Using economics alongside medical audit: a case study of the management of endometriosis Bodner C, Vale L, Ratcliffe J, Farrar S

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1 Using economics alongside medical audit: a case study of the management of endometriosis Bodner C, Vale L, Ratcliffe J, Farrar S 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 Expectant treatment, andmedical treatment in the management of patients with newly diagnosed endometriosis associated infertility were compared. Type of intervention Treatment. Economic study type Cost-effectiveness analysis and cost-utility analyses. Study population Patients with newly diagnosed endometriosis associated infertility. Setting Hospital. The economic study was carried out in Aberdeen, Scotland. Dates to which data relate The data for the effectiveness analysis were collected during the first six months of The data for the quantities of resources used were, partly, collected in the same period prices were used. Source of effectiveness data Effectiveness datawere derived from a single study and a meta-analysis. Link between effectiveness and cost data The costing was not undertaken on the same patient sample as that used in the effectiveness analysis. It was undertaken retrospectively relying on medical audit data, direct observation and interviews with clinical managers. Study sample No power calculations were reported. A total of 60 patients was originally included in the study. Thirty-five patients received expectant treatment, whereas 21 received medical treatment. Another 4 patients originally considered for inclusion in the study were excluded, yielding a 7% rate of exclusion (2 patients were treated by surgery and two were waiting for operation). Study design This was a retrospective cohort study, carried out in 10 centres. The duration of follow-up was 6 months from the date Page: 1 / 5

2 of the initial diagnosis. The overall loss to follow up was 48.3%. The loss to follow-up in the medical treatment group was 66.6%, and in the expectant treatment group was 37.2%. Analysis of effectiveness The analysis was based on treatment completers only. The primary health outcome used was the pregnancy rate achieved. In addition, level of pain experienced, physical mobility, anxiety and depression were measured by means of a postal questionnaire, measuring the health status both at the specific and the general level. Short Form 36 (SF-36) and a condition specific instrument were used. These were administered at diagnosis and 6 months later. The outcome used was the mean change in score (mean score at diagnosis minus mean score six months later), based on a scale of 0 to 100, which for the SF-36 meant an increasing health status range, whereas for the specific questionnaire 0 meant best possible status and 100 worst. There was no discussion of the comparability of groups with respect to demographic characteristics, prognostic features or confounding variables. Effectiveness results The occurrence of pregnancies was too low (2 of the 60 women) to allow a comparison between groups, so the results from a previously published meta-analysis were used. The expectant treatment group had a mean change in the pain dimension score of (negative numbers indicating improvement in the SF-36), with p<0.01. All other changes had p values higher than Clinical conclusions The authors concluded that the results suggested no differences in health outcomes between the treatment strategies. Outcomes assessed in the review The pregnancy rate achieved was derived froma meta-analysis. Study designs and other criteria for inclusion in the review Sources searched to identify primary studies Criteria used to ensure the validity of primary studies Methods used to judge relevance and validity, and for extracting data Number of primary studies included One meta-analysis. Methods of combining primary studies Meta-analysis. Investigation of differences between primary studies Page: 2 / 5

3 Results of the review The results showed no statistically significantdifference in terms of the cumulative pregnancy rate for surgical and medical management with respect to that obtained by expectant treatment where the endometriosis was minimal or mild. Measure of benefits used in the economic analysis No summary benefit measure was identified in the economic study, and only separate clinical and health outcomes were reported. Direct costs Capital costs were discounted at 6%. The quantities of resources used were not reported. The costs measured were operating costs, costs of complications and capital costs. The cost boundary adopted was hospital and patient. The costs were based on actual data, experts' opinions, authors' assumptions and observation of current practice. The drug unit costs were obtained from NHS prices. Regarding the capital costs, a life span for the facilities involved was assumed, and the overhead costs were approximated by floor use and length of time of operation. The quantities were measured in part during the period January - June The prices used were those of Indirect Costs The quantities were not analysed separately. The costs measured were production losses. The boundary adopted was that of the patient. The estimation of costs was based on actual data provided by the patients by means of a questionnaire administered after treatment and by review of case note records. These notes were completed from January to June The prices used were those of Currency UK pounds sterling (). Sensitivity analysis The variables used in the analysis were the discount rate, the life span of capital and reusable equipment, the salary scales and length of stay after operation. Some values were tried and results compared to baseline. Estimated benefits used in the economic analysis Not applicable. Cost results The average cost per patient for the medical and surgical management options were , and 1,594.06, respectively. The average cost per patient for the expectant management option was The duration of costs was 6 months. Synthesis of costs and benefits Costs and benefits were not combined as the expectant management option was the weakly dominant strategy. The sensitivity analysis showed results were sensitive to the change in the length of stay (from 2 to 3 days for operative laparoscopy, and 4 to 6 days for laparotomy). Authors' conclusions Page: 3 / 5

4 The authors concluded in the following terms: "The results of the economic assessment add cautious support to the growing volume of clinical evidence indicating expectant management as the first line treatment of choice although further research is required to substantiate these results in a larger sample of women presenting with this condition (endometriosis associated infertility)." CRD COMMENTARY - Selection of comparators No health technology was regarded as the comparator since there was no consensus on the appropriate treatment strategy for endometriosis. Validity of estimate of measure of benefit The internal validity of the effectiveness results may be weakened by the lack of randomisation, small sample size,comparison between groups in terms of demographic and prognostic characteristics, and lack of a comprehensive literature review. Furthermore, the authors recognised that 6 months is a short time span over which to assess the effectiveness of the treatment strategies (since "there is evidence to suggest that surgical intervention to remove anatomical distortion improves the likelihood of future pregnancy in cases where the endometriosis is severe. In the long term, treatment may also benefit some patients with a concurrent symptom of pain"). Validity of estimate of costs The quantities of resources used were not reported. No adequate details of cost estimation were given with no breakdown of costs being reported. The hospital costs were reported as obtained only from one institution and this could be potentially important once geographical differences in the way endometriosis is treated are taken into account. Other issues The authors' conclusions were justified by referring to previous evidence consistent with the results reported and, also, based on the sensitivity analysis. The issue of generalisability to other settings or countries was not addressed. A more detailed comparison report would have been appropriate in order to assess the relevance of the results. The results were not presented selectively. Source of funding None stated. Bibliographic details Bodner C, Vale L, Ratcliffe J, Farrar S. Using economics alongside medical audit: a case study of the management of endometriosis. Health Bulletin 1996; 54(3): PubMedID Other publications of related interest Hughes E G, Fewdorkow D M, Collins J A. A quantitative overview of controlled trials in endometriosis-associated infertility. Fertility and Sterility 1993;59: Indexing Status Subject indexing assigned by NLM MeSH Endometriosis /complications /economics; Female; Hospital Costs; Humans; Infertility /economics /etiology /therapy; Medical Audit /economics /methods; Reproducibility of Results; Scotland; Treatment Outcome Page: 4 / 5

5 Powered by TCPDF ( AccessionNumber Date bibliographic record published 31/07/1999 Date abstract record published 31/07/1999 Page: 5 / 5