Setting The setting was secondary care. It was unclear where the study was conducted.

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1 Is helium thermal coagulator therapy for the treatment of women with minimal to moderate endometriosis cost-effective: a prospective randomised controlled trial Lalchandani S, Baxter A, Phillips K 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 Helium thermal coagulator (HTC) therapy was the focus of the study. The technique combines a flow of energy with helium within a Helica generator to produce an ionised plasma beam or corona-type flame, the energy from which is delivered to the patient's target tissue via a probe. Type of intervention Treatment for endometriosis. Economic study type Cost-effectiveness analysis. Study population The study population comprised women presenting to a gynaecology outpatient clinic with a history of pelvic pain, dysmenorrhoea, dyspareunia, and dyschesia suggestive of endometriosis, or who had previously been diagnosed with the disease. Patients were excluded if they were younger than 16 years, were pregnant, or were sub-fertile. Setting The setting was secondary care. It was unclear where the study was conducted. Dates to which data relate The effectiveness and resource use data referred to women recruited between September 1999 and March A 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 costing was carried out prospectively on the same sample of patients as that used in the effectiveness study. Study sample The study sample comprised all women presenting to the clinic who met the inclusion and exclusion criteria. The authors reported that power calculations were carried out. These demonstrated that 25 patients were required in both the active (HTC) treatment arm and the control (GnRH-a) medical arm of the trial. Despite their best intentions to secure a sufficient sample size, the authors reported that two in three women had a preference for surgery and, therefore, could not be randomised. Only one in three women presenting were therefore recruited to the study, giving a total sample size Page: 1 / 5

2 of just 35. Of these, 18 women received medical treatment and 17 received surgical treatment. The mean age of the participants was 32.8 years (range: 20 to 45). Study design The authors designed a randomised controlled trial, with HTC being the treatment of interest and GnRH-a being the control treatment. Randomisation occurred at the time of diagnostic laparoscopy. The study seems to have been carried out at a single centre, although the location of the centre itself was not clear. The patients were compared at the time of treatment and at 3, 6 and 12 months after the end of treatment. There was no loss to follow-up and it was not possible to blind either the patients or the physicians. Analysis of effectiveness The patient outcomes were analysed on an intention to treat basis. The primary health outcomes were the operating time and treatment outcomes. The authors did not report any comparison of the two groups at analysis. Effectiveness results The mean operating time was minutes (range: 20 to 50) in the surgical arm and minutes (range: 15 to 35) in the medical arm. Within the medical arm, this time covered only the time to carry out the diagnostic laparoscopy. In the surgical arm, this time included time for diagnosis and time for treatment. Therefore, the marginal time to carry out treatment in the surgical arm was minutes. In the medical arm, 3 women (17%) were symptom free, 11 required surgical treatment of endometriosis, 1 had a laparoscopically-assisted vaginal hysterectomy, and 3 became pregnant before their final reviews. In the surgical arm, 9 women (53%) were symptom free, 4 required Zoladex therapy, 1 required oral contraceptive pills, and 3 required repeat surgical treatment. Clinical conclusions The authors concluded that it is better to see and treat mild to moderate endometriosis where facilities are available and that "surgical treatment is safe...and more effective therapy". Measure of benefits used in the economic analysis The authors did not estimate a summary measure of health benefit. The study was, in effect, a cost-consequence analysis. Direct costs A perspective for the costing analysis was not reported. The authors seem to have estimated the direct costs associated with medical and surgical treatment, and thus appear to be concerned with the perspective of the health care provider. The cost of surgical treatment was estimated as the direct costs associated with the use of the HTC generator. The authors negotiated with the HTC generator company to have the machine on loan at no cost, and agreed to purchase 10 probes per month (one probe is required per patient treated). The costs in the medical arm focused on the cost of a 6-month course of injectable Zoladex (goserelin 3.6 mg and Livial (tibolone; add-back, 28 pack). Discounting was not required because of the short time horizon of the study. Resource use, in terms of the operating time, was measured during the effectiveness study. The source of the drug costs was unclear and although it seems that the authors have included a cost associated with operating time, the source of the unit cost was not clear. Statistical analysis of costs The costs were analysed using the Mann-Whitney test. A p-value of less than 0.05 was considered statistically significant. Page: 2 / 5

3 Indirect Costs The indirect costs to the wider society were not estimated. Currency UK pounds sterling (). Sensitivity analysis There was no report that sensitivity analyses were carried out. Estimated benefits used in the economic analysis See the 'Effectiveness Results' section. Cost results The mean total cost per patient was in the surgical arm and in the medical arm, (p<0.0001). Synthesis of costs and benefits Not relevant. Authors' conclusions The costs involved were significantly higher in the medical group. The study showed the cost-effectiveness of surgical treatment. CRD COMMENTARY - Selection of comparators The authors compared two types of treatment, surgical and medical, for endometriosis. Although a medical comparator has some logic, several medical therapies are available and it was not explicitly stated why GnRH-a was specifically chosen. However, the authors reported that a meta-analysis of GnRH-a had already been conducted and perhaps this alternative represented the most cost-effective option available in the authors( setting. In addition, there appear to have been alternative surgical techniques. Readers should assess whether this is a valid and most appropriate comparator in their own setting. Validity of estimate of measure of effectiveness The authors designed a randomised controlled trial. This was not only appropriate for addressing the aims of the authors in terms of comparing the two treatment strategies, but it also helped to reduce systematic differences between patients. The latter increases the internal validity of the results by reducing the potential for confounding factors that might affect the results. However, the authors did not report a comparison of patients between the two groups at analysis, thereby excluding the possibility of identifying any remaining confounding factors and adjusting accordingly. Validity of estimate of measure of benefit The authors did not estimate a summary measure of health benefits. The study was, in effect, a cost-consequences analysis. Since the authors did not report pain scores, the outcomes reported might not have fully covered the health outcomes of the patient. Validity of estimate of costs The authors did not report a perspective for the costing carried out, thus it is not possible to assess whether all the Page: 3 / 5

4 relevant costs were included. However, the costs incorporated, the direct costs associated with use of the generator and the costs of medication, would seem to indicate that the perspective of the health care provider (i.e. the hospital) was adopted. The analysis might have been improved by stating the precise perspective, reporting the exact source of the costs for medications, and stating explicitly how the cost for operating time was estimated and whether this included overheads such as hospitality costs and surgeon time. The authors found statistical significance between cost estimates for the two groups, so small additions or alterations might not alter the principle conclusion that surgery represents the cheaper treatment alternative. Other issues The authors were only able to make limited comparisons of their work since they reported that, to their knowledge, this was the first study assessing the cost-effectiveness of HTC therapy in treating mild to moderate endometriosis. Nevertheless, they were able to compare effectiveness results and contribute to the debate over the optimal length of GnRH-a therapy. The authors reported that their cost results conflicted with some others, but suggested this may be due to several patients in the medical group undergoing subsequent surgical treatment. The issue of generalisability to other settings was not addressed. The effectiveness results might generalise well to other populations given the broad inclusion criteria, but generalisation of the costing analysis is potentially limited since the sources of the unit costs were not fully reported. The authors concluded that their analysis "factors in the large number of women with chronic pelvic pain, direct and indirect costs of the condition". This statement should be interpreted with care. It was unclear how the authors took the large number of women with chronic pelvic pain, which might have been addressed with a budgetary analysis, into account. In addition, the indirect costs (i.e. those affecting the wider society such as lost production due to illness or treatment) were not included in the analysis. Overall, the finding of the study, that HTC therapy represents a more-effective and cheaper alternative, sits well with the authors' observation that most women had a preference for surgical treatment. Implications of the study The authors did not highlight any recommendations or changes for policy or practice following on from their study. They reported that they would be publishing further work relating to the pain scores and success rates of the two treatments. Further work might extend the body of evidence by recruiting patients over a longer period of time in order to improve the power of the study to detect significant differences. Source of funding None stated. Bibliographic details Lalchandani S, Baxter A, Phillips K. Is helium thermal coagulator therapy for the treatment of women with minimal to moderate endometriosis cost-effective: a prospective randomised controlled trial. Gynecological Surgery 2005; 2(4): Other publications of related interest Winkel CA. A cost-effective approach to the management of endometriosis. Curr Opin Obstet Gynaecol 2000;12: Indexing Status Subject indexing assigned by CRD MeSH Cost-Benefit Analysis; Electrocoagulation /adverse effects /instrumentation /methods; Endometriosis /surgery /therapy; Female; Goserelin; Humans; Middle Aged; Pelvic Pain; Postoperative Complications; Treatment Outcome AccessionNumber Page: 4 / 5

5 Powered by TCPDF ( Date bibliographic record published 30/09/2006 Date abstract record published 30/09/2006 Page: 5 / 5