Win Ratio Analyses of Piperacillin-Tazobactam Versus Meropenem for Ceftriaxone-Nonsusceptible Escherichia coli or Klebsiella pneumoniae Bloodstream Infections: Post Hoc Insights From the MERINO Trial.

BACKGROUND: Clinical trials of treatments for serious infections commonly use the primary endpoint of all-cause mortality. However, many trial participants survive their infection and this endpoint may not truly reflect important benefits and risks of therapy. The win ratio uses a hierarchical composite endpoint that can incorporate and prioritize outcome measures by relative clinical importance. METHODS: The win ratio methodology was applied post hoc to outcomes observed in the MERINO trial, which compared piperacillin-tazobactam with meropenem. We quantified the win ratio with a primary hierarchical composite endpoint, including all-cause mortality, microbiological relapse, and secondary infection. A win ratio of 1 would correspond to no difference between the 2 antibiotics, while a ratio <1 favors meropenem. Further analyses were performed to calculate the win odds and to introduce a continuous outcome variable in order to reduce ties. RESULTS: With the hierarchy of all-cause mortality, microbiological relapse, and secondary infection, the win ratio estimate was 0.40 (95% confidence interval [CI], .22-.71]; P = .002), favoring meropenem over piperacillin-tazobactam. However, 73.4% of the pairs were tied due to the small proportion of events. The win odds, a modification of the win ratio accounting for ties, was 0.79 (95% CI, .68-.92). The addition of length of stay to the primary composite greatly minimized the number of ties (4.6%) with a win ratio estimate of 0.77 (95% CI, .60-.99; P = .04). CONCLUSIONS: The application of the win ratio methodology to the MERINO trial data illustrates its utility and feasibility for use in antimicrobial trials.

Using Power Analysis to Choose the Unit of Randomization, Outcome, and Approach for Subgroup Analysis for a Multilevel Randomized Controlled Clinical Trial to Reduce Disparities in Cardiovascular Health.

We give examples of three features in the design of randomized controlled clinical trials which can increase power and thus decrease sample size and costs. We consider an example multilevel trial with several levels of clustering. For a fixed number of independent sampling units, we show that power can vary widely with the choice of the level of randomization. We demonstrate that power and interpretability can improve by testing a multivariate outcome rather than an unweighted composite outcome. Finally, we show that using a pooled analytic approach, which analyzes data for all subgroups in a single model, improves power for testing the intervention effect compared to a stratified analysis, which analyzes data for each subgroup in a separate model. The power results are computed for a proposed prevention research study. The trial plans to randomize adults to either telehealth (intervention) or in-person treatment (control) to reduce cardiovascular risk factors. The trial outcomes will be measures of the Essential Eight, a set of scores for cardiovascular health developed by the American Heart Association which can be combined into a single composite score. The proposed trial is a multilevel study, with outcomes measured on participants, participants treated by the same provider, providers nested within clinics, and clinics nested within hospitals. Investigators suspect that the intervention effect will be greater in rural participants, who live farther from clinics than urban participants. The results use published, exact analytic methods for power calculations with continuous outcomes. We provide example code for power analyses using validated software.

Statistical methods and graphical displays of quality of life with survival outcomes in oncology clinical trials for supporting the estimand framework.

BACKGROUND: Although there are discussions regarding standards of the analysis of patient-reported outcomes and quality of life (QOL) in oncology clinical trials, that of QOL with death events is not within their scope. For example, ignoring death can lead to bias in the QOL analysis for patients with moderate or high mortality rates in the palliative care setting. This is discussed in the estimand framework but is controversial. Information loss by summary measures under the estimand framework may make it challenging for clinicians to interpret the QOL analysis results. This study illustrated the use of graphical displays in the framework. They can be helpful for discussions between clinicians and statisticians and decision-making by stakeholders. METHODS: We reviewed the time-to-deterioration analysis, prioritized composite outcome approach, semi-competing risk analysis, survivor analysis, linear mixed model for repeated measures, and principal stratification approach. We summarized attributes of estimands and graphs in the statistical analysis and evaluated them in various hypothetical randomized controlled trials. RESULTS: Graphs for each analysis method provide different information and impressions. In the time-to-deterioration analysis, it was not easy to interpret the difference in the curves as an effect on QOL. The prioritized composite outcome approach provided new insights for QOL considering death by defining better conditions based on the distinction of OS and QOL. The semi-competing risk analysis provided different insights compared with the time-to-deterioration analysis and prioritized composite outcome approach. Due to the missing assumption, graphs by the linear mixed model for repeated measures should be carefully interpreted, even for descriptive purposes. The principal stratification approach provided pure comparison, but the interpretation was difficult because the target population was unknown. CONCLUSIONS: Graphical displays can capture different aspects of treatment effects that should be described in the estimand framework.

Design and Rationale of HiLo: A Pragmatic, Randomized Trial of Phosphate Management for Patients Receiving Maintenance Hemodialysis.

RATIONALE & OBJECTIVE: Hyperphosphatemia is a risk factor for poor clinical outcomes in patients with kidney failure receiving maintenance dialysis. Opinion-based clinical practice guidelines recommend the use of phosphate binders and dietary phosphate restriction to lower serum phosphate levels toward the normal range in patients receiving maintenance dialysis, but the benefits of these approaches and the optimal serum phosphate target have not been tested in randomized trials. It is also unknown if aggressive treatment that achieves unnecessarily low serum phosphate levels worsens outcomes. STUDY DESIGN: Multicenter, pragmatic, cluster-randomized clinical trial. SETTING & PARTICIPANTS: HiLo will randomize 80-120 dialysis facilities operated by DaVita Inc and the University of Utah to enroll 4,400 patients undergoing 3-times-weekly, in-center hemodialysis. INTERVENTION: Phosphate binder prescriptions and dietary recommendations to achieve the "Hi" serum phosphate target (≥6.5 mg/dL) or the "Lo" serum phosphate target (<5.5 mg/dL). OUTCOMES: Primary outcome: Hierarchical composite outcome of all-cause mortality and all-cause hospitalization. Main secondary outcomes: Individual components of the primary outcome. RESULTS: The trial is currently enrolling. LIMITATIONS: HiLo will not adjudicate causes of hospitalizations or mortality and does not protocolize use of specific phosphate binder classes. CONCLUSIONS: HiLo aims to address an important clinical question while more generally advancing methods for pragmatic clinical trials in nephrology by introducing multiple innovative features including stakeholder engagement in the study design, liberal eligibility criteria, use of electronic informed consent, engagement of dietitians to implement the interventions in real-world practice, leveraging electronic health records to eliminate dedicated study visits, remote monitoring of serum phosphate separation between trial arms, and use of a novel hierarchical composite outcome. TRIAL REGISTRATION: Registered at ClinicalTrials.gov with study number NCT04095039.

A framework for considering the risk-benefit trade-off in designing noninferiority trials using composite outcome approaches.

When a new treatment regimen is expected to have comparable or slightly worse efficacy to that of the control regimen but has benefits in other domains such as safety and tolerability, a noninferiority (NI) trial may be appropriate but is fraught with difficulty in justifying an acceptable NI margin that is based on both clinical and statistical input. To overcome this, we propose to utilize composite risk-benefit outcomes that combine elements from domains of importance (eg, efficacy, safety, and tolerability). The composite outcome itself may be analyzed using a superiority framework, or it can be used as a tool at the design stage of a NI trial for selecting an NI margin for efficacy that balances changes in risks and benefits. In the latter case, the choice of NI margin may be based on a novel quantity called the maximum allowable decrease in efficacy (MADE), defined as the marginal difference in efficacy between arms that would yield a null treatment effect for the composite outcome given an assumed distribution for the composite outcome. We observe that MADE: (1) is larger when the safety improvement for the experimental arm is larger, (2) depends on the association between the efficacy and safety outcomes, and (3) depends on the control arm efficacy rate. We use a numerical example for power comparisons between a superiority test for the composite outcome vs a noninferiority test for efficacy using the MADE as the NI margin, and apply the methods to a TB treatment trial.

COVID-19 hospitalizations in five California hospitals: a retrospective cohort study.

BACKGROUND: The novel coronavirus pandemic has had a differential impact on communities of color across the US. The University of California hospital system serves a large population of people who are often underrepresented elsewhere. Data from hospital stays can provide much-needed localized information on risk factors for severe cases and/or death. METHODS: Patient-level retrospective case series of laboratory-confirmed COVID-19 hospital admissions at five UC hospitals (N = 4730). Odds ratios of ICU admission, death, and a composite of both outcomes were calculated with univariate and multivariate logistic regression based on patient characteristics, including sex, race/ethnicity, and select comorbidities. Associations between comorbidities were quantified and visualized with a correlation network. RESULTS: Overall mortality rate was 7.0% (329/4,730). ICU mortality rate was 18.8% (225/1,194). The rate of the composite outcome (ICU admission and/or death) was 27.4% (1298/4730). Comorbidity-controlled odds of a composite outcome were increased for age 75-84 (OR 1.47, 95% CI 1.11-1.93) and 85-59 (OR 1.39, 95% CI 1.04-1.87) compared to 18-34 year-olds, males (OR 1.39, 95% CI 1.21-1.59) vs. females, and patients identifying as Hispanic/Latino (OR 1.35, 95% CI 1.14-1.61) or Asian (OR 1.43, 95% CI 1.23-1.82) compared to White. Patients with 5 or more comorbidities were exceedingly likely to experience a composite outcome (OR 2.74, 95% CI 2.32-3.25). CONCLUSIONS: Males, older patients, those with multiple pre-existing comorbidities, and those identifying as Hispanic/Latino or Asian experienced an increased risk of ICU admission and/or death. These results are consistent with reported risks among the Hispanic/Latino population elsewhere in the United States, and confirm multiple concerns about heightened risk among the Asian population in California.

Applying a Risk-benefit Analysis to Outcomes in Tuberculosis Clinical Trials.

Although it is common to analyze efficacy and safety separately in clinical trials, this could yield a misleading study conclusion if an increase in efficacy is accompanied by a decrease in safety. A risk-benefit analysis is a systematic approach to examine safety and efficacy jointly. Both the "rank-based" and "partial-credit" methods described in this paper allow researchers to create a single, composite outcome incorporating efficacy, safety, and other factors. The first approach compares the distribution of rankings between arms. In the second approach, a score can be assigned to each outcome category, considering its severity and comparing the mean or median scores of arms. The methods were applied to the A5279/Brief Rifapentine-Isoniazid Efficacy for TB Prevention study, and design considerations for future clinical trials are discussed, including the challenge of arriving at a consensus on rankings/scorings. If well designed, a risk-benefit analysis may allow for a superiority comparison and, therefore, avoid setting a noninferiority margin. Clinical Trials Registration. NCT01404312 (A5279).

Methodologies for pragmatic and efficient assessment of benefits and harms: Application to the SOCRATES trial.

BACKGROUND/AIMS: Standard approaches to trial design and analyses can be inefficient and non-pragmatic. Failure to consider a range of outcomes impedes evidence-based interpretation and reduces power. Traditional approaches synthesizing information obtained from separate analysis of each outcome fail to incorporate associations between outcomes and recognize the cumulative nature of outcomes in individual patients, suffer from competing risk complexities during interpretation, and since efficacy and safety analyses are often conducted on different populations, generalizability is unclear. Pragmatic and efficient approaches to trial design and analyses are needed. METHODS: Approaches providing a pragmatic assessment of benefits and harms of interventions, summarizing outcomes experienced by patients, and providing sample size efficiencies are described. Ordinal outcomes recognize finer gradations of patient responses. Desirability of outcome ranking is an ordinal outcome combining benefits and harms within patients. Analysis of desirability of outcome ranking can be based on rank-based methodologies including the desirability of outcome ranking probability, the win ratio, and the proportion in favor of treatment. Partial credit analyses, involving grading the levels of the desirability of outcome ranking outcome similar to an academic test, provides an alternative approach. The methodologies are demonstrated using the acute stroke or transient ischemic attack treated with aspirin or ticagrelor and patient outcomes study (SOCRATES; NCT01994720), a randomized clinical trial. RESULTS: Two 5-level ordinal outcomes were developed for SOCRATES. The first was based on a modified Rankin scale. The odds ratio is 0.86 (95% confidence interval = 0.75, 0.99; p = 0.04) indicating that the odds of worse stroke categorization for a trial participant assigned to ticagrelor is 0.86 times that of a trial participant assigned to aspirin. The 5-level desirability of outcome ranking outcome incorporated and prioritized survival; the number of strokes, myocardial infarction, and major bleeding events; and whether a stroke event was disabling. The desirability of outcome ranking probability and win ratio are 0.504 (95% confidence interval = 0.499, 0.508; p = 0.10) and 1.11 (95% confidence interval = 0.98, 1.26; p = 0.10), respectively, implying that the probability of a more desirable result with ticagrelor is 50.4% and that a more desirable result occurs 1.11 times more frequently on ticagrelor versus aspirin. CONCLUSION: Ordinal outcomes can improve efficiency through required pre-specification, careful construction, and analyses. Greater pragmatism can be obtained by composing outcomes within patients. Desirability of outcome ranking provides a global assessment of the benefits and harms that more closely reflect the experience of patients. The desirability of outcome ranking probability, the proportion in favor of treatment, the win ratio, and partial credit can more optimally inform patient treatment, enhance the understanding of the totality of intervention effects on patients, and potentially provide efficiencies over standard analyses. The methods provide the infrastructure for incorporating patient values and estimating personalized effects.

Composite Outcomes for Clinical Trials in Critical Care: The Devil is in the Detail.

How to cite this article: Lalgudi Ganesan S, Parameswaran N. Composite Outcomes for Clinical Trials in Critical Care: The Devil is in the Detail. Indian J Crit Care Med 2020;24(10):903-904.

Comparison of Ventilator-free Days at 14 and 28 days as a Clinical Trial Outcome in Low- and Middle-income Countries.

AIMS AND OBJECTIVES: Reporting ventilator-free days (VFDs) with time frame of 28 days is a popular composite outcome measure (COM) in trials. However, early deaths and shorter pediatric intensive care unit (PICU) stay predominate in low- and middle-income countries (LMICs). A shorter time frame may reduce sample size required. We planned to compute sample size requirements for different effect sizes from datasets of previously conducted prospective studies for 28-day and 14-day time frames (VFD28 vs VFD14) to examine the hypothesis. MATERIALS AND METHODS: The VFD28 and VFD14 were defined. Datasets of five prospective studies from PICU of our hospital were analyzed to estimate sample sizes for target reductions of 1-9 days in VFDs and other COMs for the two time frames. Reconfirmation of results was done with datasets of two other studies from PICUs of two geographical extremes of the country. RESULTS: Time-to-event occurred within 14 days in majority of patients. Sample size required for VFD14 is about one-fifth to one-sixth of what is required for VFD28 for target reductions of 1-9 days for all the enrolled studies. The same was true for other COMs as well. The hypothesis was supported by datasets of two other studies used for reconfirmation. CONCLUSION: Choice of time frame for assessing VFDs and other COMs in clinical trials should be guided by the clinical context. A shorter time frame may be rewarding in terms of smaller sample size in the prevalent clinical setting of LMICs. Further confirmation with more datasets and prospective studies is desirable. HOW TO CITE THIS ARTICLE: Baranwal AK, Kumar MP, Gupta PK. Comparison of Ventilator-free Days at 14 and 28 days as a Clinical Trial Outcome in Low- and Middle-income Countries. Indian J Crit Care Med 2020;24(10):960-966.

Clinical evaluation of the Uphold LITE mesh for the surgical treatment of anterior and apical prolapse: A prospective, multicentre trial.

AIMS: To evaluate the safety and efficacy of the Uphold LITE mesh in the treatment of pelvic organ prolapse at 12-month follow-up. METHODS: Women undergoing a mesh surgery due to an anterior prolapse plus a symptomatic anterior prolapse (classed as pelvic organ prolapse quantification stage ≥2) were included in this prospective, multicentre, observational study. The primary endpoint was a composite outcome including a good anatomical correction, no prolapse symptoms, and no reintervention for an anterior or apical recurrent prolapse within 12 months of surgery. Secondary outcomes included safety, improvements in quality of life (QoL), and risk factor for recurrence. This study was registered with ClinicalTrials.gov, number NCT01559168. RESULTS: A total of 121 patients were included. Symptomatic and anatomic cure rates were 94% (95 of 101) and 76.8% (76 of 99), respectively. The composite success rate was 72.4% (71 of 98). The rate of reoperation for apical or anterior recurrent prolapse was 3.9% (4 of 103). Anatomical anterior or apical recurrence occurred in 18.2% (18 of 97) and 7.2% (7 of 97) of patients, respectively. The composite success rate was significantly higher in centres where more than 30 patients had been treated (80% vs 50%; P = .045). The rate of serious complication was 5.4% (6 of 111). Improvements were recorded in QoL including sexual function. CONCLUSIONS: The Uphold LITE mesh procedure provides satisfactory outcomes in the treatment of anterior and apical prolapse, particularly in high-volume centres. The rates of adverse effects and reintervention for recurrent prolapse were acceptable.

MTL, a composite measure for objectively profiling hospitals on surgical performance in colorectal cancer surgery.

PURPOSE: MTL is a composite outcome measure based on routine administrative data defined as (a) postoperative mortality and/or (b) postoperative transfer to another hospital and/or (c) length of hospital stay ≥ the prespecified time period. Aim of the present study was to investigate MTL for profiling hospitals on surgical performance in colorectal cancer surgery, using data from the national registers of the German Society of General and Visceral Surgery (DGAV) and to determine the time interval for length of stay with the highest accuracy regarding major complications (Clavien-Dindo grade ≥ 3). METHODS: All patients undergoing colorectal cancer resection between January 2010 and February 2017 were included. MTL rates were calculated and compared to well-established single outcome measures using multivariate regression analysis. For each outcome measure, postoperative complications were tested regarding their predictability. RESULTS: Data from 14,978 patients were analyzed. Length of stay was significantly prolonged if postoperative complications occurred (p < 0.0001). Thirty-day mortality and the indication for a transfer to another hospital mainly resulted from cardiopulmonary complications. MTL occurs significantly more often than any of the single-outcome parameters. The time interval of 22 days demonstrated the highest accuracy regarding severe complications (Clavien-Dindo grade ≥ 3). CONCLUSIONS: MTL reflects the complete spectrum of postoperative complications. Compared to individual surgical outcome parameters, MTL may have a better discriminatory power and is therefore suitable to mirror surgical quality. Because of its high accuracy regarding surgical major morbidity, 22 days is the best cut-off for length of stay within the German healthcare system.

Partially absorbable mesh or native tissue repair for pelvic organ prolapse: a randomized controlled trial.

INTRODUCTION AND HYPOTHESIS: The objective was to compare medium-term efficacy and safety of a partially absorbable mesh kit and native tissue repair in pelvic organ prolapse (POP). MATERIALS AND METHODS: Women with primary POP stage ≥ II were randomized to transvaginal trocar-guided partially absorbable mesh (81 women) or native tissue repair (82 women). Primary outcome was overall anatomical success (POP < stage II) at 24 months. Secondary outcomes were composite success, global improvement, and adverse events. RESULTS: Sixty-nine (85%) of the women allocated to partially absorbable mesh underwent mesh surgery; 8 (10%) crossed over to native tissue repair and 4 women (5%) withdrew from the study. Eighty (98%) of the women allocated to native tissue repair underwent the assigned treatment and 2 (2%) withdrew. Twenty-four months later, 140 surgically treated women (89%) demonstrated an overall anatomical success of 39%; 45% (32 out of 71 women) for mesh, and 32% (22 out of 69) for native tissue repair (RR 1.4, 95% CI 0.92 to 2.2). Composite success was 88 and 73% respectively (RR: 1.1, 95% CI 0.93 to 1.4). There was global improvement in 86% (48 out of 56 women) in the mesh group and in 77% (47 out of 60 women) in the native tissue group (RR: 1.1, 95% CI 0.92 to 1.3). Four women were diagnosed with mesh exposure at 2 years (6%). CONCLUSION: At 24 months, no significant anatomical or composite benefit of partially absorbable mesh over native tissue repair could be demonstrated in women who had been surgically treated for primary POP.

Effectiveness of adherence to recommended clinical examinations of diabetic patients in preventing diabetes-related hospitalizations.

OBJECTIVE: To validate a set of indicators for quality of diabetes care through their relationship with measurable clinical outcomes. DESIGN: A retrospective cohort study was carried out from 2010 to 2015. SETTING: Population-based study. Data were retrieved from healthcare utilization databases of three Italian regions (Lombardy, Emilia Romagna and Lazio) on the whole covering 20 million citizens. PARTICIPANTS: The 77 285 individuals who were newly taken in care for diabetes during 2010 entered into the cohort. INTERVENTIONS: Exposure to selected clinical recommendations (i.e. periodic controls for glycated hemoglobin, lipid profile, urine albumin excretion, serum creatinine and dilated eye exams) was recorded. MAIN OUTCOMES MEASURES: A composite outcome was employed taking into account hospitalizations for brief-term diabetes complications, uncontrolled diabetes, long-term vascular outcomes and no traumatic lower limb amputation. A multivariable proportional hazards model was fitted to estimate hazard ratio, and 95% confidence intervals (CI), for the exposure-outcome association. RESULTS: Among the newly taken in care patients with diabetes, those who adhered to almost none (0 or 1), just some (2 or 3) or almost all (4 or 5) recommendations during the first year after diagnosis were 44%, 36% and 20%, respectively. Compared patients who adhered to almost none recommendation, significant risk reductions of 16% (95% CI, 6-24%) and 20% (7-28%) were observed for those who adhered to just some and almost all recommendations, respectively. CONCLUSIONS: Tight control of patients with diabetes through regular clinical examinations must to be considered the cornerstone of national guidance, national audits and quality improvement incentives schemes.

A composite outcome for mild traumatic brain injury in trials of hyperbaric oxygen.

INTRODUCTION: Global outcomes can strengthen inferences from clinical trials. We evaluate global outcomes for persistent post-concussive symptoms (PCS) after mild traumatic brain injury (mTBI) in two clinical trials of hyperbaric oxygen (HBO2) in United States service members. METHODS: During study design, outcomes of symptom, cognitive, and functional impairments planned for a trial of HBO2 for PCS (HOPPS) were weighted and grouped into different domains to formulate the composite outcome total score. The composite outcome was compared between the intervention groups in HOPPS and those in a subsequent HBO2 trial (BIMA) for validation. Additionally, two post hoc global outcome measures were explored, including one composed of components that demonstrated favorable characteristics in both studies and another via components used in another TBI randomized trial (COBRIT). RESULTS: In total, 143 active-duty or veteran military personnel were randomized across the two studies. Composite total scores improved from baseline for HBO2 (mean ± SD -2.9±9.0) and sham (-2.9±6.6) groups in HOPPS but did not differ significantly between groups (p=0.33). In BIMA, 13-week changes from baseline favored the HBO2 group (-3.6±6.4) versus sham (-0.3±5.2; p=0.02). No between-group differences were found when COBRIT composite scoring was applied to BIMA. Overall, HBO2 effects were maximized when the post hoc global measure derived from both studies was applied to the data. CONCLUSIONS: Composite total scores in HOPPS and BIMA were consistent with primary study results. The global measures considered may offer utility as endpoints to achieve maximal HBO2 effect in future trials of the mTBI population. IDS: clinicaltrials.gov Identifiers NCT01611194 (BIMA) and NCT01306968 (HOPPS).

Partially hidden multi-state modelling of a prolonged disease state defined by a composite outcome.

For rheumatic diseases, Minimal Disease Activity (MDA) is usually defined as a composite outcome which is a function of several individual outcomes describing symptoms or quality of life. There is ever increasing interest in MDA but relatively little has been done to characterise the pattern of MDA over time. Motivated by the aim of improving the modelling of MDA in psoriatic arthritis, the use of a two-state model to estimate characteristics of the MDA process is illustrated when there is particular interest in prolonged periods of MDA. Because not all outcomes necessary to define MDA are measured at all clinic visits, a partially hidden multi-state model with latent states is used. The defining outcomes are modelled as conditionally independent given these latent states, enabling information from all visits, even those with missing data on some variables, to be used. Data from the Toronto Psoriatic Arthritis Clinic are analysed to demonstrate improvements in accuracy and precision from the inclusion of data from visits with incomplete information on MDA. An additional benefit of this model is that it can be extended to incorporate explanatory variables, which allows process characteristics to be compared between groups. In the example, the effect of explanatory variables, modelled through the use of relative risks, is also summarised in a potentially more clinically meaningful manner by comparing times in states, and probabilities of visiting states, between patient groups.

Properties of composite time to first event versus joint marginal analyses of multiple outcomes.

Many clinical studies (eg, cardiovascular outcome trials) investigate the effect of an intervention on multiple event time outcomes. The most common method of analysis is a so-called "composite" analysis of a composite outcome defined as the time to the first component event. Other approaches have been proposed, including the win ratio (or win difference) for ordered outcomes and the application of the Wei-Lachin test. Herein, we assess the influence of the marginal and joint distributions of the component events, and their correlation structures, on the operating characteristics of these methods for the analysis of multiple events. The operating characteristics are investigated using a bivariate exponential model with a shared frailty, under which these properties are obtained in closed form. While the composite time-to-first-event analysis provides an unbiased test of the hypothesis of equality of the distribution of the time to first event, we show that it can provide a biased test of the joint null hypothesis of equal marginal hazards when the correlation of event times differs between groups. The same applies to the win ratio. However, the operating characteristics of the Wei-Lachin or other tests of the joint equality of the marginal hazards are unaffected. Furthermore, when the correlations are equal, the Wei-Lachin test is more powerful to detect a difference in marginal hazards than the composite analysis test. Careful consideration of the properties of the various methods for analysis of composite outcome measures are in order before adopting one as primary analysis in a clinical study.

Failure to Rescue - a Closer Look at Mortality Rates Has No Added Value for Hospital Comparisons but Is Useful for Team Quality Assessment in Abdominal Aortic Aneurysm Surgery in The Netherlands.

OBJECTIVES: Failure to rescue (FTR) is a composite quality indicator, defined as the proportion of deceased patients following major complications. The aims of this study were to compare FTR with mortality for hospital comparisons in abdominal aortic aneurysm (AAA) surgery in The Netherlands and investigate hospital volume and associated factors. METHODS: Patients prospectively registered between 2013 and 2015 in the Dutch Surgical Aneurysm Audit (DSAA) were analysed. FTR was analysed for AAA patients and subgroups elective (EAAA) and acute (AAAA; symptomatic or ruptured) aneurysms. Variables and hospital volume were analysed by uni- and multivariable regression analysis. Adjusted hospital comparisons for mortality, major complications, and FTR were presented in funnel plots. Isomortality lines were constructed when presenting FTR and major complication rates. RESULTS: A total of 9258 patients were analysed in 61 hospitals: 7149 EAAA patients (77.2%) and 2109 AAAA patients (22.8%). There were 2785 (30.1%) patients with complications (unadjusted range 5-65% per hospital): 2161 (77.6%) with major and 624 (28.4%) patients with minor complications. Overall mortality was 6.6% (adjusted range 0-16% per hospital) and FTR was 28.4% (n = 613) (adjusted range 0-60% per hospital). Glasgow Coma Scale, age, pulse, creatinine, electrocardiography, and operative setting were independently associated with FTR. Hospital volume was not associated with FTR. In AAAA patients hospital volume was significantly associated with a lower adjusted major complication and mortality rate (OR 0.62, 95% CI 0.49-0.78; and 0.64, 95% CI 0.48-0.87). Four hospitals had a significant lower adjusted FTR with different major complication rates on different isomortality lines. CONCLUSIONS: There was more variation in FTR than in mortality between hospitals. FTR identified the same best performing hospitals as for mortality and therefore was of limited additional value in measuring quality of care for AAA surgery. FTR can be used for internal quality improvement with major complications in funnel plots and diagrams with isomortality lines.

Use of composite outcomes to assess risk-benefit in clinical trials.

Before a novel treatment can be deemed a clinical success, an assessment of its risk-benefit profile must be made. One of the inherent challenges for this assessment comes from the multiplicity that arises from comparing treatment groups across multiple outcomes. Composite outcomes that summarize a patient's clinical status, or severity, across a prioritized list of safety and efficacy outcomes have become increasing popular. In this article, we review these approaches and illustrate through examples some of the challenges and complexities of a composite derived from prioritized outcomes, such as the win ratio. These challenges include the difficult tension between the analytical validity that comes from choosing a pre-specified outcome and an evaluation that is responsive to unexpected safety events that arise during the course of a trial. Other challenges include a sensitivity of the resulting test statistic to the underlying censoring distribution and other nuisance parameters. Approaches that resolve some of the difficulties of the analytical challenges associated with prioritized outcomes are then discussed. Ultimately, a composite outcome of net clinical benefit is another decision tool, but one to be used alongside more traditional analyses of efficacy and safety, and with the broader perspective that investigators, the data safety monitoring board, and regulators bring to an evaluation of risk-benefit.

No evidence of disease activity in patients receiving daclizumab versus intramuscular interferon beta-1a for relapsing-remitting multiple sclerosis in the DECIDE study.

BACKGROUND: No evidence of disease activity (NEDA) is a composite endpoint being increasingly applied as an outcome measure in clinical trials as well as proposed for individual therapeutic decisions in multiple sclerosis (MS). OBJECTIVE: Assess the proportion of patients with relapsing-remitting MS achieving NEDA in the DECIDE study of daclizumab 150 mg subcutaneous versus intramuscular interferon beta-1a 30 µg for 96-144 weeks. METHODS: NEDA was defined as no relapses, no onset of 12-week confirmed disability progression (CDP), no new/newly enlarging T2 hyperintense lesions (NET2), and no gadolinium-enhancing (Gd+) lesions. Logistic regression models adjusted for baseline covariates compared treatment groups for baseline to week 96, weeks 0-24, and weeks 24-96. RESULTS: From baseline to week 96, more daclizumab versus intramuscular interferon beta-1a patients achieved NEDA (24.6% vs 14.2%; odds ratio (OR; 95% confidence interval): 2.059 (1.592-2.661); p < 0.0001). ORs for clinical NEDA (no relapses, no CDP) and magnetic resonance imaging (MRI) NEDA (no NET2, no Gd+ lesions) were 1.651 (1.357-2.007; p < 0.0001) and 2.051 (1.628-2.582; p < 0.0001), respectively. ORs in favor of daclizumab for weeks 24-96 were consistently higher than for weeks 0-24. CONCLUSION: More daclizumab versus intramuscular interferon beta-1a patients achieved NEDA early in DECIDE, with effects increasing over time.