|
Induction of labour versus expectant management for prelabour rupture of the membranes at term: an economic evaluation |
Gafni A, Goeree R, Myhr T L, Hannah M E, Blackhouse G, Willan A R, Weston J A, Wang E E, Hodnett E D, Hewson S A, Farine D, Ohlsson A |
|
|
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 Induction of labour versus expectant management for prelabour rupture of the membranes at term. Four different health management strategies were compared including induction with oxytocin (IwO), induction with prostaglandin (IwP), expectant management and induction with oxytocin (EM-O) or prostaglandin (EM-P) if complications developed.
Type of intervention Labour management strategies.
Economic study type Since no statistically significant differences were found between the 4 management strategy groups in terms of the primary and secondary outcomes, then a cost-minimisation form of cost-effectiveness analysis was performed.
Study population Women with prelabour rupture of membranes at term.
Setting Community and secondary care. The economic analysis was conducted in Ontario, Canada.
Dates to which data relate Effectiveness data in the TERMPROM trial were collected between 1 January 1992 and 31 May 1995. Cost data were calculated for the year 1995.
Source of effectiveness data The estimate for final outcomes was derived from a single study.
Link between effectiveness and cost data Costing was undertaken prospectively alongside the clinical portion of the TERMPROM study. Unit costs were calculated by analysing resource utilisation in only 16% of the hospitals considered for effectiveness analysis.
Study sample 5,041 women participated in the study and were randomly assigned to 1 of the 4 management strategies: 1,263 to the EM-O group, 1,258 to the IwO group, 1,259 to the IwP group and 1,261 to the EM-P group. A computerised randomisation program was used. To ensure that the four groups were comparable, randomisation was carried out in blocks of 4 and 8 and stratified according to centre and parity. Power calculations relating to the sample size were performed.
Study design This was an economic analysis conducted alongside a large, multicentre, randomised controlled clinical trial, using a third-party payer perspective.
Analysis of effectiveness The primary health outcome measure used was neonatal infection and the secondary outcome measures were rates of caesarean section and women's evaluation of their treatment. The analysis was based on intention to treat.
Effectiveness results The rates of neonatal infection and caesarean section were not significantly different across the study groups. The rates of neonatal infection were 2.0% for the IwP group, 3.0% for the IwO group, 2.8% for the EM-O group and 2.7% for the EM-P group. The rates for caesarean section ranged from 9.6% to 10.9%. Women in the induction groups were less likely to say they liked 'nothing' about their treatment than those in the expectant-management groups.
Clinical conclusions In women with prelabour rupture of the membranes at term, induction of labour with oxytocin and prostaglandin E2 gel and expectant management resulted in similar rates of neonatal infection and caesarean section. Clinical chorioamnionitis was less likely to develop in women in the IwO group than in those in the EM-O group (4% versus 8.6%), as was postpartum fever (1.9% versus 3.6%).
Measure of benefits used in the economic analysis The authors did not provide any measure of benefits as the economic information was presented as a cost-minimisation analysis. Worthy of note is that the authors stressed that the management strategy of choice by fully informed women is important at the point of decision-making. For clinical effectiveness information consult Hannah, 1996.
Direct costs A third-party-payer perspective was chosen for the cost analysis. Accordingly, all hospital expenses (for nursing services, operative procedures and diagnostic services), professional fees and the cost of induction medications were included. The analysis included all treatment costs incurred for both mother and baby from the time of randomisation to hospital discharge. Costs were calculated for the year 1995. Costs and quantities were reported separately and estimation of quantities and costs was based on actual data.
Statistical analysis of costs Costs were treated in a stochastic way and treatment groups were compared by means of the Wilcoxon rank-sum test. Statistical analyses were conducted to compare: IwO versus EM-O, IwP versus EM-P and IoW versus IwP.
Indirect Costs Indirect costs such as the patient's expenses and time off work were excluded and, given the third party payer perspective, this was appropriate.
Currency Costs were given in the currency of the particular country to which they refer, i.e. Canadian dollars (Can$), Pounds sterling () and Australian dollars (Aus$) and all are for 1995.
Sensitivity analysis Sensitivity analyses were conducted to explore the robustness of results to a range of alternative values of costs (generalisability of results). One-way simple sensitivity analyses were undertaken and results were checked to see if they were sensitive to the set (base, low and high) of unit costs chosen.
Estimated benefits used in the economic analysis Cost results The median cost of IwO per patient was statistically significantly lower than that of EM-O and IwP. This result held in all 3 countries compared (-Can$114 and -Can$46 in Canada, -113 and -63 in the UK, and -Aus$30 and -Aus$49 in Australia) after an extensive sensitivity analysis. There was no statistically significant difference in median cost per patient between IwP and EM-P.
Synthesis of costs and benefits Costs and benefits were not synthesised.
Authors' conclusions In the clinical evaluation study (TERMPROM trial), even though IwO was not found to be preferable to the other treatment alternatives, the economic evaluation found it to be less costly. The authors noted that these cost differences, even though statistically significant, are not likely to be important in many countries and they suggest that, if this is so, then women should be offered a choice between management strategies.
CRD COMMENTARY - Selection of comparators The reason for the choice of the comparators (4 labour management strategies) is clear as all were widely used in the settings analysed.
Validity of estimate of measure of benefit Whilst clinical benefits were analysed in a previous study (and no statistically significant differences in neonatal infection and Cesarean infection were found) no economic benefits were analysed in this study.
Validity of estimate of costs Costs appear to be valid, with no important cost elements missing and with a thorough statistical analysis to support them. Since no statistically significant differences were found between the 4 management strategy groups in terms of the primary and secondary outcomes, then a cost-minimisation form of cost-effectiveness analysis was performed.
Other issues As the authors themselves acknowledged, the cost results may not be generalisable to other countries. Within countries there were substantial variation in unit costs for high-cost services.
Source of funding Supported by a grant (MA-11392) from the Medical research Council of Canada.
Bibliographic details Gafni A, Goeree R, Myhr T L, Hannah M E, Blackhouse G, Willan A R, Weston J A, Wang E E, Hodnett E D, Hewson S A, Farine D, Ohlsson A. Induction of labour versus expectant management for prelabour rupture of the membranes at term: an economic evaluation. CMAJ: Canadian Medical Association Journal 1997; 157(11): 1519-1525 Other publications of related interest Comment in: Canadian Medical Association Journal 1997;157(11):1541-2.
Hannah M E, Ohlsson A, Farine M D, et al. Induction of labour compared with expectant management for prelabour rupture of the membranes at term. New England Journal of Medicine 1996;334(16): 1005-10.
Indexing Status Subject indexing assigned by NLM MeSH Australia; Canada; Dinoprostone /economics /therapeutic use; Female; Fetal Membranes, Premature Rupture /economics /therapy; Great Britain; Health Care Costs /statistics & Humans; Labor, Induced /economics /methods /statistics & Oxytocics /economics /therapeutic use; Oxytocin /economics /therapeutic use; Pregnancy; Pregnancy Trimester, Third; Statistics, Nonparametric; numerical data; numerical data AccessionNumber 21997008380 Date bibliographic record published 31/10/2000 Date abstract record published 31/10/2000 |
|
|
|