Assessing the cost-effectiveness of medical treatments in acid-related diseases. The Markov chain approach applied to a comparison between intermittent and maintenance treatment of reflux esophagitis

The role of proton pump inhibitors in the treatment of gastro-oesophageal reflux disease

Efficacy (healing, symptom relief) and cost-effectiveness are the principal reasons for the rapidly increasing use of proton pump inhibitors (PPIs) for the management of gastro-oesophageal reflux disease.

EFFICACY

Mean healing rates pooled from clinical trials are as follows: on omeprazole (OME) 20 mg vs. H2-receptor antagonist. H2RA (cimetidine (CIM) 1.6 g or ranitidine (RAN) 300 mg) (eight studies) at 4 weeks, 67% vs. 37%: at 8 weeks, 81% vs. 49%: on lansoprazole (LAN) 30 mg vs. H2RA (three studies), 83% vs. 47% and 91% vs. 63% at 4 and 8 weeks, respectively. The benefit is greatest in severe disease because the H2RAs are disproportionately less effective. Heartburn is more rapidly relieved and in a higher proportion: at 4 weeks, on OME 20 mg vs. H2RA. 77% vs. 47% and on LAN 30 mg vs. H2RA, 81% vs. 46%. Both PPIs are effective in H2RA-refractory disease, approximately 80% healing occurring in 8 weeks. Relapse rates after healing vary from 25% to 85% at 6 months. Maintenance therapy sustains remissions: relapse at 1 year is, on OME 20 mg vs. RAN 300 mg (2 studies), 12% vs. 79%, and 28% vs. 55% (and 38% on OME 10 mg); on LAN 30 mg vs. 10 mg vs. RAN 600 mg, 20% vs. 31% vs. 68%. The effectiveness of the lower dose allows for dose titration.

COST EFFECTIVENESS

The higher drug costs for the PPIs are offset by their higher efficacy, making their use cost effective, particularly in severe disease. Efficacy and cost effectiveness are likely to further expand the use of PPIs at the expense of H2RAs as increasing numbers of patients with milder disease are treated.

Review article: gastro-oesophageal reflux disease--the health economic implications

For the vast majority of patients with gastro-oesophageal reflux disease appropriate care involves the management of symptoms with lifestyle advice and drugs. However, there is dissension about the appropriate use of endoscopy, whether drugs should be stepped up or down according to potency, how long drugs should be used for, the role of lifestyle advice, and, related to this, the role of patients' lifestyle choices. This exploration of the economics of gastro-oesophageal reflux disease reviews its cost burden to the UK, assesses published economic models for their strengths and weaknesses and examines current recommendations for gastro-oesophageal reflux disease management from a socioeconomic perspective. Drugs prescribed predominantly for dyspepsia cost the UK National Health Service a projected pound sterling 625 million in 2004, 7% of the primary care prescribing budget. When general practitioners consultations, endoscopies, over-the-counter sales and sickness absences are included the UK cost rises to pound sterling 1.5 billion: approximately half of this cost can be ascribed to gastro-oesophageal reflux disease. Emphasis upon regular review and stepping down treatment (while maintaining adequate symptom relief) is both clinically appropriate and resource efficient. Other cost-effectiveness issues largely lack objective answers because investment in treatment for gastro-oesophageal reflux disease depends upon how much more, at the margin, society wishes to invest for further but diminishing symptom relief.

Patient-centred endpoints in economic evaluations of gastro-oesophageal reflux disease

AIM

To perform a systematic review of the economic literature on gastro-oesophageal reflux disease to evaluate (a) the use of patient-centred effectiveness end-points, or (b) the use of patient-centred economic end-points, and the influence of these end-points on the outcome of the model.

METHODS

Three electronic databases (EMBASE, BIOSIS and Medline) were used, together with a manual search of meeting abstracts for relevant articles. The quality of the studies was determined by the Drummond criteria.

RESULTS

Our initial search identified 179 articles and a manual search revealed 78 abstracts and articles. A total of 47 studies (36 fully published articles and 11 abstracts) met the seven Drummond criteria for inclusion in our evaluation.

CONCLUSIONS

This systematic review demonstrates that many of the published economic evaluations available today take the perspective of the third-party payer and focus on pharmaceutical costs relevant to the third-party payer. Our study also demonstrates that there are a number of costs of illness determinations, such that pharmaceutical costs account for only a small proportion of the total costs of managing gastro-oesophageal reflux disease. Future economic analyses should consider an evaluation of the patient's desire for complete symptom relief by including cost-utility assessments or willingness to pay data.

Economic considerations in the treatment of gastroesophageal reflux disease: a review

Gastroesophageal reflux disease is a common problem. Most patients with erosive GERD require long-term treatment, without which relapse is common. The cost of ongoing medical care for GERD is substantial, and patients with symptomatic GERD have impaired quality of life. Treatment strategies for GERD should aim to improve patient outcome at a reasonable cost. Cost-effectiveness methodology facilitates the integration of costs and patient outcomes, enabling the clinician to choose the most cost-effective therapy in a variety of clinical circumstances. The published studies reviewed in this paper show that proton pump inhibitors are the most cost-effective initial and maintenance medical therapy for GERD under most circumstances. However, variations in drug acquisition costs, such as may occur in managed care practice settings, may lead to H2-receptor antagonists being preferred under some circumstances. In the long-term management of GERD, laparoscopic surgery is effective, but its high initial cost makes it less cost-effective than proton pump inhibitors in the early treatment years. Also, recent data suggest that the long-term morbidity is higher than previously suspected. Finally, appropriate application of cost-effectiveness analyses to clinical practice requires critical appraisal of model design and the perspective adopted. The purpose of this article is to describe the interpretation and application of the results of cost-effectiveness analyses in clinical practice, and to examine the published literature on the cost-effectiveness of treatment options for GERD.

Special review: game theory to analyse management options in gastro-oesophageal reflux disease

This study aims to demonstrate the applicability of linear programming to threshold analysis, using, as an example, patients with new onset of gastro-oesophageal reflux disease (GERD). The choice amongst competing management options is modelled as a decision tree, using threshold analysis, as well as an m x n matrix on an Excel spreadsheet. The different options of medical management correspond to the m rows, whilst the different disease states correspond to the n columns of the matrix. Each number at the intersection of a row and a column represents the outcome associated with that particular combination of management and disease state. The threshold values are calculated by the built-in functions for linear programming of Excel using its Solver tool. Varying the cost estimates in the sensitivity analysis translates into solving a set of different matrices. Threshold analysis provides a formalism to phrase problems of medical decision analysis in a concise fashion.

Economic evaluation of Helicobacter pylori eradication for the treatment of duodenal ulcer disease in Japan: a decision analysis to assess eradication strategy in comparison with a conventional strategy

To evaluate the socio-economic effects of Helicobacter pylori eradication in the treatment of duodenal ulcer disease in Japan, a clinical decision analysis was performed to assess H. pylori eradication therapy compared with the conventional strategy of maintenance with histamine-2 receptor antagonists. A decision tree-based state transition model (Markov chain approach) implemented to simulate a 5 year period of follow up was constructed. The H. pylori eradication strategy was found to be superior to the conventional maintenance strategy with regard to clinical effectiveness and other dimensions of a patient's outcome. Furthermore, in a long-term perspective, the eradication strategy was less costly than the maintenance strategy. Helicobacter pylori eradication should be recommended as the first choice treatment of H. pylori-positive duodenal ulcer patients. The clinical implication of H. pylori eradication entails an improvement in clinical effectiveness and other dimensions of a patient's outcome and a significant reduction in the costs of duodenal ulcer treatment. The long-term total costs do not depend on the initial drug cost of an eradication regimen. Pursuing a high eradication rate of H. pylori is essential in improving the patient's outcome and the cost-effectiveness of treatment.

Prevention of recurrences of erosive reflux esophagitis: a cost-effectiveness analysis of maintenance proton pump inhibition

PURPOSE

To determine the cost-effectiveness of three management strategies for healed erosive reflux esophagitis: maintenance therapy with a proton pump inhibitor (PPI) from the outset; no maintenance therapy unless a patient's symptoms recur once over a year; and no maintenance therapy unless a patient's symptoms recur twice over a year.

MATERIALS AND METHODS

Decision analysis using data from randomized trials of lansoprazole, case series, and expert opinion.

RESULTS

For patients with grade 4 esophagitis, maintenance from the outset is the most efficient approach. For all other patients, providing maintenance PPI after a patient experiences two recurrences is the least costly but least effective approach. The other two approaches prevent more recurrences: waiting to initiate maintenance therapy until symptoms recur once requires an additional $73 for each recurrence prevented whereas maintenance PPI from the outset requires an additional $819 for each recurrence prevented. Maintenance therapy from the outset is cost effective if symptoms of esophagitis cause a 22% or greater decrement in quality of life (using $50,000 per quality-adjusted life year gained as a cost-effectiveness definition). However, withholding maintenance until the time of a first recurrence is cost effective if symptoms cause a 2% or greater decrement in quality of life.

CONCLUSION

For grades 2 and 3 esophagitis, providing maintenance therapy after a patient experiences a further recurrence is a preferred option that appears cost-effective across a wide array of assumptions. Maintenance therapy from the outset, however, appears cost-effective only for those patients who report a significant decline in quality of life associated with esophagitis or for those patients with baseline grade 4 esophagitis.

Medical Therapy of GERD: current state of the art

A proton pump inhibitor is the most cost-effective choice for severe disease and, in low doses, for moderate disease. Patients with mild disease and infrequent relapses can be managed with a H2-receptor antagonist, an antacid, or cisapride.

The diagnosis and management of gastroesophageal reflux disease

GERD is a common clinical problem. Generally, its clinical presentation and management are straightforward. Greater awareness of the numerous extraesophageal manifestations of the disease aids patients and physicians in appropriate recognition and treatment. Medical therapy is effective in the majority of cases but often requires long-term medication for acceptable symptom control. A small, but significant proportion of patients presents with or develops complications of GERD, most importantly Barrett's esophagus. Although the logistics of long-term surveillance of persons with Barrett's esophagus is unclear, the association of this metaplastic change with esophageal adenocarcinoma underscores the importance of regular follow-up.