|Decision analysis of Helicobacter pylori eradication therapy using omeprazole with either clarithromycin or amoxicillin
|Craig A M, Davey P, Malek M, Murray F
This is a critical abstract of an economic evaluation that meets the criteria for inclusion on NHS EED. Each abstract contains a brief summary of the methods, the results and conclusions followed by a detailed critical assessment on the reliability of the study and the conclusions drawn.
Helicobacter pylori eradication therapy using omeprazole with either clarithromycin or amoxicillin.
Economic study type
The analysis was carried out for three distinct patient groups: patients with proven duodenal ulcer who were already receiving maintenance treatment with a histamine H2 receptor antagonist, and new patients with dyspepsia who were subdivided into those aged above or below 45 years.
General practice and hospital. The study was carried out in the United Kingdom.
Dates to which data relate
Effectiveness data were collected from a UK national survey, from studies published between 1986 and 1994, and from the 1994 Medical Data Index. Resource use and cost data were taken from the same survey and a 1995 source. The price year was 1995.
Source of effectiveness data
Effectiveness data were collected from a UK national survey of hospital specialists, Family Health Service Authority advisers, and GPs, from published studies, and from the Medical Data Index supplied by Intercontinental Medical Statistics.
A decision analytic model was constructed to identify under which circumstances the additional drug costs would offset the savings from reduced hospital referral.
Outcomes assessed in the review
The review assessed the following outcomes: the pattern of initiation of investigation or eradication therapy for H. pylori infection in general practice or in hospital, the proportion of patients with dyspepsia who have a duodenal ulcer, the probability that a patient with duodenal ulcer is infected with Helicobacter pylori, the probability that a clinical diagnosis of peptic ulcer will be made in a patient with dyspepsia, the probability that a clinical diagnosis of duodenal ulcer is correct, and the effectiveness of eradication regimens.
Study designs and other criteria for inclusion in the review
Data were collected from 502 completed questionnaires sent to UK consultants in gastroenterology, consultants with an interest in gastroenterology, Family Health Service Authority advisers, GPs with an interest in gastroenterology and GPs with no specified interest in gastroenterology. This information was supplemented by published data and data from a medical database.
Sources searched to identify primary studies
Criteria used to ensure the validity of primary studies
Methods used to judge relevance and validity, and for extracting data
The authors used data from individual studies.
Number of primary studies included
Approximately 5 studies were included.
Methods of combining primary studies
Data from individual studies were not combined.
Investigation of differences between primary studies
Results of the review
Therapy for H. pylori infection initiated in general practice consisted of duodenal biopsy (0%), urea breath test (3.6%), serology (14.8%), dual therapy with OA (29.1%), other dual drug regimens (22.9%), standard triple therapy (26.9%), or other triple or quadruple drug regimens (29.1%). Therapy for H. pylori infection initiated in hospital consisted of duodenal biopsy (100%), urea breath test (59.1%), serology (40.6%), dual therapy with OA (16.1%), other dual drug regimens (15.7%), standard triple therapy (33.9%), or other triple or quadruple drug regimens (39.4%). The proportion of patients with dyspepsia who have a duodenal ulcer was 20%. The probability that a patient with duodenal ulcer is infected with Helicobacter pylori was 95%. The probability that a clinical diagnosis of peptic ulcer will be made in a patient with dyspepsia was 34%. The probability that a clinical diagnosis of duodenal ulcer is correct was 57%. Eradication of H. pylori was achieved in 50% of patients who receive OA, compared with 80% in patients who received OC.
Methods used to derive estimates of effectiveness
The principles of management of patients with dyspepsia were discussed with a panel of 9 doctors (7 specialist gastroenterologists and 2 GPs).
Estimates of effectiveness and key assumptions
Serology is the test most likely to be used to diagnose H. pylori in general practice. The OA regimen was the most commonly used eradication therapy in general practice. Eradication therapy does not benefit patients unless they have a duodenal ulcer and are infected with H. pylori. Failure of eradication therapy can be diagnosed and results in referral to hospital. Patients referred to hospital wait for an average of 2.3 months for an appointment, during which time the GP prescribes an H2RA for symptomatic relief.
Measure of benefits used in the economic analysis
Cost savings arising from reduced hospital referrals were used as the measure of benefits.
Costs were not discounted given the short time frame of the study (less than 1 year). Quantities and costs were reported separately. Direct costs included referral and drug costs. The quantity/cost boundary adopted was that of a budget-holding general practice. The estimation of quantities and costs was based on actual data. Referral costs were obtained from the UK national survey. Costs for proprietary and generic products were obtained from the January 1995 issues of Monthly Index of Medical Specialities and Drug Tariff, respectively. The price year was 1995.
Statistical analysis of costs
A one-way sensitivity analysis was conducted on the following parameters: referral with endoscopy, costs, the efficacy of the 2 regimens, the probability of correct clinical diagnosis
Estimated benefits used in the economic analysis
Synthesis of costs and benefits
For patients with dyspepsia and a proven duodenal ulcer who are already receiving maintenance therapy, the expected cost to a GP of prescribing OC is 156.61 and of prescribing OA is 173.18. This result was sensitive to changes in the parameter "referral with endoscopy". For patients aged over 45 years who have dyspepsia, expected costs of prescribing OC and OA would be 349.46 and $334.53, respectively. These results were sensitive to outpatient referral costs, UBT costs, and the efficacy of the 2 regimens. The cost per additional asymptomatic patient after eradication therapy with OC was 50 considering total treatment costs. For patients aged under 45 years who have dyspepsia, expected costs of prescribing OC and OA would be 253.29 and $251.14, respectively. These results were sensitive to the cost estimates and the probability of correct clinical diagnosis. The cost per additional asymptomatic patient after eradication therapy with OC was 13 considering total treatment costs.
The model clearly shows that the higher drug cost of OC is likely to be substantially offset by savings in other healthcare costs. If the direct healthcare costs of OC are higher than OA, then the decision-maker must consider the indirect and intangible costs associated with failure of eradication therapy.
CRD COMMENTARY - Selection of comparators
rationale for the choice of the comparator was clear. You, as a user of this database, should verify whether these health technologies are relevant to your setting.
Validity of estimate of measure of benefit
results critically depend on some of the assumptions, such as the efficacy of both regimens and the probability of having a correct clinical diagnosis. It was also assumed that only patients with peptic ulcer would benefit from eradication therapy. A more comprehensive study might consider quality of life as a measure of benefits and include a wider variety of the treatment regimens now available.
Validity of estimate of costs
ts used in this study were charges to the GP for buying the necessary services, which do not necessarily reflect the actual resources used. Only direct costs associated with the diagnosis and treatment of H. pylori were included. Other direct healthcare costs (the cost of the GP's time), indirect financial costs (loss of productivity through patient's time off work), and intangible costs (patient's discomfort arising from unsuccessful treatment or additional endoscopy) were not included. Inclusion of those indirect or intangible costs would have favoured the OC regimen, because it is more effective.
authors adopted a robust approach and presented their findings in a clear and concise manner. The authors did not discuss the generalisability of the results to other settings or countries. Before applying these results to a particular setting, the reader should take into account the uncertainty surrounding the effectiveness measures (discussed in the literature and reported by the authors), the assumptions on which the model was based, and the small number of treatment regimens that were considered.
Implications of the study
The authors point to the potential benefits of conducting more comprehensive studies based on the comments recorded above.
Source of funding
Sponsored by Abbott Laboratories.
Craig A M, Davey P, Malek M, Murray F. Decision analysis of Helicobacter pylori eradication therapy using omeprazole with either clarithromycin or amoxicillin. PharmacoEconomics 1996; 10(1): 79-92
Other publications of related interest
1. Briggs A H, Sculpher M J, Logan R P H, Aldous J, Ramsay M E, Baron J H. Cost effectiveness of screening for and eradication of Helicobacter pylori in management of dyspeptic patients under 45 years of age. BMJ 1996;312:1321-1325. 2. Carrere M-O, Lamouliatte H & Ruszniewski P. Is Helicobacter pylori eradication a cost-effective treatment of duodenal ulcer disease? PharmacoEconomics 1997;11(3):216-224.
3. Laheij R J F, Severens J L, Jansen J B M J, van de Lisdonk E H, Verbeek A L M. Management in general practice of patients with persistent dyspepsia: a decision analysis. Journal of Clinical Gastroenterology 1997;25(4):563-567.
4. O'Brien B, Goeree R, Hunt R, Wilkinson J, Levine M, William A. Cost effectiveness of alternative helicobacter pylori eradication strategies in the management of duodenal ulcer. Canadian Journal of Gastroenterology 1997;11(4):323-331.
Subject indexing assigned by NLM
Adult; Amoxicillin /administration & Anti-Ulcer Agents /administration & Clarithromycin /administration & Costs and Cost Analysis; Decision Support Techniques; Drug Therapy, Combination /administration & Duodenal Ulcer /drug therapy /economics; Helicobacter Infections /drug therapy /economics; Helicobacter pylori; Humans; Middle Aged; Models, Economic; Omeprazole /administration & dosage /economics; dosage /economics; dosage /economics; dosage /economics; dosage /economics
Date bibliographic record published
Date abstract record published