Comprehensive surgical treatment of migraine headaches Guyuron B, Kriegler J S, Davis J, Amini S B

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1 Comprehensive surgical treatment of migraine headaches Guyuron B, Kriegler J S, Davis J, Amini S B 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 Patients with migraine were given 25 units of botulinum toxin A (BT-A) in one or more trigger sites, according to an algorithm in which more trigger sites were injected unless the migraine was completely eliminated by the earlier injection. If there was a significant improvement (at least a 50% reduction from baseline), or the elimination of migraine lasted for 4 consecutive weeks, the patient was considered for surgery on the trigger sites. A comparator group of patients was given the same kind of injections, but of a placebo (0.5 ml saline). Type of intervention Treatment. Economic study type Cost-effectiveness analysis. Study population The study population comprised patients with migraine. The neurologist conducting the research confirmed the diagnosis, according to criteria laid down by the International Headache Society. No inclusion or exclusion criteria were described. Setting The setting was secondary care. The economic study was carried out in the USA. Dates to which data relate The dates to which the effectiveness and resource evidence referred were not reported. The price year was not reported. Source of effectiveness data The effectiveness data were derived from a single study. Link between effectiveness and cost data The same patients provided both the effectiveness and the cost data. Study sample No power calculations or method of sample selection were reported. A total of 125 volunteers were recruited and randomly assigned to either the treatment group (n=100) or the control group (n=25). The mean age of the participants was 43.4 (+/- 1.1) years in the treatment group and 42.9 (+/- 1.7) years in the control group, (p=0.8). Page: 1 / 5

2 Study design This was a randomised controlled trial (RCT) that was carried out in a single centre. The patients were followed up for 1 year. Eleven patients were lost to follow-up in the intervention group. Of these, 2 patients declined to take part in the study after assignment, 1 patient did not respond to BT-A injections, 6 either declined the surgery or were excluded for non-compliance, and 2 did not complete follow-up requirements. Six patients in the control group did not complete the follow-up requirements. Analysis of effectiveness The analysis was conducted on the basis of treatment completers only. The following health outcomes were used to assess the patients: the frequency of migraine headaches (MH) per month; the intensity of the migraines; the duration of the migraines; an MH index; a migraine disability assessment score (MIDAS); a migraine-specific questionnaire, emotional (MSQEM); a migraine-specific questionnaire, preventive (MSQPRE); a migraine-specific questionnaire, restrictive (MSQRES); and the SF-36 health survey, both mental (SFMEN) and physical (SFPH). The two groups were generally comparable at baseline. The exception was the MSQEM, for which the treatment group had a higher score (implying better emotional health) than the control group (51.9 +/- 3.4 versus /- 4.9; p=0.002). Effectiveness results When outcomes at one year were compared with baseline, all the measures of patient health, apart from the SFMEN, showed a statistically significant improvement in the intervention group, (p</=0.001). Only the migraine headache intensity and duration were improved in the control group (p<0.001 and p=0.018, respectively). When the two groups were compared, there were statistically significant improvements in all measured variables after one year in the treatment group versus the control group: frequency (MH per month), 3.8 (+/- 0.4) versus 10.2 (+/- 1.7), (p<0.001); MH intensity, 4.0 (+/- 0.3) versus 7.0 (+/- 0.3), (p<0.001); MH duration, 0.35 (+/- 0.05) hours versus 0.99 (+/- 0.2) hours, (p=0.007); MH index, 12.6 (+/- 3.1) versus 90.6 (+/- 33.6), (p=0.03); MIDAS, 1.84 (+/- 0.18) versus 3.67 (+/- 0.59), (p<0.001); MSQEM, 88.1 (+/- 2.6) versus 34.0 (+/- 5.7), (p<0.001); MSQPRE, 89.7 (+/- 2.2) versus 57.2 (+/- 4.7), (p<0.001); MSQRES, 83.1 (+/- 2.9) versus 38.2 (+/- 3.5), (p<0.001); Page: 2 / 5

3 SFMEN, 48.1 (+/- 1.3) versus 40.2 (+/- 2.7), (p=0.014); SFPH, 51.6 (+/- 1.3) versus 46.6 (+/- 1.6), (p=0.033). Overall, 82 of the 89 patients in the treatment group (92%) benefited from the surgery, 31 (35%) reported elimination of MH and 51 (57%) experienced improvement. Only 3 of the 19 patients in the control group (15.8%) noted such improvement after one-year follow up, (p<0.001), and no patient reported the elimination of MH. When changes over time (3, 6, 9 and 12 months after surgery) were compared, there was significant improvement in all measurements for the treatment group versus the control group, (p<0.001). The authors reported the number of adverse effects following the BT-A injection. More specifically, discomfort at the injection site 27 (20 at occipital site 6 at temporal site and 1 frontal site), temple hollowing 19, neck weakness or stiffness 15, eyelid ptosis 9, flu-like symptoms 5, and bruising or swelling 6. The number of adverse effects following surgery were temporary nasal dryness 12, rhinorrhoea 11, slight recurrence of septal deviation 8, intense itching 7, minor hair loss 5, abnormal intraoperative bleeding 4, short-term neck stiffness 3, epistaxis requiring desmopressin 3, sinus infection 3, long-term neck stiffness 1, haematoma 1, unilateral airway reduction 1, and significant major hair loss 1. Clinical conclusions The authors concluded that the BT-A injections followed by surgery on trigger sites had resulted in improvements in health for the migraine patients, as far as migraines were concerned. Measure of benefits used in the economic analysis No summary measure of benefits was produced. In effect, the authors carried out a cost-consequences analysis. Direct costs No discounting was carried out as the costs were incurred during less than 2 years. The quantities and the costs were not analysed separately. It was unclear which costs were included since no details were given. The costs appear to have been derived from actual data. One of the data sources must have been the hospital, but patients also recorded their migrainerelated expenses. No price year was given. Statistical analysis of costs No statistical analysis of the costs was carried out. Indirect Costs The number of days lost from work was recorded, but no monetary value was put on this cost. The source of these data was the patients' diaries. No dates were given. Currency US dollars ($). Sensitivity analysis No sensitivity analysis was carried out. Estimated benefits used in the economic analysis Page: 3 / 5

4 See the 'Effectiveness Results' section. Cost results The average baseline annual cost of care for MH was $7,612 (+/- 1,680) for patients in the treatment group. This cost decreased to a mean of $925 (+/- 121) during the first postoperative year, (p<0.001), which was less than the average annual cost of care for the control group ($5,530 +/- 873), (p<0.001). The costs were calculated for one year. It was unclear whether the costs of dealing with adverse effects were included in these costs. Synthesis of costs and benefits The costs and benefits were not combined as the study was a cost-consequences analysis. Authors' conclusions The authors did not draw a conclusion for both the effectiveness and cost results. They concluded that "surgical deactivation of MH (migraine headache) trigger sites can eliminate or significantly reduce migraine symptoms". However, according to the results of this study, the conclusion should be that the surgical deactivation of MH trigger sites is more effective and less costly than the conventional treatment and, therefore, is the dominant treatment. CRD COMMENTARY - Selection of comparators The comparator treatment (the use of drugs to treat MH) was justified by it being current practice in many settings. You should decide whether the comparator represents current practice in your own setting. Validity of estimate of measure of effectiveness The source of the effectiveness data was a single study. The study design, an RCT, was appropriate given the study question. With the exception of the MSQEM measure, the two patient groups were shown to be comparable in terms of the baseline criteria. Some aspects of the study procedure might have influenced its internal validity. In particular, the absence of power calculations when determining the sample size and the treatment-completers-only basis for the analysis represented significant drawbacks. In addition, the lack of blinding of the outcome assessment presented a potential limitation to the reliability of the findings. The authors did not explain how volunteers for the study were recruited; the reader can examine the baseline criteria of the study sample to determine whether it appears representative of other populations of migraine sufferers. The authors do not appear to have considered adverse events in their analysis of effectiveness. The main strength of the study was that appropriate statistical analyses were carried out to detect significant differences in clinical outcomes between the groups. Validity of estimate of measure of benefit The authors did not derive a measure of health benefit. The analysis was one of cost-consequences. Validity of estimate of costs Although the perspective of the cost analysis was unclear, it appears that the costs relevant to the health care system have been included. The authors did not break down all the costs, so it is uncertain whether they were all included. In particular, it was unclear if the costs of adverse events were included. The authors did not account for the indirect costs in their cost calculations, which would have shown a bigger cost advantage to the treatment group since patients lost fewer days off work. The costs were not reported separately from the quantities, and this may hinder the reproducibility of the results. The resource use quantities were taken from a single study, while the prices were taken from the authors' setting. No statistical, sensitivity or any other kind of analysis of the quantities or prices was undertaken. The year to which the prices referred was not stated, and this may hinder the generalisability of the results. These limitations may Page: 4 / 5

5 Powered by TCPDF ( well influence the internal validity of the cost analysis. Other issues The authors did make appropriate comparisons of their results with those from other studies. The issue of generalisability to other settings was not addressed. The authors did not present their results selectively. However, their conclusions did not reflect the scope of the analysis, for the reasons described above and because the authors did not draw a conclusion based on both the cost and effectiveness results. The main drawbacks, as mentioned by the authors, were the sample size and the follow-up period. The authors stated that a sufficient number of patients should be followed for a meaningful period of time to ensure that the cure is permanent. Implications of the study The authors recommended that further studies be conducted with a longer follow-up. They are researching better methods for identifying trigger sites, in order to make surgery more effective, and recommend research to explain the mechanism by which the surgery is effective. Source of funding None stated. Bibliographic details Guyuron B, Kriegler J S, Davis J, Amini S B. Comprehensive surgical treatment of migraine headaches. Plastic and Reconstructive Surgery 2005; 115(1): 1-9 PubMedID Indexing Status Subject indexing assigned by NLM MeSH Absenteeism; Adult; Alopecia /etiology; Blood Loss, Surgical; Botulinum Toxins, Type A /adverse effects /therapeutic use; Female; Follow-Up Studies; Health Care Costs; Humans; Male; Middle Aged; Migraine Disorders /economics /surgery; Muscular Atrophy /chemically induced; Nasal Septum /surgery; Postoperative Complications /etiology; Pruritus /etiology; Surveys and Questionnaires; Treatment Outcome; Turbinates /surgery AccessionNumber Date bibliographic record published 31/01/2006 Date abstract record published 31/01/2006 Page: 5 / 5