Statistical methods to compare functional outcomes in randomized controlled trials with high mortality

Stepped Palliative Care for Patients With Advanced Lung Cancer: A Randomized Clinical Trial

Importance

Despite the evidence for early palliative care improving outcomes, it has not been widely implemented in part due to palliative care workforce limitations.

Objective

To evaluate a stepped-care model to deliver less resource-intensive and more patient-centered palliative care for patients with advanced cancer.

Design, Setting, and Participants

Randomized, nonblinded, noninferiority trial of stepped vs early palliative care conducted between February 12, 2018, and December 15, 2022, at 3 academic medical centers in Boston, Massachusetts, Philadelphia, Pennsylvania, and Durham, North Carolina, among 507 patients who had been diagnosed with advanced lung cancer within the past 12 weeks.

Intervention

Step 1 of the intervention was an initial palliative care visit within 4 weeks of enrollment and subsequent visits only at the time of a change in cancer treatment or after a hospitalization. During step 1, patients completed a measure of quality of life (QOL; Functional Assessment of Cancer Therapy-Lung [FACT-L]; range, 0-136, with higher scores indicating better QOL) every 6 weeks, and those with a 10-point or greater decrease from baseline were stepped up to meet with the palliative care clinician every 4 weeks (intervention step 2). Patients assigned to early palliative care had palliative care visits every 4 weeks after enrollment.

Main Outcomes and Measures

Noninferiority (margin = -4.5) of the effect of stepped vs early palliative care on patient-reported QOL on the FACT-L at week 24.

Results

The sample (n = 507) mostly included patients with advanced non-small cell lung cancer (78.3%; mean age, 66.5 years; 51.4% female; 84.6% White). The mean number of palliative care visits by week 24 was 2.4 for stepped palliative care and 4.7 for early palliative care (adjusted mean difference, -2.3; P < .001). FACT-L scores at week 24 for the stepped palliative care group were noninferior to scores among those receiving early palliative care (adjusted FACT-L mean score, 100.6 vs 97.8, respectively; difference, 2.9; lower 1-sided 95% confidence limit, -0.1; P < .001 for noninferiority). Although the rate of end-of-life care communication was also noninferior between groups, noninferiority was not demonstrated for days in hospice (adjusted mean, 19.5 with stepped palliative care vs 34.6 with early palliative care; P = .91).

Conclusions and Relevance

A stepped-care model, with palliative care visits occurring only at key points in patients' cancer trajectories and using a decrement in QOL to trigger more intensive palliative care exposure, resulted in fewer palliative care visits without diminishing the benefits for patients' QOL. While stepped palliative care was associated with fewer days in hospice, it is a more scalable way to deliver early palliative care to enhance patient-reported outcomes.

Trial Registration

ClinicalTrials.gov Identifier: NCT03337399.

Tackling Brain and Muscle Dysfunction in Acute Respiratory Distress Syndrome Survivors: NHLBI Workshop Report

Acute respiratory distress syndrome (ARDS) is associated with long-term impairments in brain and muscle function that significantly impact the quality of life of those who survive the acute illness. The mechanisms underlying these impairments are not yet well understood, and evidence-based interventions to minimize the burden on patients remain unproved. The NHLBI of the NIH assembled a workshop in April 2023 to review the state of the science regarding ARDS-associated brain and muscle dysfunction, to identify gaps in current knowledge, and to determine priorities for future investigation. The workshop included presentations by scientific leaders across the translational science spectrum and was open to the public as well as the scientific community. This report describes the themes discussed at the workshop as well as recommendations to advance the field toward the goal of improving the health and well-being of ARDS survivors.

Oxygen-Saturation Targets and Cognitive and Functional Outcomes in Mechanically Ventilated Adults

Rationale: Among mechanically ventilated critically ill adults, the PILOT (Pragmatic Investigation of Optimal Oxygen Targets) trial demonstrated no difference in ventilator-free days among lower, intermediate, and higher oxygen-saturation targets. The effects on long-term cognition and related outcomes are unknown.Objectives: To compare the effects of lower (90% [range, 88-92%]), intermediate (94% [range, 92-96%]), and higher (98% [range, 96-100%]) oxygen-saturation targets on long-term outcomes.Methods: Twelve months after enrollment in the PILOT trial, blinded neuropsychological raters conducted assessments of cognition, disability, employment status, and quality of life. The primary outcome was global cognition as measured using the Telephone Montreal Cognitive Assessment. In a subset of patients, an expanded neuropsychological battery measured executive function, attention, immediate and delayed memory, verbal fluency, and abstraction.Measurements and Main Results: A total of 501 patients completed follow-up, including 142 in the lower, 186 in the intermediate, and 173 in the higher oxygen target groups. Median (interquartile range) peripheral oxygen saturation values in the lower, intermediate, and higher target groups were 94% (91-96%), 95% (93-97%), and 97% (95-99%), respectively. Telephone Montreal Cognitive Assessment score did not differ between lower and intermediate (adjusted odds ratio [OR], 1.36 [95% confidence interval (CI), 0.92-2.00]), intermediate and higher (adjusted OR, 0.90 [95% CI, 0.62-1.29]), or higher and lower (adjusted OR, 1.22 [95% CI, 0.83-1.79]) target groups. There was also no difference in individual cognitive domains, disability, employment, or quality of life.Conclusions: Among mechanically ventilated critically ill adults who completed follow-up at 12 months, oxygen-saturation targets were not associated with cognition or related outcomes.

Self-Reported Everyday Functioning After COVID-19 Infection

Importance

Changes in everyday functioning are crucial to assessing the long-term impact of COVID-19 infection.

Objective

To examine the impact of COVID-19 infection on everyday functioning 18 months after infection among veterans with and without histories of COVID-19 infection.

Design, Setting, and Participants

This cohort study used data from the US Veterans Affairs (VA) and included 186 veterans who had COVID-19 between October 2020 and April 2021 (ie, COVID-19 cohort) and 186 matched comparators who did not have documented COVID-19 infections (ie, control cohort). This match balanced the risk of COVID-19 based on 39 variables measured in the 24 months before infection or match, using principles of target trial emulation. Data were analyzed from December 2022 to December 2023.

Exposure

First documented COVID-19.

Main Outcome and Measures

The differences in self-reported everyday functioning 18 months after COVID-19 infection were estimated and compared with their matched comparators. Within-matched pair logistic and linear regressions assessed differences in outcomes and were weighted to account for sampling and nonresponse.

Results

Among the 186 matched pairs of participants, their weighted mean age was 60.4 (95% CI, 57.5 to 63.2) years among veterans in the COVID-19 cohort (weighted sample, 91 459 of 101 133 [90.4%] male; 30 611 [30.3%] Black or African American veterans; 65 196 [64.4%] White veterans) and 61.1 (95% CI, 57.8 to 64.4) years among their comparators in the control cohort (91 459 [90.4%] male; 24 576 [24.3%] Black or African American veterans; 70 157 [69.4%] White veterans). A high proportion of veterans in the COVID-19 cohort (weighted percentage, 44.9% [95% CI, 34.2% to 56.2%]) reported that they could do less than what they felt they could do at the beginning of 2020 compared with the control cohort (weighted percentage, 35.3%; [95% CI, 25.6% to 46.4%]; within-matched pair adjusted odds ratio [OR], 1.52 [95% CI, 0.79 to 2.91]). There was no association of documented COVID-19 infection with fatigue, substantial pain, limitations in either activities of daily living and instrumental activities of daily living, severely curtailed life-space mobility, employment, or mean health-related quality of life on a utility scale.

Conclusions and Relevance

In this cohort study of veterans with and without documented COVID-19, many reported a substantial loss of everyday functioning during the pandemic regardless of whether or not they had a documented infection with COVID-19. Future work with larger samples is needed to validate the estimated associations.

Health-related quality of life trajectories in critical illness: Protocol for a Monte Carlo simulation study

BACKGROUND

Health-related quality of life (HRQoL) is a patient-centred outcome increasingly used as a secondary outcome in critical care research. It may cover several important dimensions of clinical status in intensive care unit (ICU) patients that arguably elude other more easily quantified outcomes such as mortality. Poor associations with harder outcomes, conflicting data on HRQoL in critically ill compared to the background population, and paradoxical effects on HRQoL and mortality complicate the current operationalisation in critical care trials. This protocol outlines a simulation study that will gauge if the areas under the HRQoL trajectories could be a viable alternative.

METHODS

We will gauge the behaviour of the proposed HRQoL operationalisation through Monte Carlo simulations, under clinical scenarios that reflect a broad critical care population eligible for inclusion in a large pragmatic trial. We will simulate 15,360 clinical scenarios based on a full factorial design with the following seven simulation parameters: number of patients per arm, relative mortality reduction in the interventional arm, acceleration of HRQoL improvement in the interventional arm, the relative improvement in final HRQoL in the interventional arm, dampening effect of mortality on HRQoL values at discharge from the ICU, proportion of so-called mortality benefiters in the interventional arm and mortality trajectory shape. For each clinical scenario, we will simulate 100,000 two-arm trials with 1:1 randomisation. HRQoL will be sampled fortnightly after ICU discharge. Outcomes will include HRQoL in survivors and all patients at the end of follow-up; mean areas under the HRQoL trajectories in both arms; and mean difference between areas under the HRQoL trajectories and single-sampled HRQoLs at the end of follow-up.

DISCUSSION

In the outlined simulation study, we aim to assess whether the area under the HRQoL trajectory curve could be a candidate for reconciling the seemingly paradoxical effects on improved mortality and reduced HRQoL while remaining sensitive to early or accelerated improvement in patient outcomes. The resultant insights will inform subsequent methodological work on prudent collection and statistical analysis of such data from real critically ill patients.

The survival-incorporated median vs the median in the survivors or in the always-survivors: What are we measuring? and Why?

Many clinical studies evaluate the benefit of a treatment based on both survival and other continuous/ordinal clinical outcomes, such as quality of life scores. In these studies, when subjects die before the follow-up assessment, the clinical outcomes become undefined and are truncated by death. Treating outcomes as "missing" or "censored" due to death can be misleading for treatment effect evaluation. We show that if we use the median in the survivors or in the always-survivors as estimands to summarize clinical outcomes, we may conclude that a trade-off exists between the probability of survival and good clinical outcomes, even in settings where both the probability of survival and the probability of any good clinical outcome are better for one treatment. Therefore, we advocate not always treating death as a mechanism through which clinical outcomes are missing, but rather as part of the outcome measure. To account for the survival status, we describe the survival-incorporated median as an alternative summary measure for outcomes in the presence of death. The survival-incorporated median is the threshold such that 50% of the population is alive with an outcome above that threshold. Through conceptual examples and an application to a prostate cancer treatment study, we show that the survival-incorporated median provides a simple and useful summary measure to inform clinical practice.

Cefepime vs Piperacillin-Tazobactam in Adults Hospitalized With Acute Infection: The ACORN Randomized Clinical Trial

Importance

Cefepime and piperacillin-tazobactam are commonly administered to hospitalized adults for empirical treatment of infection. Although piperacillin-tazobactam has been hypothesized to cause acute kidney injury and cefepime has been hypothesized to cause neurological dysfunction, their comparative safety has not been evaluated in a randomized clinical trial.

Objective

To determine whether the choice between cefepime and piperacillin-tazobactam affects the risks of acute kidney injury or neurological dysfunction.

Design, Setting, and Participants

The Antibiotic Choice on Renal Outcomes (ACORN) randomized clinical trial compared cefepime vs piperacillin-tazobactam in adults for whom a clinician initiated an order for antipseudomonal antibiotics within 12 hours of presentation to the hospital in the emergency department or medical intensive care unit at an academic medical center in the US between November 10, 2021, and October 7, 2022. The final date of follow-up was November 4, 2022.

Interventions

Patients were randomized in a 1:1 ratio to cefepime or piperacillin-tazobactam.

Main Outcomes and Measures

The primary outcome was the highest stage of acute kidney injury or death by day 14, measured on a 5-level ordinal scale ranging from no acute kidney injury to death. The 2 secondary outcomes were the incidence of major adverse kidney events at day 14 and the number of days alive and free of delirium and coma within 14 days.

Results

There were 2511 patients included in the primary analysis (median age, 58 years [IQR, 43-69 years]; 42.7% were female; 16.3% were Non-Hispanic Black; 5.4% were Hispanic; 94.7% were enrolled in the emergency department; and 77.2% were receiving vancomycin at enrollment). The highest stage of acute kidney injury or death was not significantly different between the cefepime group and the piperacillin-tazobactam group; there were 85 patients (n = 1214; 7.0%) in the cefepime group with stage 3 acute kidney injury and 92 (7.6%) who died vs 97 patients (n = 1297; 7.5%) in the piperacillin-tazobactam group with stage 3 acute kidney injury and 78 (6.0%) who died (odds ratio, 0.95 [95% CI, 0.80 to 1.13], P = .56). The incidence of major adverse kidney events at day 14 did not differ between groups (124 patients [10.2%] in the cefepime group vs 114 patients [8.8%] in the piperacillin-tazobactam group; absolute difference, 1.4% [95% CI, -1.0% to 3.8%]). Patients in the cefepime group experienced fewer days alive and free of delirium and coma within 14 days (mean [SD], 11.9 [4.6] days vs 12.2 [4.3] days in the piperacillin-tazobactam group; odds ratio, 0.79 [95% CI, 0.65 to 0.95]).

Conclusions and Relevance

Among hospitalized adults in this randomized clinical trial, treatment with piperacillin-tazobactam did not increase the incidence of acute kidney injury or death. Treatment with cefepime resulted in more neurological dysfunction.

Trial Registration

ClinicalTrials.gov Identifier: NCT05094154.

Impact of Kaposi Sarcoma on Quality of Life Amongst HIV-infected Adults Initiating Antiretroviral Therapy in East Africa

BACKGROUND

In sub-Saharan Africa, increased antiretroviral therapy (ART) availability has improved survival after diagnosis of Kaposi sarcoma (KS) compared to the pre-ART era, but mortality among patients with KS is still considerably higher than HIV-infected persons without KS. Furthermore, among those patients with KS who are treated initially with ART without adjunct chemotherapy and who do survive, little is known about how well they function and feel - quality of life (QOL) - compared to those without KS.

METHODS

Among HIV-infected adults initiating ART in two prospective studies in Uganda, we compared those presenting with KS to those without KS. QOL was measured using the Medical Outcomes Survey-HIV instrument prior to ART initiation and at 16, 32, and 48 weeks thereafter; higher scores indicate better QOL. To ascertain the independent effect of KS versus non-KS on 11 domains of QOL and two summary scores, we created mixed effects models adjusted for directed acyclic graph-informed confounders.

RESULTS

We examined 224 participants with KS and 730 without KS, among whom 64% were women and median age was 34 years. Prior to ART initiation, participants had a median CD4+ T count of 159 cells/mm3 and plasma HIV RNA of 5.1 log10 copies/ml. In adjusted analyses prior to ART initiation, those with KS had lower mean scores in 8 of 11 QOL domains and both physical and mental health summary scores compared to those without KS. After 48 weeks of ART, those with KS had higher mean QOL scores compared those without KS in 4 domains and the mental health summary score, and lower scores in only one domain. There was no significant difference in 6 domains and the physical health summary score.

CONCLUSIONS

Amongst HIV-infected adults in East Africa, at time of ART initiation, those with KS had worse mean QOL compared to those without KS. Over the first year of ART, those with KS became comparable to or exceeded those without KS in most QOL domains. The findings indicate that some patients with KS can be treated with ART alone and further emphasize the need to predict those who will do well with ART alone versus those who need additional initial therapy.

Obesity Weight Loss Phenotypes in CKD: Findings From the Chronic Renal Insufficiency Cohort Study

Introduction

Although people with chronic kidney disease (CKD) and obesity have important motivations to lose weight, weight loss is also associated with health risks. We examined whether patterns of change in systolic blood pressure (SBP), serum albumin level, and fat-free mass (FFM) can help to differentiate between healthy and high-risk weight loss in this population.

Methods

Using data from the Chronic Renal Insufficiency Cohort Study (CRIC), we estimated a joint multivariate latent class model with 6 classes to identify distinct trajectories of body mass index (BMI), albumin, and SBP among participants with obesity (BMI ≥30 kg/m2 at baseline), accounting for informative missingness from death. In a secondary analysis, we fit a 6-class model with BMI and FFM.

Results

Among 2831 participants (median baseline BMI 35.6, interquartile range [IQR] 32.4-40.0 kg/m2), median follow-up was 6.8 (IQR 4.8-12.9) years, median age was 61 (IQR 54-67) years, 53% were male, 50% were non-Hispanic Black, and 82% were trying to control or lose weight at baseline. Latent classes were associated with mortality risk (5-year cumulative incidence of mortality 6.8% and 1.5% in class 6 and 3, respectively). Class 6 had the highest mortality rate and was characterized by early, steep BMI loss, early serum albumin decline, and late SBP increase. In the secondary analysis, a class characterized by steep BMI and FFM loss was associated with the highest death risk.

Conclusions

Among adults with CKD and obesity, BMI loss with concomitant serum albumin or FFM loss was associated with a high risk of death.

Long-term effects of restriction of intravenous fluid in adult ICU patients with septic shock

PURPOSE

To assess long-term outcomes of restrictive versus standard intravenous (IV) fluid therapy in adult intensive care unit (ICU) patients with septic shock included in the European Conservative versus Liberal Approach to Fluid Therapy in Septic Shock in Intensive Care (CLASSIC) trial.

METHODS

We conducted the pre-planned analyses of mortality, health-related quality of life (HRQoL) using EuroQol (EQ)-5D-5L index values and EQ visual analogue scale (VAS), and cognitive function using Mini Montreal Cognitive Assessment (Mini MoCA) test at 1 year. Deceased patients were assigned numerical zero for HRQoL as a state equal to death and zero for cognitive function outcomes as worst possible score, and we used multiple imputation for missing data on HRQoL and cognitive function.

RESULTS

Among 1554 randomized patients, we obtained 1-year data on mortality in 97.9% of patients, HRQoL in 91.3%, and cognitive function in 86.3%. One-year mortality was 385/746 (51.3%) in the restrictive-fluid group versus 383/767 (49.9%) in the standard-fluid group, absolute risk difference 1.5%-points [99% confidence interval (CI) - 4.8 to 7.8]. Mean differences were 0.00 (99% CI - 0.06 to 0.05) for EQ-5D-5L index values, - 0.65 for EQ VAS (- 5.40 to 4.08), and - 0.14 for Mini MoCA (- 1.59 to 1.14) for the restrictive-fluid group versus the standard-fluid group. The results for survivors only were similar in both groups.

CONCLUSIONS

Among adult ICU patients with septic shock, restrictive versus standard IV fluid therapy resulted in similar survival, HRQoL, and cognitive function at 1 year, but clinically important differences could not be ruled out.

A Bayesian Approach for Estimating the Survivor Average Causal Effect When Outcomes Are Truncated by Death in Cluster-Randomized Trials

Many studies encounter clustering due to multicenter enrollment and nonmortality outcomes, such as quality of life, that are truncated due to death-that is, missing not at random and nonignorable. Traditional missing-data methods and target causal estimands are suboptimal for statistical inference in the presence of these combined issues, which are especially common in multicenter studies and cluster-randomized trials (CRTs) carried out among the elderly or seriously ill. Using principal stratification, we developed a Bayesian estimator that jointly identifies the always-survivor principal stratum in a clustered/hierarchical data setting and estimates the average treatment effect among them (i.e., the survivor average causal effect (SACE)). In simulations, we observed low bias and good coverage with our method. In a motivating CRT, the SACE and the estimate from complete-case analysis differed in magnitude, but both were small, and neither was incompatible with a null effect. However, the SACE estimate has a clear causal interpretation. The option to assess the rigorously defined SACE estimand in studies with informative truncation and clustering can provide additional insight into an important subset of study participants. Based on the simulation study and CRT reanalysis, we provide practical recommendations for using the SACE in CRTs and software code to support future research.

On logistic regression with right censored data, with or without competing risks, and its use for estimating treatment effects

Simple logistic regression can be adapted to deal with right-censoring by inverse probability of censoring weighting (IPCW). We here compare two such IPCW approaches, one based on weighting the outcome, the other based on weighting the estimating equations. We study the large sample properties of the two approaches and show that which of the two weighting methods is the most efficient depends on the censoring distribution. We show by theoretical computations that the methods can be surprisingly different in realistic settings. We further show how to use the two weighting approaches for logistic regression to estimate causal treatment effects, for both observational studies and randomized clinical trials (RCT). Several estimators for observational studies are compared and we present an application to registry data. We also revisit interesting robustness properties of logistic regression in the context of RCTs, with a particular focus on the IPCW weighting. We find that these robustness properties still hold when the censoring weights are correctly specified, but not necessarily otherwise.

Vasopressin Response and Clinical Trajectory in Septic Shock Patients

BACKGROUND

In septic shock, vasopressors aim to improve tissue perfusion and prevent persistent organ dysfunction, a characteristic of chronic critical illness (CCI). Adjunctive vasopressin is often used to decrease catecholamine dosage, but the association of vasopressin response with subsequent patient outcomes is unclear. We hypothesized vasopressin response is associated with favorable clinical trajectory.

METHODS

We included patients with septic shock receiving vasopressin as a catecholamine adjunct in this retrospective cohort study. We defined vasopressin response as a lowering of the catecholamine dose required to maintain mean arterial pressure ≥65 mm Hg, 6 h after vasopressin initiation. Clinical trajectories were adjudicated as early death (ED; death before day 14), CCI (ICU stay ≥14 days with persistent organ dysfunction), or rapid recovery (RR; not meeting ED or CCI criteria). Trajectories were placed on an ordinal scale with ED the worst outcome, CCI next, and RR the best outcome. The association of vasopressin response with clinical trajectory was assessed with multivariable ordinal logistic regression.

RESULTS

In total 938 patients were included; 426 (45.4%) were vasopressin responders. The most frequent trajectory was ED (49.8%), 29.7% developed CCI, and 20.5% had rapid recovery. In survivors to ICU day 14 (those without ED), 59.2% had CCI and 40.8% experienced RR. Compared with vasopressin non-responders, vasopressin responders less frequently experienced ED (42.5% vs. 55.9%) and more frequently experienced RR (24.6% vs. 17.0%; P < 0.01). After controlling for confounders, vasopressin response was independently associated with higher odds of developing a better clinical trajectory (OR 1.63; 95% CI 1.26-2.10). Medical patients most frequently developed ED and survivors more commonly developed CCI than RR; surgical patients developed the three trajectories with similar frequency (P < 0.01).

CONCLUSIONS

Vasopressin responsive status was associated with improved clinical trajectory in septic shock patients. Early vasopressin response is a potential novel prognostic marker for short-term clinical trajectory.

MetfOrmin BenefIts Lower Extremities with Intermittent Claudication (MOBILE IC): randomized clinical trial protocol

BACKGROUND

Peripheral artery disease (PAD) affects over 230 million people worldwide and is due to systemic atherosclerosis with etiology linked to chronic inflammation, hypertension, and smoking status. PAD is associated with walking impairment and mobility loss as well as a high prevalence of coronary and cerebrovascular disease. Intermittent claudication (IC) is the classic presenting symptom for PAD, although many patients are asymptomatic or have atypical presentations. Few effective medical therapies are available, while surgical and exercise therapies lack durability. Metformin, the most frequently prescribed oral medication for Type 2 diabetes, has salient anti-inflammatory and promitochondrial properties. We hypothesize that metformin will improve function, retard the progression of PAD, and improve systemic inflammation and mitochondrial function in non-diabetic patients with IC.

METHODS

200 non-diabetic Veterans with IC will be randomized 1:1 to 180-day treatment with metformin extended release (1000 mg/day) or placebo to evaluate the effect of metformin on functional status, PAD progression, cardiovascular disease events, and systemic inflammation. The primary outcome is 180-day maximum walking distance on the 6-min walk test (6MWT). Secondary outcomes include additional assessments of functional status (cardiopulmonary exercise testing, grip strength, Walking Impairment Questionnaires), health related quality of life (SF-36, VascuQoL), macro- and micro-vascular assessment of lower extremity blood flow (ankle brachial indices, pulse volume recording, EndoPAT), cardiovascular events (amputations, interventions, major adverse cardiac events, all-cause mortality), and measures of systemic inflammation. All outcomes will be assessed at baseline, 90 and 180 days of study drug exposure, and 180 days following cessation of study drug. We will evaluate the primary outcome with linear mixed-effects model analysis with covariate adjustment for baseline 6MWT, age, baseline ankle brachial indices, and smoking status following an intention to treat protocol.

DISCUSSION

MOBILE IC is uniquely suited to evaluate the use of metformin to improve both systematic inflammatory responses, cellular energetics, and functional outcomes in patients with PAD and IC.

TRIAL REGISTRATION

The prospective MOBILE IC trial was publicly registered (NCT05132439) November 24, 2021.

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.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12874-022-01735-1.

Rethinking intercurrent events in defining estimands for tuberculosis trials

BACKGROUND/AIMS

Tuberculosis remains one of the leading causes of death from an infectious disease globally. Both choices of outcome definitions and approaches to handling events happening post-randomisation can change the treatment effect being estimated, but these are often inconsistently described, thus inhibiting clear interpretation and comparison across trials.

METHODS

Starting from the ICH E9(R1) addendum's definition of an estimand, we use our experience of conducting large Phase III tuberculosis treatment trials and our understanding of the estimand framework to identify the key decisions regarding how different event types are handled in the primary outcome definition, and the important points that should be considered in making such decisions. A key issue is the handling of intercurrent (i.e. post-randomisation) events (ICEs) which affect interpretation of or preclude measurement of the intended final outcome. We consider common ICEs including treatment changes and treatment extension, poor adherence to randomised treatment, re-infection with a new strain of tuberculosis which is different from the original infection, and death. We use two completed tuberculosis trials (REMoxTB and STREAM Stage 1) as illustrative examples. These trials tested non-inferiority of new tuberculosis treatment regimens versus a control regimen. The primary outcome was a binary composite endpoint, 'favourable' or 'unfavourable', which was constructed from several components.

RESULTS

We propose the following improvements in handling the above-mentioned ICEs and loss to follow-up (a post-randomisation event that is not in itself an ICE). First, changes to allocated regimens should not necessarily be viewed as an unfavourable outcome; from the patient perspective, the potential harms associated with a change in the regimen should instead be directly quantified. Second, handling poor adherence to randomised treatment using a per-protocol analysis does not necessarily target a clear estimand; instead, it would be desirable to develop ways to estimate the treatment effects more relevant to programmatic settings. Third, re-infection with a new strain of tuberculosis could be handled with different strategies, depending on whether the outcome of interest is the ability to attain culture negativity from infection with any strain of tuberculosis, or specifically the presenting strain of tuberculosis. Fourth, where possible, death could be separated into tuberculosis-related and non-tuberculosis-related and handled using appropriate strategies. Finally, although some losses to follow-up would result in early treatment discontinuation, patients lost to follow-up before the end of the trial should not always be classified as having an unfavourable outcome. Instead, loss to follow-up should be separated from not completing the treatment, which is an ICE and may be considered as an unfavourable outcome.

CONCLUSION

The estimand framework clarifies many issues in tuberculosis trials but also challenges trialists to justify and improve their outcome definitions. Future trialists should consider all the above points in defining their outcomes.

Using principal stratification in analysis of clinical trials

The ICH E9(R1) addendum (2019) proposed principal stratification (PS) as one of five strategies for dealing with intercurrent events. Therefore, understanding the strengths, limitations, and assumptions of PS is important for the broad community of clinical trialists. Many approaches have been developed under the general framework of PS in different areas of research, including experimental and observational studies. These diverse applications have utilized a diverse set of tools and assumptions. Thus, need exists to present these approaches in a unifying manner. The goal of this tutorial is threefold. First, we provide a coherent and unifying description of PS. Second, we emphasize that estimation of effects within PS relies on strong assumptions and we thoroughly examine the consequences of these assumptions to understand in which situations certain assumptions are reasonable. Finally, we provide an overview of a variety of key methods for PS analysis and use a real clinical trial example to illustrate them. Examples of code for implementation of some of these approaches are given in Supplemental Materials.

Missing data in palliative care research: estimands and estimators

There are several methodological challenges when conducting randomised controlled trials in palliative care. These include worsening function and high mortality, leading to treatment discontinuation, some of which will be unrelated to the intervention being evaluated.Recently, a new framework for handling postrandomisation events, such as attrition, has been released. This framework aims to align trial objectives, design, conduct and analysis by clarifying what and how to estimate treatment effects in the presence of data affected by postrandomisation events.The purpose of this paper is to introduce palliative care researchers to this framework and how it can guide trial design, and efficacy and safety analysis in a palliative care context where individual withdrawal from the trial is common.In this paper, we describe the estimand framework and the background for it. We also consider postrandomisation events that are frequently encountered in palliative care trials and how these might affect objectives of interest. We then construct efficacy and safety estimands for a trial in palliative care. Better trial design and alignment of objectives with analysis can improve our understanding of what treatments do and do not work in palliative care.

Six-month and 12-month patient outcomes based on inflammatory subphenotypes in sepsis-associated ARDS: secondary analysis of SAILS-ALTOS trial

BACKGROUND

Prior acute respiratory distress syndrome (ARDS) trials have identified hypoinflammatory and hyperinflammatory subphenotypes, with distinct differences in short-term outcomes. It is unknown if such differences extend beyond 90 days or are associated with physical, mental health or cognitive outcomes.

METHODS

568 patients in the multicentre Statins for Acutely Injured Lungs from Sepsis trial of rosuvastatin versus placebo were included and assigned a subphenotype. Among 6-month and 12-month survivors (N=232 and 219, respectively, representing 243 unique survivors), subphenotype status was evaluated for association with a range of patient-reported outcomes (eg, mental health symptoms, quality of life). Patient subsets also were evaluated with performance-based tests of physical function (eg, 6 min walk test) and cognition.

FINDINGS

The hyperinflammatory versus hypoinflammatory subphenotype had lower overall 12-month cumulative survival (58% vs 72%, p<0.01); however, there was no significant difference in survival beyond 90 days (86% vs 89%, p=0.70). Most survivors had impairment across the range of outcomes, with little difference between subphenotypes at 6-month and 12-month assessments. For instance, at 6 months, in comparing the hypoinflammatory versus hyperinflammatory subphenotypes, respectively, the median (IQR) patient-reported SF-36 mental health domain score was 47 (33-56) vs 44 (35-56) (p=0.99), and the per cent predicted 6 min walk distance was 66% (48%, 80%) vs 66% (49%, 79%) (p=0.76).

INTERPRETATION

Comparing the hyperinflammatory versus hypoinflammatory ARDS subphenotype, there was no significant difference in survival beyond 90 days and no consistent findings of important differences in 6-month or 12-month physical, cognitive and mental health outcomes. These findings, when considered with prior results, suggest that inflammatory subphenotypes largely reflect the acute phase of illness and its short-term impact.

Association of Delirium during Critical Illness With Mortality: Multicenter Prospective Cohort Study

BACKGROUND

The temporal association of delirium during critical illness with mortality is unclear, along with the associations of hypoactive and hyperactive motoric subtypes of delirium with mortality. We aimed to evaluate the relationship of delirium during critical illness, including hypoactive and hyperactive motoric subtypes, with mortality in the hospital and after discharge up to 1 year.

METHODS

We analyzed a prospective cohort study of adults with respiratory failure and/or shock admitted to university, community, and Veterans Affairs hospitals. We assessed patients using the Richmond Agitation-Sedation Scale and the Confusion Assessment Method for the intensive care unit (ICU) and defined the motoric subtype according to the corresponding Richmond Agitation-Sedation Scale if delirium was present. We used Cox proportional hazard models, adjusted for baseline characteristics, coma, and daily hospital events, to determine whether delirium on a given day predicted mortality the following day in patients in the hospital and also to determine whether delirium presence and duration predicted mortality after discharge up to 1 year in patients who survived to hospital discharge. We performed similar analyses for hypoactive and hyperactive subtypes of delirium.

RESULTS

Among 1040 critically ill patients, 214 (21%) died in the hospital and 204 (20%) died out-of-hospital by 1 year. Delirium was common, occurring in 740 (71%) patients for a median (interquartile range [IQR]) of 4 (2-7) days. Hypoactive delirium occurred in 733 (70%) patients, and hyperactive occurred in 185 (18%) patients, with a median (IQR) of 3 (2-7) days and 1 (1-2) days, respectively. Delirium on a given day (hazard ratio [HR], 2.87; 95% confidence interval [CI], 1.32-6.21; P = .008), in particular the hypoactive subtype (HR, 3.35; 95% CI, 1.51-7.46; P = .003), was independently associated with an increased risk of death the following day in the hospital. Hyperactive delirium was not associated with an increased risk of death in the hospital (HR, 4.00; 95% CI, 0.49-32.51; P = .19). Among hospital survivors, neither delirium presence (HR, 1.01; 95% CI, 0.82-1.24; P = .95) nor duration (HR, 0.99; 95% CI, 0.97-1.01; P = .56), regardless of motoric subtype, was associated with mortality after hospital discharge up to 1 year.

CONCLUSIONS

Delirium during critical illness is associated with nearly a 3-fold increased risk of death the following day for patients in the hospital but is not associated with mortality after hospital discharge. This finding appears primarily driven by the hypoactive motoric subtype. The independent relationship between delirium and mortality occurs early during critical illness but does not persist after hospital discharge.

Effect of Hemodiafiltration on the Progression of Neuropathy with Kidney Failure: A Randomized Controlled Trial

BACKGROUND AND OBJECTIVES

Neuropathy is a common complication of kidney disease that lacks proven disease-modifying treatments. Hemodiafiltration improves clearance of uremic toxins and is associated with better nerve function than hemodialysis. We aimed to determine whether hemodiafiltration reduces the progression of neuropathy in people receiving hemodialysis.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

The Filtration in the Neuropathy of End-Stage Kidney Disease Symptom Evolution (FINESSE) study was an open-label, blinded end point assessment, controlled trial that randomized maintenance hemodialysis recipients to hemodiafiltration or high-flux hemodialysis for 48 months or until death or cessation of dialysis at four study centers. The primary outcome was the mean change in the yearly modified total neuropathy score from baseline, with time points weighted equally.

RESULTS

A total of 124 participants were randomized and followed for a mean of 41 months. At baseline, neuropathy was present in 91 (73%) participants (modified total neuropathy score greater than or equal to two), and 38 (31%) had moderate to severe neuropathy (modified total neuropathy score 9-28). Convection volume in the hemodiafiltration arm was a median of 24.7 (interquartile range, 22.4-26.5) L. The mean modified total neuropathy score (SEM) worsened by 1.7 (0.4)/28 and 1.2 (0.4)/28 in the hemodiafiltration and hemodialysis groups, respectively, with a mean difference of 0.5 (95% confidence interval, -0.7 to 1.7; P=0.37). There was no difference in survival (hazard ratio, 1.24; 95% confidence interval, 0.61 to 2.51; log rank P=0.55) or any of the prespecified adverse events. There was no difference between groups in the number of participants who suffered an adverse event adjusted by follow-up time (relative risk, 1.05; 95% confidence interval, 0.83 to 1.32; P=0.68).

CONCLUSIONS

Neuropathy is still a common complication of kidney disease without disease-altering therapy. Hemodiafiltration did not affect neuropathy progression compared with hemodialysis.

CLINICAL TRIAL REGISTRY NAME AND REGISTRATION NUMBER

Filtration in the Neuropathy of End-Stage Kidney Disease Symptom Evolution (FINESSE), ACTRN12609000615280.

The implications of outcome truncation in reproductive medicine RCTs: a simulation platform for trialists and simulation study

BACKGROUND

Randomised controlled trials in reproductive medicine are often subject to outcome truncation, where the study outcomes are only defined in a subset of the randomised cohort. Examples include birthweight (measurable only in the subgroup of participants who give birth) and miscarriage (which can only occur in participants who become pregnant). These outcomes are typically analysed by making a comparison between treatment arms within the subgroup (for example, comparing birthweights in the subgroup who gave birth or miscarriages in the subgroup who became pregnant). However, this approach does not represent a randomised comparison when treatment influences the probability of being observed (i.e. survival). The practical implications of this for the design and interpretation of reproductive trials are unclear however.

METHODS

We developed a simulation platform to investigate the implications of outcome truncation for reproductive medicine trials. We used this to perform a simulation study, in which we considered the bias, type 1 error, coverage, and precision of standard statistical analyses for truncated continuous and binary outcomes. Simulation settings were informed by published assisted reproduction trials.

RESULTS

Increasing treatment effect on the intermediate variable, strength of confounding between the intermediate and outcome variables, and the presence of an interaction between treatment and confounder were found to adversely affect performance. However, within parameter ranges we would consider to be more realistic, the adverse effects were generally not drastic. For binary outcomes, the study highlighted that outcome truncation could cause separation in smaller studies, where none or all of the participants in a study arm experience the outcome event. This was found to have severe consequences for inferences.

CONCLUSION

We have provided a simulation platform that can be used by researchers in the design and interpretation of reproductive medicine trials subject to outcome truncation and have used this to conduct a simulation study. The study highlights several key factors which trialists in the field should consider carefully to protect against erroneous inferences. Standard analyses of truncated binary outcomes in small studies may be highly biassed, and it remains to identify suitable approaches for analysing data in this context.

Proceedings of the First Curing Coma Campaign NIH Symposium: Challenging the Future of Research for Coma and Disorders of Consciousness

Coma and disorders of consciousness (DoC) are highly prevalent and constitute a burden for patients, families, and society worldwide. As part of the Curing Coma Campaign, the Neurocritical Care Society partnered with the National Institutes of Health to organize a symposium bringing together experts from all over the world to develop research targets for DoC. The conference was structured along six domains: (1) defining endotype/phenotypes, (2) biomarkers, (3) proof-of-concept clinical trials, (4) neuroprognostication, (5) long-term recovery, and (6) large datasets. This proceedings paper presents actionable research targets based on the presentations and discussions that occurred at the conference. We summarize the background, main research gaps, overall goals, the panel discussion of the approach, limitations and challenges, and deliverables that were identified.

Heterogeneity in design and analysis of ICU delirium randomized trials: a systematic review

BACKGROUND

There is a growing number of randomized controlled trials (RCTs) evaluating interventions to prevent or treat delirium in the intensive care unit (ICU). Efforts to improve the conduct of delirium RCTs are underway, but none address issues related to statistical analysis. The purpose of this review is to evaluate heterogeneity in the design and analysis of delirium outcomes and advance methodological recommendations for delirium RCTs in the ICU.

METHODS

Relevant databases, including PubMed and Embase, were searched with no restrictions on language or publication date; the search was conducted on July 8, 2019. RCTs conducted on adult ICU patients with delirium as the primary outcome were included where trial results were available. Data on frequency and duration of delirium assessments, delirium outcome definitions, and statistical methods were independently extracted in duplicate. The review was registered with PROSPERO (CRD42020141204).

RESULTS

Among 65 eligible RCTs, 44 (68%) targeted the prevention of delirium. The duration of follow-up varied, with 31 (48%) RCTs having ≤7 days of follow-up, and only 24 (37%) conducting delirium assessments after ICU discharge. The incidence of delirium was the most common outcome (50 RCTs, 77%) for which 8 unique statistical methods were applied. The most common method, applied to 51 of 56 (91%) delirium incidence outcomes, was the two-sample test comparing the proportion of patients who ever experienced delirium. In the presence of censoring of patients at ICU discharge or death, this test may be misleading. The impact of censoring was also not considered in most analyses of the duration of delirium, as evaluated in 24 RCTs, with 21 (88%) delirium duration outcomes analyzed using a non-parametric test or two-sample t test. Composite outcomes (e.g., rank-based delirium- and coma-free days), used in 11 (17%) RCTs, seldom explicitly defined how ICU discharge, and death were incorporated into the definition and were analyzed using non-parametric tests (11 of 13 (85%) composite outcomes).

CONCLUSIONS

To improve delirium RCTs, outcomes should be explicitly defined. To account for censoring due to ICU discharge or death, survival analysis methods should be considered for delirium incidence and duration outcomes; non-parametric tests are recommended for rank-based delirium composite outcomes.

TRIAL REGISTRATION

PROSPERO CRD42020141204 . Registration date: 7/3/2019.

Statistical analysis plan for the Surgery for Cancer with Option of Palliative Care Expert (SCOPE) trial: a randomized controlled trial of a specialist palliative care intervention for patients undergoing surgery for cancer

BACKGROUND

The impact of specialist palliative care intervention in patients undergoing surgery for cancer has not been studied extensively. The SCOPE randomized controlled trial will investigate the effect of specialist palliative care intervention in cancer patients undergoing surgery for selected abdominal malignancies. The study protocol of the SCOPE Trial was published in December 2019.

METHODS AND DESIGN

The SCOPE Trial is a single-center, single-blind, prospective, randomized controlled trial that will investigate specialist palliative care intervention for cancer patients undergoing surgery for selected abdominal malignancies. The study plans to enroll 236 patients that will be randomized to specialist palliative care (intervention arm) and usual care (control arm) in a 1:1 ratio.

RESULTS

The primary outcome of the study is the Functional Assessment of Cancer Therapy-General (FACT-G) Trial Outcome Index (TOI) at 90 days postoperatively. Secondary outcomes of the study include the total FACT-G score at 90 days postoperatively, days alive at home without an emergency room visit within 90 days of operation, and all-cause mortality at 1 year after operation. Time frames for all outcomes will start on the day of surgery.

CONCLUSION

This manuscript serves as the formal statistical analysis plan (version 1.0) for the SCOPE randomized controlled trial. The statistical analysis plan was completed on 6 April 2021.

TRIAL REGISTRATION

ClinicalTrials.gov NCT03436290 . Registered on 16 February 2018.

Essential statistical principles of clinical trials of pain treatments

This article presents an overview of fundamental statistical principles of clinical trials of pain treatments. Statistical considerations relevant to phase 2 proof of concept and phase 3 confirmatory randomized trials investigating efficacy and safety are discussed, including (1) research design; (2) endpoints and analyses; (3) sample size determination and statistical power; (4) missing data and trial estimands; (5) data monitoring and interim analyses; and (6) interpretation of results. Although clinical trials of pharmacologic treatments are emphasized, the key issues raised by these trials are also directly applicable to clinical trials of other types of treatments, including biologics, devices, nonpharmacologic therapies (eg, physical therapy and cognitive-behavior therapy), and complementary and integrative health interventions.

Study protocol for a multicentre, prospective cohort study of the association of angiotensin II type 1 receptor blockers on outcomes of coronavirus infection

INTRODUCTION

The COVID-19 epidemic grows and there are clinical trials of antivirals. There is an opportunity to complement these trials with investigation of angiotensin II type 1 receptor blockers (ARBs) because an ARB (losartan) was effective in murine influenza pneumonia.

METHODS AND ANALYSIS

Our innovative design includes: ARBs; alignment with the WHO Ordinal Scale (primary endpoint) to align with other COVID-19 trials; joint longitudinal analysis; and predictive biomarkers (angiotensins I, 1-7, II and ACE1 and ACE2). Our hypothesis is: ARBs decrease the need for hospitalisation, severity (need for ventilation, vasopressors, extracorporeal membrane oxygenation or renal replacement therapy) or mortality of hospitalised COVID-19 infected adults. Our two-pronged multicentre pragmatic observational cohort study examines safety and effectiveness of ARBs in (1) hospitalised adult patients with COVID-19 and (2) out-patients already on or not on ARBs. The primary outcome will be evaluated by ordinal logistic regression and main secondary outcomes by both joint longitudinal modelling analyses. We will compare rates of hospitalisation of ARB-exposed versus not ARB-exposed patients. We will also determine whether continuing ARBs or not decreases the primary outcome. Based on published COVID-19 cohorts, assuming 15% of patients are ARB-exposed, a total sample size of 497 patients can detect a proportional OR of 0.5 (alpha=0.05, 80% power) comparing WHO scale of ARB-exposed versus non-ARB-exposed patients.

ETHICS AND DISSEMINATION

This study has core institution approval (UBC Providence Healthcare Research Ethics Board) and site institution approvals (Health Research Ethics Board, University of Alberta; Comite d'etique de la recerche, CHU Sainte Justine (for McGill University and University of Sherbrook); Conjoint Health Research Ethics Board, University of Calgary; Queen's University Health Sciences & Affiliated Hospitals Research Ethics Board; Research Ethics Board, Sunnybrook Health Sciences Centre; Veritas Independent Research Board (for Humber River Hospital); Mount Sinai Hospital Research Ethics Board; Unity Health Toronto Research Ethics Board, St. Michael's Hospital). Results will be disseminated by peer-review publication and social media releases.

TRIAL REGISTRATION NUMBER

NCT04510623.

Mortality and HRQoL in ICU patients with delirium: Protocol for 1-year follow-up of AID-ICU trial

BACKGROUND

Intensive care unit (ICU)-acquired delirium is frequent and associated with poor short- and long-term outcomes for patients in ICUs. It therefore constitutes a major healthcare problem. Despite limited evidence, haloperidol is the most frequently used pharmacological intervention against ICU-acquired delirium. Agents intervening against Delirium in the ICU (AID-ICU) is an international, multicentre, randomised, blinded, placebo-controlled trial investigates benefits and harms of treatment with haloperidol in patients with ICU-acquired delirium. The current pre-planned one-year follow-up study of the AID-ICU trial population aims to explore the effects of haloperidol on one-year mortality and health related quality of life (HRQoL).

METHODS

The AID-ICU trial will include 1000 participants. One-year mortality will be obtained from the trial sites; we will validate the vital status of Danish participants using the Danish National Health Data Registers. Mortality will be analysed by Cox-regression and visualized by Kaplan-Meier curves tested for significance using the log-rank test. We will obtain HRQoL data using the EQ-5D instrument. HRQoL analysis will be performed using a general linear model adjusted for stratification variables. Deceased participants will be designated the worst possible value.

RESULTS

We expect to publish results of this study in 2022.

CONCLUSION

We expect that this one-year follow-up study of participants with ICU-acquired delirium allocated to haloperidol vs. placebo will provide important information on the long-term consequences of delirium including the effects of haloperidol. We expect that our results will improve the care of this vulnerable patient group.

Operationalizing needs-focused palliative care for older adults in intensive care units: Design of and rationale for the PCplanner randomized clinical trial

INTRODUCTION

The number of older adults who receive life support in an intensive care unit (ICU), now 2 million per year, is increasing while survival remains unchanged. Because the quality of ICU-based palliative care is highly variable, we developed a mobile app intervention that integrates into the electronic health records (EHR) system called PCplanner (Palliative Care planner) with the goal of improving collaborative primary and specialist palliative care delivery in ICU settings.

OBJECTIVE

To describe the methods of a randomized clinical trial (RCT) being conducted to compare PCplanner vs. usual care.

METHODS AND ANALYSIS

The goal of this two-arm, parallel group mixed methods RCT is to determine the clinical impact of the PCplanner intervention on outcomes of interest to patients, family members, clinicians, and policymakers over a 3-month follow up period. The primary outcome is change in unmet palliative care needs measured by the NEST instrument between baseline and 1 week post-randomization. Secondary outcomes include goal concordance of care, patient-centeredness of care, and quality of communication at 1 week post-randomization; length of stay; as well as symptoms of depression, anxiety, and post-traumatic stress disorder at 3 months post-randomization. We will use general linear models for repeated measures to compare outcomes across the main effects and interactions of the factors. We hypothesize that compared to usual care, PCplanner will have a greater impact on the quality of ICU-based palliative care delivery across domains of core palliative care needs, psychological distress, patient-centeredness, and healthcare resource utilization.

Implications for post critical illness trial design: sub-phenotyping trajectories of functional recovery among sepsis survivors

BACKGROUND

Patients who survive critical illness suffer from a significant physical disability. The impact of rehabilitation strategies on health-related quality of life is inconsistent, with population heterogeneity cited as one potential confounder. This secondary analysis aimed to (1) examine trajectories of functional recovery in critically ill patients to delineate sub-phenotypes and (2) to assess differences between these cohorts in both clinical characteristics and clinimetric properties of physical function assessment tools.

METHODS

Two hundred ninety-one adult sepsis survivors were followed-up for 24 months by telephone interviews. Physical function was assessed using the Physical Component Score (PCS) of the Short Form-36 Questionnaire (SF-36) and Activities of Daily Living and the Extra Short Musculoskeletal Function Assessment (XSFMA-F/B). Longitudinal trajectories were clustered by factor analysis. Logistical regression analyses were applied to patient characteristics potentially determining cluster allocation. Responsiveness, floor and ceiling effects and concurrent validity were assessed within clusters.

RESULTS

One hundred fifty-nine patients completed 24 months of follow-up, presenting overall low PCS scores. Two distinct sub-cohorts were identified, exhibiting complete recovery or persistent impairment. A third sub-cohort could not be classified into either trajectory. Age, education level and number of co-morbidities were independent determinants of poor recovery (AUROC 0.743 ((95%CI 0.659-0.826), p < 0.001). Those with complete recovery trajectories demonstrated high levels of ceiling effects in physical function (PF) (15%), role physical (RP) (45%) and body pain (BP) (57%) domains of the SF-36. Those with persistent impairment demonstrated high levels of floor effects in the same domains: PF (21%), RP (71%) and BP (12%). The PF domain demonstrated high responsiveness between ICU discharge and at 6 months and was predictive of a persistent impairment trajectory (AUROC 0.859 (95%CI 0.804-0.914), p < 0.001).

CONCLUSIONS

Within sepsis survivors, two distinct recovery trajectories of physical recovery were demonstrated. Older patients with more co-morbidities and lower educational achievements were more likely to have a persistent physical impairment trajectory. In regard to trajectory prediction, the PF score of the SF-36 was more responsive than the PCS and could be considered for primary outcomes. Future trials should consider adaptive trial designs that can deal with non-responders or sub-cohort specific outcome measures more effectively.

Treatment estimands in clinical trials of patients hospitalised for COVID-19: ensuring trials ask the right questions

When designing a clinical trial, explicitly defining the treatment estimands of interest (that which is to be estimated) can help to clarify trial objectives and ensure the questions being addressed by the trial are clinically meaningful. There are several challenges when defining estimands. Here, we discuss a number of these in the context of trials of treatments for patients hospitalised with COVID-19 and make suggestions for how estimands should be defined for key outcomes. We suggest that treatment effects should usually be measured as differences in proportions (or risk or odds ratios) for outcomes such as death and requirement for ventilation, and differences in means for outcomes such as the number of days ventilated. We further recommend that truncation due to death should be handled differently depending on whether a patient- or resource-focused perspective is taken; for the former, a composite approach should be used, while for the latter, a while-alive approach is preferred. Finally, we suggest that discontinuation of randomised treatment should be handled from a treatment policy perspective, where non-adherence is ignored in the analysis (i.e. intention to treat).

Identifying Clinical Research Priorities in Adult Pulmonary and Critical Care. NHLBI Working Group Report

Preventing, treating, and promoting recovery from critical illness due to pulmonary disease are foundational goals of the critical care community and the NHLBI. Decades of clinical research in acute respiratory distress syndrome, acute respiratory failure, pneumonia, and sepsis have yielded improvements in supportive care, which have translated into improved patient outcomes. Novel therapeutics have largely failed to translate from promising preclinical findings into improved patient outcomes in late-phase clinical trials. Recent advances in personalized medicine, "big data," causal inference using observational data, novel clinical trial designs, preclinical disease modeling, and understanding of recovery from acute illness promise to transform the methods of pulmonary and critical care clinical research. To assess the current state of, research priorities for, and future directions in adult pulmonary and critical care research, the NHLBI assembled a multidisciplinary working group of investigators. This working group identified recommendations for future research, including 1) focusing on understanding the clinical, physiological, and biological underpinnings of heterogeneity in syndromes, diseases, and treatment response with the goal of developing targeted, personalized interventions; 2) optimizing preclinical models by incorporating comorbidities, cointerventions, and organ support; 3) developing and applying novel clinical trial designs; and 4) advancing mechanistic understanding of injury and recovery to develop and test interventions targeted at achieving long-term improvements in the lives of patients and families. Specific areas of research are highlighted as especially promising for making advances in pneumonia, acute hypoxemic respiratory failure, and acute respiratory distress syndrome.

Hydroxychloroquine versus Azithromycin for Hospitalized Patients with Suspected or Confirmed COVID-19 (HAHPS). Protocol for a Pragmatic, Open-Label, Active Comparator Trial

Coronavirus disease (COVID-19) is a potentially fatal illness with no proven therapy beyond excellent supportive care. Treatments are urgently sought. Adaptations to traditional trial logistics and design to allow rapid implementation, evaluation of trials within a global trials context, flexible interim monitoring, and access outside traditional research hospitals (even in settings where formal placebos are unavailable) may be helpful. Thoughtful adaptations to traditional trial designs, especially within the global context of related studies, may also foster collaborative relationships among government, community, and the research enterprise. Here, we describe the protocol for a pragmatic, active comparator trial in as many as 300 patients comparing two current "off-label" treatments for COVID-19-hydroxychloroquine and azithromycin-in academic and nonacademic hospitals in Utah. We developed the trial in response to local pressures for widespread, indiscriminate off-label use of these medications. We used a hybrid Bayesian-frequentist design for interim monitoring to allow rapid, contextual assessment of the available evidence. We also developed an inference grid for interpreting the range of possible results from this trial within the context of parallel trials and prepared for a network meta-analysis of the resulting data. This trial was prospectively registered (ClinicalTrials.gov Identifier: NCT04329832) before enrollment of the first patient.Clinical trial registered with www.clinicaltrials.gov (NCT04329832).

Physical health-related quality of life at higher achieved hemoglobin levels among chronic kidney disease patients: a systematic review and meta-analysis

BACKGROUND

The impact of anemia treatment with erythropoietin stimulating agents (ESA) on health-related quality of life (HRQOL) in chronic kidney disease (CKD) patients is controversial, particularly regarding optimal hemoglobin (Hb) target ranges.

METHODS

We conducted a systematic review and meta-analysis of observational studies and randomized controlled trials (RCT) with ESA to estimate the effect of different achieved Hb values on physical HRQOL and functionality. We searched PubMed, EMBASE, CENTRAL, PEDro, PsycINFO and Web of Science databases, until May 2020. Two authors independently extracted data from studies. We included observational and RCTs that enrolled CKD patients undergoing anemia treatment with ESA with different achieved Hb levels among groups. We excluded studies with achieved Hb < 9 g/dL. For the meta-analysis, we included RCTs with control groups achieving Hb 10-11.5 g/dL and active groups with Hb > 11.5 g/dL. We analyzed the standardized mean difference (SMD) between groups for physical HRQOL.

RESULTS

Among 8496 studies, fifteen RCTs and five observational studies were included for the systematic review. We performed the meta-analysis in a subset of eleven eligible RCTs. For physical role and physical function, SMDs were 0.0875 [95% CI: - 0.0025 - 0.178] and 0.08 [95% CI: - 0.03 - 0.19], respectively. For fatigue, SMD was 0.16 [95% CI: 0.09-0.24]. Subgroup analysis showed that trials with greater achieved Hb had greater pooled effects sizes - 0.21 [95% CI: 0.07-0.36] for Hb > 13 g/dL vs. 0.09 [95% CI: 0.02-0.16] for Hb 11.5-13 g/dL. Proportion of older and long-term diabetic patients across studies were associated with lower effect sizes.

CONCLUSION

Achieved hemoglobin higher than currently recommended targets may be associated with small but potentially clinically significant improvement in fatigue, but not in physical role or physical function. Younger and non-diabetic patients may experience more pronounced benefits of higher Hb levels after treatment with ESAs.

Changes in Self-Rated Health After Sepsis in Older Adults: A Retrospective Cohort Study

BACKGROUND

As more individuals survive sepsis, there is an urgent need to understand its effects on patient-reported outcomes.

RESEARCH QUESTION

What is the effect of sepsis on self-rated health, and what role, if any, does functional disability play in mediating this effect?

STUDY DESIGN AND METHODS

We conducted a survey- and administrative claims-based retrospective cohort study using the US Health and Retirement Study, a nationally representative cohort-based survey of older adults in the United States, from 2000 through 2016. We matched Medicare beneficiaries hospitalized with sepsis in 2000 to 2008 to nonhospitalized individuals. Self-rated health and functional disability were tracked biannually for 8 years. Differences in self-rated health between the cohorts were measured using mixed models with and without controlling for changes in functional disability.

RESULTS

Seven hundred fifty-eight individuals with sepsis were matched 1:1 to 758 nonhospitalized individuals, all aged 65 years and older. Among survivors, sepsis was associated with worse self-rated health in years 2 and 4 (adjusted absolute difference in self-rated health on a 5-point scale in year 2: -0.24 [95% CI, -0.38 to -0.10] and year 4: -0.17 [95% CI, -0.33 to -0.02]) but not in years 6 or 8. After accounting for changes in functional status, the association between sepsis and self-rated health was still present but reduced in year 2 (adjusted absolute difference in self-rated health, -0.18 [95% CI, -0.31 to -0.05]) and was not present in years 4, 6, or 8.

INTERPRETATION

Self-rated health worsened initially after sepsis but returned to the level of that of nonhospitalized control subjects by year 6. Mitigating sepsis-related functional disability may play a key role in improving self-rated health after sepsis.

Response to physical rehabilitation and recovery trajectories following critical illness: individual participant data meta-analysis protocol

INTRODUCTION

The number of inconclusive physical rehabilitation randomised controlled trials for patients with critical illness is increasing. Evidence suggests critical illness patient subgroups may exist that benefit from targeted physical rehabilitation interventions that could improve their recovery trajectory. We aim to identify critical illness patient subgroups that respond to physical rehabilitation and map recovery trajectories according to physical function and quality of life outcomes. Additionally, the utilisation of healthcare resources will be examined for subgroups identified.

METHODS AND ANALYSIS

This is an individual participant data meta-analysis protocol. A systematic literature review was conducted for randomised controlled trials that delivered additional physical rehabilitation for patients with critical illness during their acute hospital stay, assessed chronic disease burden, with a minimum follow-up period of 3 months measuring performance-based physical function and health-related quality of life outcomes. From 2178 records retrieved in the systematic literature review, four eligible trials were identified by two independent reviewers. Principal investigators of eligible trials were invited to contribute their data to this individual participant data meta-analysis. Risk of bias will be assessed (Cochrane risk of bias tool for randomised trials). Participant and trial characteristics, interventions and outcomes data of included studies will be summarised. Meta-analyses will entail a one-stage model, which will account for the heterogeneity across and the clustering between studies. Multiple imputation using chained equations will be used to account for the missing data.

ETHICS AND DISSEMINATION

This individual participant data meta-analysis does not require ethical review as anonymised participant data will be used and no new data collected. Additionally, eligible trials were granted approval by institutional review boards or research ethics committees and informed consent was provided for participants. Data sharing agreements are in place permitting contribution of data. The study findings will be disseminated at conferences and through peer-reviewed publications.

PROSPERO REGISTRATION NUMBER

CRD42019152526.

Assessing the Course of Organ Dysfunction Using Joint Longitudinal and Time-to-Event Modeling in the Vasopressin and Septic Shock Trial

Supplemental Digital Content is available in the text.

Non-mortality septic shock outcomes (e.g., Sequential Organ Failure Assessment score) are important clinical endpoints in pivotal sepsis trials. However, comparisons of observed longitudinal non-mortality outcomes between study groups can be biased if death is unequal between study groups or is associated with an intervention (i.e., informative censoring). We compared the effects of vasopressin versus norepinephrine on the Sequential Organ Failure Assessment score in the Vasopressin and Septic Shock Trial to illustrate the use of joint modeling to help minimize potential bias from informative censoring.

Home and Community-Based Physical Therapist Management of Adults With Post-Intensive Care Syndrome

More than 4 million adults survive a stay in the intensive care unit each year, with many experiencing new or worsening physical disability, mental health problems, and/or cognitive impairments, known as post-intensive care syndrome (PICS). Given the prevalence and magnitude of physical impairments after critical illness, many survivors, including those recovering from COVID-19, could benefit from physical therapist services after hospital discharge. However, due to the relatively recent recognition and characterization of PICS, there may be limited awareness and understanding of PICS among physical therapists practicing in home health care and community-based settings. This lack of awareness may lead to inappropriate and/or inadequate rehabilitation service provision. While this perspective article provides information relevant to all physical therapists, it is aimed toward those providing rehabilitation services outside of the acute and postacute inpatient settings. This article reports the prevalence and clinical presentation of PICS and provides recommendations for physical examination and outcomes measures, plan of care, and intervention strategies. The importance of providing patient and family education, coordinating community resources including referring to other health care team members, and community-based rehabilitation service options is emphasized. Finally, this perspective article discusses current challenges for optimizing outcomes for people with PICS and suggests future directions for research and practice.

Computerised speech and language therapy or attention control added to usual care for people with long-term post-stroke aphasia: the Big CACTUS three-arm RCT

BACKGROUND

People with aphasia may improve their communication with speech and language therapy many months/years after stroke. However, NHS speech and language therapy reduces in availability over time post stroke.

OBJECTIVE

This trial evaluated the clinical effectiveness and cost-effectiveness of self-managed computerised speech and language therapy to provide additional therapy.

DESIGN

A pragmatic, superiority, single-blind, parallel-group, individually randomised (stratified block randomisation, stratified by word-finding severity and site) adjunct trial.

SETTING

Twenty-one UK NHS speech and language therapy departments.

PARTICIPANTS

People with post-stroke aphasia (diagnosed by a speech and language therapist) with long-standing (> 4 months) word-finding difficulties.

INTERVENTIONS

The groups were (1) usual care; (2) daily self-managed computerised word-finding therapy tailored by speech and language therapists and supported by volunteers/speech and language therapy assistants for 6 months plus usual care (computerised speech and language therapy); and (3) activity/attention control (completion of puzzles and receipt of telephone calls from a researcher for 6 months) plus usual care.

MAIN OUTCOME MEASURES

Co-primary outcomes - change in ability to find treated words of personal relevance in a bespoke naming test (impairment) and change in functional communication in conversation rated on the activity scale of the Therapy Outcome Measures (activity) 6 months after randomisation. A key secondary outcome was participant-rated perception of communication and quality of life using the Communication Outcomes After Stroke questionnaire at 6 months. Outcomes were assessed by speech and language therapists using standardised procedures. Cost-effectiveness was estimated using treatment costs and an accessible EuroQol-5 Dimensions, five-level version, measuring quality-adjusted life-years.

RESULTS

A total of 818 patients were assessed for eligibility and 278 participants were randomised between October 2014 and August 2016. A total of 240 participants (86 usual care, 83 computerised speech and language therapy, 71 attention control) contributed to modified intention-to-treat analysis at 6 months. The mean improvements in word-finding were 1.1% (standard deviation 11.2%) for usual care, 16.4% (standard deviation 15.3%) for computerised speech and language therapy and 2.4% (standard deviation 8.8%) for attention control. Computerised speech and language therapy improved word-finding 16.2% more than usual care did (95% confidence interval 12.7% to 19.6%; p < 0.0001) and 14.4% more than attention control did (95% confidence interval 10.8% to 18.1%). Most of this effect was maintained at 12 months (n = 219); the mean differences in change in word-finding score were 12.7% (95% confidence interval 8.7% to 16.7%) higher in the computerised speech and language therapy group (n = 74) than in the usual-care group (n = 84) and 9.3% (95% confidence interval 4.8% to 13.7%) higher in the computerised speech and language therapy group than in the attention control group (n = 61). Computerised speech and language therapy did not show significant improvements on the Therapy Outcome Measures or Communication Outcomes After Stroke scale compared with usual care or attention control. Primary cost-effectiveness analysis estimated an incremental cost per participant of £732.73 (95% credible interval £674.23 to £798.05). The incremental quality-adjusted life-year gain was 0.017 for computerised speech and language therapy compared with usual care, but its direction was uncertain (95% credible interval -0.05 to 0.10), resulting in an incremental cost-effectiveness ratio of £42,686 per quality-adjusted life-year gained. For mild and moderate word-finding difficulty subgroups, incremental cost-effectiveness ratios were £22,371 and £28,898 per quality-adjusted life-year gained, respectively, for computerised speech and language therapy compared with usual care.

LIMITATIONS

This trial excluded non-English-language speakers, the accessible EuroQol-5 Dimensions, five-level version, was not validated and the measurement of attention control fidelity was limited.

CONCLUSIONS

Computerised speech and language therapy enabled additional self-managed speech and language therapy, contributing to significant improvement in finding personally relevant words (as specifically targeted by computerised speech and language therapy) long term post stroke. Gains did not lead to improvements in conversation or quality of life. Cost-effectiveness is uncertain owing to uncertainty around the quality-adjusted life-year gain, but computerised speech and language therapy may be more cost-effective for participants with mild and moderate word-finding difficulties. Exploring ways of helping people with aphasia to use new words in functional communication contexts is a priority.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN68798818.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 24, No. 19. See the NIHR Journals Library website for further project information. The Tavistock Trust for Aphasia provided additional support to enable people in the control groups to experience the intervention after the trial had ended.

Outcomes Six Months after Delivering 100% or 70% of Enteral Calorie Requirements during Critical Illness (TARGET). A Randomized Controlled Trial

Rationale: The long-term effects of delivering approximately 100% of recommended calorie intake via the enteral route during critical illness compared with a lesser amount of calories are unknown.Objectives: Our hypotheses were that achieving approximately 100% of recommended calorie intake during critical illness would increase quality-of-life scores, return to work, and key life activities and reduce death and disability 6 months later.Methods: We conducted a multicenter, blinded, parallel group, randomized clinical trial, with 3,957 mechanically ventilated critically ill adults allocated to energy-dense (1.5 kcal/ml) or routine (1.0 kcal/ml) enteral nutrition.Measurements and Main Results: Participants assigned energy-dense nutrition received more calories (percent recommended energy intake, mean [SD]; energy-dense: 103% [28] vs. usual: 69% [18]). Mortality at Day 180 was similar (560/1,895 [29.6%] vs. 539/1,920 [28.1%]; relative risk 1.05 [95% confidence interval, 0.95-1.16]). At a median (interquartile range) of 185 (182-193) days after randomization, 2,492 survivors were surveyed and reported similar quality of life (EuroQol five dimensions five-level quality-of-life questionnaire visual analog scale, median [interquartile range]: 75 [60-85]; group difference: 0 [95% confidence interval, 0-0]). Similar numbers of participants returned to work with no difference in hours worked or effectiveness at work (n = 818). There was no observed difference in disability (n = 1,208) or participation in key life activities (n = 705).Conclusions: The delivery of approximately 100% compared with 70% of recommended calorie intake during critical illness does not improve quality of life or functional outcomes or increase the number of survivors 6 months later.

Long-term patient-important outcomes after septic shock: A protocol for 1-year follow-up of the CLASSIC trial

BACKGROUND

In patients with septic shock, mortality is high, and survivors experience long-term physical, mental and social impairments. The ongoing Conservative vs Liberal Approach to fluid therapy of Septic Shock in Intensive Care (CLASSIC) trial assesses the benefits and harms of a restrictive vs standard-care intravenous (IV) fluid therapy. The hypothesis is that IV fluid restriction improves patient-important long-term outcomes.

AIM

To assess the predefined patient-important long-term outcomes in patients randomised into the CLASSIC trial.

METHODS

In this pre-planned follow-up study of the CLASSIC trial, we will assess all-cause mortality, health-related quality of life (HRQoL) and cognitive function 1 year after randomisation in the two intervention groups. The 1-year mortality will be collected from electronic patient records or central national registries in most participating countries. We will contact survivors and assess EuroQol 5-Dimension, -5-Level (EQ-5D-5L) and EuroQol-Visual Analogue Scale and Montreal Cognitive Assessment 5-minute protocol score. We will analyse mortality by logistic regression and use general linear models to assess HRQoL and cognitive function.

DISCUSSION

With this pre-planned follow-up study of the CLASSIC trial, we will provide patient-important data on long-term survival, HRQoL and cognitive function of restrictive vs standard-care IV fluid therapy in patients with septic shock.

Contemporary strategies to improve clinical trial design for critical care research: insights from the First Critical Care Clinical Trialists Workshop

BACKGROUND

Conducting research in critically-ill patient populations is challenging, and most randomized trials of critically-ill patients have not achieved pre-specified statistical thresholds to conclude that the intervention being investigated was beneficial.

METHODS

In 2019, a diverse group of patient representatives, regulators from the USA and European Union, federal grant managers, industry representatives, clinical trialists, epidemiologists, and clinicians convened the First Critical Care Clinical Trialists (3CT) Workshop to discuss challenges and opportunities in conducting and assessing critical care trials. Herein, we present the advantages and disadvantages of available methodologies for clinical trial design, conduct, and analysis, and a series of recommendations to potentially improve future trials in critical care.

CONCLUSION

The 3CT Workshop participants identified opportunities to improve critical care trials using strategies to optimize sample size calculations, account for patient and disease heterogeneity, increase the efficiency of trial conduct, maximize the use of trial data, and to refine and standardize the collection of patient-centered and patient-informed outcome measures beyond mortality.

Alive and Ventilator Free: A Hierarchical, Composite Outcome for Clinical Trials in the Acute Respiratory Distress Syndrome

OBJECTIVES

Survival from acute respiratory distress syndrome is improving, and outcomes beyond mortality may be important for testing new treatments. The "ventilator-free days" score, is an established composite that equates ventilation on day 28 to death. A hierarchical outcome treating death as a worse than prolonged ventilation would enhance face validity, but performance characteristics and reporting of such an outcome are unknown. We therefore evaluated the performance of a novel hierarchical composite endpoint, the Alive and Ventilator Free score.

DESIGN

Using data from four Acute Respiratory Distress Syndrome Network clinical trials, we compared Alive and Ventilator Free to the ventilator-free days score. Alive and Ventilator Free compares each patient with every other patient in a win-lose-tie for each comparison. Duration of mechanical ventilation is only compared if both patients survived. We evaluated power of Alive and Ventilator Free versus ventilator-free days score under various circumstances.

SETTING

ICUs within the Acute Respiratory Distress Syndrome Network.

PATIENTS

Individuals enrolled in four Acute Respiratory Distress Syndrome Network trials.

INTERVENTIONS

None for this analysis.

MEASUREMENTS AND MAIN RESULTS

Within the four trials (n = 2,410 patients), Alive and Ventilator Free and ventilator-free days score had similar power, with Alive and Ventilator Free slightly more powerful when a mortality difference was present, and ventilator-free days score slightly more powerful with a difference in duration of mechanical ventilation. Alive and Ventilator Free less often found in favor of treatments that increased mortality and increased days free of ventilation among survivors.

CONCLUSIONS

A hierarchical composite endpoint, Alive and Ventilator Free, preserves statistical power while improving face validity. Alive and Ventilator Free is less prone to favor a treatment with discordant effects on survival and days free of ventilation. This general approach can support complex outcome hierarchies with multiple constituent outcomes. Approaches to interpretation of differences in Alive and Ventilator Free are also presented.

Time to onset of gastrointestinal bleeding in the SUP-ICU trial: A pre-planned substudy

BACKGROUND

The aetiology and risk factors for clinically important gastrointestinal bleeding (CIB) in adult ICU patients may differ according to the onset of CIB, which could affect the balance between benefits and harms of stress ulcer prophylaxis (SUP).

METHODS

We assessed the time to CIB in the Stress Ulcer Prophylaxis in the Intensive Care Unit (SUP-ICU) trial. We assessed if associations between baseline characteristics including allocation to SUP and CIB changed during time in the ICU, specifically in the later (after day 2) compared to the earlier (first 2 days) period, using Cox models adjusted for SAPS II and allocation to SUP. Additionally, we described baseline characteristics and CIB episodes stratified by earlier/later/no CIB and 90-day mortality status.

RESULTS

Clinically important gastrointestinal bleeding occurred in 110/3291 (3.3%) patients after a median of 6 (interquartile range 2-13) days; 25.5% of the episodes occurred early. Higher SAPS II was consistently associated with increased risk of CIB (hazard ratio (HR) 1.03, 95% confidence interval (CI) 1.01-1.05 in the earlier period vs HR 1.02, 95% CI 1.01-1.03 in the later period; P = .37); university hospital admission was associated with decreased risk of earlier CIB (HR 0.30, 95% CI 0.14-0.63); this significantly increased in the later period (to HR 0.85, 95% CI 0.53-1.37; P = .02). Patients with later compared to earlier CIB received more transfusions and had more diagnostic/therapeutic procedures for CIB.

CONCLUSIONS

Clinically important gastrointestinal bleeding mostly occurred more than 2 days after randomization. University hospital admission was associated with significantly decreased risk of CIB in the earlier period only.

Epidemiology of Cause of Death in Pediatric Acute Respiratory Distress Syndrome

OBJECTIVES

Investigations of acute respiratory distress syndrome in adults suggest hypoxemia is an uncommon cause of death. However, the epidemiology of death in pediatric acute respiratory distress syndrome is not well characterized. We aimed to describe the cause, mode, and timing of death in pediatric acute respiratory distress syndrome nonsurvivors. We hypothesized that most deaths would be due to nonpulmonary factors, rather than hypoxemia.

DESIGN

Retrospective, decedent-only analysis.

SETTING

Two large, academic PICUs.

PATIENTS

Nonsurvivors with pediatric acute respiratory distress syndrome.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Of 798 subjects with pediatric acute respiratory distress syndrome, there were 153 nonsurvivors (19% mortality). Median time to death was 6 days (interquartile range, 3-13 d) after pediatric acute respiratory distress syndrome onset. Patients dying less than 7 days after pediatric acute respiratory distress syndrome onset had greater illness severity and worse oxygenation. Patients dying less than 7 days were more likely to die of a neurologic cause, including brain death. Patients dying greater than or equal to 7 days after pediatric acute respiratory distress syndrome onset were more commonly immunocompromised. Multisystem organ failure predominated in deaths greater than or equal to 7 days. Withdrawal of therapy was the most common mode of death at all timepoints, accounting for 66% of all deaths. Organ dysfunction was common at time of death, irrespective of cause of death. Refractory hypoxemia accounted for only a minority of pediatric acute respiratory distress syndrome deaths (20%).

CONCLUSIONS

In pediatric acute respiratory distress syndrome, early deaths were due primarily to neurologic failure, whereas later deaths were more commonly due to multisystem organ failure. Deaths from neurologic causes accounted for a substantial portion of nonsurvivors. Refractory hypoxemia accounted for only a minority of deaths. Our study highlights limitations associated with using death as an endpoint in therapeutic pediatric acute respiratory distress syndrome trials.

Measuring and Analyzing Length of Stay in Critical Care Trials

BACKGROUND

In randomized clinical trials among critically ill patients, it is uncertain how choices regarding the measurement and analysis of nonmortal outcomes measured in terms of duration, such as intensive care unit (ICU) length of stay (LOS), affect studies' conclusions.

OBJECTIVES

Assess the definitions and analytic methods used for ICU LOS analyses in published randomized clinical trials.

RESEARCH DESIGN

This is a systematic review and statistical simulation study.

RESULTS

Among the 80 of 150 trials providing sufficient information regarding the chosen definition of ICU LOS, 3 different start times (ICU admission, trial enrollment/randomization, receipt of intervention) and 2 end times (discharge readiness, actual discharge) were used. In roughly three quarters of these studies, ICU LOS was compared using approaches that did not explicitly account for death, either by ignoring it entirely or stratifying the analyses by survival status. The remaining studies used time-to-event (discharge) models censoring at death or applied a fixed LOS value to patients who died. In statistical simulations, we showed that each analytic approach tested a different question regarding ICU LOS, and that approaches that do not explicitly account for death often produce misleading or ambiguous conclusions when treatments produce small effects on mortality, even if those are not detected as significant in the trial.

CONCLUSIONS

There is considerable variability in how ICU LOS is measured and analyzed which impairs the ability to compare results across trials and can produce spurious conclusions. Analyses of duration-based outcomes such as LOS should jointly assess the impact of the intervention on mortality to yield correct interpretations.