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Pharmacoeconomic analysis of stress ulcer prophylaxis for critically ill patients |
Schumock G T, Lam N P, Winkler S R, Kong S X |
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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 Commonly used stress ulcer prophylaxis in critically ill and/or intensive care unit (ICU) patients, using:
(1) antacid ('Mylanta II') 30 ml orally (PO) or nasogastrically (NG) every 4 hours for 7 days,
(2) sucralfate ('Carafate') 1 g PO/NG 4 times daily for 7 days,
(3) ranitidine ('Zantac')50 mg intravenously (IV) every 8 hours for 7 days,
(4) cimetidine ('Tagamet') 300mg IV every 6 hours for 7 days,
(5) famotidine ('Pepcid')20 mg IV every 12 hours for 7 days, and
(6)no prophylaxis.
Economic study type Cost-effectiveness analysis.
Study population Critically ill patients and intensive care unit patients.
Setting Hospital. The economic study was carried out in Chicago, Illinois, USA.
Dates to which data relate The effectiveness analysis and resource use data were obtained from studies published between 1976 and 1993. The prices are those of 1994.
Source of effectiveness data Effectiveness data were derived from a synthesis of previously published studies.
Modelling A decision tree was used to obtain estimates of costs and benefits.
Outcomes assessed in the review The outcomes analysed were the probabilities of acute upper gastrointestinal bleeding (AUGB) and nosocomial pneumonia.
Study designs and other criteria for inclusion in the review Studies were included in the review if:
(1) the respective sample included critically ill or ICU patients;
(2) 2 or more of the prophylactic regimens were evaluated;
(3) a randomisation method was used; and
(4)end-points of either AUGB and/or nosocomial pneumonia were used.
Sources searched to identify primary studies Medline was searched for the years between 1970-1993 and 5 published meta-analyses were also searched.
Criteria used to ensure the validity of primary studies Methods used to judge relevance and validity, and for extracting data There were four reviewers (authors) who independently identified the relevant studies. The data extracted were summary statistics in terms of the probability of outcomes.
Number of primary studies included Thirty three studies (randomised trials) were included.
Methods of combining primary studies Results from primary studies were pooled and weighted according to their respective sample sizes.
Investigation of differences between primary studies Differences in the definition of outcomes existed across the primary studies, however the authors believed that, although the internal validity of the results of the study may be reduced because of the differences among the studies included, "the external validity is increased".
Results of the review With respect to AUGB, the pooled probability of occurrence was:
with H2 Ras, 0.0984, (95% CI: 0.0815 - 0.1153);
with anatacids, 0.0311 (95% CI: 0.021 - 0.0412);
with sucralfate, 0.0440 (95% CI: 0.0298 - 0.0582);
no prophylaxis, 0.1540 (95% CI: 0.1297 - 0.1781).
Nosocomial pneumonia had a probability of occurrence, as follows:
with H2RAs, 0.3390 (95% CI: 0.293 - 0.385);
with anatacids, 0.279 (95% CI: 0.2082 - 0.3498);
with sucralfate, 0.2070 (95% CI: 0.1695 - 0.2445);
no prophylaxis 0.2070 (sucralfate was used as a proxy).
Measure of benefits used in the economic analysis The measure of benefits was the number of AUGB averted per 1,000 patients.
Direct costs Only quantities related to dosage regimenswere reported separately from the costs. Cost items were reported separately. The costs measured were operating costs (treatment costs, drug acquisition costs, hotel) and cost of complications (cost of treatment of AUGB and nosocomial pneumonia, with long term costs included for the former). The cost boundary adopted was that of a healthcare payer. The estimation of quantities related to dosage regimens was based on experts' opinions. Charge data were used as a proxy for cost data. The estimation of costs was based on standard prices (average wholesale prices, for drugs, and Medicare diagnosis-related groups (DRG) reimbursement rates for hospital costs). The prices were from 1994.
Sensitivity analysis Range of costs was analysed, with the upper and lower bounds obtained by multiplying the baseline values times 2 and 0.5, respectively. Threshold analysis was carried out for the probability of occurrence of AUGB and nosocomial pneumonia as well as a break-even cost analysis.
Estimated benefits used in the economic analysis The number of cases of AUGB averted with sucralfate per 1,000 patients was 110, with antacids was 122.9, with H2RA famotidine was 55.6, with H2RA ranitidine was 55.6 and with H2RA cimetidine was 55.6 (figures were calculatedwith respect to no prophylaxis).
Cost results The cost for an average patient was:
sucralfate, $1,457;
antacids, $1,737;
H2RA famotidine, $2,638;
H2RA ranitidine, $2,678;
H2RA cimetidine, $2,712;
no prophylaxis, $2,268.
Synthesis of costs and benefits The cost per AUGB averted was used as a cost effectiveness measure.
The incremental cost per AUGB averted was:
sucralfate, -$7,373;
antacids, -$4,321;
H2RA famotidine, $6,655;
H2RA ranitidine, $7,374;
H2RA cimetidine, $7,986.
The threshold analysis (keeping sucralfate's probability of AUGB constant at 4.4%) resulted in sucralfate being the optimal choice even though the rate of AUGB for the other options dropped to zero. No prophylaxis becomes the optimal choice at AUGB rates of occurrence less than 4.7%, under the same analysis. For nosocomial pneumonia, the results did not change up to the point at which H2RAs (ranitidine), antacids and no prophylaxis fell below 10.9%, 22.6%, and 5.4%, respectively (with sucralfate's rate held constant at 20.7%). Over the range of costs chosen for sensitivity analysis, the rank order of the options' costs did not change. The break even analysis resulted in the optimal choice costing less even though acquisition costs for H2RAs and antacids diminished to zero, with sucralfate's acquisition cost per patient held constant at $23.76 and the rates of incidence of outcomes also held constant.
Authors' conclusions The analysis demonstrates, according to the authors, that the common practice of using H2RAs may not be cost-effective. In fact, using no prophylaxis at all may be more cost-effective than using H2RAs. This conclusion was supported by recent studies which demonstrated that prophylaxis against stress ulcer can be safely withheld in many critically ill patients. When stress ulcer prophylaxis is required, the present results suggest that sucralfate is the most cost-effective choice, followed by antacids.
CRD COMMENTARY - Selection of comparators The reason for the choice of the comparator is clear.
Validity of estimate of measure of benefit The internal validity of the estimates of benefit measure may be weakened fully by the fact that no test for the homogeneity of results among the primary studies was performed, the possibility of publication bias, and the exclusion of mortality from the list of the complications.
Validity of estimate of costs The resource utilisation was not fully reported separately from the costs, although adequate details of the methods of cost estimation were given.
Source of funding Supported in part by a grant from Hoechst Marion Roussel, Kansas City, MI, USA.
Bibliographic details Schumock G T, Lam N P, Winkler S R, Kong S X. Pharmacoeconomic analysis of stress ulcer prophylaxis for critically ill patients. PharmacoEconomics 1996; 9(5): 455-465 Indexing Status Subject indexing assigned by NLM MeSH Anti-Ulcer Agents /economics /therapeutic use; Cost-Benefit Analysis; Critical Illness /economics; Decision Trees; Humans; Stomach Ulcer /economics /etiology /prevention & Stress, Psychological /complications; control AccessionNumber 21996008263 Date bibliographic record published 31/05/1999 Date abstract record published 31/05/1999 |
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