Statistical Issues and Recommendations for Clinical Trials Conducted During the COVID-19 Pandemic

Evaluation of adapted parent training for challenging behaviour in pre-school children with moderate to severe intellectual developmental disabilities: A randomised controlled trial

OBJECTIVES

There is limited evidence on the effectiveness of parenting interventions to improve disruptive behaviour in children with intellectual developmental disabilities. This clinical trial evaluated whether an adapted group parenting intervention for preschool children with intellectual developmental disabilities who display challenging behaviour is superior to treatment as usual in England.

STUDY DESIGN

261 children aged 30-59 months with moderate to severe intellectual developmental disabilities and challenging behaviour were randomised to either the intervention (Stepping Stones Triple P) and treatment as usual or treatment as usual alone. The primary outcome was the parent-rated Child Behaviour Checklist at 52 weeks after randomisation. A health economic evaluation was also completed.

RESULTS

We found no significant difference between arms on the primary outcome (mean difference -4.23; 95% CI: -9.99 to 1.53; p = 0.147). However, a subgroup analysis suggests the intervention was effective for participants randomised before the COVID-19 pandemic (mean difference -7.12; 95% CI: -13.44 to -0.81; p = 0.046). Furthermore, a complier average causal effects analysis (mean difference -11.53; 95% CI: -26.97 to 3.91; p = 0.143) suggests the intervention requires participants to receive a sufficient intervention dose. The intervention generated statistically significant cost savings (-£1,057.88; 95% CI -£3,218.6 to -£46.67) but the mean point estimate in Quality Adjusted Life Years was similar in both groups.

CONCLUSION

This study did not find an effect of the intervention on reducing challenging behaviour, but this may have been influenced by problems with engagement. The intervention could be considered by services as an early intervention if families are supported to attend, especially given its low cost.

Agile response to critical need for clinical trial accessibility during the first COVID-19 pandemic wave

This article discusses some of the major challenges that the clinical research community faced during the early days of the coronavirus disease 2019 pandemic. A model is offered that may assist other institutions while planning for future pandemics or disasters.

Interactions among stress, behavioral inhibition, and delta-beta coupling predict adolescent anxiety during the COVID-19 pandemic

The COVID-19 pandemic brought about unprecedented changes and uncertainty to the daily lives of youth. The range of adjustment in light of a near-universal experience of COVID restrictions highlights the importance of identifying factors that may render some individuals more susceptible to heightened levels of anxiety during stressful life events than others. Two risk factors to consider are temperamental behavioral inhibition (BI) and difficulties in emotion regulation (ER). As such, the current paper focused on BI examined prior to COVID, because of its developmental link to anxiety and ER, as difficulties may be associated with differences in anxiety. We examined a neurocognitive marker of ER processes, delta-beta coupling (DBC). The current paper had two goals: (1) to examine BI in relation to COVID-related worry and social anxiety experienced during the pandemic, and (2) to explore the role of individual differences in early DBC in the relationship between BI and anxiety outcomes 6 months apart during COVID-19 (n = 86; T1 Mage  = 15.95, SD = 1.73; T6 Mage  = 16.43, SD = 1.73). We found support for the moderating role of DBC in the relationship between BI levels and social anxiety disorder (SAD) symptom severity during the pandemic. Here, high BI was predictive of increased SAD symptom levels in adolescents with stronger DBC.

Lisocabtagene Maraleucel in Relapsed/Refractory Mantle Cell Lymphoma: Primary Analysis of the Mantle Cell Lymphoma Cohort From TRANSCEND NHL 001, a Phase I Multicenter Seamless Design Study

PURPOSE

To report the primary analysis results from the mantle cell lymphoma (MCL) cohort of the phase I seamless design TRANSCEND NHL 001 (ClinicalTrials.gov identifier: NCT02631044) study.

METHODS

Patients with relapsed/refractory (R/R) MCL after ≥two lines of previous therapy, including a Bruton tyrosine kinase inhibitor (BTKi), an alkylating agent, and a CD20-targeted agent, received lisocabtagene maraleucel (liso-cel) at a target dose level (DL) of 50 × 106 (DL1) or 100 × 106 (DL2) chimeric antigen receptor-positive T cells. Primary end points were adverse events (AEs), dose-limiting toxicities, and objective response rate (ORR) by independent review committee per Lugano criteria.

RESULTS

Of 104 leukapheresed patients, liso-cel was infused into 88. Median (range) number of previous lines of therapy was three (1-11) with 30% receiving ≥five previous lines of therapy, 73% of patients were age 65 years and older, 69% had refractory disease, 53% had BTKi refractory disease, 23% had TP53 mutation, and 8% had secondary CNS lymphoma. Median (range) on-study follow-up was 16.1 months (0.4-60.5). In the efficacy set (n = 83; DL1 + DL2), ORR was 83.1% (95% CI, 73.3 to 90.5) and complete response (CR) rate was 72.3% (95% CI, 61.4 to 81.6). Median duration of response was 15.7 months (95% CI, 6.2 to 24.0) and progression-free survival was 15.3 months (95% CI, 6.6 to 24.9). Most common grade ≥3 treatment-emergent AEs were neutropenia (56%), anemia (37.5%), and thrombocytopenia (25%). Cytokine release syndrome (CRS) was reported in 61% of patients (grade 3/4, 1%; grade 5, 0), neurologic events (NEs) in 31% (grade 3/4, 9%; grade 5, 0), grade ≥3 infections in 15%, and prolonged cytopenia in 40%.

CONCLUSION

Liso-cel demonstrated high CR rate and deep, durable responses with low incidence of grade ≥3 CRS, NE, and infections in patients with heavily pretreated R/R MCL, including those with high-risk, aggressive disease.

Clinical and cost-effectiveness of an adapted intervention for preschoolers with moderate to severe intellectual disabilities displaying behaviours that challenge: the EPICC-ID RCT

Background

Stepping Stones Triple P is an adapted intervention for parents of young children with developmental disabilities who display behaviours that challenge, aiming at teaching positive parenting techniques and promoting a positive parent-child relationship.

Objective

To evaluate the clinical and cost-effectiveness of level 4 Stepping Stones Triple P in reducing behaviours that challenge in children with moderate to severe intellectual disabilities.

Design, setting, participants

A parallel two-arm pragmatic multisite single-blind randomised controlled trial recruited a total of 261 dyads (parent and child). The children were aged 30-59 months and had moderate to severe intellectual disabilities. Participants were randomised, using a 3 : 2 allocation ratio, into the intervention arm (Stepping Stones Triple P; n = 155) or treatment as usual arm (n = 106). Participants were recruited from four study sites in Blackpool, North and South London and Newcastle.

Intervention

Level 4 Stepping Stones Triple P consists of six group sessions and three individual phone or face-to-face contacts over 9 weeks. These were changed to remote sessions after 16 March 2020 due to the coronavirus disease 2019 pandemic.

Main outcome measure

The primary outcome measure was the parent-reported Child Behaviour Checklist, which assesses the severity of behaviours that challenge.

Results

We found a small non-significant difference in the mean Child Behaviour Checklist scores (-4.23, 95% CI -9.98 to 1.52, p = 0.146) in the intervention arm compared to treatment as usual at 12 months. Per protocol and complier average causal effect sensitivity analyses, which took into consideration the number of sessions attended, showed the Child Behaviour Checklist mean score difference at 12 months was lower in the intervention arm by -10.77 (95% CI -19.12 to -2.42, p = 0.014) and -11.53 (95% CI -26.97 to 3.91, p = 0.143), respectively. The Child Behaviour Checklist mean score difference between participants who were recruited before and after the coronavirus disease 2019 pandemic was estimated as -7.12 (95% CI -13.44 to -0.81) and 7.61 (95% CI -5.43 to 20.64), respectively (p = 0.046), suggesting that any effect pre-pandemic may have reversed during the pandemic. There were no differences in all secondary measures. Stepping Stones Triple P is probably value for money to deliver (-£1057.88; 95% CI -£3218.6 to -£46.67), but decisions to roll this out as an alternative to existing parenting interventions or treatment as usual may be dependent on policymaker willingness to invest in early interventions to reduce behaviours that challenge. Parents reported the intervention boosted their confidence and skills, and the group format enabled them to learn from others and benefit from peer support. There were 20 serious adverse events reported during the study, but none were associated with the intervention.

Limitations

There were low attendance rates in the Stepping Stones Triple P arm, as well as the coronavirus disease 2019-related challenges with recruitment and delivery of the intervention.

Conclusions

Level 4 Stepping Stones Triple P did not reduce early onset behaviours that challenge in very young children with moderate to severe intellectual disabilities. However, there was an effect on child behaviours for those who received a sufficient dose of the intervention. There is a high probability of Stepping Stones Triple P being at least cost neutral and therefore worth considering as an early therapeutic option given the long-term consequences of behaviours that challenge on people and their social networks.

Future work

Further research should investigate the implementation of parenting groups for behaviours that challenge in this population, as well as the optimal mode of delivery to maximise engagement and subsequent outcomes.

Study registration

This study is registered as NCT03086876 (https://www.clinicaltrials.gov/ct2/show/NCT03086876?term=Hassiotis±Angela&draw=1&rank=1).

Funding

This award was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme (NIHR award ref: HTA 15/162/02) and is published in full in Health Technology Assessment; Vol. 28, No. 6. See the NIHR Funding and Awards website for further award information.

A randomized double-blind clinical trial on safety and efficacy of tauroursodeoxycholic acid (TUDCA) as add-on treatment in patients affected by amyotrophic lateral sclerosis (ALS): the statistical analysis plan of TUDCA-ALS trial

BACKGROUND

Amyotrophic lateral sclerosis (ALS) is a highly debilitating neurodegenerative condition. Despite recent advancements in understanding the molecular mechanisms underlying ALS, there have been no significant improvements in therapeutic options for ALS patients in recent years. Currently, there is no cure for ALS, and the only approved treatment in Europe is riluzole, which has been shown to slow the disease progression and prolong survival by approximately 3 months. Recently, tauroursodeoxycholic acid (TUDCA) has emerged as a promising and effective treatment for neurodegenerative diseases due to its neuroprotective activities.

METHODS

The ongoing TUDCA-ALS study is a double-blinded, parallel arms, placebo-controlled, randomized multicenter phase III trial with the aim to assess the efficacy and safety of TUDCA as add-on therapy to riluzole in patients with ALS. The primary outcome measure is the treatment response defined as a minimum of 20% improvement in the ALS Functional Rating Scale-Revised (ALSFRS-R) slope during the randomized treatment period (18 months) compared to the lead-in period (3 months). Randomization will be stratified by country. Primary analysis will be conducted based on the intention-to-treat principle through an unadjusted logistic regression model. Patient recruitment commenced on February 22, 2019, and was closed on December 23, 2021. The database will be locked in September 2023.

DISCUSSION

This paper provides a comprehensive description of the statistical analysis plan in order to ensure the reproducibility of the analysis and avoid selective reporting of outcomes and data-driven analysis. Sensitivity analyses have been included in the protocol to assess the impact of intercurrent events related to the coronavirus disease 2019. By focusing on clinically meaningful and robust outcomes, this trial aims to determine whether TUDCA can be effective in slowing the disease progression in patients with ALS.

TRIAL REGISTRATION

ClinicalTrials.gov NCT03800524 . Registered on January 11, 2019.

General independent censoring in event-driven trials with staggered entry

Randomized clinical trials with time-to-event endpoints are frequently stopped after a prespecified number of events has been observed. This practice leads to dependent data and nonrandom censoring, which can in general not be solved by conditioning on the underlying baseline information. In case of staggered study entry, matters are complicated substantially. The present paper demonstrates that the study design at hand entails general independent censoring in the counting process sense, provided that the analysis is based on study time information only. To illustrate that the filtrations must not use abundant information, we simulated data of event-driven trials and evaluated them by means of Cox regression models with covariates for the calendar times. The Breslow curves of the cumulative baseline hazard showed considerable deviations, which implies that the analysis is disturbed by conditioning on the calendar time variables. A second simulation study further revealed that Efron's classical bootstrap, unlike the (martingale-based) wild bootstrap, may lead to biased results in the given setting, as the assumption of random censoring is violated. This is exemplified by an analysis of data on immunotherapy in patients with advanced, previously treated nonsmall cell lung cancer.

COVID-19 and the Physio4FMD trial: Impact, mitigating strategies and analysis plans

Introduction

Functional motor disorder (FMD) is a common cause of disabling neurological symptoms such as weakness and tremor. Physio4FMD is a pragmatic, multicentre single blind randomised controlled trial to evaluate effectiveness and cost effectiveness of specialist physiotherapy for FMD. Like many other studies this trial was affected by the COVID-19 pandemic.

Methods

The planned statistical and health economics analyses for this trial are described, as well as the sensitivity analyses designed to assess the disruption caused by COVID-19. The trial treatment of at least 89 participants (33%) was disrupted due to the pandemic. To account for this, we have extended the trial to increase the sample size. We have identified four groups based on how participants’ involvement in Physio4FMD was affected; A: 25 were unaffected; B: 134 received their trial treatment before the start of the COVID-19 pandemic and were followed up during the pandemic; C: 89 were recruited in early 2020 and had not received any randomised treatment before clinical services closed because of COVID-19; D: 88 participants were recruited after the trial was restarted in July 2021. The primary analysis will involve groups A, B and D. Regression analysis will be used to assess treatment effectiveness. We will conduct descriptive analyses for each of the groups identified and sensitivity regression analyses with participants from all groups, including group C, separately.

Discussion

The COVID-19 mitigation strategy and analysis plans are designed to maintain the integrity of the trial while providing meaningful results.

Trial registration

ISRCTN56136713.

New reporting items and recommendations for randomized trials impacted by COVID-19 and force majeure events: a targeted approach

Background

Appropriate analyses and reporting are essential to the reproducibility and interpretation of clinical trials. However, the coronavirus disease 19 (COVID-19) pandemic and other force majeure events, like the war in Ukraine, have impacted the conduct of clinical trials.

Methods

The number of clinical trials potentially impacted were estimated from clinicaltrials.gov. To identify reporting items considered vital for assessing the impact of COVID-19, we reviewed 35 randomized phase III trials from three top oncology journals published between July and December 2020. For validation, we reviewed 29 phase III trials published between January and December 2021.

Results

Our results show that the number of clinical trials being potentially impacted in cancer, cardiovascular diseases, and diabetes is at least 1,484, 535, and 145, respectively. The magnitude of disruption is most significant in oncology trials. Based on the review of 35 trials, a modified checklist with ten new and four modified items covering pandemic's impact on trial conduct, protocol changes, delays, data capture, analysis and interpretation was developed to ensure comprehensive and transparent reporting. Our validation shows that six out of seven applicable reporting items were reported in less than 21% of the articles.

Conclusions

Our recommendations were proposed to improve the reporting of randomized clinical trials impacted by COVID-19 and force majeure events that are broadly applicable to different areas of medical research.

Estimands and Complex Innovative Designs

Since the release of the ICH E9(R1) (International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use Addendum on Estimands and Sensitivity Analysis in Clinical Trials to the Guideline on Statistical Principles for Clinical Trials) document in 2019, the estimand framework has become a fundamental part of clinical trial protocols. In parallel, complex innovative designs have gained increased popularity in drug development, in particular in early development phases or in difficult experimental situations. While the estimand framework is relevant to any study in which a treatment effect is estimated, experience is lacking as regards its application to these designs. In a basket trial for example, should a different estimand be specified for each subpopulation of interest, defined, for example, by cancer site? Or can a single estimand focusing on the general population (defined, for example, by the positivity to a certain biomarker) be used? In the case of platform trials, should a different estimand be proposed for each drug investigated? In this work we discuss possible ways of implementing the estimand framework for different types of complex innovative designs. We consider trials that allow adding or selecting experimental treatment arms, modifying the control arm or the standard of care, and selecting or pooling populations. We also address the potentially data-driven, adaptive selection of estimands in an ongoing trial and disentangle certain statistical issues that pertain to estimation rather than to estimands, such as the borrowing of nonconcurrent information. We hope this discussion will facilitate the implementation of the estimand framework and its description in the study protocol when the objectives of the trial require complex innovative designs.

The case against censoring of progression-free survival in cancer clinical trials - A pandemic shutdown as an illustration

Background

Missing data may lead to loss of statistical power and introduce bias in clinical trials. The Covid-19 pandemic has had a profound impact on patient health care and on the conduct of cancer clinical trials. Although several endpoints may be affected, progression-free survival (PFS) is of major concern, given its frequent use as primary endpoint in advanced cancer and the fact that missed radiographic assessments are to be expected. The recent introduction of the estimand framework creates an opportunity to define more precisely the target of estimation and ensure alignment between the scientific question and the statistical analysis.

Methods

We used simulations to investigate the impact of two basic approaches for handling missing tumor scans due to the pandemic: a “treatment policy” strategy, which consisted in ascribing events to the time they are observed, and a “hypothetical” approach of censoring patients with events during the shutdown period at the last assessment prior to that period. We computed the power of the logrank test, estimated hazard ratios (HR) using Cox models, and estimated median PFS times without and with a hypothetical 6-month shutdown period with no patient enrollment or tumor scans being performed, varying the shutdown starting times.

Results

Compared with the results in the absence of shutdown, the “treatment policy” strategy slightly overestimated median PFS proportionally to the timing of the shutdown period, but power was not affected. Except for one specific scenario, there was no impact on the estimated HR. In general, the pandemic had a greater impact on the analyses using the “hypothetical” strategy, which led to decreased power and overestimated median PFS times to a greater extent than the “treatment policy” strategy.

Conclusion

As a rule, we suggest that the treatment policy approach, which conforms with the intent-to-treat principle, should be the primary analysis to avoid unnecessary loss of power and minimize bias in median PFS estimates.

Research interrupted: applying the CONSERVE 2021 Statement to a randomized trial of rehabilitation during critical illness affected by the COVID-19 pandemic

RATIONALE

The COVID-19 pandemic disrupted non-COVID critical care trials globally as intensive care units (ICUs) prioritized patient care and COVID-specific research. The international randomized controlled trial CYCLE (Critical Care Cycling to Improve Lower Extremity Strength) was forced to halt recruitment at all sites in March 2020, creating immediate challenges. We applied the CONSERVE (CONSORT and SPIRIT Extension for RCTs Revised in Extenuating Circumstance) statement as a framework to report the impact of the pandemic on CYCLE and describe our mitigation approaches.

METHODS

On March 23, 2020, the CYCLE Methods Centre distributed a standardized email to determine the number of patients still in-hospital and those requiring imminent 90-day endpoint assessments. We assessed protocol fidelity by documenting attempts to provide the in-hospital randomized intervention (cycling or routine physiotherapy) and collect the primary outcome (physical function 3-days post-ICU discharge) and 90-day outcomes. We advised sites to prioritize data for the study's primary outcome. We sought feedback on pandemic barriers related to trial procedures.

RESULTS

Our main Methods Centre mitigation strategies included identifying patients at risk for protocol deviations, communicating early and frequently with sites, developing standardized internal tools focused on high-risk points in the protocol for monitoring patient progress, data entry, and validation, and providing guidance to conduct some research activities remotely. For study sites, our strategies included determining how institutional pandemic research policies applied to CYCLE, communicating with the Methods Centre about capacity to continue any part of the research, and developing contingency plans to ensure the protocol was delivered as intended. From 15 active sites (12 Canada, 2 US, 1 Australia), 5 patients were still receiving the study intervention in ICUs, 6 required primary outcomes, and 17 required 90-day assessments. With these mitigation strategies, we attempted 100% of ICU interventions, 83% of primary outcomes, and 100% of 90-day assessments per our protocol.

CONCLUSIONS

We retained all enrolled patients with minimal missing data using several time-sensitive strategies. Although CONSERVE recommends reporting only major modifications incurred by extenuating circumstances, we suggest that it also provides a helpful framework for reporting mitigation strategies with the goal of improving research transparency and trial management.

TRIAL REGISTRATION

NCT03471247. Registered on March 20, 2018.

Principles and recommendations for incorporating estimands into clinical study protocol templates

Clinical study protocols are the foundation of good clinical studies. Prospective and multidisciplinary collaboration that pays attention to the design of all components of the study protocol can ensure that a clinical study will answer the research questions posed in a reliable manner that is meaningful for decision-makers and patients. The ICH E9(R1) addendum on estimands and sensitivity analysis in clinical trials provides a framework for clinical study planning to ensure alignment between study objectives, design, conduct, and analysis. The estimand or clinical question posed can be regarded as the backbone of the study and the clinical study protocol should reflect estimands accordingly. In practice, stakeholders are still learning how to embrace the estimand framework and how it impacts studies and study documents. In this paper, we anticipate that a protocol structure centred around estimands, or objectives rather than endpoints alone will prevail for all types of studies. To assist sponsors during this paradigm shift, this paper provides discussion and guidance for implementing the estimand framework in protocol templates.

The effect of intravenous iron supplementation on exercise capacity in iron-deficient but not anaemic patients with chronic kidney disease: study design and baseline data for a multicentre prospective double-blind randomised controlled trial

BACKGROUND

Many people living with chronic kidney disease (CKD) are iron deficient, even though they may not be anaemic. The Iron and Muscle study aims to evaluate whether iron supplementation reduces symptoms of fatigue, improves muscle metabolism, and leads to enhanced exercise capacity and physical function. We report here the trial design and baseline characteristics.

METHODS

This is a prospective, double-blind multicentre randomised controlled trial (RCT) including 75 non-dialysis stage 3-4 CKD patients with iron deficiency but without anaemia. Patients were randomly (1:1) assigned to either: i) intravenous iron therapy, or ii) placebo, with concurrent recruitment of eight CKD non-iron deficient participants and six healthy volunteers. The primary outcome of the study is the six-minute walk test (6MWT) distance between baseline and four-weeks. An additional exercise training programme for patients in both groups was initiated and completed between 4 and 12 weeks, to determine the effect of iron repletion compared to placebo treatment in the context of patients undertaking an exercise programme. Additional secondary outcomes include fatigue, physical function, muscle strength, muscle metabolism, quality of life, resting blood pressure, clinical chemistry, safety and harms associated with the iron therapy intervention and the exercise training intervention, and hospitalisations. All outcomes were conducted at baseline, 4, and 12 weeks, with a nested qualitative study, to investigate the experience of living with iron deficiency and intervention acceptability. The cohort have been recruited and baseline assessments undertaken.

RESULTS

Seventy-five individuals were recruited. 44% of the randomised cohort were male, the mean (SD) age was 58 (14) years, and 56% were White. Body mass index was 31 (7) kg/m²; serum ferritin was 59 (45) μg/L, transferrin saturation was 22 (10) %, and haemoglobin was 125 (12) g/L at randomisation for the whole group. Estimated glomerular filtration rate was 35 (12) mL/min/1.73 m² and the baseline 6MWT distance was 429 (174) m.

CONCLUSION

The results from this study will address a substantial knowledge gap in the effects of intravenous iron therapy, and offer potential clinical treatment options, to improve exercise capacity, physical function, fatigue, and muscle metabolism, for non-dialysis patients with CKD who are iron-deficient but not anaemic. It will also offer insight into the potential novel effects of an 8-week exercise training programme.

TRIAL REGISTRATION

EudraCT: 2018-000,144-25 Registered 28/01/2019.

A hybrid return to baseline imputation method to incorporate MAR and MNAR dropout missingness

Missing data are inevitable in longitudinal clinical trials due to intercurrent events (ICEs) such as treatment interruption or premature discontinuation for different reasons. Missing at random (MAR) assumption is usually unverifiable and sensitivity analyses are often requested under missing not at random (MNAR) assumption. Return to baseline (RTB) imputation is a commonly used MNAR method. In practice, not all dropout missingness can be assumed MNAR. For example, missingness or dropouts due to COVID-19 can be reasonably assumed MAR. Therefore, traditional RTB is not applicable when there is both MAR and MNAR dropout missingness. Here we propose a hybrid strategy for RTB imputation which can handle missing data due to MAR and MNAR dropouts at the same time. Standard multiple imputation approach is proposed and an analytic likelihood based approach is derived to improve efficiency.

Marking 2-Years of New Thinking in Clinical Trials: The Estimand Journey

The ICH E9(R1) addendum on Estimands and Sensitivity Analyses in Clinical Trials has introduced a new estimand framework for the design, conduct, analysis, and interpretation of clinical trials. We share Pharmaceutical Industry experiences of implementing the estimand framework in the first two years since the final guidance became available with key lessons learned and highlight what else needs to be done to continue the journey in embedding the estimand framework in clinical trials. Emerging best practices and points to consider on strategies for implementing a new estimand thinking process are provided. Whilst much of the focus of implementing ICH E9(R1) to date has been on defining estimands, we highlight some of the important aspects relating to the choice of statistical analysis methods and sensitivity analyses to ensure estimands can be estimated robustly with minimal bias. In particular, we discuss the implications if complete follow-up is not possible when the treatment policy strategy is being used to handle intercurrent events. ICH E9(R1) was introduced just before the start of the COVID-19 pandemic, but a positive outcome from the pandemic has been an acceleration in the adoption of the estimand framework, including differentiating intercurrent events related or not related to the pandemic. In summary, much has been learned on the estimand journey and continued sharing of case studies will help to further advance the understanding and increase awareness across all clinical researchers of the estimand framework.

Estimators for handling COVID-19-related intercurrent events with a hypothetical strategy

The COVID-19 pandemic has affected clinical trials across disease areas, raising the questions how interpretable results can be obtained from impacted studies. Applying the estimands framework, analyses may seek to estimate the treatment effect in the hypothetical absence of such impact. However, no established estimators exist. This simulation study, based on an ongoing clinical trial in patients with Tourette syndrome, compares the performance of candidate estimators for estimands including either a continuous or binary variable and applying a hypothetical strategy for COVID-19-related intercurrent events (IE). The performance is investigated in a wide range of scenarios, under the null and the alternative hypotheses, including different modeling assumptions for the effect of the IE and proportions of affected patients ranging from 10% to 80%. Bias and type I error inflation were minimal or absent for most estimators under most scenarios, with only multiple imputation- and weighting-based methods displaying a type I error inflation in some scenarios. Of more concern, all methods that discarded post-IE data displayed a sharp decrease of power proportional to the proportion of affected patients, corresponding to both a reduced precision of estimation and larger confidence intervals. The simulation study shows that de-mediation via g-estimation is a promising approach. Besides showing the best performance in our simulation study, these approaches allow to estimate the effect of the IE on the outcome and cross-compare between different studies affected by similar IEs. Importantly, the results can be extrapolated to IEs not related to COVID-19 that follow a similar causal structure.

Incorporating estimands into clinical trial statistical analysis plans

BACKGROUND

International Council for Harmonisation (ICH) E9 Statistical Principles for Clinical Trials was developed as a consensus guidance document to encourage worldwide harmonization of the principles of statistical methodology in clinical trials. Addendum E9 (R1) clarified and extended ICH E9 with a focus on estimands and sensitivity analyses. Since the release of E9 (R1), clinical trial protocols have included estimands, but there is variation in how they are presented. Statistical analysis plans (SAPs) are increasingly becoming publicly available (e.g. posting on ClinicalTrials.gov) and present an opportunity to link estimands with planned analyses to present the alignment of trial objectives, design, conduct, and analysis.

METHODS

A table format was used to create a template for inclusion in SAPs that satisfies ICH E9 (R1) guidance to align statistical analysis to the estimand. The template provides a consistent structure for presentation of estimands and the associated analysis, and is applicable to a wide range of trial designs. We illustrate use of the template with a hypothetical clinical trial in HIV-1.

RESULTS

The estimand-to-analysis table template starts with the study objective describing the clinical question of interest as written in the trial protocol. The remainder of the table describes each attribute of the estimand (treatment, target population, variable, intercurrent events, and population-level summary) in the left column (ESTIMAND), while the right column describes how each attribute will be handled using the data collected in the clinical trial (ANALYSIS). The template was applied to a hypothetical, early-phase single-arm trial, modeled after a pediatric trial in HIV, where the objective was to determine the safety of a new antiretroviral drug as part of a combination antiretroviral treatment regimen in the pediatric population. Three intercurrent events were illustrated in the table: death, premature treatment discontinuation before 24 weeks, and pregnancy. An estimand-to-analysis table from a grant application that addresses the primary objective of a placebo-controlled randomized trial is also presented to demonstrate an alternative usage.

CONCLUSION

We found the template to be useful in study design, providing a snapshot of the objective, target population, potential intercurrent events, analysis plan, and considerations for missing data in one place and facilitating discussion among stakeholders. The proposed standardized presentation of estimand attributes and analysis considerations in SAPs will provide guidance to SAP authors and consistency across studies to facilitate reviews.

The impact of Covid-19 on the initiation of clinical trials in Europe and the United States

The coronavirus disease 2019 (COVID‐19) pandemic has a major impact not only on public health and daily living, but also on clinical trials worldwide. To investigate the potential impact of the COVID‐19 pandemic on the initiation of clinical trials, we have descriptively analyzed the longitudinal change in phase II and III interventional clinical trials initiated in Europe and in the United States. Based on the public clinical trial register EU Clinical Trials Register and clinicaltrials.gov, we conducted (i) a yearly comparison of the number of initiated trials from 2010 to 2020 and (ii) a monthly comparison from January 2020 to February 2021 of the number of initiated trials. The analyses indicate that the COVID‐19 pandemic affected both the initiation of clinical trials overall and the initiation of non‐COVID‐19 trials. An increase in the overall numbers of clinical trials could be observed both in Europe and the United States in 2020 as compared with 2019. However, the number of non‐COVID‐19 trials initiated is reduced as compared with the previous decade, with a slightly larger relative decrease in the United States as compared to Europe. Additionally, the monthly trend for the initiation of non‐COVID‐19 trials differs between regions. In the United States, after a sharp decrease in April 2020, trial numbers reached the levels of 2019 from June 2020 onward. In Europe, the decrease was less pronounced, but trial numbers mainly remained below the 2019 average until February 2021.

Multiple imputation for longitudinal data using Bayesian lasso imputation model

Multiple imputation is a promising approach to handle missing data and is widely used in analysis of longitudinal clinical studies. A key consideration in the implementation of multiple imputation is to obtain accurate imputed values by specifying an imputation model that incorporates auxiliary variables potentially associated with missing variables. The use of informative auxiliary variables is known to be beneficial to make the missing at random assumption more plausible and help to reduce uncertainty of the imputations; however, it is not straightforward to pre-specify them in many cases. We propose a data-driven specification of the imputation model using Bayesian lasso in the context of longitudinal clinical study, and develop a built-in function of the Bayesian lasso imputation model which is performed within the framework of multiple imputation using chained equations. A simulation study suggested that the Bayesian lasso imputation model worked well in a variety of longitudinal study settings, providing unbiased treatment effect estimates with well-controlled type I error rates and coverage probabilities of the confidence interval; in contrast, ignorance of the informative auxiliary variables led to serious bias and inflation of type I error rate. Moreover, the Bayesian lasso imputation model offered higher statistical powers compared with conventional imputation methods. In our simulation study, the gains in statistical power were remarkable when the sample size was small relative to the number of auxiliary variables. An illustration through a real example also suggested that the Bayesian lasso imputation model could give smaller standard errors of the treatment effect estimate.

Attenuated efficacy of pediatric obesity treatment during the COVID-19 pandemic

OBJECTIVE

This study examined whether the efficacy of a standard-of-care pediatric obesity treatment was affected by the COVID-19 pandemic.

METHODS

Analyses leveraged data from an ongoing pediatric obesity treatment trial involving 230 lower-income, urban children aged 6 to 12 years. Mixed-effects regression models compared children who participated in a 12-month weight-management intervention before versus during the COVID-19 pandemic on change from baseline in BMI z score (ΔzBMI) at 3, 6, 9, and 12 months.

RESULTS

The observed pattern of ΔzBMI was significantly different before versus during the pandemic (χ² = 22.73, p < 0.0001). Children treated before the pandemic maintained an average weight loss of -0.06 ΔzBMI at 12 months, whereas children treated during the pandemic steadily gained weight over time, averaging a net gain of 0.11 ΔzBMI at 12 months (χ² = 34.99, p < 0.0001). Treatment session completion did not differ before versus during the pandemic (60.4% vs. 55.7%, respectively; p = 0.30) or account for differences in ΔzBMI.

CONCLUSIONS

Similar reductions in intervention efficacy may be anticipated in other pediatric obesity treatment trials conducted during the COVID-19 pandemic. Many families that have struggled with managing their child's weight during this period may need encouragement to continue engaging in structured weight management as society renormalizes.

Evaluation of a program for routine implementation of shared decision-making in cancer care: results of a stepped wedge cluster randomized trial

BACKGROUND

Shared decision-making (SDM) is preferred by many patients in cancer care. However, despite scientific evidence and promotion by health policy makers, SDM implementation in routine health care lags behind. This study aimed to evaluate an empirically and theoretically grounded implementation program for SDM in cancer care.

METHODS

In a stepped wedge design, three departments of a comprehensive cancer center sequentially received the implementation program in a randomized order. It included six components: training for health care professionals (HCPs), individual coaching for physicians, patient activation intervention, patient information material/decision aids, revision of quality management documents, and reflection on multidisciplinary team meetings (MDTMs). Outcome evaluation comprised four measurement waves. The primary endpoint was patient-reported SDM uptake using the 9-item Shared Decision Making Questionnaire. Several secondary implementation outcomes were assessed. A mixed-methods process evaluation was conducted to evaluate reach and fidelity. Data were analyzed using mixed linear models, qualitative content analysis, and descriptive statistics.

RESULTS

A total of 2,128 patient questionnaires, 559 questionnaires from 408 HCPs, 132 audio recordings of clinical encounters, and 842 case discussions from 66 MDTMs were evaluated. There was no statistically significant improvement in the primary endpoint SDM uptake. Patients in the intervention condition were more likely to experience shared or patient-lead decision-making than in the control condition (d=0.24). HCPs in the intervention condition reported more knowledge about SDM than in the control condition (d = 0.50). In MDTMs the quality of psycho-social information was lower in the intervention than in the control condition (d = - 0.48). Further secondary outcomes did not differ statistically significantly between conditions. All components were implemented in all departments, but reach was limited (e.g., training of 44% of eligible HCPs) and several adaptations occurred (e.g., reduced dose of coaching).

CONCLUSIONS

The process evaluation provides possible explanations for the lack of statistically significant effects in the primary and most of the secondary outcomes. Low reach and adaptations, particularly in dose, may explain the results. Other or more intensive approaches are needed for successful department-wide implementation of SDM in routine cancer care. Further research is needed to understand factors influencing implementation of SDM in cancer care.

TRIAL REGISTRATION

clinicaltrials.gov, NCT03393351 , registered 8 January 2018.

The Selah study protocol of three interventions to manage stress among clergy: a preference-based randomized waitlist control trial

INTRODUCTION

Like many helping professionals in emotional labor occupations, clergy experience high rates of mental and physical comorbidities. Regular stress management practices may reduce stress-related symptoms and morbidity, but more research is needed into what practices can be reliably included in busy lifestyles and practiced at a high enough level to meaningfully reduce stress symptoms.

METHODS AND ANALYSIS

The overall design is a preference-based randomized waitlist control trial. United Methodist clergy in North Carolina will be eligible to participate. The intervention and waitlist control groups will be recruited by email. The interventions offered are specifically targeted to clergy preference and include mindfulness-based stress reduction, Daily Examen, and stress inoculation training. Surveys will be conducted at 0, 12, and 24 weeks with heart rate data collected at 0 and 12 weeks. The primary outcomes for this study are self-reported symptoms of stress and heart rate at week 12 for each intervention compared to waitlist control; the secondary outcome is symptoms of anxiety comparing each intervention vs waitlist control.

ETHICS AND DISSEMINATION

Ethical approval was obtained from the Duke University Campus IRB (2019-0238). The results will be made available to researchers, funders, and members of the clergy community.

STRENGTHS AND LIMITATIONS OF THIS STUDY

While evidence-based stress reduction practices such as mindfulness-based stress reduction (MBSR) exist, a wider variety of practices should be tested to appeal to different individuals. Clergy in particular may prefer, and consequently enact, spiritual practices like the Daily Examen, and individuals such as clergy who spend most of their time thinking and feeling may prefer experiential-based practices like stress inoculation training. If efficacious, the Daily Examen and stress inoculation training practices have high feasibility in that they require few minutes per day. This study is limited by the inclusion of Christian clergy of only one denomination.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04625777 . November 12, 2020.

Patient-centered HCV care via telemedicine for individuals on medication for opioid use disorder: Telemedicine for Evaluation, Adherence and Medication for Hepatitis C (TEAM-C)

BACKGROUND

Telemedicine has the potential to increase healthcare access especially for vulnerable populations. Telemedicine for Evaluation, Adherence, and Medication for Hepatitis C (TEAM-C) is comparing telemedicine access to specialty medical care to usual care for management of hepatitis C virus (HCV) infection among persons with opioid use disorder (PWOUD). PWOUD have the highest hepatitis C virus (HCV) prevalence and incidence, yet they infrequently receive HCV care. The study objectives are to compare access to specialty care via telemedicine to offsite specialty referral (usual care) on 1) treatment initiation, completion, and sustained virological response, 2) patient satisfaction with health care delivery, and 3) HCV reinfection after successful HCV cure.

METHODS

TEAM-C is a multi-site, non-blinded, randomized pragmatic clinical trial conducted at 12 opioid treatment programs (OTP) throughout New York State that utilizes the stepped-wedge design. The unit of randomization is the OTP with a total sample size of 624 participants. HCV-infected PWOUD were treated via telemedicine or referral. Telemedicine encounters are conducted onsite in the OTP with co-administration of direct acting antivirals for HCV with medications for opioid use disorder. The primary outcome is undetectable HCV RNA obtained 12 weeks post-treatment cessation. We also follow participants for two years to assess for reinfection.

CONCLUSIONS

The study utilizes a rigorous study design to evaluate the effectiveness and implementation of virtual treatment for HCV integrated into behavioral treatment. We demonstrate the feasibility, engagement principles and lessons learned from the initial prospective randomized trial of telemedicine targeted to a vulnerable population.

Use of the Estimand Framework to Manage the Disruptive Effects of COVID-19 on Stroke Clinical Trials

The coronavirus disease 2019 (COVID-19) pandemic has presented unique challenges to stroke care and research internationally. In particular, clinical trials in stroke are vulnerable to the impacts of the pandemic at multiple stages, including design, recruitment, intervention, follow-up, and interpretation of outcomes. A carefully considered approach is required to ensure the appropriate conduct of stroke trials during the pandemic and to maintain patient and participant safety. This has been recently addressed by the International Council for Harmonisation which, in November 2019, released an addendum to the Statistical Principles for Clinical Trials guidelines entitled Estimands and Sensitivity Analysis in Clinical Trials. In this article, we present the International Council for Harmonisation estimand framework for the design and conduct of clinical trials, with a specific focus on its application to stroke clinical trials. This framework aims to align the clinical and scientific objectives of a trial with its design and end points. It also encourages the prospective consideration of potential postrandomization intercurrent events which may occur during a trial and either impact the ability to measure an end point or its interpretation. We describe the different categories of such events and the proposed strategies for dealing with them, specifically focusing on the COVID-19 pandemic as a source of intercurrent events. We also describe potential practical impacts posed by the COVID-19 pandemic on trials, health systems, study groups, and participants, all of which should be carefully reviewed by investigators to ensure an adequate practical and statistical strategy is in place to protect trial integrity. We provide examples of the implementation of the estimand framework within hypothetical stroke trials in intracerebral hemorrhage and stroke recovery. While the focus of this article is on COVID-19 impacts, the strategies and principles proposed are well suited for other potential events or issues, which may impact clinical trials in the field of stroke.

Modified reference based imputation and tipping point analysis in the presence of missing data due to COVID-19

In longitudinal clinical trials, missing data are inevitable due to intercurrent events (ICEs) such as treatment interruption or premature discontinuation for different reasons. The COVID-19 pandemic has had substantial impact on clinical trials since early 2020 as it may result in missing data due to missed visits and premature discontinuations. The missing data due to COVID-19 can reasonably be assumed as missing at random (MAR).

We propose a combined hypothetical strategy for sensitivity analyses to handle missing data due to both COVID-19 and non-COVID reasons. We modify the commonly used missing not at random (MNAR) methods, reference based imputation (RBI) and tipping point analysis, under this strategy. We propose the standard multiple imputation approach and derive an analytic likelihood based approach to implement the proposed methods to improve efficiency in applications. The proposed strategy and methods are applicable to a more general scenario when there are missing data due to both MAR and MNAR reasons.

Implementation of ICH E9 (R1): A Few Points Learned During the COVID-19 Pandemic

The current COVID-19 pandemic poses numerous challenges for ongoing clinical trials and provides a stress-testing environment for the existing principles and practice of estimands in clinical trials. The pandemic may increase the rate of intercurrent events (ICEs) and missing values, spurring a great deal of discussion on amending protocols and statistical analysis plans to address these issues. In this article, we revisit recent research on estimands and handling of missing values, especially the ICH E9 (R1) Addendum on Estimands and Sensitivity Analysis in Clinical Trials. Based on an in-depth discussion of the strategies for handling ICEs using a causal inference framework, we suggest some improvements in applying the estimand and estimation framework in ICH E9 (R1). Specifically, we discuss a mix of strategies allowing us to handle ICEs differentially based on reasons for ICEs. We also suggest ICEs should be handled primarily by hypothetical strategies and provide examples of different hypothetical strategies for different types of ICEs as well as a road map for estimation and sensitivity analyses. We conclude that the proposed framework helps streamline translating clinical objectives into targets of statistical inference and automatically resolves many issues with defining estimands and choosing estimation procedures arising from events such as the pandemic.

Power walking based outpatient cardiac rehabilitation in patients with post-coronary angioplasty: Randomized control trial

PURPOSE

The purpose of this trial was to compare the effectiveness of standardized outpatient cardiac rehabilitation combined with treadmill power walking versus standardized outpatient cardiac rehabilitation alone on health-related quality of life (HQoL), functional exercise capacity (FEC), left ventricular ejection fraction (LVEF) and metabolic equivalent of tasks (METs) in patients who went post coronary angioplasty (CA). Further this study evaluated the association between average numbers of steps taken with above clinical outcomes.

METHODS

In a pragmatic sequential randomized clinical trial, 24 patients were randomized into two groups (n = 12) and participated in a standardized outpatient cardiac rehabilitation program (SOCRP) with treadmill power walking as an intervention group and SOCRP alone in control group. Scores obtained before and after 4 weeks of intervention, that is, after 12 treatment sessions were assessed using a HQoL questionnaire and 6-min walk test (6 MWT). Average number of steps taken throughout the 4 weeks, METs and LVEF values were obtained by pedometer, exercise stress testing and echocardiogram respectively.

RESULTS

Significant improvements were found in intergroup and intragroup comparison after 4 weeks of cardiac rehabilitation (p < 0.05). Scores of 6 MWT and LVEF significantly improved in the intervention group (p < 0.003) compared to the control group (p < 0.032). HQoL components that is, global and physical, MET values and average number of steps were significantly higher in the intervention group compared to the control group (p < 0.001).

CONCLUSION

SOCRP with power walking was more effective in improving HQoL, FEC, LVEF, METs and average numbers of steps than SOCRP alone although both interventions were significant after 4 weeks in patients underwent CA and completed cardiac rehabilitation program. Positive significant associations were found between the average number of steps taken with scores of METs and scores of global and physical domains of HQoL.

Addressing COVID-19 challenges in a randomised controlled trial on exercise interventions in a high-risk population

BACKGROUND

The coronavirus disease 2019 (COVID-19) pandemic is a threat to ongoing clinical trials necessitating regular face-to-face, in-person meetings, particularly in participants with a high risk of complications. Guidance on how to handle and safely continue such trials is lacking. Chronically ill elderly individuals require-in addition to protection from infection-regular physical exercise and social contact to remain healthy. Solutions on how to handle these conflicting necessities are needed. The ENTAIER-randomised controlled trial was investigating the influence of mindful movements on fall risk, fear of falling, mobility, balance, life quality, and other outcomes. The study population was planned to comprise of 550 chronically ill elderly individuals with a high risk of falling. The movements were regularly performed in coached groups over 6 months. After the trial began, COVID-19 lockdowns stopped all in-person meetings, and it was expected that the limitations of this pandemic would continue for a long term. Therefore, the exercise programme, which involved complex movements and was typically conducted face-to-face in groups, had to be substituted by a telemedicine programme within a short timeframe. The objectives, therefore, were to identify challenges and tasks that could to be resolved and steps that could to be taken to achieve high-quality, efficacy, safety, and enable human encounter and motivation.

METHODS

We proceeded with four steps: 1) A literature review on the quality and feasibility issues of telemedicine in general, and specifically, in exercise training in elderly individuals. 2) Participation in two international telemedicine task forces on integrative medicine, particularly, mind-body medicine. 3) Interviews with study therapists, (for practical purposes, eurythmy therapists and Tai Chi teachers are summarized here as therapists) personnel, and international experts on providing mindful movement exercises and other physiotherapies via live telecommunication technology, and with scientists and patient representatives. 4) Final evaluation by the core trial team and subsequent planning and implementation of changes in the trial organisation.

RESULTS

Various tasks and challenges were identified: for the technical equipment for therapists and patients; for the ability of therapists and trial participants to adequately manage the technology and telemedicine intervention; the reservations and concerns about the technology among therapists and participants; safety and data protection in using the technology; and study design. The two major options found on how to continue the trial in the COVID-19 situation were a complete switch to telemedicine and a partial switch in the form of risk management implemented into the former design.

CONCLUSIONS

The management of an ongoing clinical trial in a national or international crisis with a minimum of available time and extra financial resources, alongside with two checklists on steps and procedures for trial continuation and telemedicine implementation, may be informative for other researchers or healthcare providers faced with similar challenges and making similar decisions in the current situation or similar future scenarios. TRAIL REGISTRATION: www.drks.de . DRKS00016609. Registered July 30, 2019.

Conducting clinical trials during the COVID-19 pandemic-a collaborative trial network response

The unprecedented demand placed on healthcare systems from the COVID-19 pandemic has forced a reassessment of clinical trial conduct and feasibility. Consequently, the Australasian Kidney Trials Network (AKTN), an established collaborative research group known for conducting investigator-initiated global clinical trials, had to efficiently respond and adapt to the changing landscape during COVID-19. Key priorities included ensuring patient and staff safety, trial integrity and network sustainability for the kidney care community. New resources have been developed to enable a structured review and contingency plan of trial activities during the pandemic and beyond.

Perspectives on Virtual (Remote) Clinical Trials as the "New Normal" to Accelerate Drug Development

Although the digital revolution has transformed many areas of human endeavor, pharmaceutical drug development has been relatively slow to embrace the emerging technologies to enhance efficiency and optimize value in clinical trials. The topic has garnered even greater attention in the face of the coronavirus disease 2019 (COVID-19) outbreak, which has caused unprecedented disruption in the conduct of clinical trials and presented considerable challenges and opportunities for clinical trialists and data analysts. In this paper, we highlight the potential opportunity with virtual or digital clinical trials as viable options to enhance efficiency in drug development and, more importantly, in offering diverse patients easier and attractive means to participate in clinical trials. Special reference is made to the implication of artificial intelligence and machine-learning tools in trial execution and data acquisition, processing, and analysis in a virtual trial setting. Issues of patient safety, measurement validity, and data integrity are reviewed, and considerations are put forth with reference to the mitigation of underlying regulatory and operational barriers.

Clinical trial preparations for the next pandemic

This paper describes the need to prepare for the development of antiviral therapeutics for the next pandemic. Preparation would consist of a stockpiling of best practices for clinical trial design, analysis and operations during the current SARS-CoV-2 pandemic as well as continuous development of treatments and methodology between pandemics. This development would be facilitated by a global clinical trial pandemic reserve similar to the military reserves consisting of medical and quantitative methods professionals who would remain engaged between pandemics. Continuous identification of potential antiviral drugs and diagnostic methods would also be needed. Specific methodology addressed includes the importance of large simple trials, follow up time, efficacy endpoint, appropriate estimands, non-inferiority trials, more sophisticated patient accrual models and procedures for data sharing between clinical trials.

Potential impact of COVID-19 on ongoing clinical trials: a simulation study with the neurological Yale Global Tic Severity Scale based on the CANNA-TICS study

The COVID‐19 pandemic has manifold impacts on clinical trials. In response, drug regulatory agencies and public health bodies have issued guidance on how to assess potential impacts on ongoing clinical trials and stress the importance of a risk‐assessment as a pre‐requisite for modifications to the clinical trial conduct. This article presents a simulation study to assess the impact on the power of an ongoing clinical trial without the need to unblind trial data and compromise trial integrity. In the context of the CANNA‐TICS trial, investigating the effect of nabiximols on reducing the total tic score of the Yale Global Tic Severity Scale (YGTSS‐TTS) in patients with chronic tic disorders and Tourette syndrome, the impact of the two COVID‐19 related intercurrent events handled by a treatment policy strategy is investigated using a multiplicative and additive data generating model. The empirical power is examined for the analysis of the YGTSS‐TTS as a continuous and dichotomized endpoint using analysis techniques adjusted and unadjusted for the occurrence of the intercurrent event. In the investigated scenarios, the simulation studies showed that substantial power losses are possible, potentially making sample size increases necessary to retain sufficient power. However, we were also able to identify scenarios with only limited loss of power. By adjusting for the occurrence of the intercurrent event, the power loss could be diminished to different degrees in most scenarios. In summary, the presented risk assessment approach may support decisions on trial modifications like sample size increases, while maintaining trial integrity.

Infectious diseases epidemiology, quantitative methodology, and clinical research in the midst of the COVID-19 pandemic: Perspective from a European country

Starting from historic reflections, the current SARS-CoV-2 induced COVID-19 pandemic is examined from various perspectives, in terms of what it implies for the implementation of non-pharmaceutical interventions, the modeling and monitoring of the epidemic, the development of early-warning systems, the study of mortality, prevalence estimation, diagnostic and serological testing, vaccine development, and ultimately clinical trials. Emphasis is placed on how the pandemic had led to unprecedented speed in methodological and clinical development, the pitfalls thereof, but also the opportunities that it engenders for national and international collaboration, and how it has simplified and sped up procedures. We also study the impact of the pandemic on clinical trials in other indications. We note that it has placed biostatistics, epidemiology, virology, infectiology, and vaccinology, and related fields in the spotlight in an unprecedented way, implying great opportunities, but also the need to communicate effectively, often amidst controversy.

Risk and mitigation actions for clinical trials during COVID-19 pandemic (RiMiCOPa)

The COVID-19 virus diffusion is, nowadays, global and any clinical trial is potentially affected by the direct and indirect consequences of the COVID-19 during the pandemic. Any step, from protocol design to result's disclosure, needs to be revised to assess the impact of the COVID-19 on the study, evaluate the potential risks, and establish a mitigation plan. We have developed a series of recommendations, belonging to our experience in any aspect of clinical trials. We hope that the Risk and Mitigation actions for clinical trials during COVID-19 Pandemic (RiMiCOPa) will help all clinical trial professionals, patients, auditors, and assessors to ensure effective data management, statistics, and medical writing standards while conducting clinical trials in the pandemic.

Coronavirus Disease 2019: Considerations for Health Technology Assessment From the National Centre for Pharmacoeconomics Review Group

It is expected that the coronavirus disease 2019 (COVID-19) pandemic will leave large deficits in the budgets of many jurisdictions. Funding for other treatments, in particular new treatments, may become more constrained than previously expected. Therefore, a robust health technology assessment (HTA) system is vital. Many clinical trials carried out during the pandemic may have been temporarily halted, while others may have had to change their protocols. Even trials that continue as normal may experience external changes as other aspects of the healthcare service may not be available to the patients in the trial, or the patients themselves may contract COVID-19. Consequently, many limitations are likely to arise in the provision of robust HTAs, which could have profound consequences on the availability of new treatments. Therefore, the National Centre for Pharmacoeconomics Review Group wishes to discuss these issues and make recommendations for applicants submitting to HTA agencies, in ample time for these HTAs to be prepared and assessed. We discuss how the pandemic may affect the estimation of the treatment effect, costs, life-years, utilities, discontinuation rates, and methods of evidence synthesis and extrapolation. In particular, we note that trials conducted during the pandemic will be subject to a higher degree of uncertainty than before. It is vital that applicants clearly identify any parameters that may be affected by the pandemic. These parameters will require considerably more scenario and sensitivity analyses to account for this increase in uncertainty.

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).

Clinical Trial Drug Safety Assessment for Studies and Submissions Impacted by COVID-19

Abstract-In this article, we provide guidance on how safety analyses and reporting of clinical trial safety data may need to be modified, given potential impact from the COVID-19 pandemic. Impact could include missed visits, alternative methods for assessments (such as virtual visits), alternative locations for assessments (such as local labs), and study drug interruptions. Starting from the safety analyses typically included in Clinical Study Reports for Phase 2-4 clinical trials and integrated submission documents, we assess what modifications might be needed. If the impact from COVID-19 affects treatment arms equally, analyses of adverse events from controlled data can, to a large extent, remain unchanged. However, interpretation of summaries from uncontrolled data (summaries that include open-label extension data) will require even more caution than usual. Special consideration will be needed for safety topics of interest, especially events expected to have a higher incidence due to a COVID-19 infection or due to quarantine or travel restrictions (e.g., depression). Analyses of laboratory measurements may need to be modified to account for the combination of measurements from local and central laboratories.

Clinical Trials Impacted by the COVID-19 Pandemic: Adaptive Designs to the Rescue?

Very recently the new pathogen severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was identified and the coronavirus disease 2019 (COVID-19) declared a pandemic by the World Health Organization. The pandemic has a number of consequences for ongoing clinical trials in non-COVID-19 conditions. Motivated by four current clinical trials in a variety of disease areas we illustrate the challenges faced by the pandemic and sketch out possible solutions including adaptive designs. Guidance is provided on (i) where blinded adaptations can help; (ii) how to achieve Type I error rate control, if required; (iii) how to deal with potential treatment effect heterogeneity; (iv) how to use early read-outs; and (v) how to use Bayesian techniques. In more detail approaches to resizing a trial affected by the pandemic are developed including considerations to stop a trial early, the use of group-sequential designs or sample size adjustment. All methods considered are implemented in a freely available R shiny app. Furthermore, regulatory and operational issues including the role of data monitoring committees are discussed.

Machine learning for clinical trials in the era of COVID-19

The world is in the midst of a pandemic. We still know little about the disease COVID-19 or about the virus (SARS-CoV-2) that causes it. We do not have a vaccine or a treatment (aside from managing symptoms). We do not know if recovery from COVID-19 produces immunity, and if so for how long, hence we do not know if "herd immunity" will eventually reduce the risk or if a successful vaccine can be developed - and this knowledge may be a long time coming. In the meantime, the COVID-19 pandemic is presenting enormous challenges to medical research, and to clinical trials in particular. This paper identifies some of those challenges and suggests ways in which machine learning can help in response to those challenges. We identify three areas of challenge: ongoing clinical trials for non-COVID-19 drugs; clinical trials for repurposing drugs to treat COVID-19, and clinical trials for new drugs to treat COVID-19. Within each of these areas, we identify aspects for which we believe machine learning can provide invaluable assistance.