An economic analysis of sumatriptan for acute migraine Ilersich L 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 Oral and subcutaneous sumatriptan for aborting or relieving migraine attacks. Type of intervention Treatment. Economic study type Cost-effectiveness analysis, cost-utility analysis and cost-benefit analysis. Study population Patients presenting with moderate or severe migraine events. Setting Primary care and hospital. The economic study was carried out in Canada. Dates to which data relate The effectiveness data were obtained from a previously completed meta-analysis published in 1996. No specific date was given for the resource use data. Only the price for the drug acquisition costs was reported (1996). Source of effectiveness data Effectiveness data were derived from a synthesis of previously completed studies. Outcomes assessed in the review The principal outcome was response rate in terms of improvement in migraine pain (defined as the conversion of moderate or severe headache to mild or no headache, one and two hours after drug administration for the subcutaneous and oral therapies, respectively). Utility values were attributed to the following health states used in the meta analysis: migraine relief with no recurrence; migraine relief, recurrence within 24 hours, and secondary relief; no relief, patient endures migraine episode; no relief, patient attends emergency room, finds relief; no relief, patient attends emergency room, finds no relief and is hospitalised. Other outcomes were recurrence rate associated with the interventions and the comparators, and some probabilities, Page: 1 / 5
including probability of emergency room visit, probability of hospitalisation, mean number of severe attacks per person per year, and mean duration of attack. Study designs and other criteria for inclusion in the review Sources searched to identify primary studies The authors reported only that clinical trials were identified from an "on-line literature search". Criteria used to ensure the validity of primary studies Methods used to judge relevance and validity, and for extracting data The data were extracted through summary statistics. Number of primary studies included Twenty eight (28) primary studies were reported. Methods of combining primary studies Meta-analysis. Investigation of differences between primary studies Results of the review The response rates and recurrence rates were as follows: subcutaneous sumatriptan, 70%, 32%; subcutaneous dihydroergotamine, 49%, 5%; oral sumatriptan, 56%, 41%; oral ergotamine/caffeine, 38%, 30%; oral ASA and metoclopramide, 44%, 30%; intranasal butorphanol, 50%, 0%. The probability of emergency room visit and probability of hospitalisation were 8% and 0.2% respectively. The mean number of severe attacks per person per year was 9.5 and the mean duration of attack was 24 hours. The utility values attributed to the various health states were: migraine relief with no recurrence, 1.00; migraine relief - recurrence within 24 hours and secondary relief, 0.90; Page: 2 / 5
no relief - patient endures migraine episode, -0.30; no relief - patient attends emergency room and finds relief, 0.10; no relief - patient attends emergency room finds no relief and is hospitalised, -0.3. Measure of benefits used in the economic analysis Cases avoided (response rate), quality-adjusted life years (QALYs) gained and monetary benefits gained with the intervention relative to the corresponding comparator, were the measures of benefits used in the analysis. The benefits related to the cases avoided were measured at one hour for the intravenously administered drug regimens and at two hours for the orally administered therapies. In order to carry out the utility assessment, the Quality of Well-Being (QWB) tool was used to evaluate the symptom scores (symptom prevalence). The human capital approach was used for the valuation of monetary benefits, based on age and gender specific earnings for Canadian estimates. Direct costs Quantities were not fully reported separately from the prices. Some of the cost items were reported separately. The costs measured were operating costs (those associated with medications, disposables, and physicians required) and the cost of complications (hospitalization and visits to the emergency department). The Ministry of Health and society were the boundaries adopted in the analysis. The estimation of costs associated with the medication use was based on data from a survey of community pharmacy retail prices for specific drugs. 1996 prices were used. Indirect Costs Quantities were not fully reported separately from the prices. The costs measured were those associated with productivity losses. The boundary adopted was patient. The estimation of costs was based on data from Canada (weighted annual income). No dates were explicitly reported. Currency Canadian dollars (Can$). Sensitivity analysis The parameter values investigated in the analysis were the drug prices, hospitalization and emergency service costs, utilities, the relative effectiveness of different therapies, average earnings, and the frequency of attacks. One-way simple sensitivity and probabilistic sensitivity analyses were performed. Estimated benefits used in the economic analysis The probability of case avoided per patient associated with each strategy was reported as follows: subcutaneous sumatriptan, 70%; subcutaneous dihydroergotamine, 49%; oral sumatriptan, 56%; oral ergotamine/caffeine, 38%; oral ASA and metoclopramide, 44%; intranasal butorphanol, 50%. Page: 3 / 5
Cost results The total incremental costs for the oral intervention were as follows: relative to oral ergotamine/caffeine, -Can$4.5;relative to ASA plus metoclopramide, Can$3.84. The total incremental cost associated with the intervention relative to each comparator was reported as follows: relative to subcutaneous dihydroergotamine, Can$16.59;relative to intranasal butorphanol, Can$17.4; relative to oral sumatriptan, Can$10.36. Synthesis of costs and benefits The incremental cost per severe or moderate migraine event avoided, the incremental cost per quality-adjusted life year (QALY) gained and the net economic benefit were the outcome measures used to synthesise the incremental costs and benefits associated with the intervention relative to each one of the comparators. The price date was not clearly reported but appeared to be 1996. The oral intervention dominated the comparator of oral ergotamine/caffeine: the incremental cost per severe or moderate event of migraine avoided was -Can$25. The oral intervention had an incremental cost per severe or moderate migraine event avoided of Can$32, with respect to ASA plus metoclopramide. The sumatriptan injection had an incremental cost per severe or moderate migraine event avoided of Can$79, Can$87, and Can$74, when compared with subcutaneous dihydroergotamine, intranasal butorphanol, and oral sumatriptan, respectively. The corresponding cost-utility (incremental cost per QALY gained) ratios for oral sumatriptan were as follows: -Can$7,500 (oral ergotamine/caffeine), Can$9,700 (ASA plus metoclopramide). For sumatriptan injection the corresponding cost-utility rations were: Can$24,500 (subcutaneous dihydroergotamine), Can$27,500 (intranasal butorphanol), and Can$21,200 (oral sumatriptan). The cost-benefit figures (net benefit) were as follows: Can$42, -Can$37, -Can$159, -Can$171, -Can$101, respectively. The authors reported that the sensitivity analysis revealed that the results were "not very sensitive to simultaneous and probable changes in the input variables". The study results included in this section were based on the societal perspective; the authors also reported cost calculations from the perspective of the health care system (government), which were arrived at by subtracting the costs associated with productivity losses. This resulted in higher (incremental) cost-effectiveness and cost-utility ratios. For the latter, the highest figures of all corresponded to sumatriptan injection relative to intranasal butorphanol (Can$66,100). Authors' conclusions The authors reported no specific conclusions other than a summary of their findings. CRD COMMENTARY - Selection of comparators The authors reported the comparators used as being some of the commonly used health care strategies for dealing with moderate or severe migraine events. However, they also stated that the choice was limited by the availability of published clinical trials. You should consider whether these are commonly used health technologies in your own setting. Validity of estimate of measure of benefit The internal validity of the study cannot be assessed given the lack of information from the effectiveness study, which is reported in a separate publication. Validity of estimate of costs Only some of the resource quantities were reported separately from the prices and no breakdown of costs was given. With the exception of the drug acquisition costs, price date for the cost components were not clearly reported. It appears that no important costs were omitted. Other issues Page: 4 / 5
Powered by TCPDF (www.tcpdf.org) The authors noted the principal limitations of the study as being: the exclusion from the study of other commonly used drug regimens for therapy against migraine (including sumatriptan when used as a second-line therapy); the difficulty in generalising the result to other groups such as children, the elderly, pregnant women, those with only mild symptoms, or those with complicated migraine; limitations of the QWB tool used in the cost-utility analysis including the fact that it gives no indication of the societal value of each health state. The long term benefits and costs were not included in the analysis, even though they are likely to differ between groups. Source of funding None stated. Bibliographic details Ilersich L. An economic analysis of sumatriptan for acute migraine. Ottawa, ON, Canada: Canadian Coordinating Office for Health Technology Assessment. Technology Overview: Pharmaceuticals, 6. 1997 Original Paper URL http://www.ccohta.ca Other publications of related interest The study is based in part on a technical report: Evans K, Boan J, Evans J, Shuaib A. Meta-analysis and economic evaluation of sumatriptan for migraine. Ottawa, Ontario: Canadian Co-ordinating Centre for Health Technology Assessment 1997?. Indexing Status Subject indexing assigned by CRD MeSH Analgesics /therapeutic use; Aspirin /economics /therapeutic use; Cost-Benefit Analysis; Ergotamine /economics /therapeutic use; Metoclopramide /economics /therapeutic use; Migraine Disorders /drug therapy; Sumatriptan /adverse effects /therapeutic use /economics; Treatment Outcome AccessionNumber 21997008320 Date bibliographic record published 31/03/1999 Date abstract record published 31/03/1999 Page: 5 / 5