Sofía S. Villar
YOU?
Author Swipe
View article: Statistical analysis plan for continuous positive airway pressure plus mandibular advancement therapy (PAPMAT): an adaptive randomised crossover trial comparing the benefits and costs of combining two established treatments for obstructive sleep apnoea
Statistical analysis plan for continuous positive airway pressure plus mandibular advancement therapy (PAPMAT): an adaptive randomised crossover trial comparing the benefits and costs of combining two established treatments for obstructive sleep apnoea Open
View article: Implementing response-adaptive randomisation in stratified rare-disease trials: Design challenges and practical solutions
Implementing response-adaptive randomisation in stratified rare-disease trials: Design challenges and practical solutions Open
Although response-adaptive randomisation (RAR) has gained substantial attention in the literature, it still has limited use in clinical trials. Amongst other reasons, the implementation of RAR in real world trials raises important practica…
View article: Drug Development for Pulmonary Arterial Hypertension: Unleashing the Potential of Single‐Patient Studies Using Continuous Monitoring
Drug Development for Pulmonary Arterial Hypertension: Unleashing the Potential of Single‐Patient Studies Using Continuous Monitoring Open
View article: A computational method for type I error rate control in power-maximizing response-adaptive randomization
A computational method for type I error rate control in power-maximizing response-adaptive randomization Open
Maximizing statistical power in experimental design often involves imbalanced treatment allocation, but several challenges hinder its practical adoption: (1) the misconception that equal allocation always maximizes power, (2) when only tar…
View article: Implementing response-adaptive designs when responses are missing: Impute or ignore?
Implementing response-adaptive designs when responses are missing: Impute or ignore? Open
Missing data is a widespread issue in clinical trials, but is particularly problematic for digital health interventions where disengagement is common and outcomes are likely to be missing not at random (MNAR). Trials that use response-adap…
View article: Is 1:1 Always Most Powerful? Why Careful Determination of Allocation Ratios Matters in Trial Design
Is 1:1 Always Most Powerful? Why Careful Determination of Allocation Ratios Matters in Trial Design Open
The principle of allocating an equal number of patients to each arm in a randomized controlled trial remains widely believed to be optimal for maximising statistical power. However, this long-held belief only holds true if the treatment gr…
View article: StratosPHere 2: statistical analysis plan for a response-adaptive randomised placebo-controlled phase II trial to evaluate hydroxychloroquine and phenylbutyrate in pulmonary arterial hypertension caused by mutations in BMPR2
StratosPHere 2: statistical analysis plan for a response-adaptive randomised placebo-controlled phase II trial to evaluate hydroxychloroquine and phenylbutyrate in pulmonary arterial hypertension caused by mutations in BMPR2 Open
Background The StratosPHere 2 trial will evaluate the efficacy of hydroxychloroquine and phenylbutyrate in pulmonary arterial hypertension caused by mutations in BMPR2 by focussing on the novel biomarker and other endpoints including safet…
View article: Revisiting optimal allocations for binary responses: insights from considering type-I error rate control
Revisiting optimal allocations for binary responses: insights from considering type-I error rate control Open
This work revisits optimal response-adaptive designs from a type-I error rate perspective, highlighting when and how much these allocations exacerbate type-I error rate inflation—an issue previously undocumented. We explore a range of appr…
View article: Reply to Ding <i>et al.</i>: Imatinib: A Promising Therapeutic Shining Light on Pulmonary Arterial Hypertension Treatment
Reply to Ding <i>et al.</i>: Imatinib: A Promising Therapeutic Shining Light on Pulmonary Arterial Hypertension Treatment Open
View article: On the finite-sample and asymptotic error control of a randomization-probability test for response-adaptive clinical trials
On the finite-sample and asymptotic error control of a randomization-probability test for response-adaptive clinical trials Open
It is now commonly known that using response-adaptive designs for data collection offers great potential in terms of optimizing expected outcomes, but poses multiple challenges for inferential goals. In many settings, such as phase-II or c…
View article: Positioning Imatinib for Pulmonary Arterial Hypertension: A Dose-Finding Phase 2 Study
Positioning Imatinib for Pulmonary Arterial Hypertension: A Dose-Finding Phase 2 Study Open
Rationale: Imatinib, 400 mg daily, reduces pulmonary vascular resistance and improves exercise capacity in patients with pulmonary arterial hypertension. Concerns about safety and tolerability limit its use. Objectives: We so…
View article: Revisiting Optimal Allocations for Binary Responses: Insights from Considering Type-I Error Rate Control
Revisiting Optimal Allocations for Binary Responses: Insights from Considering Type-I Error Rate Control Open
This work revisits optimal response-adaptive designs from a type-I error rate perspective, highlighting when and how much these allocations exacerbate type-I error rate inflation - an issue previously undocumented. We explore a range of ap…
View article: Thompson, Ulam, or Gauss? Multi-criteria recommendations for posterior probability computation methods in Bayesian response-adaptive trials
Thompson, Ulam, or Gauss? Multi-criteria recommendations for posterior probability computation methods in Bayesian response-adaptive trials Open
Bayesian adaptive designs enable flexible clinical trials by adapting features based on accumulating data. Among these, Bayesian Response-Adaptive Randomization (BRAR) skews patient allocation towards more promising treatments based on int…
View article: Effect of high-flow nasal therapy on patient-centred outcomes in patients at high risk of postoperative pulmonary complications after cardiac surgery: update to the statistical analysis plan for NOTACS, a multicentre adaptive randomised controlled trial
Effect of high-flow nasal therapy on patient-centred outcomes in patients at high risk of postoperative pulmonary complications after cardiac surgery: update to the statistical analysis plan for NOTACS, a multicentre adaptive randomised controlled trial Open
View article: StratosPHere 2: study protocol for a response-adaptive randomised placebo-controlled phase II trial to evaluate hydroxychloroquine and phenylbutyrate in pulmonary arterial hypertension caused by mutations in BMPR2
StratosPHere 2: study protocol for a response-adaptive randomised placebo-controlled phase II trial to evaluate hydroxychloroquine and phenylbutyrate in pulmonary arterial hypertension caused by mutations in BMPR2 Open
View article: Implementing Response-Adaptive Randomisation in Stratified Rare-disease Trials: Design Challenges and Practical Solutions
Implementing Response-Adaptive Randomisation in Stratified Rare-disease Trials: Design Challenges and Practical Solutions Open
Although response-adaptive randomisation (RAR) has gained substantial attention in the literature, it still has limited use in clinical trials. Amongst other reasons, the implementation of RAR in real world trials raises important practica…
View article: Unleashing the full potential of digital outcome measures in clinical trials: eight questions that need attention
Unleashing the full potential of digital outcome measures in clinical trials: eight questions that need attention Open
View article: Exact statistical analysis for response-adaptive clinical trials: A general and computationally tractable approach
Exact statistical analysis for response-adaptive clinical trials: A general and computationally tractable approach Open
Response-adaptive clinical trial designs allow targeting a given objective by skewing the allocation of participants to treatments based on observed outcomes. Response-adaptive designs face greater regulatory scrutiny due to potential type…
View article: Unleashing the Full Potential of Digital Endpoints: Eight Questions that Need Attention
Unleashing the Full Potential of Digital Endpoints: Eight Questions that Need Attention Open
The use of Digital Health Technologies to measure endpoints in clinical trials opens new opportunities as well as methodological challenges. Digital endpoints may provide more sensitive and higher-frequency measurements of participants' he…
View article: Implementing and assessing Bayesian response-adaptive randomisation for backfilling in dose-finding trials
Implementing and assessing Bayesian response-adaptive randomisation for backfilling in dose-finding trials Open
Traditional approaches in dose-finding trials, such as the continual reassessment method, focus on identifying the maximum tolerated dose. In contemporary early-phase dose-finding trials, especially in oncology with targeted agents or immu…
View article: How could a pooled testing policy have performed in managing the early stages of the COVID‐19 pandemic? Results from a simulation study
How could a pooled testing policy have performed in managing the early stages of the COVID‐19 pandemic? Results from a simulation study Open
A coordinated testing policy is an essential tool for responding to emerging epidemics, as was seen with COVID‐19. However, it is very difficult to agree on the best policy when there are multiple conflicting objectives. A key objective is…
View article: Using Adaptive Bandit Experiments to Increase and Investigate Engagement in Mental Health
Using Adaptive Bandit Experiments to Increase and Investigate Engagement in Mental Health Open
Digital mental health (DMH) interventions, such as text-message-based lessons and activities, offer immense potential for accessible mental health support. While these interventions can be effective, real-world experimental testing can fur…
View article: Response-Adaptive Randomization Designs Based on Optimal Allocation Proportions
Response-Adaptive Randomization Designs Based on Optimal Allocation Proportions Open
This book chapter discusses response-adaptive randomization procedures which are based on optimal allocation proportions, e.g. derived from theoretical optimization problems. We elucidate the objectives of these proportions, emphasizing th…
View article: 22 Vaccine Trial Designs
22 Vaccine Trial Designs Open
Vaccine efficacy trials conducted during epidemics of emerging infectious diseases have three main objectives: (1) to test the null hypothesis in a rigorous fashion, (2) to estimate the efficacy of the vaccine candidate, and (3) to maximiz…
View article: Evaluating pooled testing for asymptomatic screening of healthcare workers in hospitals
Evaluating pooled testing for asymptomatic screening of healthcare workers in hospitals Open
Background There is evidence that during the COVID pandemic, a number of patient and HCW infections were nosocomial. Various measures were put in place to try to reduce these infections including developing asymptomatic PCR (polymerase cha…
View article: Correction: Medicines and Healthcare products Regulatory Agency’s “Consultation on proposals for legislative changes for clinical trials”: a response from the Trials Methodology Research Partnership Adaptive Designs Working Group, with a focus on data sharing
Correction: Medicines and Healthcare products Regulatory Agency’s “Consultation on proposals for legislative changes for clinical trials”: a response from the Trials Methodology Research Partnership Adaptive Designs Working Group, with a focus on data sharing Open
View article: StratosPHere 2: A response-adaptive randomised placebo-controlled Phase II trial to evaluate hydroxychloroquine and phenylbutyrate in pulmonary arterial hypertension caused by mutations in BMPR2
StratosPHere 2: A response-adaptive randomised placebo-controlled Phase II trial to evaluate hydroxychloroquine and phenylbutyrate in pulmonary arterial hypertension caused by mutations in BMPR2 Open
Background • Pulmonary arterial hypertension is a life-threatening progressive disorder characterised by high blood pressure (hypertension) in the arteries of the lungs (pulmonary artery). Although treatable, there is no known cure for thi…
View article: Medicines and Healthcare products Regulatory Agency’s “Consultation on proposals for legislative changes for clinical trials”: a response from the Trials Methodology Research Partnership Adaptive Designs Working Group, with a focus on data sharing
Medicines and Healthcare products Regulatory Agency’s “Consultation on proposals for legislative changes for clinical trials”: a response from the Trials Methodology Research Partnership Adaptive Designs Working Group, with a focus on data sharing Open
View article: Evaluating pooled testing for asymptomatic screening of healthcare workers in hospitals
Evaluating pooled testing for asymptomatic screening of healthcare workers in hospitals Open
Background : There is evidence that during the COVID pandemic, a number of patient and HCW infections were nosocomial. Various measures were put in place to try to reduce these infections including developing asymptomatic PCR (polymerase c…
View article: Continuous Positive Airway Pressure plus Mandibular Advancement Therapy (PAPMAT): study protocol for an adaptive randomised crossover trial comparing the benefits and costs of combining two established treatments for obstructive sleep apnoea
Continuous Positive Airway Pressure plus Mandibular Advancement Therapy (PAPMAT): study protocol for an adaptive randomised crossover trial comparing the benefits and costs of combining two established treatments for obstructive sleep apnoea Open