Pediatric oncology sedation trial (POST): A double-blind randomized study

BACKGROUND

There is limited evidence to support the use of an anti-emetic with the administration of intra-thecal chemotherapy. Nor is there adequate clarity on analgesic strategies for children with cancer undergoing painful procedures.

PROCEDURES

A double-blind, randomized, placebo-controlled, factorial trial was performed in children with acute lymphoblastic leukemia undergoing combined bone marrow aspirations and lumbar punctures during maintenance therapy. The study was designed to measure the effect of adding ondansetron and fentanyl to a standard combination of midazolam and propofol.

RESULTS

During the first 12 hr following the procedures, patients experienced significantly less vomiting/retching and less disruption of activity while receiving ondansetron, and recorded significantly lower pain scores while receiving fentanyl.

CONCLUSIONS

This study provides evidence that the addition of an analgesic (fentanyl) and an anti-emetic (ondansetron) to the combination of a sedative (midazolam) and an anesthetic (propofol) is of measurable benefit in children who undergo procedures that are painful and risk the consequence of nausea and vomiting.

Effect on birth outcomes of a formalised approach to care in hospital labour assessment units: international, randomised controlled trial

OBJECTIVE

To determine if a complex nursing and midwifery intervention in hospital labour assessment units would increase the likelihood of spontaneous vaginal birth and improve other maternal and neonatal outcomes.

DESIGN

Multicentre, randomised controlled trial with prognostic stratification by hospital.

SETTING

20 North American and UK hospitals.

PARTICIPANTS

5002 nulliparous women experiencing contractions but not in active labour; 2501 were allocated to structured care and 2501 to usual care.

INTERVENTIONS

Usual nursing or midwifery care or a minimum of one hour of care by a nurse or midwife trained in structured care, consisting of a formalised approach to assessment of and interventions for maternal emotional state, pain, and fetal position.

MAIN OUTCOME MEASURES

Primary outcome was spontaneous vaginal birth. Other outcomes included intrapartum interventions, women's views of their care, and indicators of maternal and fetal health during hospital stay and 6-8 weeks after discharge.

RESULTS

Outcome data were obtained for 4996 women. The rate of spontaneous vaginal birth was 64.0% (n=1597) in the structured care group and 61.3% (n=1533) in the usual care group (odds ratio 1.12, 95% confidence interval 0.96 to 1.27). Fewer women allocated to structured care (n=403, 19.5%) rated staff helpfulness as less than very helpful than those allocated to usual care (n=544, 26.4%); odds ratio 0.67, 98.75% confidence interval 0.50 to 0.85. Fewer women allocated to structured care (n=233, 11.3%) were disappointed with the amount of attention received from staff than those allocated to usual care (n=407, 19.7%); odds ratio 0.51, 98.75% confidence interval 0.32 to 0.70. None of the other results met prespecified levels of statistical significance.

CONCLUSION

A structured approach to care in hospital labour assessment units increased satisfaction with care and was suggestive of a modest increase in the likelihood of spontaneous vaginal birth. Further study to strengthen the intervention is warranted.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN16315180.

Cost-effectiveness analysis of a multinational RCT with a binary measure of effectiveness and an interacting covariate

In a recent multinational randomized clinical trial, 1356 patients from 14 countries were randomized between two arms. The primary measure of effectiveness was 30-day survival. Health care utilization was collected on all patients and was combined with a single country's price weights to provide patient-level cost data. The purpose of this paper is to report the results of the cost-effectiveness analysis for the country that provided the cost weights, so as to provide a case study for illustrating recently proposed methodologies that account for skewed cost data, the between-country variation in treatment effects, possible interactions between treatment and baseline covariates, and the difficulty of estimated adjusted risk differences. A hierarchal model is used to account for the two sources of variation (between country and between patients, within a country). The model, which uses gamma distributions for cost data and recent methods for estimating adjusted risk differences, provides overall and country-specific estimates of treatment effects. Model estimation is facilitated by Markov chain Monte Carlo methods using the WinBUGS software. In addition, the theory of expected value of information is used to determine if the data provided by the trial are sufficient for decision making.

Time and expected value of sample information wait for no patient

OBJECTIVE

The expected value of sample information (EVSI) from prospective trials has previously been modeled as the product of EVSI per patient, and the number of patients across the relevant time horizon less those "used up" in trials. However, this implicitly assumes the eligible patient population to which information from a trial can be applied across a time horizon are independent of time for trial accrual, follow-up and analysis.

METHODS

This article demonstrates that in calculating the EVSI of a trial, the number of patients who benefit from trial information should be reduced by those treated outside as well as within the trial over the time until trial evidence is updated, including time for accrual, follow-up and analysis.

RESULTS

Accounting for time is shown to reduce the eligible patient population: 1) independent of the size of trial in allowing for time of follow-up and analysis, and 2) dependent on the size of trial for time of accrual, where the patient accrual rate is less than incidence. Consequently, the EVSI and expected net gain (ENG) at any given trial size are shown to be lower when accounting for time, with lower ENG reinforced in the case of trials undertaken while delaying decisions by additional opportunity costs of time.

CONCLUSIONS

Appropriately accounting for time reduces the EVSI of trial design and increase opportunity costs of trials undertaken with delay, leading to lower likelihood of trialing being optimal and smaller trial designs where optimal.

Health Technology Assessment in the Cost-Disutility Plane

Previously, comparisons of multiple strategies in health technology assessment have been undertaken on the incremental cost-effectiveness plane using efficiency frontiers and cost-effectiveness acceptability curves. This article proposes shifting the comparison of multiple strategies to the cost-disutility plane. Evidence-based decision making requires comparison of all strategies against each other. Consequently, the origin in the incremental cost-effectiveness plane cannot be the appropriate reference point in comparing multiple nondominated strategies. A linear transformation onto the cost-disutility plane allows an equivalent comparison of net benefit and permits the use of standard efficiency measurement methods to estimate 1) the degree of dominance (technical inefficiency) of dominated strategies and 2) the net benefit inefficiency (i.e., losses in net benefit relative to an optimal strategy). In comparing strategies under uncertainty, a comparison of loss in net benefit leads to the expected net loss frontier, which, unlike cost effectiveness acceptability curves, directly identifies differences in expected net benefit (net loss) and the expected value of perfect information. Thus, decision makers can be better informed about the choice of optimal strategy and the potential value of future research to resolve uncertainty. Comparing strategies in the cost-disutility plane is suggested to better inform decision making and to provide a link between the cost-effectiveness literature and efficiency measurement methods.

The Option Value of Delay in Health Technology Assessment

Processes of health technology assessment (HTA) inform decisions under uncertainty about whether to invest in new technologies based on evidence of incremental effects, incremental cost, and incremental net benefit monetary (INMB). An option value to delaying such decisions to wait for further evidence is suggested in the usual case of interest, in which the prior distribution of INMB is positive but uncertain. Methods of estimating the option value of delaying decisions to invest have previously been developed when investments are irreversible with an uncertain payoff over time and information is assumed fixed. However, in HTA decision uncertainty relates to information (evidence) on the distribution of INMB. This article demonstrates that the option value of delaying decisions to allow collection of further evidence can be estimated as the expected value of sample of information (EVSI). For irreversible decisions, delay and trial (DT) is demonstrated to be preferred to adopt and no trial (AN) when the EVSI exceeds expected costs of information, including expected opportunity costs of not treating patients with the new therapy. For reversible decisions, adopt and trial (AT) becomes a potentially optimal strategy, but costs of reversal are shown to reduce the EVSI of this strategy due to both a lower probability of reversal being optimal and lower payoffs when reversal is optimal. Hence, decision makers are generally shown to face joint research and reimbursement decisions (AN, DT and AT), with the optimal choice dependent on costs of reversal as well as opportunity costs of delay and the distribution of prior INMB.

Recommendations for reporting economic evaluations of haemophilia prophylaxis: a nominal groups consensus statement on behalf of the Economics Expert Working Group of The International Prophylaxis Study Group

BACKGROUND

The need for clearly reported studies evaluating the cost of prophylaxis and its overall outcomes has been recommended from previous literature.

OBJECTIVES

To establish minimal ''core standards'' that can be followed when conducting and reporting economic evaluations of hemophilia prophylaxis.

METHODS

Ten members of the IPSG Economic Analysis Working Group participated in a consensus process using the Nominal Groups Technique (NGT). The following topics relating to the economic analysis of prophylaxis studies were addressed; Whose perspective should be taken? Which is the best methodological approach? Is micro- or macro-costing the best costing strategy? What information must be presented about costs and outcomes in order to facilitate local and international interpretation?

RESULTS

The group suggests studies on the economic impact of prophylaxis should be viewed from a societal perspective and be reported using a Cost Utility Analysis (CUA) (with consideration of also reporting Cost Benefit Analysis [CBA]). All costs that exceed $500 should be used to measure the costs of prophylaxis (macro strategy) including items such as clotting factor costs, hospitalizations, surgical procedures, productivity loss and number of days lost from school or work. Generic and disease specific quality of lífe and utility measures should be used to report the outcomes of the study.

CONCLUSIONS

The IPSG has suggested minimal core standards to be applied to the reporting of economic evaluations of hemophilia prophylaxis. Standardized reporting will facilitate the comparison of studies and will allow for more rational policy decisions and treatment choices.

The Control of Hypertension In Pregnancy Study pilot trial

OBJECTIVE

To determine whether 'less tight' (versus 'tight') control of nonsevere hypertension results in a difference in diastolic blood pressure (dBP) between groups.

DESIGN

Randomised controlled trial (ISRCTN#57277508).

SETTING

Seventeen obstetric centres in Canada, Australia, New Zealand, and UK.

POPULATION

Inclusion: pregnant women, dBP 90-109 mmHg, pre-existing/gestational hypertension; live fetus(es); and 20-33(+6) weeks. Exclusion: systolic blood pressure > or = 170 mmHg and proteinuria, contraindication, or major fetal anomaly.

METHODS

Randomisation to less tight (target dBP, 100 mmHg) or tight (target dBP, 85 mmHg) blood pressure control.

MAIN OUTCOME MEASURES

Primary: mean dBP at 28, 32 and 36 weeks. Secondary: clinician compliance and women's satisfaction. Other: serious perinatal and maternal complications.

RESULTS

A total of 132 women were randomised to less tight (n = 66; seven had no study visit) or tight control (n= 66; one was lost to follow up; seven had no study visit). Mean dBP was significantly lower with tight control: -3.5 mmHg, 95% credible interval (-6.4, -0.6). Clinician compliance was 79% in both groups. Women were satisfied with their care. With less tight (versus tight) control, the rates of other treatments and outcomes were the following: post-randomisation antenatal antihypertensive medication use: 46 (69.7%) versus 58 (89.2%), severe hypertension: 38 (57.6%) versus 26 (40.0%), proteinuria: 16 (24.2%) versus 20 (30.8%), serious maternal complications: 3 (4.6%) versus 2 (3.1%), preterm birth: 24 (36.4%) versus 26 (40.0%), birthweight: 2675 +/- 858 versus 2501 +/- 855 g, neonatal intensive care unit (NICU) admission: 15 (22.7%) versus 22 (34.4%), and serious perinatal complications: 9 (13.6%) versus 14 (21.5%).

CONCLUSION

The CHIPS pilot trial confirms the feasibility and importance of a large definitive trial to determine the effects of less tight control on serious perinatal and maternal complications.

A randomized, controlled trial of a removable brace versus casting in children with low-risk ankle fractures

OBJECTIVES

Isolated distal fibular ankle fractures in children are very common and at very low risk for future complications. Nevertheless, standard therapy for these fractures still consists of casting, a practice that carries risks, inconveniences, and use of subspecialty health care resources. Therefore, the main objective of this study was to determine whether children who have these low-risk ankle fractures that are treated with a removable ankle brace have at least as effective a recovery of physical function as those that are treated with a cast.

METHODS

This was a noninferiority, randomized, single-blind trial in which children who were 5 to 18 years of age and treated in a pediatric emergency department for low-risk ankle fractures were randomly assigned to a removable ankle brace or a below-knee walking cast. The primary outcome at 4 weeks was physical function, measured by using the modified Activities Scale for Kids. Additional outcomes included patient preferences and costs.

RESULTS

The mean activity score at 4 weeks was 91.3% in the brace group (n = 54), and this was significantly higher than the mean of 85.3% in the cast group (n = 50). Significantly more children who were treated with a brace had returned to baseline activities by 4 weeks compared with those who were casted (80.8% vs 59.5%). Fifty-four percent of the casted children would have preferred the brace, but only 5.7% of children who received the brace would have preferred the cast. The cost-effectiveness acceptability curve was always >80%; therefore, the brace was cost-effective compared with the cast.

CONCLUSIONS

The removable ankle brace is more effective than the cast with respect to recovery of physical function, is associated with a faster return to baseline activities, is superior with respect to patient preferences, and is also cost-effective.

Expected value of information and decision making in HTA

Decision makers within a jurisdiction facing evidence of positive but uncertain incremental net benefit of a new health care intervention have viable options where no further evidence is anticipated to:(1)adopt the new intervention without further evidence;(2)adopt the new intervention and undertake a trial; or(3)delay the decision and undertake a trial.Value of information methods have been shown previously to allow optimal design of clinical trials in comparing option (2) against option (1), by trading off the expected value and cost of sample information. However, this previous research has not considered the effect of cost of reversal on expected value of information in comparing these options. This paper demonstrates that, where a new intervention is adopted, the expected value of information is reduced under optimal decision making with costs of reversing decisions. Further, the paper shows that comparing expected net gain of optimally designed trials for option (2) vs (1) conditional on cost of reversal, and (3) vs (1) conditional on opportunity cost of delay allow systematic identification of an optimal decision strategy and trial design.

The effect of pharmacist education on asthma treatment plans for simulated patients

OBJECTIVE

To determine if an educational program designed for community pharmacists to help patients self manage their asthma could improve pharmacists abilities to facilitate asthma treatment plans. Setting Hamilton and Toronto, Ontario, Canada.

METHOD

A randomized controlled trial involving volunteer community pharmacists who received either an asthma education program (AEP; intervention group) or a delayed AEP (control group). The AEP consisted of a one-day workshop and two follow-up telephone calls. Teaching methods progressed from a didactic approach to self-directed learning and role playing with simulated patients (SPs). The primary outcome was measured by SPs who conducted unannounced pharmacy visits.

MAIN OUTCOMES MEASURES

The number of appropriate (defined a priori) action plans facilitated by the pharmacist was the primary outcome. Facilitated was defined as the pharmacist recommending a specific plan, taking responsibility for telephoning the physician, or ensuring the patient would take responsibility for contacting the physician.

RESULTS

Thirty-three pharmacists were randomized to the intervention group and 31 pharmacists were randomized to the control group. Pharmacists in the intervention group facilitated an appropriate plan in 44.8% of situations (117 out of a possible 261) compared with 29.3% (79 out of a possible 270) in the control group, (mean difference 15.5% (95% CI: 7.4-23.8%; P = 0.0004)). Intervention group pharmacists were better able to facilitate plans for the 'under use of inhaled corticosteroids,' 'exposure to pet dander as an asthma trigger,' and 'overuse of short-acting beta-agonist' problems. Intervention group pharmacists exhibited better overall communication skills (including empathy, coherence, verbal skills, and nonverbal skills).

CONCLUSION

This AEP produced improvements in pharmacists' abilities to facilitate plans for SPs in a community pharmacy setting.

Semi-parametric regression models for cost-effectiveness analysis: improving the efficiency of estimation from censored data

In a cost-effectiveness analysis using clinical trial data, estimates of the between-treatment difference in mean cost and mean effectiveness are needed. Several methods for handling censored data have been suggested. One of them is inverse-probability weighting, and has the advantage that it can also be applied to estimate the parameters from a linear regression of the mean. Such regression models can potentially estimate the treatment contrast more precisely, since some of the residual variance can be explained by baseline covariates. The drawback, however, is that inverse-probability weighting may not be efficient. Using existing results on semi-parametric efficiency, this paper derives the semi-parametric efficient parameter estimates for regression of mean cost, mean quality-adjusted survival time and mean survival time. The performance of these estimates is evaluated through a simulation study. Applying both the new estimators and the inverse-probability weighted estimators to the results of the EVALUATE trial showed that the new estimators achieved a halving of the variance of the estimated treatment contrast for cost. Some practical suggestions for choosing an estimator are offered.

Health Status Measurements at Diagnosis As Predictors of Survival Among Adults With Brain Tumors

Purpose

The intent of this study was to determine whether baseline measures of functional capacity and performance could be used to predict survival in adults following the diagnosis of brain tumors.

Patients and Methods

Comprehensive health status and health-related quality of life (HRQL) were measured using the Health Utilities Index (HUI; McMaster University, Hamilton, Canada) system by a self-assessment questionnaire in a survey of 100 consecutive patients. The Karnofsky Performance Score (KPS) and Folstein's Mini-Mental State Examination (MMSE) scores were measured by a physician blinded to the HUI results. The patients were observed for up to 5 years to recorded dates of death.

Results

An HUI questionnaire was completed for 93% of the patients and 69% died within 5 years of assessment. The HUI revealed a burden of morbidity and complexity of disability that far exceeded that reported for the general population. KPS and MMSE correlated strongly with each other (r = 0.52; P < .001). A decrease of 0.1 units in HUI Mark 2 (HUI2) self-care single-attribute utility score was associated with an increased hazard of death of 30% (P = .023) for patients with low-grade tumors (n=25). For patients with high-grade tumors (n=56), a 10 unit decrease in the KPS, a 5 unit decrease in MMSE, and a 0.1 decrease in HUI Mark 3 (HUI3) speech and dexterity single-attribute scores were associated with an increased hazard of death of 20% (P = .022), 26% (P = .015), 36% (P = .021), and 18% (P = .035), respectively.

Conclusion

Scores derived from the measurement of HRQL following diagnosis can predict survival in adults with brain tumors.

Pediatric stroke initiatives and preliminary studies: What is known and what is needed?

Cerebrovascular disorders are increasingly recognized as important causes of mortality and morbidity in the pediatric population. However, there have been no clinical trials performed to assess the safety and tolerability of acute interventions or secondary preventative treatments. In 2002, the International Pediatric Stroke Study was launched to create a network of investigators, with an interest in developing standards of practice, as well as design and implement the first-ever clinical trials in pediatric stroke. This article reviews existing studies in pediatric stroke epidemiology, risk factors, outcomes, as well as experience with antithrombotic trials in children. From there, current and future initiatives in the development of clinical trials in pediatric stroke are evaluated.

Perspectives on the management of the short cervix identified by transvaginal ultrasound during pregnancy: an update for Canadian obstetrical caregivers

A shortened cervix is often considered to be equivalent to cervical insufficiency, and a cerclage may be offered as an intervention to prolong pregnancy; however, we may not be differentiating between true cervical insufficiency and intrauterine causes of cervical shortening. A recent meta-analysis found no significant reduction in preterm birth < 35 weeks' gestation in women with cerclage compared with no cerclage in the total population of women studied. However, there was a potentially significant reduction in preterm birth < 35 weeks among women with a singleton pregnancy (relative risk [RR] 0.74; 95% confidence intervals [CI] 0.57-0.96), with a singleton pregnancy and a previous preterm birth (RR 0.61; 95% CI 0.40-0.92), and with a singleton pregnancy with a previous mid-trimester loss (RR 0.57; 95% CI 0.33-0.99). An increase was found in preterm birth among twin gestations with cerclage placed for a shortened cervix on transvaginal ultrasound (RR 2.15; 95% CI 1.15-4.01). This unexpected finding underscores the possibility of harm with this intervention. This intervention deserves further study. A national registry or database would allow us to identify women who may benefit more significantly from cerclage by collecting data on possible confounding effects such as concomitant intrauterine infection or placental disease.

The costs of planned cesarean versus planned vaginal birth in the Term Breech Trial

BACKGROUND

The Term Breech Trial compared the safety of planned cesarean and planned vaginal birth for breech presentations at term. The combined outcome of perinatal or neonatal death and serious neonatal morbidity was found to be significantly lower among babies delivered by planned cesarean section. In this study we conducted a cost analysis of the 2 approaches to breech presentations at delivery.

METHODS

We used a third-party-payer (i.e., Ministry of Health) perspective. We included all costs for physician services and all hospital-related costs incurred by both the mother and the infant. We collected health care utilization and outcomes for all study participants during the trial. We used only the utilization data from countries with low national rates of perinatal death (< or = 20/1000). Seven hospitals across Canada (4 teaching and 3 community centres) were selected for unit cost calculations.

RESULTS

The estimated mean cost of a planned cesarean was significantly lower than that of a planned vaginal birth (7165 dollars v. 8042 dollars per mother and infant; mean difference -877 dollars, 95% credible interval -1286 dollars to -473 dollars). The estimated mean cost of a planned cesarean was lower than that of a planned vaginal birth for both women having a first birth (7255 dollars v. 8440 dollars) and women having had at least one prior birth (7071 dollars v. 7559 dollars). Although the treatment effect was largest in the subgroup of women having their first child, there was no statistically significant interaction between treatment and parity since the 95% credible intervals for difference in treatment effects between parity equalling zero and parity of one or greater all include zero.

INTERPRETATION

Planned cesarean section was found to be less costly than planned vaginal birth for the singleton fetus in a breech presentation at term in the Term Breech Trial.

Economic evaluation of rivastigmine in patients with Parkinson's disease dementia

BACKGROUND

The positive results of a randomised clinical trial of rivastigmine in patients with dementia associated with Parkinson's disease have been published recently. Patient-level healthcare utilisation data were also collected, and this report is the economic evaluation based on these data.

OBJECTIVE

To determine the cost effectiveness of rivastigmine 3-12 mg/day in patients in whom mild to moderate dementia developed at least 2 years after they received a clinical diagnosis of Parkinson's disease.

METHODS

A cost-effectiveness analysis was performed by applying Canadian and UK cost weights (year 2004 values) to healthcare utilisation data collected prospectively during a randomised, double-blind, multinational, 24-week trial of rivastigmine 3-12 mg/day (n = 362) versus placebo (n = 179). Patients were > or =50 years of age, had a Mini-Mental State Examination (MMSE) score of between 20 and 24 and had contact with a responsible caregiver at least 3 days a week.Quality-adjusted survival time, transformed from MMSE scores, was the measure of effectiveness. Caregiver costs included paid and unpaid time, and direct costs included concomitant medications, outpatient care, hospitalisations, long-term care and study medications. Analysis was conducted from a societal perspective with a time horizon of 24 weeks.

RESULTS

Consistent with the improvement in clinical outcomes, there was an observed increase in quality-adjusted survival time in the rivastigmine arm of 2.81 quality-adjusted life-days (two-sided p-value 0.13 [90% CI -0.243, 5.86]). Using Canadian price weights, there was an observed increase in cost in the rivastigmine arm of Can 55.76 dollars(two-sided p-value 0.98 [90% CI -3431, 3543]), with a resulting incremental cost-effectiveness ratio of Can 7429 dollars per QALY. Using UK price weights, there was an observed decrease in cost in the rivastigmine arm of pound 26.18 (two-sided p-value 0.99 [90% CI -2407, 2355]).

CONCLUSION

Although no between-treatment differences in cost were seen, the small sample size, highly variable cost distributions and short time horizon prevent us from making strong conclusions with regard to the effect of rivastigmine on total costs and, by inference, on cost effectiveness.

'Lost in translation': accounting for between-country differences in the analysis of multinational cost-effectiveness data

Cost-effectiveness analysis has gained status over the last 15 years as an important tool for assisting resource allocation decisions in a budget-limited environment such as healthcare. Randomised (multicentre) multinational controlled trials are often the main vehicle for collecting primary patient-level information on resource use, cost and clinical effectiveness associated with alternative treatment strategies. However, trial-wide cost effectiveness results may not be directly applicable to any one of the countries that participate in a multinational trial, requiring some form of additional modelling to customise the results to the country of interest. This article proposes an algorithm to assist with the choice of the appropriate analytical strategy when facing the task of adapting the study results from one country to another. The algorithm considers different scenarios characterised by: (a) whether the country of interest participated in the trial; and (b) whether individual patient-level data (IPD) from the trial are available. The analytical options available range from the use of regression-based techniques to the application of decision-analytic models. Decision models are typically used when the evidence base is available exclusively in summary format whereas regression-based methods are used mainly when the country of interest actively recruited patients into the trial and there is access to IPD (or at least country-specific summary data). Whichever method is used to reflect between-country variability in cost-effectiveness data, it is important to be transparent regarding the assumptions made in the analysis and (where possible) assess their impact on the study results.

Randomized controlled trial of hands-and-knees positioning for occipitoposterior position in labor

BACKGROUND

Hands-and-knees positioning during labor has been recommended on the theory that gravity and buoyancy may promote fetal head rotation to the anterior position and reduce persistent back pain. A Cochrane review found insufficient evidence to support the effectiveness of this intervention during labor. The purpose of this study was to evaluate the effect of maternal hands-and-knees positioning on fetal head rotation from occipitoposterior to occipitoanterior position, persistent back pain, and other perinatal outcomes.

METHODS

Thirteen labor units in university-affiliated hospitals participated in this multicenter randomized, controlled trial. Study participants were 147 women laboring with a fetus at >or=37 weeks' gestation and confirmed by ultrasound to be in occipitoposterior position. Seventy women were randomized to the intervention group (hands-and-knees positioning for at least 30 minutes over a 1-hour period during labor) and 77 to the control group (no hands-and-knees positioning). The primary outcome was occipitoanterior position determined by ultrasound following the 1-hour study period and the secondary outcome was persistent back pain. Other outcomes included operative delivery, fetal head position at delivery, perineal trauma, Apgar scores, length of labor, and women's views with respect to positioning.

RESULTS

Women randomized to the intervention group had significant reductions in persistent back pain. Eleven women (16%) allocated to use hands-and-knees positioning had fetal heads in occipitoanterior position following the 1-hour study period compared with 5 (7%) in the control group (relative risk 2.4; 95% CI 0.88-6.62; number needed to treat 11). Trends toward benefit for the intervention group were seen for several other outcomes, including operative delivery, fetal head position at delivery, 1-minute Apgar scores, and time to delivery.

CONCLUSIONS

Maternal hands-and-knees positioning during labor with a fetus in occipitoposterior position reduces persistent back pain and is acceptable to laboring women. Given this evidence, hands-and-knees positioning should be offered to women laboring with a fetus in occipitoposterior position in the first stage of labor to reduce persistent back pain. Although this study demonstrates trends toward improved birth outcomes, further trials are needed to determine if hands-and-knees positioning promotes fetal head rotation to occipitoanterior and reduces operative delivery.

The value of information and optimal clinical trial design

Traditional sample size calculations for randomized clinical trials depend on somewhat arbitrarily chosen factors, such as type I and II errors. Type I error, the probability of rejecting the null hypothesis of no difference when it is true, is most often set to 0.05, regardless of the cost of such an error. In addition, the traditional use of 0.2 for the type II error means that the money and effort spent on the trial will be wasted 20 per cent of the time, even when the true treatment difference is equal to the smallest clinically important one and, again, will not reflect the cost of making such an error. An effectiveness trial (otherwise known as a pragmatic trial or management trial) is essentially an effort to inform decision-making, i.e. should treatment be adopted over standard? As such, a decision theoretic approach will lead to an optimal sample size determination. Using incremental net benefit and the theory of the expected value of information, and taking a societal perspective, it is shown how to determine the sample size that maximizes the difference between the cost of doing the trial and the value of the information gained from the results. The methods are illustrated using examples from oncology and obstetrics.

Asthma in remission: can relapse in early adulthood be predicted at 18 years of age?

STUDY OBJECTIVE

To determine the frequency of relapse of asthma in young adults in remission at 18 years of age, during a follow-up period of 8 years, and to identify possible prognostic markers for relapse.

DESIGN

Longitudinal study of birth cohort (n = 1,037) born in New Zealand in 1972-1973.

SETTING

University hospital research clinic.

MEASUREMENTS

Participants were assessed at 9, 11, 13, 15, 18, 21, and 26 years of age using a respiratory questionnaire (all ages), spirometry (all ages), bronchodilator response (18 years and 26 years of age), methacholine challenge (9, 11, 13, 15, and 21 years of age), and allergen skin-prick testing (13 years and 21 years of age).

RESULTS

Approximately one third of study members (35%) with asthma in remission at 18 years of age relapsed by 21 years or 26 years of age. Atopy and lower FEV(1)/FVC ratio at 18 years of age were significant independent prognostic factors for relapse in multiple logistic regression analyses. Increased responsiveness to methacholine (provocative concentration < 8 mg/mL) or bronchodilator (improvement in FEV(1) >/= 10%) at 21 years of age were more common among those with relapse, but the positive and negative predictive values for a previous positive methacholine challenge test result at 15 years of age were low. Asthma after relapse was generally mild (mean FEV(1) 97.1% predicted). Totally new adult asthma developed by 26 years of age in 9% of study members who had no asthma or wheezing at any time up to 18 years of age.

CONCLUSIONS

Subsequent relapse of previously diagnosed asthma in remission at 18 years of age occurs in one in three young adults. Such relapse is not easily predicted, especially by measurements of airway responsiveness. A history of asthma currently in remission should not be used to prejudice employment opportunities for young adults.

Country specific cost comparisons from multinational clinical trials using empirical Bayesian shrinkage estimation: the Canadian ASSENT-3 economic analysis

The growing number of multinational clinical trials in which patient-level health care resource data are collected have raised the issue of which is the best approach for making inference for individual countries with respect to the between-treatment difference in mean cost. We describe and discuss the relative merits of three approaches. The first uses the random effects pooled estimate from all countries to estimate the difference for any particular country. The second approach estimates the difference using only the data from the specific country in question. Using empirical Bayes estimation a third approach estimates the country-specific difference using a variance-weighted linear sum of the estimates provided by the other two approaches. The approaches are illustrated and compared using the data from the ASSENT-3 trial.

Conducting economic evaluations alongside multinational clinical trials: toward a research consensus

Demand for economic evaluations in multinational clinical trials is increasing, but there is little consensus about how such studies should be conducted and reported. At a workshop in Durham, North Carolina, we sought to identify areas of agreement about how the primary findings of economic evaluations in multinational clinical trials should be generated and presented. In this paper, we propose a framework for classifying multinational economic evaluations according to (a) the sources of an analyst's estimates of resource use and clinical effectiveness and (b) the analyst's method of estimating costs. We review existing studies in the cardiology literature in the context of the proposed framework. We then describe important methodological and practical considerations in conducting multinational economic evaluations and summarize the advantages and disadvantages of each approach. Finally, we describe opportunities for future research. Delineation of the various approaches to multinational economic evaluation may assist researchers, peer reviewers, journal editors, and decision makers in evaluating the strengths and limitations of particular studies.