|
An economic evaluation of laparoscopy and open surgery in the treatment of tubal pregnancy |
Mol B W, Hajenius P J, Engelsbel S, Ankum W M, van der Veen F, Hemrika D J, Bossuyt P 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 surgery and open surgery in the treatment of tubal pregnancy.
Economic study type Cost-effectiveness analysis (cost-minimisation analysis).
Study population The study population was all patients who underwent primary surgical treatment for tubal pregnancy in the study setting. 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.
Setting Hospital. Two institutions took part in the study which was carried out in Amsterdam, the Netherlands.
Dates to which data relate Effectiveness and resource data were collected retrospectively for surgery carried out before 1993 and prospectively for surgery carried out after 1993. The price year was 1993
Source of effectiveness data The evidence for final outcomes was derived from a single study.
Link between effectiveness and cost data The cost data were based on the sample used for the effectiveness analysis.
Study sample 287 patients were included in the study. 16 were excluded because of shock, three because of heterotopic pregnancy, and 13 patients because of insufficient data. Therefore, 255 patients were available for analysis, of whom 118 underwent radical open surgery, 22 conservative open surgery, 39 radical laparoscopic surgery and 76 conservative laparoscopic surgery. Power calculations to determine the sample size were not undertaken.
Study design This was a cohort study carried out in two centres. Patients were allocated to either the laparoscopic or the open procedures based on the clinical situation and the skills of the operating gynecologists.
Analysis of effectiveness The analysis of the clinical study was based on treatment completers only. In terms of baseline demographic comparisons across the groups, the authors indicated that there were no significant differences in clinical symptoms, gestational age, serum hCG concentration and peritubal adhesions. There was a significantly higher incidence of tubal rupture in patients undergoing radical surgery than in those undergoing conservative surgery. The principal clinical outcomes assessed included success rate, reintervention for persistent trophoblast and number of out-patient visits.
Effectiveness results For both groups the success rate was reported to be 100%. Reintervention for persistent trophoblast was necessary in 19 patients; in one patient (3%) after radical laparoscopic surgery, in one patient (5%) after conservative open surgery, and in 17 patients (22%) after conservative laparoscopic surgery. Seventeen of these patients were treated by systemic MTX on an outpatient basis. One patient was treated by salpingectomy, and one was managed expectantly. One patient, in whom MTX therapy failed, required a second intervention using radical open surgery.
Clinical conclusions Laparoscopy is as effective as open surgery in the treatment of tubal pregnancy.
Measure of benefits used in the economic analysis As the study demonstrated equivalent effectiveness for the clinical outcomes assessed, the benefit was expressed in terms of the reduction in costs. As such the authors conducted a cost-minimisation analysis.
Direct costs Costs and quantities were reported separately. No discounting was carried out due to the short period of the cost analysis (less than 1 year). The costs were based on a provider perspective. 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. The number of visits to the outpatient clinic was not recorded and therefore the authors assumed that each patient visited the outpatient department only once after discharge. Resource unit prices reflected the unit costs for staff, materials, equipment, housing depreciation and overheads. The estimation of quantities was based on calculated means. The price year was not stated.
Statistical analysis of costs The costs of the four strategies were compared using the analysis of variance.
Sensitivity analysis Threshold analysis was performed for those resource units that caused a major difference between radical and conservative surgery. This analysis identified the hypothetical increase for a given resource unit for which the costs of laparoscopy and open surgery would be equal.
Estimated benefits used in the economic analysis The reader is referred to the effectiveness results reported earlier.
Cost results The total costs of radical surgery were $3,490 per patient. The total costs of radical surgery performed by laparoscopy were $1,872 per patient, a reduction of $1,618, (p=0.001). This difference was caused by the hospital stay after open surgery, which was 6.2 days longer than after laparoscopic surgery i.e. 9 days after radical open surgery compared to 2.8 days after radical laparoscopic surgery. The total costs of conservative open surgery were $3,420 per patient. The total costs of conservative surgery by laparoscopy were $2,125 a reduction of $1,295 (38%) per patient, (p=0.001) This difference was also caused by the longer hospital stay required after open surgery (5.3 days longer). This was partially compensated by an increase in persistent trophoblast rate from 5% after conservative open surgery to 22% after conservative laparoscopic surgery.
Synthesis of costs and benefits Laparoscopic surgery reduced costs by almost 46% from $3,500 to $1,900 for radical surgery and by 38% from $3,400 to $2,100 for conservative surgery. The threshold analysis showed that the length of stay after both conservative and radical open surgery would need to reduce from 8.9 days to 3.2 days to render the costs of open surgery equal to those of laparoscopy. Conservative laparoscopic surgery remained less costly then conservative open surgery as long as the persistent trophoblast rate was less than 38%.
Authors' conclusions The authors concluded that the use of laparoscopic surgery reduced costs considerably without loss of effectiveness in the elimination of trophoblast and for future fertility.
CRD COMMENTARY - Selection of comparators The rationale for the choice comparator was clear as the new technology of laparoscopic procedures was compared with an existing practice.
Validity of estimate of measure of benefit The non-randomised nature of the effectiveness analysis and the means of patient allocation (based on clinical circumstances and the available surgical skills) meant that it is likely that a degree of selection bias is present. Within these limitations, the authors demonstrated equivalent effectiveness and their cost-minimisation approach was, therefore, justified. Although future fertility was mentioned, it was not taken into account in the analysis but may clearly be an issue in the long-term for these patients. The measure of estimate of benefit may have been compromised by the exclusion of patients who were in shock, as laparoscopic treatment was not an option offered to these patients. However, the authors justified this exclusion criterion.
Validity of estimate of costs The reporting of costs was comprehensive as the authors considered costs and quantities for each intervention separately. However, the validity of the estimate of cost may have been compromised by the fact that they were based on resource use units derived from a non-randomised study. The authors also acknowledged that they did not collect the number of outpatient visits made and introduced an estimate to cover this aspect of their analysis. The authors undertook good sensitivity analysis on sensitive cost variables. The lack of a price year limits the generalisability of the cost results.
Other issues As the authors mentioned the prolonged hospital stay for open surgery patients with complications compared with open surgery without complications only marginally explains the difference in costs between the interventions. The principal factor in explaining the cost results is clearly identified in the differences in length of stay between the two procedures.
Implications of the study Laparoscopic surgery should be performed in preference to open surgery in the treatment of uncomplicated tubal pregnancy.
Bibliographic details Mol B W, Hajenius P J, Engelsbel S, Ankum W M, van der Veen F, Hemrika D J, Bossuyt P M. An economic evaluation of laparoscopy and open surgery in the treatment of tubal pregnancy. Acta Obstetricia et Gynecologica Scandinavica 1997; 76(6): 596-600 Indexing Status Subject indexing assigned by NLM MeSH Adult; Analysis of Variance; Chi-Square Distribution; Female; Humans; Laparoscopy /economics; Netherlands; Pregnancy; Pregnancy, Tubal /surgery AccessionNumber 21997001033 Date bibliographic record published 30/11/2000 Date abstract record published 30/11/2000 |
|
|
|