) required elevated anxiety severity levels in TR-AD. After synthesis of the results, the consensus definition considers TR-AD present after both at least one first-line pharmacological and one psychological treatment failure, provided for an adequate duration (at least 8 weeks) with anxiety severity remaining above a specified threshold. This definition could contribute to improving course prediction and identifying more targeted treatment options for the highly burdened subgroup of TR-AD patients.

Cost-effectiveness of interventions for treating anxiety disorders: A systematic review

BACKGROUND

Anxiety disorders are highly prevalent mental disorders that constitute a major burden on patients and society. As a consequence, economic evaluations of the interventions have become increasingly important. However, no recent overview of these economic evaluations is currently available and the quality of the published economic evaluations has not yet been assessed. Therefore, the current study has two aims: to provide an overview of the evidence regarding the cost-effectiveness of interventions for anxiety disorders, and to assess the quality of the studies identified.

METHODS

A systematic review was conducted using PubMed, PsycINFO, NHS-EED, and the CEA registry. We included full economic evaluations on interventions for all anxiety disorders published before April 2016, with no restrictions on study populations and comparators. Preventive interventions were excluded. Study characteristics and cost-effectiveness data were collected. The quality of the studies was appraised using the Consensus on Health Economic Criteria.

RESULTS

Forty-two out of 826 identified studies met the inclusion criteria. The studies were heterogeneous and the quality was variable. Internet-delivered cognitive behavioural therapy (iCBT) appeared to be cost-effective in comparison with the control conditions. Four out of five studies comparing psychological interventions with pharmacological interventions showed that psychological interventions were more cost-effective than pharmacotherapy.

LIMITATIONS

Comparability was limited by heterogeneity in terms of interventions, study design, outcome and study quality.

CONCLUSIONS

Forty-two studies reporting cost-effectiveness of interventions for anxiety disorders were identified. iCBT was cost-effective in comparison with the control conditions. Psychological interventions for anxiety disorders might be more cost-effective than pharmacological interventions.

Clinical and economic outcomes of adjunctive therapy with pregabalin or usual care in generalized anxiety disorder patients with partial response to selective serotonin reuptake inhibitors

BACKGROUND

This study is done to compare the effect of adjunctive therapy with pregabalin versus usual care (UC) on health-care costs and clinical and patients consequences in generalized anxiety disorder (GAD) subjects with partial response (PR) to a previous selective serotonin reuptake inhibitor (SSRI) course in medical practice in Spain.

METHODS

Post hoc analysis of patients with PR to SSRI monotherapy enrolled in a prospective 6-month naturalistic study was done. PR was defined as a Clinical Global Impression (CGI) scale score ≥3 and insufficient response with persistence of anxiety symptoms ≥16 in the Hamilton Anxiety Rating Scale (HAM-A). Two groups were analyzed: 1) adjunctive therapy (AT) with pregabalin (150-600 mg/day) to existing therapy and 2) UC (switching to a different SSRI or adding another anxiolytic different than pregabalin). Costs included GAD-related health-care resources utilization. Consequences were a combination of psychiatrist-based measurements [HAM-A, CGI, and Montgomery-Asberg Depression Rating Scale (MADRS)] and patient-reported outcomes [Medical Outcomes Study Sleep (MOS-sleep) scale, disability (World Health Organization Disability Assessment Schedule II (WHO-DAS II) and quality-of-life (Euro Qol-5D (EQ-5D)]. Changes in both health-care costs and scale scores were compared separately at end-of-trial visit by a general linear model with covariates.

RESULTS

Four hundred eighty-six newly prescribed pregabalin and 239 UC GAD patients [mean (SD) HAM-A 26.7 (6.9) and CGI 4.1 (0.5)] were analyzed. Adding pregabalin was associated with significantly higher mean (95% CI) score reductions vs. UC in HAM-A [-14.9 (-15.6; -14.2) vs. -11.2 (-12.2; -10.2), p < 0.001] and MADRS [-11.6 (-12.2; -10.9) vs. -7.8 (-8.7; -6.8), p < 0.001]. Changes in all patient-reported outcomes favored significantly patients receiving pregabalin, including quality-of-life gain; 26.4 (24.7; 28.1) vs. 19.4 (17.1; 21.6) in the EQ-VAS, p < 0.001. Health-care costs were significantly reduced in both cohorts yielding similar 6-month costs; €1,565 (1,426; 1,703) pregabalin and €1,406 (1,200; 1,611) UC, p = 0.777. The effect of sex on costs and consequences were negligible.

CONCLUSION

In medical practice, GAD patients with PR to SSRI experienced greater consequence improvements with adjunctive therapy with pregabalin versus UC, without increasing health-care cost. The effect of pregabalin was independent of patient gender.

Pregabalin: a review of its use in adults with generalized anxiety disorder

Pregabalin (Lyrica(®)), a well established anxiolytic agent, has been approved in the EU for the treatment of generalized anxiety disorder (GAD) in adults. It has a distinct mechanism of action relative to other anti-anxiety agents (α2δ binding at presynaptic voltage dependent calcium channels leading to inhibition of excitatory neurotransmission), a rapid onset of effect (typically ≤1 week) and broad spectrum activity against both the psychic and somatic symptoms of GAD. In long-term studies, pregabalin maintained improvements in anxiety symptoms that occurred in response to short-term treatment and delayed the time to relapse of GAD compared with placebo. Common comorbidities of GAD, such as insomnia, gastrointestinal symptoms and subsyndromal depression, have no effect on the anxiolytic efficacy of, and moreover are specifically improved by, pregabalin. Treatment with pregabalin is generally well tolerated; the drug has an adverse event profile that includes dizziness, somnolence and weight gain. The potential for abuse of pregabalin is low; the risk of withdrawal symptoms is generally low when the drug is discontinued gradually (over 1 week). Alongside selective serotonin reuptake inhibitors (SSRIs) and serotonin-noradrenaline reuptake inhibitors (SNRIs), pregabalin is considered a first-line agent for the long-term treatment of GAD by the World Federation of Societies of Biological Psychiatry. It should be stressed, however, that definitive head-to-head studies comparing pregabalin with SSRI/SNRIs, including in patients with GAD and co-morbid major depressive disorder, are currently lacking. Recently, a study of SSRI/SNRI augmentation with pregabalin yielded positive results, while another study of switching from long-term benzodiazepine therapy to pregabalin was inconclusive; further investigations on these topics are warranted.

Pharmacoeconomic outcomes for pregabalin: a systematic review in neuropathic pain, generalized anxiety disorder, and epilepsy from a Spanish perspective

INTRODUCTION

Pregabalin is an anticonvulsant approved in Europe for the treatment of neuropathic pain, as an adjunct therapy for epileptic seizures, and recently for generalized anxiety disorder. The aim of this study was to conduct a systematic review to evaluate the cost-effectiveness of pregabalin associated with the treatment of its labeled indications from a societal perspective in Spain.

METHODS

Data from the MEDLINE database were searched using algorithms to identify relevant economic evaluations published in English or Spanish on pregabalin for the management of neuropathic pain, generalized anxiety disorder (GAD), and epilepsy in Spanish patients over the last 10 years.

RESULTS

In total, 52 potentially relevant abstracts were identified from the MEDLINE database. Twenty manuscripts met the inclusion criteria. The majority of the selected papers (14/20) evaluated pregabalin for neuropathic pain from a societal perspective in Spain (5 economic models of pregabalin vs. gabapentin, 4 economic analyses of pregabalin in comparison with usual care, 4 economic evaluations comparing pregabalin monotherapy with add-on strategies, and one that evaluated different times of initiating pregabalin therapy). Five studies analyzed the use of pregabalin in Spain for the management of GAD (one cost-effectiveness model that compared pregabalin with venlafaxine, 2 secondary analyses in benzodiazepine-refractory patients, and 2 studies evaluating pregabalin vs. usual care in patients refractory to standard regimens). The last manuscript described a cost-effectiveness model that compared pregabalin versus levetiracetam use for the treatment of refractory partial epilepsy.

CONCLUSION

The majority of published evidence supports the possibility that pregabalin could be a cost-effective and/or cost-saving alternative for the treatment of refractory epilepsy, GAD, and neuropathic pain, in both treatment-naïve patients and in those who have demonstrated inadequate response or intolerance to previous therapy.