An economic evaluation of laparoscopy and

Transcription

1 Acta Obstetricia et Gynecologica Scandinavica ISSN ORIGINAL ARTICLE An economic evaluation of laparoscopy and open surgery in the treatment of tubal pregnancy BEN W.J MOL'?~, PETRA J. HAJENIUS~, SiMONE ENGELSBEL3, WILLEM M. ANKUM~, FULCO VAN DER VEEN*, DOUWE J. HEMRIKA3 AND PATRICK M.M. BOSSUYT' From the 'Departments of Clinical Epidemiology and Biostatistics, the 'Department of Obstetrics and Gynecology, Academic Medical Center, University of Amsterdam, and the 3Department of Obstetrics and Gynecology, Onze Lieve Vrouwe Gasthuis, Amsterdam, The Netherlands Actu Ohsret G-yneeol Scund lyy7; 76: Acta Obstet Gynecol Scand 1997 Bmkgrounrl. Laparoscopy has generally replaced open surgery in the treatment of ectopic pregnancy. This study assesses the impact of the introduction of laparoscopy in the surgical treatment of tubal pregnancy on costs. Methods. Consecutive patients undergoing primary surgery for tubal pregnancy between January 1Y92 and December 1995 were included in the study. Surgery was performed laparoscopically or hy open Cost for each treatment was calculated by multiplying resources used with calculated resource unit prices. The analysis was stratified for radical and conservative Results. Data of 255 patients were analysed. Tuba1 prcgnancy was successfully treated in all patients. Costs per patient were US$ 3,490 for radical open surgery, US$ 1,872 for radical laparoscopic surgery, US3.420 for conservative open surgery and US$2,125 for conservative laparoscopic Differences in costs were caused by a decreased duration of hospital stay after laparoscopy, and, in case of conservative surgery, by an increased persistent trophoblast rate after laparoscopy. Corzclusiuns. Laparoscopy is equally effective as open surgery in the treatment of tubal pregnancy, and considerably reduces costs. Kej wordst conservative surgery; economic evaluation; laparoscopy; open surgery; radical surgery; tubal pregnancy Sirhrnittcd 9 May, 1996 Acwpirtrl 5 J~nurrrj~, 1997 In the treatment of tubal pregnancy, laparoscopic surgery has been shown to be as effective as open surgery with respect to the occurrence of persistent trophoblast and fertility outcome in several randomized clinical trials ( 1-5). Laparoscopic techniques are currently applied in various fields of gynecologic surgery, and have been shown to reduce costs in comparison with open surgery (6-8). In a recently published economic evaluation in Sweden that was based on a randomized trial comparing laparoscopy and open surgery for conservative treatment of tubal pregnancy, lapa- roscopy was found to reduce costs by approximately US$ 700,-. (Swedish kronor 4.700,-) compared to open surgery (9). Clinical trials conducted under experimental conditions often imply services that are different from those during daily clinical practice. Results of economic evaluations based on clinical trials should therefore be confirmed by studies based on data registered in a nonexperimental setting (10). In our hospitals laparoscopy for the treatment of tubal pregnancy was introduced in The present study compares the impact of laparoscopy 6 Actu Obstet Gynecol Scund 76 (1997)

2 Costs of surgery for ecotopic pregnunucy 591 in the treatment of tubal pregnancy on medical costs. Materials and methods All patients who underwent primary surgical treatment for tubal pregnancy in the Academic Medical Center - between January 1992 and December and the Onze Lieve Vrouwe Gasthuis - between September 1993 and December in Amsterdam, The Netherlands, were included in the study. From September 1993 onwards, data were collected prospectively. Data on patients operated before September 1993 were collected retrospectively. Patients who were in shock at the time of operation were excluded from the analysis as were patients with heterotopic pregnancies and patients with insufficient data. In both cohorts, the diagnosis tubal pregnancy resulted from a diagnostic strategy based on transvaginal sonography and serum human chorionic gonadotrophin (hcg) monitoring. Whenever a tubal pregnancy was diagnosed, it was confirmed either laparoscopically or by open surgery (1 1). Handling of the Fallopian tube in laparoscopy and open surgery can be radical or conservative. A conservative approach is supposed to generate more costs than a radical approach, because of more persistent trophoblast. Therefore, the analysis in this study was stratified for a conservative or a radical approach. Four groups could be distinguished: radical surgery performed by open surgery, radical surgery performed by laparoscopy, conservative surgery performed by open surgery, and conservative surgery performed by laparoscopy. In our series, the choice of treatment depended on both the clinical situation and the skills of the operating gynecologist. In order to compare the groups at the start of treatment, clinical symptoms (abdominal pain and/ or vaginal blood loss), hcg level on the day of laparoscopy (in IU/L according to the World Health Organization Third International Standard 75/537), gestational age (calculated from the first day of the last menstrual period), presence of peritubal adhesions and tubal rupture were registered. Persistent trophoblast was defined as rising or plateauing postoperative serum hcg concentrations. This complication was treated by systemic administration of methotrexate (MTX) (4 doses 1.O mg/kg alternated with folinic acid 0.1 mg/kg) or by surgery, depending on the clinical situation of the patient. Costs for each surgical treatment were calculated by multiplying resources used and resource unit prices. Resources recorded were duration of the surgical procedure, conversions to open surgery if the treatment was started laparoscopically, hospital stay in days, complications, number of post-operative serum hcg measurements, and reinterventions for persistent trophoblast. Unfortunately, the number of visits to the outpatient clinic after discharge was not recorded. Therefore, we could only estimate this number. Each patient was supposed to visit the outpatient clinic once after discharge. Resource unit prices reflected unit costs for staff, materials, equipment, housing, depreciation, and overheads, the latter both on a department level and on a hospital level. Differences in baseline characteristics were assessed using the Chi-square test, Student's t test, or the Wilcoxon's test. Costs of the four strategies were compared using analysis of variance. Threshold analysis was performed for those resource units that caused a major difference between radical and conservative This analysis identified the hypothetical increase for a given resource Table I. Baseline characteristics Open surgery Laparoscopy Open surgery Laparoscopy n=118 n=39 n=22 n=76 pvalue Clinical symptoms None Abdominal pain Vaginal bleeding Abdominal pain and vaginal bleeding Median hcg at day of surgery (IU/I) (min - rnax) Mean gestational age (days) (SO) Peritubal adhesions Tuba1 rupture p=0.28* ,400 (120-84,000) 3,800 (150-80,000) 1,305 (110-62,650) 2,160 (140-34,300) p=o.loa 51.8 (14.3) 51.1 (11.2) 48 (9.8) 48.7 (10.2) p=0.8gb p=0.17* p<o.ol* Chi-square test a Wilcoxon's test Analysis of variance 0 Acta Ohstet Gynecol Scand 76 (1997)

3 598 B. W.J. Mol et al. Table 11. Resources used for the four surgical treatments and their unit prices Open surgery Laparoscopy Open surgery Laparoscopy Unit Price n=118 n=39 n=22 n= 76 (US Dollars) Mean operation time (minutes) 72 (27) 77 (22) 80 (22) 64 (27) open surgery: /m i n laparoscopy: imin Number of conversions laparoscopy - open surgery /rnin Mean hospital stay per patient (days) (s.d.) 9.0 (2.3)* 2.8 (0.8)* 8.3 (2.51)~ 3.0 (1.2)a 285 Number of patients with pneumonia Number of patients with urinary tract infection Number of patients with thrombo-embolism Number of patients with blood transfusions Mean number of serum hcg measurements per patient (s.d.) 1.8 (1.3) 3.2 (1.4) 2.5 (1.8) 4.6 (2.4) 23 Number of patients with reinterventions for persistent trophoblast ,223 Mean number of hospital visits after discharge per patient * Open versus laparoscopic radical surgery p=o.ool. a Open versus laparoscopic conservative surgery p=o.ool. basis Methotrexate treatment on an outpatient unit, for which the costs of laparoscopy and open surgery would be equal. Results Two hundred and eighty-seven patients were included in the study. From this group, 16 patients were excluded because of shock, three patients because of a heterotopic pregnancy, and 13 patients because of insufficient data. Therefore, 255 patients were available for analysis, of whom I18 patients underwent radical open surgery, 22 conservative open surgery, 39 radical laparoscopic surgery and 76 conservative laparoscopic Clinical symptoms, gestational age, serum hcg concentration and peritubal adhesions in each treatment group showed no significant differences (Table I). Tuba1 rupture was significantly more present in patients undergoing radical surgery than in those undergoing conservative surgery, (p=o.ol, Chi-square test) but did not differ significantly between patients undergoing laparoscopy and open Reintervention for persistent trophoblast was necessary in 19 patients; in one patient (?YO) after radical laparoscopic surgery, in one patient (5 3 11) after conservative open surgery and in 17 (22%) patients after conservative laparoscopic Seventeen of these patients were treated by systemic MTX on an out-patient basis. One patient was treated by salpingectomy, and one patient was managed expectantly. One patient, in whom MTXtherapy failed, required a second reintervention by means of radical open Resource units used for each intervention, and corresponding prices, are presented in Table 11. For open surgery, the mean hospital stay was longer than for laparoscopy. The differences were 6.2 days and 5.3 days for radical and for conservative surgery, respectively. All complications but one occurred in patients treated by open The mean hospital stay after open surgery in patients with complications was 9.0 days, and 7.7 days in patients without complications (p=0.04). Costs are presented in Table 111. Total costs of radical open surgery were US$ 3,490 per patient. Total costs of radical surgery performed by laparoscopy were US$ 1,872 per patient, a reduction by Table 111. Total costs per intervention (US Dollars) Open surgery Laparoscopy Open surgery Laparoscopy Cost of operation Cost of hospital stay 2, , Cost of complications Cost of hcg-measurement Cost of persistent trophobiast Cost of visit to the outpatient clinic Total Costs 3,490 1,872 3,420 2,125 0 Actir Ohstet Gynerol Scnnd 76 (1997)

4 Costs of surgery for ecotopic pregnanacy 599 US$ 1,618 (p=o.ool). This difference was completely caused by the hospital stay after open surgery, which was 6.2 days longer than after laparoscopic surgery, i.e. 9.0 days after radical open surgery versus 2.8 days after radical laparoscopic Total costs of conservative open surgery were US$ 3,420 per patient. Total costs of conservative surgery by laparoscopy were US$ 2,125, a reduction of US$ 1,295 (38%) per patient compared to conservative open surgery (p= 0.001). This difference was also completely caused by a 5.3 days longer hospital stay after open surgery, which was partially compensated by an increase in persistent trophoblast rate from 5% after conservative open surgery to 22% after conservative laparoscopic Threshold analysis was performed for length of hospital stay and for the occurrence of persistent trophoblast. Since the latter is very unlikely to occur after radical surgery, the threshold analysis was only performed for the comparison of laparoscopy and open surgery after conservative Threshold analysis for the length of hospital stay indicated that hospital stay after both conservative and radical open surgery should decrease from 8.9 days to 3.2 days to render the cost of open surgery equal to these of laporoscopic Conservative laparoscopic surgery remains less costly than conservative open surgery, as long as the persistent trophoblast rate is 38% or less. Discussion This paper presents the results of an economic evaluation of open surgery and laparoscopy in the treatment of tubal pregnancy. Laparoscopic surgery was equally effective as open surgery, but reduced costs by almost 46% from US$ 3,500 to US$ 1,900 for radical surgery, and by 38% from US$ 3,400 to US$ 2,100 for conservative Several economic evaluations of the surgical treatment of tubal pregnancy have been published. Laparoscopic surgery was reported to save between US$ 1,500 and US$2,500 compared to open surgery (12-16). However, cost-calculations in these studies were based on charges instead of true costs. In an economic evaluation based on a randomized trial comparing conservative open surgery and conservative laparoscopic surgery for ectopic pregnancy, laparoscopy was reported to save 4,700 Swedish Kronor (approximately US$ 700), considerably less than the savings we found (9). This difference is mainly explained by a 3 days longer hospital stay after open surgery in our patient services. Furthermore, costs of reintervention for persistent trophoblast were considerably lower in our study than in the Swedish trial, possibly due to the fact that we treated persistent trophoblast with MTX on an outpatient basis. Therefore, costs of persistent trophoblast were approximately US$ 1,235 per treatment. In the Swedish study costs of MTX-treatment were reported to be US$6,175 per patient, and cost of surgical reinterventions were US$ 7,400 per patient. The costs presented in our study are based upon used resource units counted in a nonrandomized study. Potential bias in surgical treatment modalities caused by a more severe clinical picture in the open surgery group was minimized by excluding patients who were in shock, because laparoscopic surgery was often no treatment option in these patients. The prolonged hospital stay for open surgery patients with complications compared to open surgery without complications (9.0 days versus 7.7 days) only marginally explains the difference in costs between open and laparoscopic The fact that the mean hospital stay even in patients without complications was 2 days longer than reported elsewhere might be attributed to local circumstances, such as the medical policy or the insurance system that is willing to pay for this policy. However, threshold analysis indicated that hospital stay after open surgery should decrease to 3.2 days to render the cost of open surgery equal to these of laparoscopic Fertility outcome after laparoscopy and open surgery for ectopic pregnancy has already been compared in two randomized clinical trials, showing that the introduction of laparoscopy does not affect future fertility (4, 5). Therefore, we did not take future fertility into account in the present analysis. We detected considerable cost reductions by the introduction of tubal surgery which, however, will not automatically be converted to savings. The latter will only occur if the released resources are reallocated to other products of the hospital. Otherwise, there is no saving of costs. Overall, we conclude that the use of laparoscopic surgery reduces costs considerably without a loss of effectiveness for elimination of trophoblast and for future fertility. Acknowledgments This study was partially supported by grant OG 93/007 from the Dutch Health Insurance Council, Amstelveen, The Netherlands. References 1. Vermesh M, Silva PD, Rosen GF, Stein AL, Fossum GT, Sauer MY Management of unruptured ectopic gestation by linear salpingostomy: a prospective, randomised clinical 0 Acta Obstet Gynecvl Scnnd 76 (1997)

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