Type of intervention Treatment. Economic study type Cost-effectiveness analysis.

Transcription

1 Laparoscopic vs open nephrectomy in 210 consecutive patients: outcomes, cost, and changes in practice patterns Kercher K W, Heniford B T, Matthews B D, Smith T I, Lincourt A E, Hayes D H, Eskind L B, Irby P B, Teigland C M 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 Laparoscopic versus open nephrectomy were examined. The laparoscopic approach included both pure and handassisted laparoscopic nephrectomy. Type of intervention Treatment. Economic study type Cost-effectiveness analysis. Study population The study population comprised patients undergoing elective nephrectomy for any indication. No further inclusion or exclusion criteria were reported. Setting The setting was secondary care. The study was conducted in the USA. Dates to which data relate Both the effectiveness and resource use data referred to the study period between August 1998 and September Data on open nephrectomy related to August 1998 to August 2000, whereas data on laparoscopic nephrectomy related to August 2000 to September The price year was not stated. Source of effectiveness data The effectiveness data were derived from a single study. Link between effectiveness and cost data The costing was carried out on the same sample of patients as that used in the effectiveness study. The effectiveness and cost data on open nephrectomy, referring to the first 2 years of the study, were collected retrospectively. After the introduction of laparoscopic nephrectomy at the study site in August 2000, the outcomes and costs of the laparoscopic approach were evaluated prospectively. Study sample The study sample consisted of all patients undergoing elective nephrectomy, performed by the authors 2 years before (open approach) and 2 years after (laparoscopic approach) the introduction of laparoscopic nephrectomy at the hospital where the study was carried out. No power calculations to determine the study size were performed. A total of 210 Page: 1 / 6

2 patients underwent nephrectomy performed by the authors during the study period, and were therefore included in the analysis. Of these, 118 had laparoscopic nephrectomy (87 hand-assisted and 31 pure laparoscopic) and 92 had open nephrectomy. The patients in the laparoscopic group had a mean age of 49.7 years and 56 were men. The patients in the open group had a mean age of 47.3 years and 49 were men. Study design The basis of the analysis was a prospective comparative study with historical controls that was conducted in one institution. The study was conducted over a 4-year interval. The mean duration of follow-up was 13 months (range: 1-48). No loss to follow-up was reported. Analysis of effectiveness The analysis of the clinical study appears to have been conducted on an intention to treat basis. The health outcomes measured were: the operative blood loss and the percentage of patients requiring perioperative blood transfusion; the operative time; the length of hospital stay; the time to return to normal activity for the live donor subset; and the rate of postoperative complications (wound- and non wound-related). The conversion rate from the laparoscopic to open approach was also estimated, and the warm ischaemia time for laparoscopic live donor nephrectomy was recorded. The two patient groups were shown to be comparable at analysis in terms of age, weight, the site of nephrectomy (left, right or bilateral), and the tumour size in the case of patients with renal cell carcinoma. With the exception of partial nephrectomy, which was not offered to patients treated laparoscopically, the distribution of procedure type was equivalent for the two groups. There were more men in the open surgery group (56; 47.5% of the group) than in the laparoscopic group (49; 53.2% of the group). Effectiveness results The mean operative blood loss was 97 ml (range: ) in the laparoscopic group and 216 ml (range: ) in the open surgery group, (p=0.0001). There were no significant differences in blood loss for purely laparoscopic versus hand-assisted laparoscopic nephrectomy. The percentage of patients requiring blood transfusion was 2.5% in the laparoscopic group and 5.4% in the open surgery group, (p=0.44). There were no transfusions in the laparoscopic donor group and one in the open group. The mean operative time was 230 minutes (range: ) for the laparoscopic approach and 187 minutes (range: ) for the open surgery approach, (p=0.0001). The mean operative time for hand-assisted laparoscopic nephrectomy (208 minutes, range: ) was nearly 1 hour less than cases carried out purely laparoscopically (264 minutes, range: ), (p=0.0001). Significant reductions in operative times for hand-assisted laparoscopic nephrectomy occurred with increasing experience of these techniques, (p=0.0007). The mean length of hospital stay was 3.9 days (range: 2-17) for the laparoscopically treated patients and 5.9 days Page: 2 / 6

3 (range: 3-42) for patients undergoing open surgery, (p=0.0001). For the live donor subset, the mean time to return to normal daily activities was 12.1 days (range: 4-25) for those undergoing laparoscopy and 33 days (range: 26-40) for those undergoing open nephrectomy, (p=0.02). The total postoperative complication rate was 14% for laparoscopic nephrectomy and 31% for open nephrectomy respectively, (p=0.01). The wound-related complication rate was 6.8% for the laparoscopic approach and 27.1% for the open approach, (p=0.0001), while the non-wound-related complication rates were 13% (laparoscopic) and 31% (open), respectively, (p=0.01). One case in the laparoscopic group (0.85%) was electively converted to an open procedure. The mean warm ischaemia time for laparoscopic live donor nephrectomy was 78 seconds (range: ). Clinical conclusions Laparoscopic nephrectomy resulted in significantly less blood loss, longer operative time, a shorter length of hospital stay, fewer complications and more rapid recovery than open surgery. Measure of benefits used in the economic analysis No summary measure of benefit was used on the economic analysis. The study was, in effect, a cost-consequences analysis. Direct costs The perspective of the study was consistent with that of a third-party payer. The costs consisted of hospital charges associated with the procedures evaluated. The categories of cost components that constituted the total hospital charges were not analysed. The costs and the quantities were not reported separately. The costs were estimated from actual resource use data referring to patients undergoing nephrectomy during the study period (August 1998 to September 2002). The prices were probably taken from the hospital institution where the study was conducted. The price year was not stated. Discounting was not necessary, as the cost per case was incurred during less than one year, and was therefore not carried out. Statistical analysis of costs The costs were treated stochastically, with a mean value and range being provided. A statistical analysis was undertaken to explore whether the difference in mean costs between the two groups was statistically significant. Indirect Costs The indirect costs were not included in the analysis. Currency US dollars ($). Sensitivity analysis No sensitivity analysis was carried out. Estimated benefits used in the economic analysis Page: 3 / 6

4 See the 'Effectiveness Results' section. Cost results The mean hospital charges were $19,007 (range: 15,807-22,521) for a laparoscopic nephrectomy and $13,581 (range: 9,039-27,592) for an open nephrectomy, (p=0.0001). The total hospital charges were approximately 40% greater in the laparoscopic group. There were no differences in mean hospital charges for hand-assisted laparoscopic nephrectomy versus totally laparoscopic donor nephrectomy. The mean charge for the operating room was substantially higher for laparoscopic cases than for open cases ($5,473 versus $834). It was likely that the hospital charges included costs associated with the treatment of postoperative complications, but this was not stated. Synthesis of costs and benefits Not applicable since, in effect, the study was a cost-consequences analysis. Authors' conclusions Laparoscopic nephrectomy improved patient outcomes, increased the overall case volume in the authors' hospital, and dramatically changed patient patterns. Although this technique was associated with longer operation times and higher total costs than the traditional open approach, the authors felt that its use could be justified on the basis of significant reductions in overall morbidity and a more rapid return to a normal productive life. CRD COMMENTARY - Selection of comparators The selection of the comparator was implicitly justified since it represented the traditional standard of care. You should consider whether the comparator represents widely used health technology in your own setting. Validity of estimate of measure of effectiveness The analysis was based on a prospective comparative study with historical cohort. This type of study is subject to biases. For example, measurement bias caused by the retrospective collection of data for the open nephrectomy group, and bias associated with time trends since the two interventions were not evaluated concurrently. The authors did not report any power calculations, thus the sample size might have been too small to detect some significant differences in outcomes between the groups. There was no evidence that the initial study sample was appropriate for the clinical study question (e.g. it was not shown whether the relative proportions of indications for nephrectomy among the study sample reflected respective proportions in the study population). The patient groups were shown to be comparable at analysis. Statistical analyses were carried out to investigate the association between operation time and surgery date for handassisted and pure laparoscopic cases of nephrectomy. Validity of estimate of measure of benefit The authors did not derive a measure of health benefit. The analysis was, therefore, categorised as a cost-consequences study. Validity of estimate of costs The perspective of the study was consistent with that of a third-party payer. The total hospital charges for each group were estimated. However, it was not reported what cost components these charges included. In addition, the costs and Page: 4 / 6

5 the quantities were not reported separately. Therefore, the reproducibility of the results is compromised. A statistical analysis of the costs was conducted. Hospital charges and not opportunity costs were estimated, but this was justified if the authors' intention was to evaluate the economic burden to payers (insurance companies or patients themselves). Discounting was appropriately not undertaken since the costs were incurred during less than 2 years. The price year was not reported, which hinders the generalisability of the results. Other issues The authors made appropriate comparisons of their findings with those of other studies and showed consistent clinical results. The issue of generalisability to other settings was not addressed. The results appear to have been presented in full. The authors reported, as a weakness of their study, the fact that it combined a diverse group of patients undergoing nephrectomy for a variety of indications and this resulted in difficulties when comparing the study results with those of other studies. However, they expressed the opinion that their results reflected the applicability of laparoscopic nephrectomy for multiple indications and across various surgical specialties. Their conclusions reflected the scope of the analysis. Implications of the study The authors recommended the laparoscopic approach as the technique of choice for elective nephrectomy, despite the associated higher costs and longer operation time. This view was justified based on the better patient outcomes, as well as the increased case volume observed in their hospital after the introduction of laparoscopic nephrectomy. Source of funding None stated. Bibliographic details Kercher K W, Heniford B T, Matthews B D, Smith T I, Lincourt A E, Hayes D H, Eskind L B, Irby P B, Teigland C M. Laparoscopic vs open nephrectomy in 210 consecutive patients: outcomes, cost, and changes in practice patterns. Surgical Endoscopy and Other Interventional Techniques 2003; 17(12): PubMedID DOI /s Indexing Status Subject indexing assigned by NLM MeSH Adolescent; Adult; Aged; Aged, 80 and over; Blood Loss, Surgical; Carcinoma, Renal Cell /surgery; Cohort Studies; Convalescence; Elective Surgical Procedures /economics /statistics & numerical data; Female; Hospital Costs; Humans; Kidney Neoplasms /surgery; Laparoscopy /economics /methods /statistics & numerical data; Length of Stay; Living Donors; Male; Middle Aged; Nephrectomy /economics /methods /statistics & numerical data; North Carolina /epidemiology; Postoperative Complications /epidemiology; Practice Patterns, Physicians'; Prospective Studies; Tissue and Organ Harvesting /economics /methods; Treatment Outcome; Ureter /surgery AccessionNumber Date bibliographic record published 30/04/2005 Page: 5 / 6

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