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Management of acid-related dyspepsia in general practice: cost-effectiveness analysis comparing an omeprazole vs an antacid-alginate/ranitidine management strategy |
Mason I, Marchant N J |
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Record Status 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. Health technology Management of acid-related dyspepsia in general practice using either omeprazole or antacid-alginate/ranitidine.
Economic study type Cost-effectiveness analysis.
Study population Patients with a minimum 1 month history of dyspepsia.
Setting General practice. The study was carried out in the UK and the Republic of Ireland.
Dates to which data relate Effectiveness data were collected from a single study published in 1998. Cost data were derived from 1997-1999 sources. The price year was 1999.
Source of effectiveness data Effectiveness data were derived from a single study.
Link between effectiveness and cost data The costing was undertaken on the same patient sample as that used in the effectiveness analysis and was carried out retrospectively after the effectiveness results were known.
Study sample 725 patients, aged 18 to 89 years, were recruited from 131 general practice centres in the UK and the Republic of Ireland. 22 patients, 13 from the omeprazole arm and 9 from the antacid-alginate/ranitidine treatment group, recorded only baseline symptom assessment and were excluded from the analysis. 703 patients were therefore eligible, and were randomised to the omeprazole arm (n = 345) and to the antacid-alginate/ranitidine arm (n = 349). The study had a power of 99% in detecting the observed 21% difference between treatment regimens at the 5% significance level.
Study design A prospective, open-label, randomised, parallel-group, clinical trial was carried out at multiple centres. Patients were followed up for 16 weeks. 166 patients discontinued the study before the final 16-week clinic visit (74 in the omeprazole arm and 92 in the antacid-alginate/ranitidine arm).
Analysis of effectiveness Analyses were performed on an intention to treat basis. The last value extended principle was used for patients who withdrew before completion of the study. The primary health outcomes used in the study were: sufficient and complete symptom relief, severity of dyspepsia symptoms, the frequency of symptoms and the number of treatment steps to complete relief. The groups were comparable at entry with respect to the severity of their symptoms.
Effectiveness results After 16 weeks of treatment, 61% (range: 55.9 - 66.1%) of patients receiving the omeprazole treatment strategy had achieved complete symptom relief of dyspepsia compared with 39.8% (range: 34.7 - 45.0%) of patients receiving the antacid-alginate/ranitidine strategy, (p<0.0001). For sufficient symptom relief, the equivalent figures were 70.1% (range: 65.3 - 74.8%) and 50.7% (range: 45.5 - 56.0%), respectively, (p<0.0001). Of the omeprazole-treated patients, 46% achieved symptom relief on treatment step 1 compared with 17% in the antacid-alginate/ranitidine group, (p=0.0001). 10 patients in the omeprazole arm and 2 patients in the antacid-alginate/ranitidine group experienced serious adverse events during the study period. 14 patients in the omeprazole arm and 26 patients in the antacid-alginate/ranitidine group attended for endoscopy.
Clinical conclusions Complete and sufficient symptom relief were higher in the omeprazole treatment group.
Modelling No modelling was undertaken.
Measure of benefits used in the economic analysis Sufficient and complete symptom relief were used as the two measures of benefit. Complete symptom relief was defined as severity of dyspepsia symptoms reported as 'none' and the frequency of symptoms as '0 to 1' days with symptoms in the last 7 days. Sufficient symptom relief was defined as severity of dyspepsia symptoms reported as 'none' or 'mild' and the frequency of symptoms as '0 to 1' days with symptoms in the last 7 days.
Direct costs Direct 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 costs of prescribed study medication, GP consultations, endoscopy and treatment of serious adverse events related to study medication. The quantity/cost boundary adopted was that of the health service. The estimation of quantities and costs was based on actual data. Medication costs were those quoted in the Drug Tariff. Endoscopy costs were based on the GP Fundholder tariff for an endoscopy. Costs were inflated using the GDP Deflator. The price year was 1999.
Statistical analysis of costs Sensitivity analysis Sensitivity analyses were performed on effectiveness estimates and the cost of a GP consultation. 95% confidence interval values were used as derived from the clinical trial, and variations of +/- 20% were used for the cost data.
Estimated benefits used in the economic analysis After 16 weeks of treatment, 61% (range: 55.9 - 66.1%) of patients receiving the omeprazole treatment strategy had achieved complete symptom relief of dyspepsia compared with 39.8% (range: 34.7 - 45.0%) of patients receiving the antacid-alginate/ranitidine strategy, (p<0.0001). For sufficient symptom relief, the equivalent figures were 70.1% (range: 65.3 - 74.8%) and 50.7% (range: 45.5 - 56.0%), respectively, (p<0.0001).
Cost results Total costs in the omeprazole treatment group amounted to 49,526.07 (that comprises medication costs of 35,103.47, costs of GP consultations of 10,486.08, and endoscopy costs of 3,936.52). Total costs in the antacid-alginate/ranitidine treatment group were 42,907.84 (medication costs of 22,592.52, costs of GP consultations of 13,004.64, and endoscopy costs of 7,310.68).
Synthesis of costs and benefits The cost per patient with complete symptom relief was 229.29 with omeprazole and 308.69 with antacid-alginate/ranitidine. The cost per patient with sufficient symptom relief was 199.70 with omeprazole and 242.42 with antacid-alginate/ranitidine. The sensitivity analyses showed that the cost per patient with complete symptom relief is lower in all scenarios using omeprazole (212 - 250 versus 273 - 354). The second sensitivity analysis performed showed that omeprazole remains the dominant strategy over the range tested.
Authors' conclusions Treatment of acid-related dyspepsia in general practice is more cost-effective using an omeprazole strategy compared with an antacid-alginate/ranitidine strategy.
CRD COMMENTARY - Selection of comparators The 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 own setting.
Validity of estimate of measure of benefit Relevant measures of benefit were used. Effectiveness estimates were derived from a large, randomised controlled trial and are likely to be reliable.
Validity of estimate of costs Only direct costs were considered. Costs borne by the patients, such as over-the-counter medications and antacids used as relief medication, were not included. Costs were derived from local sources, and are unlikely to be generalisable to other countries. The cost analysis was carried out retrospectively, by attributing costs to resources consumed in a clinical trial. The authors noted that some resource utilisation is protocol driven and is not necessarily reflective of clinical practice. A sensitivity analysis was performed on the cost of a GP consultation.
Other issues The generalisability of the results to other settings or countries was not discussed and comparisons with other relevant studies were not made.
Implications of the study The use of omeprazole in the management of acid-related dyspepsia in general practice is recommended.
Source of funding Supported by AstraZeneca.
Bibliographic details Mason I, Marchant N J. Management of acid-related dyspepsia in general practice: cost-effectiveness analysis comparing an omeprazole vs an antacid-alginate/ranitidine management strategy. Clinical Drug Investigation 1999; 18(2): 117-124 Other publications of related interest 1. Ebell M H, Warbasse L, Brenner C. Evaluation of the dyspeptic patient: a cost-utility study. Journal of Family Practice 1997;44(6):545-555.
2. 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.
3. McIntyre A M, MacGregor S, Malek M, Dunbar J A, Hamley J G, Cromarty J A. New patients presenting to their GP with dyspepsia: does Helicobacter pylori eradication minimise the cost of managing these patients. International Journal of Clinical Practice 1997;51(5):276-281.
4. Stal J M, Gregor J C, Preiksaitis H G, Reynolds R P E. A cost-utility analysis comparing omeprazole with ranitidine in the maintenance therapy of peptic esophageal stricture. Canadian Journal of Gastroenterology 1998;12(1):43-49.
Indexing Status Subject indexing assigned by CRD MeSH Abdominal Pain /drug therapy; Adolescent; Adult; Aged; Aged, 80 and over; Alginates /administration & Anti-Ulcer Agents /administration & Cost-Benefit Analysis; Drug Therapy, Combination; Dyspepsia /drug therapy; Endoscopes; Female; Great Britain; Heartburn /drug therapy; Histamine H2 Antagonists /administration & Male; Middle Aged; Omeprazole /administration & Outcome Assessment (Health Care); Patient Compliance; Patient Dropouts; Ranitidine /administration & Treatment Outcome; dosage /economics /therapeutic use; dosage /economics /therapeutic use; dosage /economics /therapeutic use; dosage /economics /therapeutic use; dosage /therapeutic use AccessionNumber 21999001617 Date bibliographic record published 31/05/2000 Date abstract record published 31/05/2000 |
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