The cost-utility of intravenous magnesium sulfate for treating asthma exacerbations in children.

INTRODUCTION: Although evidence supports the use of intravenous magnesium sulfate (MS) in asthma exacerbations, MS continues to be considered a second-line drug for managing pediatric asthma exacerbations. This study aimed to evaluate the cost-utility of MS in asthma exacerbations. METHODS: We used a decision tree model to estimate the cost-utility of MS compared to treatment without MS (control group) in children with asthma exacerbations. Cost data were obtained from a retrospective study from tertiary centers in Rionegro, Colombia, while utilities were collected from the literature. Probabilistic sensitivity analysis was carried out using the Monte Carlo technique with a simulation of a hypothetical cohort of 10 000 patients to generate expected cost utilities with 95% confidence intervals. We used a cost-effectiveness acceptability curve to evaluate the uncertainty surrounding the cost-utility of MS. RESULTS: The model showed that MS had a lower total cost than the control group (US $1149 vs US $1598 average cost per patient) and higher quality-adjusted life years (0.60 vs 0.52 average per patient), showing dominance. The probability that MS provides a more cost-effective use of resources compared with standard therapy exceeds 99% for all willingness-to-pay thresholds. CONCLUSION: Intravenous MS was less expensive and more effective than treatment without intravenous MS in children with asthma exacerbations. Our study provides evidence that should be used by decision-makers to improve clinical practice guidelines and should be replicated to validate its results in other middle-income countries.

Protection of brain development by antenatal magnesium sulphate for infants born preterm.

Cerebral palsy (CP) remains the most significant neurological disorder associated with preterm birth. It disrupts quality of life and places huge cost burdens on society. Antenatal magnesium sulphate administration to females before 32 weeks' gestation has proven to be an effective intervention to reduce the rate of CP. In models of hypoxia, hypoxia-ischemia, inflammation, and excitotoxicity in various animal species, magnesium sulphate preconditioning decreased the resulting lesion sizes and inflammatory cytokine levels, prevented cell death, and improved long-term cognitive and motor behaviours. In humans, meta-analyses of five randomized controlled trials using magnesium sulphate as a neuroprotectant showed prevention of CP at 2 years. The benefit remained consistent regardless of gestational age, cause of preterm birth, and total dose received. Antenatal magnesium sulphate treatment is now recommended by the World Health Organization and by many obstetric societies. Its cost-effectiveness further justifies its widespread implementation. WHAT THIS PAPER ADDS: Neuroprotective effect of magnesium sulphate to reduce cerebral palsy in infants born preterm when administered to females at risk of imminent preterm birth. Neuroprotection regardless of gestational age, cause of preterm birth, and total dose. Antenatal magnesium sulphate treatment has good cost-effectiveness.

Evaluation of a low-cost, low-power syringe pump to deliver magnesium sulfate intravenously to pre-eclamptic women in a Malawian referral hospital.

BACKGROUND: Magnesium sulfate is an affordable and effective treatment for pre-eclampsia and eclampsia. In settings where infusion pumps are not available to regulate the flow rate of intravenous delivery, healthcare providers must administer magnesium sulfate (MgSO4) via time-consuming and painful, large-volume intramuscular injections. As an alternative to costly commercially available syringe pumps, we developed AutoSyp, an accurate, low-cost, and low-powered syringe pump designed to meet the needs and constraints these low-resource settings. This paper describes results of a pilot study to evaluate the feasibility of using AutoSyp to administer MgSO4 intravenously to women suffering from pre-eclampsia at a referral hospital in Blantyre, Malawi. METHODS: AutoSyp was programmed to deliver MgSO4 following the Zuspan regimen to pregnant and post-partum women suffering from pre-eclampsia at Queen Elizabeth Central Hospital in Blatnyre, Malawi. Given the selection of either loading or maintenance dose on AutoSyp's user interface, the flow rate was automatically programmed to dispense 60 mL/h or 5 mL/h of 20% MgSO4 solution, respectively. During each treatment, the dispensed volume was automatically calculated by the device based on the plunger position and stored on a computer for accuracy analysis of the mean flow rate and total volume delivered. The clinical results for both the loading and maintenance dose administrations were compared to the device's accuracy during tests performed in the laboratory setting. RESULTS: Twenty-two women were enrolled in this study. In both the clinical and laboratory settings, the mean flow rate errors for the loading and maintenance dose infusions were under 2%. During 466 h of testing, the device sounded 129 occlusion alarms across 14 subjects. Of these, 71 alarms were false positives. CONCLUSION: Results of this study support the use of AutoSyp as a less painful and accurate means of MgSO4 administration in clinical environments that lack infusion systems. There were a large number of false alarms in the current system which will be addressed in future designs. AutoSyp maintains the comfort of intravenous MgSO4 administration, but unlike commercially available syringe pumps, it is capable of operating with a variety of syringe brands and sizes and requires no additional consumables. AutoSyp's appropriate design will benefit its implementation and sustained use in low-resource settings. TRIAL REGISTRATION: Trial registered prospectively on November 18, 2014 with ClinicalTrials.gov ( NCT02296931 ).

Economic evaluation of nebulized magnesium sulphate in acute severe asthma in children.

OBJECTIVES: The aim of this study was to estimate the cost-effectiveness of nebulized magnesium sulphate (MgSO4) in acute asthma in children from the perspective of the UK National Health Service and personal social services. METHODS: An economic evaluation was conducted based on evidence from a randomized placebo controlled multi-center trial of nebulized MgSO4 in severe acute asthma in children. Participants comprised 508 children aged 2-16 years presenting to an emergency department or a children's assessment unit with severe acute asthma across thirty hospitals in the United Kingdom. Children were randomly allocated to receive nebulized salbutamol and ipratropium bromide mixed with either 2.5 ml of isotonic MgSO4 or 2.5 ml of isotonic saline on three occasions at 20-min intervals. Cost-effectiveness outcomes were constructed around the Yung Asthma Severity Score (ASS) after 60 min of treatment; whilst cost-utility outcomes were constructed around the quality-adjusted life-year (QALY) metric. The nonparametric bootstrap method was used to present cost-effectiveness acceptability curves at alternative cost-effectiveness thresholds for either: (i) a unit reduction in ASS; or (ii) an additional QALY. RESULTS: MgSO4 had a 75.1 percent probability of being cost-effective at a GBP 1,000 (EUR 1,148) per unit decrement in ASS threshold, an 88.0 percent probability of being more effective (in terms of reducing the ASS) and a 36.6 percent probability of being less costly. MgSO4 also had a 67.6 percent probability of being cost-effective at a GBP 20,000 (EUR 22,957) per QALY gained threshold, an 8.5 percent probability of being more effective (in terms of generating increased QALYs) and a 69.1 percent probability of being less costly. Sensitivity analyses showed that the results of the economic evaluation were particularly sensitive to the methods used for QALY estimation. CONCLUSIONS: The probability of cost-effectiveness of nebulized isotonic MgSO4, given as an adjuvant to standard treatment of severe acute asthma in children, is less than 70 percent across accepted cost-effectiveness thresholds for an additional QALY.

Magnesium sulphate for fetal neuroprotection: a cost-effectiveness analysis.

BACKGROUND: The aim of this study was to assess the cost-effectiveness of administering magnesium sulphate to patients in whom preterm birth at < 32+0 weeks gestation is either imminent or threatened for the purpose of fetal neuroprotection. METHODS: Multiple decision tree models and probabilistic sensitivity analyses were used to compare the administration of magnesium sulphate with the alternative of no treatment. Two separate cost perspectives were utilized in this series of analyses: a health system and a societal perspective. In addition, two separate measures of effectiveness were utilized: cases of cerebral palsy (CP) averted and quality-adjusted life years (QALYs). RESULTS: From a health system and a societal perspective, respectively, a savings of $2,242 and $112,602 is obtained for each QALY gained and a savings of $30,942 and $1,554,198 is obtained for each case of CP averted when magnesium sulphate is administered to patients in whom preterm birth is imminent. From a health system perspective and a societal perspective, respectively, a cost of $2,083 is incurred and a savings of $108,277 is obtained for each QALY gained and a cost of $28,755 is incurred and a savings of $1,494,500 is obtained for each case of CP averted when magnesium sulphate is administered to patients in whom preterm birth is threatened. CONCLUSIONS: Administration of magnesium sulphate to patients in whom preterm birth is imminent is a dominant (i.e. cost-effective) strategy, no matter what cost perspective or measure of effectiveness is used. Administration of magnesium sulphate to patients in whom preterm birth is threatened is a dominant strategy from a societal perspective and is very likely to be cost-effective from a health system perspective.

Health system barriers to access and use of magnesium sulfate for women with severe pre-eclampsia and eclampsia in Pakistan: evidence for policy and practice.

Severe pre-eclampsia and eclampsia are rare but serious complications of pregnancy that threaten the lives of mothers during childbirth. Evidence supports the use of magnesium sulfate (MgSO4) as the first line treatment option for severe pre-eclampsia and eclampsia. Eclampsia is the third major cause of maternal mortality in Pakistan. As in many other Low- and Middle-Income Countries (LMIC), it is suspected that MgSO4 is critically under-utilized in the country. There is however a lack of information on context-specific health system barriers that prevent optimal use of this life-saving medicine in Pakistan. Combining quantitative and qualitative methods, namely policy document review, key informant interviews, focus group discussions and direct observation at health facility, we explored context-specific health system barriers and enablers that affect access and use of MgSO4 for severe pre-eclampsia and eclampsia in Pakistan. Our study finds that while international recommendations on MgSO4 have been adequately translated in national policies in Pakistan, the gap remains in implementation of national policies into practice. Barriers to access to and effective use of MgSO4 occur at health facility level where the medicine was not available and health staff was reluctant to use it. Low price of the medicine and the small market related to its narrow indications acted as disincentives for effective marketing. Results of our survey were further discussed in a multi-stakeholder round-table meeting and an action plan for increasing access to this life-saving medicine was identified.

Availability of treatment for eclampsia in public health institutions in Maharashtra, India.

Severe pre-eclampsia and eclampsia are common causes of maternal deaths worldwide and more so in developing countries. Magnesium sulphate (MgSO4) is now the most-recommended drug of choice to treat these conditions. Despite favourable policies for the use of MgSO4 treatment in India, eclampsia continues to take a high toll. This study examined the availability and use of MgSO4 treatment in the public health system and poor women's recent experiences with eclampsia treatment in Maharashtra state. A mix of qualitative and quantative methods was used. A facility-based survey of all secondary and tertiary healthcare facilities (n = 44) in 3 selected districts and interviews with public and contracted-in private sector obstetricians, health officials, and programme managers were conducted. A list of recently-delivering women from marginalized communities, with up to two livebirths, was drawn through a community-level survey in 272 villages covered by 60 subcentres selected at random. Mothers were selected for interviews, using maximum variation sampling, and interviews were conducted with 17% of the mothers who reported having experienced eclampsia; 61% of facilities had no stock of MgSO4, the stock-out position continuing from a period ranging from 3 months to 3 years while another 20% had some stock, although less than the expected minimum quantity. No treatment for eclampsia was provided in the recent 3 months at 73% facilities. Our survey of recently-delivering mothers recorded a history of eclampsia in 3.2% pregnancies/ deliveries. Interviews with 10 such mothers revealed that treatment for eclampsia has been sought from public as well as private hospitals and from traditional healers. However, facilities where women have received medical treatment are exclusively in the private sector. Almost all public and private care providers were aware of MgSO4 as the gold standard to treat eclampsia; however, it is unclear if they knew of its use to treat severe pre-eclampsia. The private care providers routinely used MgSO4 for eclampsia treatment while the public care providers seemed hesitant to use it fearing risks of complications. We stress the need for improved inventory control practices to ensure sustained availability of supplies and building confidence of care providers in using MgSO4 treatment for severe pre-eclampsia and eclampsia in public facilities, in addition to teaching expectant mothers how to recognize symptoms of these conditions.

Benefits of using magnesium sulphate (MgSO4) for eclampsia management and maternal mortality reduction: lessons from Kano State in Northern Nigeria.

BACKGROUND: Despite clear emphasis through the Millennium Development Goals, the problem of high maternal mortality persists especially within low and middle income countries. Various studies report remarkably high maternal mortality rates in northern Nigeria, where maternal mortality rates exceed 1,000 deaths per 100,000 live births and eclampsia contributes approximately 40% of maternal deaths. Across Nigeria, diazepam is routinely used for the management of eclampsia. Prior to February 2008, diazepam was widely used for the management of eclampsia in Kano State (within northern Nigeria) with case fatality rate being over 20%. While magnesium sulphate (MgSO4) is recognized as the most effective drug for the management of eclampsia; this study aims to compare MgSO4 therapy with diazepam therapy in terms of case fatality rates and costs. FINDINGS: This retrospective study, including 1045 patients with eclampsia and pre-eclampsia during the years 2008 and 2009, reports a drop in case fatality rates from 20.9% (95% CI: 18.7, 23.2) to 2.3% (95% CI: 1.4, 3.2) among eclampsia patients following the MgSO4 intervention. The study observed no significant difference in the cost of using MgSO4 therapy compared to diazepam therapy. CONCLUSIONS: The study found a remarkable reduction in case fatality rate due to eclampsia in those who received MgSO4 therapy with minimal increase in costs when compared to diazepam therapy. Concerted efforts should be focused on properly introducing MgSO4 into emergency obstetric protocols especially within developing countries to reduce maternal mortality and also impact on health system performance.

Magnesium sulfate therapy for the prevention of cerebral palsy in preterm infants: a decision-analytic and economic analysis.

OBJECTIVE: We sought to estimate the cost-effectiveness of magnesium neuroprophylaxis for all women at risk for preterm birth <32 weeks. STUDY DESIGN: A decision analytic and cost-effectiveness model was designed to compare use of magnesium for neuroprophylaxis vs no treatment for women at risk for preterm birth <32 weeks due to preterm premature rupture of membranes or preterm labor from 24-32 weeks. Outcomes included neonatal death and moderate-severe cerebral palsy. Effectiveness was reported in quality-adjusted life years. RESULTS: Magnesium for neuroprophylaxis led to lower costs ($1739 vs $1917) and better outcomes (56.684 vs 56.678 quality-adjusted life years). However, sensitivity analysis revealed the model to be sensitive to estimates of effect of magnesium on risk of moderate or severe cerebral palsy as well as neonatal death. CONCLUSION: Based on currently published evidence for efficacy, magnesium for neuroprophylaxis in women at risk to deliver preterm is cost-effective.

Loading dose of magnesium sulphate versus standard regime for prophylaxis of pre-eclampsia.

OBJECTIVE: To determine the efficacy of single dose of magnesium sulphate versus the standard Pritchard regime in the management of pre-eclampsia. STUDY DESIGN: Quasi-experimental study. PLACE AND DURATION OF STUDY: Jinnah Postgraduate Medical Centre, Karachi, from January 2004 to January 2006. METHODOLOGY: All women with severe pre-eclampsia and impending eclampsia were included in the study. Patients with pregnancy induced hypertension and mild to moderate pre-eclampsia were excluded. From the 100 women included in the study, after matching for age, parity and gestational age, 50 were given only bolus dose of magnesium sulphate and 50 were given the standard regime. They were observed for one week for the number of convulsions. Fisher's exact test and Chi-square test were used to analyze results. RESULTS: There was no significant difference in the two groups in term of occurrence of seizures, one patient developed fit with Pritchard regimen. The rate of caesarean section was lower in group A, 12% versus 30% in group B (p=0.05). There was no significant difference in perinatal outcome in either group (82% live births in group A versus 72% amongst group B (p=0.2). Few side effects like vomiting, dizziness and irritation at the site of injection were observed when standard treatment was used. Single dose treatment was also found to be cost-effective costing Pak Rs. 45 (US $ 0.56) as compared to Pak Rs. 195 (US $ 2.4) in control group. No maternal death was observed in either group. CONCLUSION: Having the equal effectiveness, ease of monitoring and cost-effectiveness, single loading dose of magnesium sulphate is preferable over the standard regime in the management of pre-eclampsia as a prophylactic measure for prevention of seizure.

The valuation of prenatal life in economic evaluations of perinatal interventions.

Perinatal interventions delivered during the prenatal period have the potential to directly impact prenatal life. The decision on when to begin 'counting' the life of an infant in the calculus has received little attention in previous economic evaluations of perinatal interventions. We illustrate, using data from a recent trial-based economic evaluation of magnesium sulphate given to women with pre-eclampsia to prevent eclampsia, how different definitions of when human life commences can have a significant impact upon cost-effectiveness estimates based on composite outcome measures such as life years or quality-adjusted life years gained or disability-adjusted life years averted. Further, we suggest ways in which methods in this area can be improved.

Intravenous magnesium sulphate and sotalol for prevention of atrial fibrillation after coronary artery bypass surgery: a systematic review and economic evaluation.

OBJECTIVES: To assess the clinical and cost-effectiveness of magnesium sulphate compared with sotalol, and to assess the clinical effectiveness of magnesium sulphate compared with placebo in the prevention of atrial fibrillation (AF) in patients who have had a coronary artery bypass graft (CABG). DATA SOURCES: Major electronic databases were searched from December 2003 to May 2007. REVIEW METHODS: Selected studies were assessed, subjected to data extraction using a standard template and quality assessment using published criteria. A simple short-term economic model was developed, informed by a systematic review of economic evaluations and populated with data from a review of costing/resource-use studies and other published studies. The cost-effectiveness of magnesium sulphate as prophylaxis was estimated for a set of base-case assumptions and the robustness of these results was assessed using deterministic and probabilistic sensitivity analysis. RESULTS: Twenty-two papers met the inclusion criteria reporting 15 trials which all compared magnesium sulphate with placebo or control. They ranged in size from 15 to 176 patients randomised, and were conducted in Europe, the USA and Canada. The standard of reporting was generally poor, with details of key methodological attributes difficult to elucidate. No trials were identified that specifically aimed to compare magnesium sulphate with sotalol. Of 1070 patients in the pooled magnesium group, 230 (21%) developed postoperative AF, compared with 307 of 1031 (30%) patients in the placebo or (control) group. Meta-analysis using a fixed-effects model generated a pooled odds ratio (OR) that was significantly less than 1.0 [OR=0.65, 95% confidence interval (CI) 0.53 to 0.79, test for overall effect p<0.0001], but with statistically significant heterogeneity (I2=63.4%, p=0.0005). Two randomised controlled trials (RCTs) were notable as they had relatively lower ORs in favour of magnesium sulphate. When these were removed from the analyses the pooled OR remained statistically significant, but heterogeneity no longer remained significant. These two studies tended to impart a highly significant reduction in the odds of AF to whichever subgroup they were analysed in. When studies were ordered by total duration of prophylaxis, an apparent relationship between duration and odds of AF was evident, with decreasing odds of AF as duration of prophylaxis increased. This was confirmed by linear regression analysis (R2=0.743, p<0.001). When the data were grouped into three classes according to duration, a statistically significant intervention effect was only present for the longest duration (OR=0.12, 95% CI 0.06 to 0.23, p=0.00001). Statistically significant intervention effects were associated with the initiation of prophylaxis 12 hours or more before surgery (OR 0.26; 95% CI 0.16 to 0.44, test for overall effect p=0.00001, fixed-effects model) and less than 12 hours before surgery or during the surgery itself (OR=0.73, 95% CI 0.56 to 0.97, test for overall effect p = 0.03, fixed-effects model), but not when prophylaxis was initiated at the end of surgery or postsurgery (OR=0.85, 95% CI 0.59 to 1.22, p=0.37, fixed-effects model). When studies were ordered by total dose of intravenous magnesium sulphate (<25 g), the odds of AF were independent of the dose. A notable exception was that for a total dose of 9 g magnesium sulphate; here the odds of AF were significantly reduced relative to the control group, although this may be explained by the fact that these studies had excluded patients who were on antiarrhythmic drugs and so may have been at higher risk of AF. Sixty-three potentially relevant references about cost-effectiveness were identified, but no economic evaluations of intravenous magnesium alone as prophylaxis against AF following CABG, compared with sotalol as prophylaxis or no prophylaxis, were identified. Studies reporting resource use by patients with AF following CABG suggest that while AF significantly increased inpatient stays, by up to 2.3 days in the intensive care unit (ICU) and 3.4 days on the ward, differences in length of stay and costs between patients receiving prophylaxis and those not receiving prophylaxis were not statistically significant. In the base-case analysis, magnesium sulphate prophylaxis resulted in 0.081 fewer cases of AF at an incremental cost of 2.55 pounds sterling. The incremental cost-effectiveness ratio (ICER) was 32 pounds sterling per AF case avoided. The estimated difference in average length of stay between the prophylaxis and no-prophylaxis strategies was only 0.24 days, despite a large assumed difference of 3 days for patients experiencing AF in each group (1 extra day in the ICU and 2 extra days on the ward). In a deterministic sensitivity analysis the greatest variation in ICERs was observed for input parameters relating to the baseline risk of AF following CABG and the effectiveness of prophylaxis, cost of prophylaxis and the resource consequences of postoperative AF. The largest ICER (2092 pounds sterling) in the sensitivity analysis was associated with increasing the length of patients' preoperative stay. In the base case it was assumed that admission routines would be identical under both strategies. However, patients receiving prophylaxis by intravenous infusion may have longer preoperative stays. In a probabilistic analysis the majority of the simulations were associated with improved outcomes (in this case fewer cases of AF), but also higher costs. Prophylaxis was the dominant strategy (better outcome at lower cost) in about 41% of the simulations using the base-case assumptions. Under an alternative scenario where patients receiving prophylaxis are admitted for longer before their operation, to receive their initial infusion, the proportion of simulations where prophylaxis dominates fell to around 5%. The probability of being cost-effective was 99% at a willingness to pay (WTP) threshold of 2000 pounds sterling per AF case avoided and 100% at a WTP threshold of 5000 pounds sterling per AF case avoided under the base-case assumptions. Under the alternative scenario of longer preoperative stays the probability of being cost-effective at these two threshold values fell to 48% and 93%, respectively. It is unclear what the appropriate decision threshold should be, given that this model used intermediate rather than final outcomes. CONCLUSIONS: No RCTs were identified that specifically aimed to compare intravenous magnesium with sotalol as prophylaxis for AF in patients undergoing CABG. Intravenous magnesium, compared with placebo or control, is effective in preventing postoperative AF, as confirmed by a statistically significant intervention effect based on pooled analysis of 15 RCTs. It was also found that AF was less likely to occur when a longer duration of prophylaxis was used, and the earlier that prophylaxis is started; however, this finding was associated with two RCTs that had more favourable results than the other trials. No clear relationship between dose and AF was observed, although a lower constant dose rate was associated with the lowest odds of AF. Further research should investigate the relationship between dose, dose rate, duration of prophylaxis, timing of initiation of therapy and patient characteristics, such as degree of risk for AF. This will provide stronger evidence for the optimum delivery of intravenous magnesium in patients undergoing CABG. In the base-case analysis in the economic model, magnesium sulphate prophylaxis reduced the number of postoperative AF cases at a modest increase in cost. The results of the economic analysis are highly sensitive to variation in certain key parameters. Prophylaxis is less likely to be a cost-effective option if it requires changes in admission routines that result in longer preoperative stays than would be the case without prophylaxis.

A cost decision analysis of 4 tocolytic drugs.

OBJECTIVE: The purpose of this study was to determine the optimal tocolytic agent, based on a cost decision analysis. STUDY DESIGN: A PubMed search of commonly used tocolytics was performed to determine the probability of adverse events. Cost for an agent was determined by acquisition cost and the probability and cost of adverse events. A decision tree was constructed to determine which tocolytic had the lowest total costs, with subsequent sensitivity analysis. RESULTS: A total of 19 clinical trials combined for a cohort of 1073 patients (indomethacin, 176 patients; magnesium sulfate, 451 patients; nifedipine, 176 patients; and terbutaline, 270 patients). The probability of adverse events was 57.9% for terbutaline, 22.0% for magnesium sulfate, 27.2% for nifedipine, and 11.4% for indomethacin. Nifedipine ($16.75) and indomethacin ($15.40) were the least expensive treatment options, compared with magnesium sulfate ($197.90) and terbutaline ($399.02) because of the cost of monitoring and treating adverse events. CONCLUSION: If one elects a tocolytic, both nifedipine and indomethacin should be the agents of choice, based on a cost decision analysis.

Cost-effectiveness of prophylactic magnesium sulphate for 9996 women with pre-eclampsia from 33 countries: economic evaluation of the Magpie Trial.

OBJECTIVE: To assess the cost-effectiveness of using magnesium sulphate for pre-eclampsia to prevent eclampsia. DESIGN: Multinational trial-based economic evaluation. SETTING: Thirty-three countries participating in the Magnesium Sulphate for Prevention of Eclampsia (Magpie) Trial. POPULATION: Women (9996) with pre-eclampsia from the Magpie Trial. METHODS: Outcome and hospital resource use data were available for the trial period from the Magpie Trial. Country-specific unit costs (U.S. dollar, year 2001) were obtained subsequently from participating hospitals by questionnaire. Cost-effectiveness was estimated for three categories of countries grouped by gross national income (GNI) into high, middle and low GNI countries using a regression model. Uncertainty was explored in sensitivity analyses. MAIN OUTCOME MEASURES: Eclampsia, hospital care costs and the incremental cost per case of eclampsia prevented. RESULTS: The number of women with pre-eclampsia who needed to receive magnesium sulphate to prevent one case of eclampsia was 324 [95% confidence interval (CI) 122, infinity] in high, 184 (95% CI 91, 6798) in middle and 43 (95% CI 30, 68) in low GNI countries. The additional hospital care cost per woman receiving magnesium sulphate was $65, $13 and $11, respectively. The incremental cost of preventing one case of eclampsia was $21,202 in high, $2473 in middle and $456 in low GNI countries. Reserving treatment for severe pre-eclampsia would lower these estimates to $12,942, $1179 and $263. CONCLUSIONS: Magnesium sulphate for pre-eclampsia costs less and prevents more eclampsia in low GNI than in high GNI countries. Cost-effectiveness substantially improves if it is used only for severe pre-eclampsia, or the purchase price is reduced in low GNI countries.

In vitro buffering capacities of proprietary non-particulate antacids available in New Zealand.

Four commercially available non-particulate antacid preparations were titrated against 1M hydrochloric acid to assess buffering capacity as compared to 30 ml 0.3M sodium citrate solution. All antacids were used in the manufacturers "unit dose". All antacids tested demonstrated some in vitro buffering capacity, and "Eno" (Reckitt and Colman) had a buffering capacity similar to that of sodium citrate. The retail cost per unit dose was established for each proprietary antacid and for sodium citrate. It was concluded that while proprietary antacids are cheaper per dose than sodium citrate, preparations differ in their acid-neutralising capacity.