Cost-effectiveness of proton-pump inhibitors for maintenance therapy of erosive reflux esophagitis

Barriers and Facilitators to Model Replication Within Health Economics

BACKGROUND

Model replication is important because it enables researchers to check research integrity and transparency and, potentially, to inform the model conceptualization process when developing a new or updated model.

OBJECTIVE

The aim of this study was to evaluate the replicability of published decision analytic models and to identify the barriers and facilitators to replication.

METHODS

Replication attempts of 5 published economic modeling studies were made. The replications were conducted using only publicly available information within the manuscripts and supplementary materials. The replicator attempted to reproduce the key results detailed in the paper, for example, the total cost, total outcomes, and if applicable, incremental cost-effectiveness ratio reported. Although a replication attempt was not explicitly defined as a success or failure, the replicated results were compared for percentage difference to the original results.

RESULTS

In conducting the replication attempts, common barriers and facilitators emerged. For most case studies, the replicator needed to make additional assumptions when recreating the model. This was often exacerbated by conflicting information being presented in the text and the tables. Across the case studies, the variation between original and replicated results ranged from -4.54% to 108.00% for costs and -3.81% to 0.40% for outcomes.

CONCLUSION

This study demonstrates that although models may appear to be comprehensively reported, it is often not enough to facilitate a precise replication. Further work is needed to understand how to improve model transparency and in turn increase the chances of replication, thus ensuring future usability.

Efficiency of potent gastric acid inhibition

The evidence regarding the efficiency of potent gastric acid inhibition is exposed after a systematic search and a critical evaluation of its quality, using a specific score. The aim was to review alternative options, in economic terms, especially related with gastro-oesophageal reflux disease. The results show that the superiority of the proton pump inhibitors over the histamine H2 receptor antagonist is clear in moderate and severe oesophagitis and in patients with persistent or severe symptoms. This evidence is clearly related with the intensity of the gastric inhibition. An associated benefit is the improvement of the quality of life obtained with this potent gastric acid inhibition profile.

Cost-effectiveness comparison of current proton-pump inhibitors to treat gastro-oesophageal reflux disease in the UK

OBJECTIVE

Gastro-oesophageal reflux disease (GORD) is a recurring condition with many patients requiring long-term maintenance therapy. Therefore initial choice of treatment has long-term cost implications. The aim was to compare the costs and effectiveness of treatment of GORD the (unconfirmed by endoscopy) with seven proton pump inhibitors (PPIs: esomeprazole, lansoprazole (capsules and oro-dispersible tablets), omeprazole (generic and branded), pantoprazole and rabeprazole), over one year.

DESIGN AND METHODS

A treatment model was developed of 13 interconnected Markov models incorporating acute treatment of symptoms, long-term therapy and subsequent decisions to undertake endoscopy to confirm diagnosis. Patients were allowed to stop treatment or to receive maintenance treatment either continuously or on-demand depending on response to therapy. Long-term dosing schedule (high dose or step-down dose) was based on current market data. Efficacy of treatments was based on clinical trials and follow-up studies, while resource use patterns were determined by a panel of physicians.

MAIN OUTCOME MEASURES

The model predicts total expected annual costs, number of symptom-free days and quality-adjusted life-years (QALY).

RESULTS

Generic omeprazole and rabeprazole dominated (i.e. cost less and resulted in more symptom-free days and higher QALY gains) the other PPIs. Rabeprazole had a favourable cost-effectiveness ratio of 3.42 pounds per symptom-free day and 8308 pounds/quality-adjusted life-year gained when compared with generic omeprazole. Rabeprazole remained cost-effective independent of choice of maintenance treatment (i.e. proportion of patients remaining on continuous treatment versus on-demand treatment).

CONCLUSIONS

Economic models provide a useful framework to evaluate PPIs in realistic clinical scenarios. Our findings show that rabeprazole is cost-effective for the treatment of GORD.

Review of rabeprazole in the treatment of gastro-oesophageal reflux disease

Gastro-oesophageal reflux disease (GERD) is an increasing health problem in developed countries and is associated with enormous costs in terms of reduced quality of life, loss of productivity, health expenses and mortality. The gastrointestinal disease with the highest annual direct costs in the US (in the year 2000) was GERD (9.3 billion US dollars). GERD is primarily a motility disorder of the oesophagus, however, there are no available promotility drugs on the market. The main symptoms are heartburn and acid regurgitation arising from the reflux of gastric acid, which is the only factor at present suited for pharmacological intervention. The proton pump inhibitors (PPIs) give optimal benefit in the treatment of GERD. The sales of PPIs in the year 2002 amounted to 12 billion US dollars in North America and 4 billion US dollars in Europe and the sales have been increasing by > 10% annually. This paper reviews the use of PPIs in the treatment of GERD with particular focus on one of the newer agents, rabeprazole.

A pharmacoeconomic comparison of the efficacy and costs of pantoprazole and omeprazole for the treatment of peptic ulcer or gastroesophageal reflux disease in The Netherlands

BACKGROUND

The focus of treatment of patients with peptic ulcer or gastroesuphageal reflux disease has changed during the last 15 years, with a shift from histamine2-receptor antagonists to proton-pump inhibitors (PPIs). From 1993 to 2000, expenditures for omeprazole (90% of total market share of PPIs) increased in The Netherlands from 68 million euros to 230 million euros. In 1999, expenditures for pantoprazole accounted for the majority of the rest of the market share for PPIs.

OBJECTIVE

The objective of this study was to compare the efficacy and costs of treatment with pantoprazole and omeprazole in The Netherlands.

METHODS

First, we reviewed clinical studies that compared the efficacy of different dosages of omeprazole and pantoprazole. Second, we analyzed data from a nationwide database of drug prescriptions to determine the dosages used in daily practice in 1999. The data were based on a representative sample of approximately 40% of the Dutch community pharmacies. Third, we modeled the outcome of potential substitution of pantoprazole for omeprazole and the corresponding scenarios for nationwide cost savings using the prescription information from the nationwide database. Potential savings within the Dutch health care system were estimated.

RESULTS

The 1999 prescription data indicated that pantoprazole treatment cost a mean 1.59 euros/d, compared with 2.12 euros/d for omeprazole (1.00 euro = 1.0487 US dollars). The mean cost per defined daily dose of omeprazole was 1.65 euros, compared with 1.59 euros for pantoprazole. Following the summary of product characteristics, treatment with pantoprazole appeared to be less costly for all indications. The projected annual cost savings for substituting pantoprazole for omeprazole on 90% of treatment days were estimated at 40.8 million euros. However, these projected savings may be offset by the costs of switching and the costs of upward dose adjustments that some patients may require.

CONCLUSIONS

Based on the available documentation about effectiveness and costs of omeprazole and pantoprazole, pantoprazole may provide a more favorable pharmacoeconomic profile than omeprazole. However, this is only true if the substitution of omeprazole by pantoprazole can be achieved without loss of efficacy or tolerability.

Rabeprazole: an update of its use in acid-related disorders

Rabeprazole is an inhibitor of the gastric proton pump. It causes dose-dependent inhibition of acid secretion. In 8-week studies, among patients with gastro-oesophageal reflux disease (GORD), rabeprazole 20 mg/day or 10mg twice daily was as effective as omeprazole and superior to ranitidine in the healing of GORD. Symptom relief with rabeprazole was superior to that provided by placebo and ranitidine and similar to omeprazole. In long-term trials rabeprazole 10 mg/day was similar to omeprazole 20 mg/day in a 2-year study and superior to placebo in 1-year studies, in both the maintenance of healing and prevention of symptoms in patients with healed GORD. In nonerosive GORD, 4-week studies have shown rabeprazole to be more effective than placebo in relieving heartburn and various other gastrointestinal symptoms. Data among patients with Barrett's oesophagus suggest rabeprazole 20 mg/day may be more effective than placebo in maintaining healing of associated oesophagitis after 1 year of treatment. One-week triple Helicobacter pylori eradication therapy with rabeprazole plus clarithromycin and amoxicillin achieved eradication rates of > or =85%. Rabeprazole is as effective as omeprazole and lansoprazole when included as part of a triple-therapy regimen for the eradication of H. pylori. Eradication rates of >90% were achieved when rabeprazole 20 to 40 mg/day was included as part of a quadruple eradication regimen. As monotherapy for peptic ulcer healing and symptom relief, 4- to 8-week studies have shown rabeprazole 10 to 40 mg/day to be superior to placebo and ranitidine and have similar efficacy to omeprazole. Preliminary 1-year data among 16 patients with Zollinger-Ellison syndrome suggest rabeprazole 60 to 120 mg/day can resolve and prevent the recurrence of symptoms and endoscopic lesions associated with this condition. In clinical trials of up to 2 years' duration the tolerability of rabeprazole is similar to that of placebo, ranitidine and omeprazole. Common adverse events assigned to rabeprazole have been diarrhoea, headache, rhinitis, nausea, pharyngitis and abdominal pain. Histological changes and increases in serum gastrin levels were unremarkable and typical of proton pump inhibitors. No dosage adjustment is necessary in renal and mild to moderate hepatic impairment.

CONCLUSION

Rabeprazole is a well tolerated proton pump inhibitor. It has proven efficacy in healing, symptom relief and prevention of relapse of peptic ulcers and GORD and can form part of effective H. pylori eradication regimens. It is an important alternative to H(2) antagonists and an additional treatment option to other proton pump inhibitors in the management of acid-related disorders.

[Evaluation of efficacy, safety and tolerability rabeprazole in treatment of acid-peptic diseases ]

BACKGROUND

Rabeprazole, a substituted benzimidazole, represents a new generation of proton pump inhibitors that has recently been approved by the FDA and European Union for treatment of acid-related diseases.

OBJECTIVES

To assess the efficacy and tolerability of rabeprazole 20 mg in actual conditions of use in everyday clinical practice on subjects with diagnosis of erosive gastroesophageal reflux disease and/or gastric and/or duodenal ulcer.

PATIENTS/METHODS

A total of 171 outpatients (55% men, 45% women) with a mean age of 42.5 years were enrolled in this trial. The majority of subjects (81.0%) were Caucasians. Patients with endoscopically confirmed erosive/ulcerative gastroesophageal reflux disease (Savary-Miller classification), duodenal ulcer and/or benign gastric ulcer were eligible to receive rabeprazole 20 mg once daily for 4 to 8 weeks, depending on the diagnosis and at investigators' discretion. Patients were requested to record their symptoms in a diary card in a daily basis.

RESULTS

One hundred and sixty two patients completed the study in accordance with the protocol. Reflux esophagitis was diagnosed in 78 (48.1%) patients, duodenal ulcer in 39 (24.1%) and gastric ulcer in 24 (14.8%). Eleven (6.8%) patients presented reflux esophagitis associated with duodenal ulcer and 7 (4.3%) associated with gastric ulcer. Finally, 3 (1.9%) presented both gastric and duodenal ulcer. Fifty-three percentage of patients were free of symptoms on the first day of treatment and 89.5% after a week. The healing rate was 84.4% for patients with reflux esophagitis, 90.6% for duodenal ulcer and 90.9% for gastric ulcer. The adverse effects were minimal and transitory.

CONCLUSIONS

Rabeprazole is highly effective and well tolerated in acute healing of reflux esophagitis and peptic ulcers. In addition, it provides fast symptoms relief.