Randomized controlled trials: not always the "gold standard" for evidence in obstetrics and gynecology

Randomized controlled trials are considered the "gold standard" for therapeutic interventions, and it is not uncommon for sweeping changes in medical practice to follow positive results from such trials. However, randomized controlled trials are not without their limitations. Physicians frequently view randomized controlled trials as infallible, whereas they tend to dismiss evidence derived from sources other than randomized controlled trials as less credible or reliable. In several situations in obstetrics and gynecology, there are no randomized controlled trials to help guide the clinician. In these circumstances, it is important to evaluate the entire body of evidence including observational studies, rather than dismiss interventions altogether simply because no randomized controlled trials exist. Randomized controlled trials and observational studies should be viewed as complementary rather than at odds with each other. Some reversals in widely adopted clinical practice have recently been implemented following subsequent studies that contradicted the outcomes of major randomized controlled trials. The most notable of these was the withdrawal from the market of 17-hydroxyprogesterone caproate for preterm birth prevention. Such reversals could potentially have been averted if the inherent limitations of randomized controlled trials were carefully considered before implementing these universal practice changes. This Clinical Opinion underscores the limitations of an exclusive reliance on randomized controlled trials while disregarding other evidence in determining how best to care for patients. Solutions are proposed that advocate that clinicians adopt a more balanced perspective that considers the entirety of the available medical evidence and the individual patient characteristics, needs, and wishes.

Validating claims-based definitions for deprescribing: Bridging the gap between clinical and administrative data

BACKGROUND

Limited research has evaluated the validity of claims-based definitions for deprescribing.

OBJECTIVES

Evaluate the validity of claims-based definitions of deprescribing against electronic health records (EHRs) for deprescribing of benzodiazepines (BZDs) after a fall-related hospitalization.

METHODS

We used a novel data linkage between Medicare fee-for-service (FFS) and Part D with our health system's EHR. We identified patients aged ≥66 years with a fall-related hospitalization, continuous enrollment in Medicare FFS and Part D for 6 months pre- and post-hospitalization, and ≥2 BZD fills in the 6 months pre-hospitalization. Using a standardized EHR abstraction tool, we adjudicated deprescribing for a sub-sample with a fall-related hospitalization at UNC. We evaluated the validity of claims-based deprescribing definitions (e.g., gaps in supply, dosage reductions) versus chart review using sensitivity and specificity.

RESULTS

Among 257 patients in the overall sample, 44% were aged 66-74 years, 35% had Medicare low-income subsidy, 79% were female. Among claims-based definitions using gaps in supply, the prevalence of BZD deprescribing ranged from 8.2% (no refills) to 36.6% (30-day gap). When incorporating dosage, the prevalence ranged from 55.3% to 65.8%. Among the validation sub-sample (n = 47), approximately one-third had BZDs deprescribed in the EHR. Compared to EHR, gaps in supply from claims had good sensitivity, but poor specificity. Incorporating dosage increased sensitivity, but worsened specificity.

CONCLUSIONS

The sensitivity of claims-based definitions for deprescribing of BZDs was low; however, the specificity of a 90-day gap was >90%. Replication in other EHRs and for other low-value medications is needed to guide future deprescribing research.

Importance of patient and public involvement in doctoral research involving people living with dementia

BACKGROUND

There is increasing recognition of the need to include patients and the public in the research process. There is extensive literature about patient and public involvement (PPI) in research, but fewer articles report on PPI in doctoral research.

AIM

To reflect on establishing an advisory group for a doctoral study, exploring the opportunities and challenges associated with including patients with dementia in the research process.

DISCUSSION

The authors discuss the practicalities of establishing an advisory group, the challenges of being a novice researcher, long-term commitment to PPI, the overall approach to PPI and ethical considerations.

CONCLUSION

Establishing an advisory group for a doctoral study can facilitate mutual learning and enhance the study's quality.

IMPLICATIONS FOR PRACTICE

Achieving high-quality PPI in health and social care research can ultimately improve its quality and relevance. An important aspect of the doctoral journey is developing knowledge and skills to facilitate PPI as part of a researcher's apprenticeship.

Marker selection strategies for circulating tumor DNA guided by phylogenetic inference

Motivation

Blood-based profiling of tumor DNA ("liquid biopsy") has offered great prospects for non-invasive early cancer diagnosis, treatment monitoring, and clinical guidance, but require further advances in computational methods to become a robust quantitative assay of tumor clonal evolution. We propose new methods to better characterize tumor clonal dynamics from circulating tumor DNA (ctDNA), through application to two specific questions: 1) How to apply longitudinal ctDNA data to refine phylogeny models of clonal evolution, and 2) how to quantify changes in clonal frequencies that may be indicative of treatment response or tumor progression. We pose these questions through a probabilistic framework for optimally identifying maximum likelihood markers and applying them to characterizing clonal evolution.

Results

We first estimate a distribution over plausible clonal lineage models, using bootstrap samples over pre-treatment tissue-based sequence data. We then refine these lineage models and the clonal frequencies they imply over successive longitudinal samples. We use the resulting framework for modeling and refining tree distributions to pose a set of optimization problems to select ctDNA markers to maximize measures of utility capturing ability to solve the two questions of reducing uncertain in phylogeny models or quantifying clonal frequencies given the models. We tested our methods on synthetic data and showed them to be effective at refining distributions of tree models and clonal frequencies so as to minimize measures of tree distance relative to the ground truth. Application of the tree refinement methods to real tumor data further demonstrated their effectiveness in refining a clonal lineage model and assessing its clonal frequencies. The work shows the power of computational methods to improve marker selection, clonal lineage reconstruction, and clonal dynamics profiling for more precise and quantitative assays of tumor progression.

Availability

https://github.com/CMUSchwartzLab/Mase-phi.git.

Contact

russells@andrew.cmu.edu.

The bioequivalence study design recommendations for immediate-release solid oral dosage forms in the international pharmaceutical regulators programme participating regulators and organisations: differences and commonalities

Bioequivalence (BE) studies are considered the standard for demonstrating that the performance of a generic drug product in the human body is sufficiently similar to that of its comparator product. The objective of this article is to describe the recommendations from participating Bioequivalence Working Group for Generics (BEWGG) members of the International Pharmaceutical Regulators Programme (IPRP) regarding the conduct and acceptance criteria for BE studies of immediate release solid oral dosage forms. A survey was conducted among BEWGG members regarding their BE recommendations and requirements related to study subjects, study design, sample size, single or multiple dose administration, study conditions (fasting or fed), analyte to be measured, selection of product strength, drug content, handling of endogenous substances, BE acceptance criteria, and additional design aspects. All members prefer conducting single dose cross-over designed studies in healthy subjects with a minimum of 12 subjects and utilizing the parent drug data to assess BE. However, differences emerged among the members when the drug's pharmacokinetics and pharmacodynamics become more complex, such that the study design (e.g., fasting versus fed conditions) and BE acceptance criteria (e.g., highly variable drugs, narrow therapeutic index drugs) may be affected. The survey results and discussions were shared with the ICH M13 Expert Working Group (EWG) and played an important role in identifying and analyzing gaps during the harmonization process. The draft ICH M13A guideline developed by the M13 EWG was endorsed by ICH on 20 December 2022, under Step 2.

How-To Create an Orthopaedic Systematic Review: A Step-by-Step Guide. Part III: Executing a Meta-Analysis

At the top of the evidence-based pyramid, systematic reviews stand out as the most powerful, synthesizing findings from numerous primary studies. Specifically, a quantitative systematic review, known as a meta-analysis, combines results from various studies to address a specific research question. This review serves as a guide on how to: (1) design; (2) perform; and (3) publish an orthopedic arthroplasty systematic review. In Part III, we focus on how to design and perform a meta-analysis. We delineate the advantages and disadvantages of meta-analyses compared to systematic reviews, acknowledging their potential challenges due to time constraints and the complexities posed by study heterogeneity and data availability. Despite these obstacles, a well-executed meta-analysis contributes precision and heightened statistical power, standing at the apex of the evidence-based pyramid. The design of a meta-analysis closely mirrors that of a systematic review, but necessitates the inclusion of effect sizes, variability measures, sample sizes, outcome measures, and overall study characteristics. Effective data presentation involves the use of forest plots, along with analyses for heterogeneities and subgroups. Widely-used software tools are common in this domain, and there is a growing trend toward incorporating artificial intelligence software. Ultimately, the intention is for these papers to act as foundational resources for individuals interested in conducting systematic reviews and meta-analyses in the context of orthopaedic arthroplasty, where applicable.

Staging and clean room: Constructs designed to facilitate transparency and reduce bias in comparative analyses of real-world data

PURPOSE

We describe constructs designed to protect the integrity of the results from comparative analyses using real-world data (RWD): staging and clean room.

METHODS

Staging involves performing sequential preliminary analyses and evaluating the population size available and potential bias before conducting comparative analyses. A clean room involves restricted access to data and preliminary results, policies governing exploratory analyses and protocol deviations, and audit trail. These constructs are intended to allow decisions about protocol deviations, such as changes to design or model specification, to be made without knowledge of how they might affect subsequent analyses. We describe an example for implementing staging with a clean room.

RESULTS

Stage 1 may involve selecting a data source, developing and registering a protocol, establishing a clean room, and applying inclusion/exclusion criteria. Stage 2 may involve attempting to achieve covariate balance, often through propensity score models. Stage 3 may involve evaluating the presence of residual confounding using negative control outcomes. After each stage, check points may be implemented when a team of statisticians, epidemiologists and clinicians masked to how their decisions may affect study outcomes, reviews the results. This review team may be tasked with making recommendations for protocol deviations to address study precision or bias. They may recommend proceeding to the next stage, conducting additional analyses to address bias, or terminating the study. Stage 4 may involve conducting the comparative analyses.

CONCLUSIONS

The staging and clean room constructs are intended to protect the integrity and enhance confidence in the results of analyses of RWD.

Assessing depression recurrence, cognitive burden, and neurobiological homeostasis in late life: Design and rationale of the REMBRANDT Study

Background

Late-life depression is characterized by disability, cognitive impairment and decline, and a high risk of recurrence following remission. Aside from past psychiatric history, prognostic neurobiological and clinical factors influencing recurrence risk are unclear. Moreover, it is unclear if cognitive impairment predisposes to recurrence, or whether recurrent episodes may accelerate brain aging and cognitive decline. The purpose of the REMBRANDT study (Recurrence markers, cognitive burden, and neurobiological homeostasis in late-life depression) is to better elucidate these relationships and identify phenotypic, cognitive, environmental, and neurobiological factors contributing to and predictive of depression recurrence.

Methods

Across three sites, REMBRANDT will enroll 300 depressed elders who will receive antidepressant treatment. The goal is to enroll 210 remitted depressed participants and 75 participants with no mental health history into a two-year longitudinal phase focusing on depression recurrence. Participants are evaluated every 2 months with deeper assessments occurring every 8 months, including structural and functional neuroimaging, environmental stress assessments, deep symptom phenotyping, and two weeks of 'burst' ecological momentary assessments to elucidate variability in symptoms and cognitive performance. A broad neuropsychological test battery is completed at the beginning and end of the longitudinal study.

Significance

REMBRANDT will improve our understanding of how alterations in neural circuits and cognition that persist during remission contribute to depression recurrence vulnerability. It will also elucidate how these processes may contribute to cognitive impairment and decline. This project will obtain deep phenotypic data that will help identify vulnerability and resilience factors that can help stratify individual clinical risk.

Using the principles of practice development to address challenges in recruitment and data collection when face-to-face methods are unavailable

BACKGROUND

Researchers conducting studies involving pregnant women often find recruitment challenging. The COVID-19 pandemic added further complexity to studies requiring face-to-face participation.

AIM

To demonstrate how to maintain the principles of practice development (PD) when a study must switch from face-to-face to remote methods of collecting data.

DISCUSSION

The number of participants in the authors' study increased when they moved from face-to-face to telephone engagement during the COVID-19 pandemic. They continued using PD principles when they changed method and the quality of the data they collected remained constant, even once lockdown restrictions were in place.

CONCLUSION

PD principles can offer ways for nurse researchers to engage, collaborate with and reflect with people for research projects, including when constraints compete with participation. They can also assist researchers in optimising and maintaining recruitment and data collection when face-to-face research methods are impossible.

IMPLICATIONS FOR PRACTICE

The telephone can be a valuable alternative medium for recruiting participants and collecting data when face-to-face methods are impossible to use. PD principles can be maintained and response rates and participation may even be greater when using it.

Palliative Care Interventions for Persons With Neurodegenerative Disease: A Scoping Review of Clinical Trial Study Design Features

Background: Within palliative care research, best practice guidelines to conduct scientifically rigorous clinical trials for neurodegenerative diseases are underexplored. This patient population experiences unique challenges, including fluctuations in cognitive capacity, care partner (CP) and proxy involvement, and high adverse events (AEs), that necessitate special consideration when designing clinical trials. Objective: The objective of this study was to describe and identify clinical trial design features that have been documented in studies involving a neuropalliative intervention for persons with neurodegenerative diseases, highlighting features that have been adapted for this unique patient population. Design: We conducted a scoping review of clinical trials with a neuropalliative intervention for persons with neurodegenerative disease. We searched Cochrane, Web of Science, EMBASE, Scopus, and PubMed (MEDLINE) databases for articles published in English between 1950 and 2023. Two reviewers screened, extracted, and synthesized data from the included articles. A third reviewer adjudicated instances of conflict. The data were analyzed using a thematic framework approach. Results: Of 1025 texts, 44 articles were included. Seven study design features were analyzed: (1) consent, (2) proxies and CPs, (3) recruitment strategies, (4) retention strategies, (5) choice of comparator, (6) AEs, and (7) internal validity. This scoping review found disparities in study design features around structured consent, proxies and CPs, comparators, and AEs. Conclusions: To date, neuropalliative care clinical trials have had varied study designs and the majority of research has focused on dementia. Research guideline development for high-quality neuropalliative care clinical trials is greatly needed across the range of neurodegenerative diseases. To increase the scientific rigor of clinical trials and neuropalliative care, we recommend a standardized capacity assessment for consent, defining conditions for the CP, proxy, and AEs, systematizing appropriate comparators, and outlining preemptive recruitment and retention strategies to address the broader unpredictable challenges of palliative care research.

Human-Written vs AI-Generated Texts in Orthopedic Academic Literature: Comparative Qualitative Analysis

BACKGROUND

As large language models (LLMs) are becoming increasingly integrated into different aspects of health care, questions about the implications for medical academic literature have begun to emerge. Key aspects such as authenticity in academic writing are at stake with artificial intelligence (AI) generating highly linguistically accurate and grammatically sound texts.

OBJECTIVE

The objective of this study is to compare human-written with AI-generated scientific literature in orthopedics and sports medicine.

METHODS

Five original abstracts were selected from the PubMed database. These abstracts were subsequently rewritten with the assistance of 2 LLMs with different degrees of proficiency. Subsequently, researchers with varying degrees of expertise and with different areas of specialization were asked to rank the abstracts according to linguistic and methodological parameters. Finally, researchers had to classify the articles as AI generated or human written.

RESULTS

Neither the researchers nor the AI-detection software could successfully identify the AI-generated texts. Furthermore, the criteria previously suggested in the literature did not correlate with whether the researchers deemed a text to be AI generated or whether they judged the article correctly based on these parameters.

CONCLUSIONS

The primary finding of this study was that researchers were unable to distinguish between LLM-generated and human-written texts. However, due to the small sample size, it is not possible to generalize the results of this study. As is the case with any tool used in academic research, the potential to cause harm can be mitigated by relying on the transparency and integrity of the researchers. With scientific integrity at stake, further research with a similar study design should be conducted to determine the magnitude of this issue.

How the expert nursing role was used to facilitate the co-design of a patient interview study

BACKGROUND

Co-design is a research method that seeks to engage service users in research. The approach fosters inclusivity and shared power by having researchers and research participants work together for some or all of a study.

AIM

To describe the experience of co-designing a patient interview study from the perspective of an expert stoma nurse, using a case-study approach and reflexive methods.

DISCUSSION

Valuing expert patients' experiences when conducting research about them enabled patients to be trained as participant researchers to co-design and undertake a patient interview study. The co-design process enabled the researcher to develop a greater recognition of the fact that experience of looking after people with stomas does not equate to expertise in knowing what it is like to have a stoma. This enriched her research experience and increased the authenticity of the study.

CONCLUSION

Co-designing a study with service users creates challenges for nurse researchers. They must pay attention to relational changes, time, planning and organisation to ensure that they conduct their research rigorously and ethically, and safeguard the co-researchers and other participants from potential risks.

IMPLICATIONS FOR PRACTICE

Co-designing research is critical for developing effective, patient-centred bodies of evidence. Nurse researchers can play a critical role but must be prepared to shift from directive to participatory methods to identify appropriate, patient-focused improvements.

Uncontrolled pain: a call for better study design

Studies assessing animal pain in veterinary research are often performed primarily for the benefit of animals. Frequently, the goal of these studies is to determine whether the analgesic effect of a novel treatment is clinically meaningful, and therefore has the capacity to improve the welfare of treated animals. To determine the treatment effect of a potential analgesic, control groups are necessary to allow comparison. There are negative control groups (where pain is unattenuated) and positive control groups (where pain is attenuated). Arising out of animal welfare concerns, there is growing reluctance to use negative control groups in pain studies. But for studies where pain is experimentally induced, the absence of a negative control group removes the opportunity to demonstrate that the study methods could differentiate a positive control intervention from doing nothing at all. For studies that are controlled by a single comparison group, the capacity to distinguish treatment effects from experimental noise is more difficult; especially considering that pain studies often involve small sample sizes, small and variable treatment effects, systematic error and use pain assessment measures that are unreliable. Due to these limitations, and with a focus on farm animals, we argue that many pain studies would be enhanced by the simultaneous inclusion of positive and negative control groups. This would help provide study-specific definitions of pain and pain attenuation, thereby permitting more reliable estimates of treatment effects. Adoption of our suggested refinements could improve animal welfare outcomes for millions of animals globally.

Investigating Receptivity and Affect Using Machine Learning: Ecological Momentary Assessment and Wearable Sensing Study

BACKGROUND

As mobile health (mHealth) studies become increasingly productive owing to the advancements in wearable and mobile sensor technology, our ability to monitor and model human behavior will be constrained by participant receptivity. Many health constructs are dependent on subjective responses, and without such responses, researchers are left with little to no ground truth to accompany our ever-growing biobehavioral data. This issue can significantly impact the quality of a study, particularly for populations known to exhibit lower compliance rates. To address this challenge, researchers have proposed innovative approaches that use machine learning (ML) and sensor data to modify the timing and delivery of surveys. However, an overarching concern is the potential introduction of biases or unintended influences on participants' responses when implementing new survey delivery methods.

OBJECTIVE

This study aims to demonstrate the potential impact of an ML-based ecological momentary assessment (EMA) delivery system (using receptivity as the predictor variable) on the participants' reported emotional state. We examine the factors that affect participants' receptivity to EMAs in a 10-day wearable and EMA-based emotional state-sensing mHealth study. We study the physiological relationships indicative of receptivity and affect while also analyzing the interaction between the 2 constructs.

METHODS

We collected data from 45 healthy participants wearing 2 devices measuring electrodermal activity, accelerometer, electrocardiography, and skin temperature while answering 10 EMAs daily, containing questions about perceived mood. Owing to the nature of our constructs, we can only obtain ground truth measures for both affect and receptivity during responses. Therefore, we used unsupervised and supervised ML methods to infer affect when a participant did not respond. Our unsupervised method used k-means clustering to determine the relationship between physiology and receptivity and then inferred the emotional state during nonresponses. For the supervised learning method, we primarily used random forest and neural networks to predict the affect of unlabeled data points as well as receptivity.

RESULTS

Our findings showed that using a receptivity model to trigger EMAs decreased the reported negative affect by >3 points or 0.29 SDs in our self-reported affect measure, scored between 13 and 91. The findings also showed a bimodal distribution of our predicted affect during nonresponses. This indicates that this system initiates EMAs more commonly during states of higher positive emotions.

CONCLUSIONS

Our results showed a clear relationship between affect and receptivity. This relationship can affect the efficacy of an mHealth study, particularly those that use an ML algorithm to trigger EMAs. Therefore, we propose that future work should focus on a smart trigger that promotes EMA receptivity without influencing affect during sampled time points.

Is there an advantage? Considerations for researchers studying the effects of the type of Medicare coverage

OBJECTIVE

To describe common methodological problems that arise in comparisons of Medicare Advantage (MA) and Traditional Medicare (TM) and within-MA studies and provide suggestions of how researchers can address these issues.

STUDY SETTING

Published research evaluating Medicare coverage options in the United States.

STUDY DESIGN

We considered key conceptual challenges and promising solutions that have been used thus far and suggest additional directions.

DATA COLLECTION

Not available.

PRINCIPAL FINDINGS

Many existing studies of MA versus TM include significant limitations, such as failing to account for unobserved confounders driving both beneficiary coverage choice and health outcomes once enrolled, not accounting for variation in benefit generosity, provider networks, or plan design across MA plans, and/or having been conducted at a time when MA enrollment was less than a third of all Medicare beneficiaries. We provide a review of methods that can help researchers to overcome these weaknesses and suggest additional methods and data sources that may aid future research.

CONCLUSIONS

The MA program is becoming an essential part of the US healthcare system. By accounting for non-random movement into and out of MA and studying the heterogeneity of beneficiary experience across plan and market characteristics, researchers can provide the high-quality evidence necessary for policymakers to design the program and reform TM in ways that maximize beneficiary outcomes.

Peer review of clinical and translational research manuscripts: Perspectives from statistical collaborators

Research articles in the clinical and translational science literature commonly use quantitative data to inform evaluation of interventions, learn about the etiology of disease, or develop methods for diagnostic testing or risk prediction of future events. The peer review process must evaluate the methodology used therein, including use of quantitative statistical methods. In this manuscript, we provide guidance for peer reviewers tasked with assessing quantitative methodology, intended to complement guidelines and recommendations that exist for manuscript authors. We describe components of clinical and translational science research manuscripts that require assessment including study design and hypothesis evaluation, sampling and data acquisition, interventions (for studies that include an intervention), measurement of data, statistical analysis methods, presentation of the study results, and interpretation of the study results. For each component, we describe what reviewers should look for and assess; how reviewers should provide helpful comments for fixable errors or omissions; and how reviewers should communicate uncorrectable and irreparable errors. We then discuss the critical concepts of transparency and acceptance/revision guidelines when communicating with responsible journal editors.

Antiangiogenic exclusion rules in glioma trials: Historical perspectives and guidance for future trial design

Background

Despite the lack of proven therapies for recurrent high-grade glioma (HGG), only 8%-11% of patients with glioblastoma participate in clinical trials, partly due to stringent eligibility criteria. Prior bevacizumab treatment is a frequent exclusion criterion, due to difficulty with response assessment and concerns for rebound edema following antiangiogenic discontinuation. There are no standardized trial eligibility rules related to prior antiangiogenic use.

Methods

We reviewed ClinicalTrials.gov listings for glioma studies starting between May 2009 and July 2022 for eligibility rules related to antiangiogenics. We also reviewed the literature pertaining to bevacizumab withdrawal.

Results

Two hundred and ninety-seven studies for patients with recurrent glioma were reviewed. Most were phase 1 (n = 145, 49%), non-randomized (n = 257, 87%), evaluated a drug-only intervention (n = 223, 75%), and had a safety and tolerability primary objective (n = 181, 61%). Fifty-one (17%) excluded participants who received any antiangiogenic, one (0.3%) excluded participants who received any non-temozolomide systemic therapy. Fifty-nine (20%) outlined washout rules for bevacizumab (range 2-24 weeks, 4-week washout n = 35, 12% most common). Seventy-eight required a systemic therapy washout (range 1-6 weeks, 4-week washout n = 34, 11% most common). Nine permitted prior bevacizumab use with limitations, 18 (6%) permitted any prior bevacizumab, 5 (2%) were for bevacizumab-refractory disease, and 76 (26%) had no rules regarding antiangiogenic use. A literature review is then presented to define standardized eligibility criteria with a 6-week washout period proposed for future trial design.

Conclusions

Interventional clinical trials for patients with HGG have substantial heterogeneity regarding eligibility criteria pertaining to bevacizumab use, demonstrating a need for standardizing clinical trial design.

IMPAHCT: A randomized phase 2b/3 study of inhaled imatinib for pulmonary arterial hypertension

AV-101 (imatinib) powder for inhalation, an investigational dry powder inhaled formulation of imatinib designed to target the underlying pathobiology of pulmonary arterial hypertension, was generally well tolerated in healthy adults in a phase 1 single and multiple ascending dose study. Inhaled Imatinib Pulmonary Arterial Hypertension Clinical Trial (IMPAHCT; NCT05036135) is a phase 2b/3, randomized, double-blind, placebo-controlled, dose-ranging, and confirmatory study. IMPAHCT is designed to identify an optimal AV-101 dose (phase 2b primary endpoint: pulmonary vascular resistance) and assess the efficacy (phase 3 primary endpoint: 6-min walk distance), safety, and tolerability of AV-101 dose levels in subjects with pulmonary arterial hypertension using background therapies. The study has an operationally seamless, adaptive design allowing for continuous recruitment. It includes three parts; subjects enrolled in Part 1 (phase 2b dose-response portion) or Part 2 (phase 3 intermediate portion) will be randomized 1:1:1:1 to 10, 35, 70 mg AV-101, or placebo (twice daily), respectively. Subjects enrolled in Part 3 (phase 3 optimal dose portion) will be randomized 1:1 to the optimal dose of AV-101 and placebo (twice daily), respectively. All study parts include a screening period, a 24-week treatment period, and a 30-day safety follow-up period; the total duration is ∼32 weeks. Participation is possible in only one study part. IMPAHCT has the potential to advance therapies for patients with pulmonary arterial hypertension by assessing the efficacy and safety of a novel investigational drug-device combination (AV-101) using an improved study design that has the potential to save 6-12 months of development time. ClinicalTrials.gov Identifier: NCT05036135.

The association between research design and the perceived treatment effectiveness: a cross-sectional study

Objective

To evaluate the impact of research design on the perceived medical treatment effectiveness among researchers, healthcare workers (HCWs) and consumers in Croatia.

Methods

A cross-sectional study was conducted from November 2021 to February 2022 using an online survey. The participants were researchers, HCWs and consumers from Croatia. The survey had six scenarios about the same medical treatment presented within different study designs and in random order. Participants were asked to assess on a scale from 1 to 10 if the descriptions presented a sufficient level of evidence to conclude that the treatment was effective.

Results

For researchers (n = 97), as the number of participants and degree of variable control in the study design increased, the perceived level of sufficient evidence also increased significantly. Among consumers (n = 286) and HCWs (n = 201), no significant differences in scores were observed between the cross-sectional study, cohort study, RCT, and systematic review.

Conclusion

There is a need to implement educational courses on basic research methodology in lower levels of education and as part of Continuing Medical Education for all stakeholders in the healthcare system. Trial registration: this study has been registered on the Open Science Framework prior to study commencement (https://osf.io/t7xmf).

Vaccination to Reduce Antimicrobial Resistance Burden-Data Gaps and Future Research

Antimicrobial resistance (AMR) poses an immediate danger to global health. If unaddressed, the current upsurge in AMR threatens to reverse the achievements in reducing the infectious disease-associated mortality and morbidity associated with antimicrobial treatment. Consequently, there is an urgent need for strategies to prevent or slow the progress of AMR. Vaccines potentially contribute both directly and indirectly to combating AMR. Modeling studies have indicated significant gains from vaccination in reducing AMR burdens for specific pathogens, reducing mortality/morbidity, and economic loss. However, quantifying the real impact of vaccines in these reductions is challenging because many of the study designs used to evaluate the contribution of vaccination programs are affected by significant background confounding, and potential selection and information bias. Here, we discuss challenges in assessing vaccine impact to reduce AMR burdens and suggest potential approaches for vaccine impact evaluation nested in vaccine trials.

Are postprandial glucose responses sufficiently person-specific to use in personalized dietary advice? Design of the RepEAT study: a fully controlled dietary intervention to determine the variation in glucose responses

Introduction

An elevated postprandial glucose response is associated with an increased risk of cardiometabolic diseases. Existing research suggests large heterogeneity in the postprandial glucose responses to identical meals and food products between individuals, but the effect of other consumed meals during the day and the order of meals during the day on the heterogeneity in postprandial glucose responses still needs to be investigated. In addition, the robustness of the glucose responses to meals or foods is still unknown.

Objectives

The overall aim of the project is to assess whether the glucose response to a meal is sufficiently person-specific to use in personalized dietary advice. We aim to answer the question: "How replicable are glucose responses to meals within individuals and how consistent is the variation in glucose responses between individuals?"

Methods

The question will be assessed under standardized conditions of a 9-week fully controlled dietary intervention in which all meals are the same between individuals and consumed in a fixed order at a fixed time. 63 apparently healthy men and women with a BMI of 25-40 kg/m2 and aged 45-75 years were enrolled in the RepEAT study (NCT05456815), of whom 53 participants completed the study. The RepEAT study comprised a fully controlled dietary intervention of nine weeks, consisting of three repetitive periods of three weeks. Within each three-week period, a variety of meals and food products were offered during breakfast, lunch, dinner and in between meal snacks. Throughout the dietary intervention, glucose was continuously monitored using Freestyle Libre Pro IQ monitors. Physical activity was monitored using the ActiGraph and ActivPAL. To measure the association between glucose responses and an individual's phenotype, various measurements were performed before the start of the dietary intervention including an oral glucose tolerance test, a high-fat mixed meal challenge, assessment of body fat distribution including liver fat (MRI/MRS), and cardiometabolic markers.

Discussion

The repetitive and fully controlled nature of the dietary study allows detailed assessment of the replicability of the glucose responses to meals and food products within individuals. Furthermore, the consistency of the variation between individuals independent of insulin resistance will be determined.

The ecomap: a tool for extending understanding in hermeneutic phenomenological research

BACKGROUND

Ecomaps are tools used in nursing practice to assess families' social support systems. Ecomaps have been used effectively in qualitative research but little attention has been given to their use as a tool in the methodological approach of hermeneutic phenomenology.

AIM

To demonstrate that the use of ecomaps is congruent with the Heideggerian philosophical foundations of hermeneutic phenomenology.

DISCUSSION

This article reflects on a study in which the researchers used ecomaps to explore how parents of children with cancer are supported with decision-making about their children's care. Exploration of the Heideggerian concepts of 'being in the world', 'being with' and 'temporality' prompted reflections about how constructing ecomaps furthers understanding of participants' unique contexts. Using an ecomap in an in-depth interview enabled interviewees to return to their experiences of being supported with decision-making; it also further developed the researcher's understanding of how each participant's experience was situated in their evolving relationships with others.

CONCLUSION

Constructing ecomaps in hermeneutic phenomenology is in tune with Heideggerian philosophical concepts. Ecomaps can open a door to participants' experiences, deepen the researcher's understanding and find further meaning in those experiences.

IMPLICATIONS FOR PRACTICE

Ecomaps are a useful way of shining a light on participants' experiences in hermeneutic phenomenological research. The article provides practical tips to optimise their use in future research.

Sensitivity analysis for causality in observational studies for regulatory science

Objective

The United States Congress passed the 21st Century Cures Act mandating the development of Food and Drug Administration guidance on regulatory use of real-world evidence. The Forum on the Integration of Observational and Randomized Data conducted a meeting with various stakeholder groups to build consensus around best practices for the use of real-world data (RWD) to support regulatory science. Our companion paper describes in detail the context and discussion of the meeting, which includes a recommendation to use a causal roadmap for study designs using RWD. This article discusses one step of the roadmap: the specification of a sensitivity analysis for testing robustness to violations of causal model assumptions.

Methods

We present an example of a sensitivity analysis from a RWD study on the effectiveness of Nifurtimox in treating Chagas disease, and an overview of various methods, emphasizing practical considerations on their use for regulatory purposes.

Results

Sensitivity analyses must be accompanied by careful design of other aspects of the causal roadmap. Their prespecification is crucial to avoid wrong conclusions due to researcher degrees of freedom. Sensitivity analysis methods require auxiliary information to produce meaningful conclusions; it is important that they have at least two properties: the validity of the conclusions does not rely on unverifiable assumptions, and the auxiliary information required by the method is learnable from the corpus of current scientific knowledge.

Conclusions

Prespecified and assumption-lean sensitivity analyses are a crucial tool that can strengthen the validity and trustworthiness of effectiveness conclusions for regulatory science.

Evaluation of Truncated AUC as an Alternative Measure to Assess Pharmacokinetic Comparability in Bridging Biologic-Device Using Prefilled Syringes and Autoinjectors

Pharmacokinetic (PK) comparisons between therapeutic biologics have largely been based on the total area under the concentration-time curve (AUC) and the maximum concentration (Cmax ). For biologics with a long half-life, a PK comparability study may be long in duration and costly to conduct. The goal of this study was to evaluate whether a truncated AUC (tAUC) can be used to assess PK comparability when bridging prefilled syringe (PFS) and autoinjector (AI) treatment options for biologics with a long half-life. Fifteen biologics license applications (BLAs) were included to determine the concordance and geometric percent coefficient of variation (%CV) between tAUCs evaluated on days 7, 14, 21, and 28 and AUC evaluated to infinity (AUC0-inf ). Concordance is established if the tAUCs are comparable with AUC0-inf . Trial simulation was performed to examine the effect of the absorption rate constant (ka ) and sample size on the concordance of tAUCs. The tAUCs evaluated on day 14, 21, and 28 had 100% concordance with AUC0-inf for all 15 BLAs. The concordance of tAUC evaluated at day 7 was 87.5%. Based on the trial simulation, tAUC evaluated to day 28 post-dose can achieve high concordance (≥85%) for biologics exhibiting linear or nonlinear elimination with a ka of ≥0.1/day and with a sample size of 70 subjects per arm. tAUC appears to be a promising alternative PK measure, relative to AUC0-inf , for PK comparability assessments.

Therapeutic strategies in vascular cognitive impairment: A systematic review of population, intervention, comparators, and outcomes

INTRODUCTION

Vascular cognitive impairment (VCI) is a common and heterogeneous condition, clinically and pathophysiologically, that still lacks approved treatment.

METHODS

We reviewed evidence from randomized and non-randomized clinical trials in VCI to explore whether any therapeutic option warrants further investigation and to assess possible flaws in previous studies.

RESULTS

We identified 118 studies after searching PubMed and Embase, including 19,223 participants and 5 different VCI subtypes. We found 63 different types of intervention (51 pharmacologic, 5 employing physical agent application, 7 rehabilitation approaches) compared with either placebo, best medical treatment, or other interventions. Treatment efficacy was assessed through 125 outcome measures (with a clearly pre-specified primary outcome in 50.8% of studies).

DISCUSSION

Therapeutic trials in VCI have been heterogeneous in terms of populations, types of interventions, and outcomes. Overall, a lack of clear pathophysiological rationale for tested interventions seems to emerge, together with the need to homogenize trial study design.

Statistical power and sample size calculations for time-to-event analysis

OBJECTIVE

To provide thoracic and cardiovascular surgeons with the necessary tools for performing sample size and power calculations for studies with time-to-event outcomes.

METHODS

Power and sample size calculations enhance the overall quality of research studies by providing readers with assurance and insight into the number of patients included in the study. A 5-step approach is presented for performing sample size calculations in comparing groups on time-to-event endpoints. The steps are as follows: (1) identify the primary outcome of interest, (2) define size of the effect and desired power, (3) determine the appropriate statistical test, (4) perform calculations of the required sample size, and (5) write formal power and sample size statement. This approach is demonstrated with 5 clinical examples for time-to-event studies in cardiovascular surgery, featuring Cox regression, 2-sample log-rank test, 1-sample log-rank test, and competing risks analysis.

CONCLUSIONS

Statistical power is an essential element for designing studies to ensure sufficient sample sizes for detecting treatment effects or group differences in time-to-event patient outcomes. Power and sample size justification not only adds statistical rigor and credibility to research manuscripts, but also provides the reader with assurance that the findings and conclusions are valid and based on a sufficient number of patients.

Impact of prolonged use of adjuvant tocolytics after cervical cerclage on late abortion and premature delivery

We evaluated the impact of cervical cerclage combined with one or more uterine contraction inhibitors in persistent inhibition of uterine contraction for the treatment of late abortion and premature delivery. This retrospective case series study analysed the medical data of 58 patients who underwent cervical cerclage for cervical insufficiency and simultaneously received one or more uterine contraction inhibitors (indomethacin, ritodrine, and atosiban) and magnesium sulphate at the Zibo Maternal and Child Health Hospital between January 2019 and December 2020.Patients are normal pregnancy who received cervical cerclage without complications. The rate of successful treatment was 74.14% (43/58). The prolonged gestation duration was 16.42 ± 7.84 weeks, and the average delivery gestational age was 35.91 ± 5.16 weeks. The longest duration of treatment with a uterine contraction inhibitor or inhibitors in combination or with magnesium sulphate alone was 15.34 ± 13.16 days, and nine cases developed adverse reactions. Persistent uterine contraction inhibition after cervical cerclage could prolong pregnancy and improve pregnancy outcomes.Impact statementWhat is already known on this subject? A crucial reason for treatment failure of cervical cerclage is that uterine contraction was not effectively inhibited.What do the results of this study add? Persistent inhibition of uterine contraction after cervical cerclage prolonged pregnancy duration, increased gestational age at delivery, and improved pregnancy outcomes.What are the implications of these findings for clinical practice and/or further research? This study may provide a clinical basis for prolonging gestational age, preventing late abortion and premature delivery, and improving the survival rate and quality of life of premature infants.

The curious case of Prevotella copri

Prevotella copri is an abundant member of the human gastrointestinal microbiome, whose relative abundance has curiously been associated with positive and negative impacts on diseases, such as Parkinson's disease and rheumatoid arthritis. Yet, the verdict is still out on the definitive role of P. copri in human health, and on the effect of different diets on its relative abundance in the gut microbiome. The puzzling discrepancies among P. copri studies have only recently been attributed to the diversity of its strains, which substantially differ in their encoded metabolic patterns from the commonly used reference strain. However, such strain differences cannot be resolved by common 16S rRNA amplicon profiling methods. Here, we scrutinize P. copri, its versatile metabolic potential, and the hypotheses behind the conflicting observations on its association with diet and human health. We also provide suggestions for designing studies and bioinformatics pipelines to better research P. copri.

A Novel Randomized Trial Protocol for Evaluating Wound Healing Interventions

Background: Randomized controlled trials using complete healing as an endpoint suffer from poor statistical power, owing to the heterogeneity of wounds and their healing trajectories. The Food and Drug Administration (FDA) has recently consulted with expert groups to consider percentage area reduction (PAR) of the wound over a 4-week period as a valid intermediate endpoint, creating the opportunity for more powerful study designs. Methods: A within-subject controlled study design comparing the PAR of venous leg ulcers (VLU) in patients over 4 weeks receiving different interventions. Twenty-nine patients received multilayer compression over 4 weeks, followed by neuromuscular electrostimulation (NMES) of the leg muscle pump in addition to compression for a further 4 weeks. Paired comparison was then made of PAR between the two phases. A second cohort of 22 patients received only multilayer compression throughout both 4-week phases. Results: Patients randomized to NMES saw a significant increase in healing rate compared with compression alone, whereas patients receiving compression only saw no significant change in healing rate throughout the course of the study. Conclusions: Intermittent NMES of the common peroneal nerve significantly accelerates the healing of VLU. It is well tolerated by patients and deserves serious consideration as an adjuvant to compression therapy. PAR is a useful metric for comparing the performance of wound healing interventions, and the self-controlled trial design allows sensitive discrimination with a relatively small number of subjects over a reasonably short trial period. The study is reported according to the CONSORT reporting guidelines. Clinical Trial Registration: NCT03396731 (ClinicalTrials.gov).

Sample size and power determination for multiparameter evaluation in nonlinear regression models with potential stratification

Sample size and power determination are crucial design considerations for biomedical studies intending to formally test the effects of key variables on an outcome. Other known prognostic factors may exist, necessitating the use of techniques for covariate adjustment when conducting this evaluation. Moreover, the main interest often includes assessing the impact of more than one variable on an outcome, such as multiple treatments or risk factors. Regression models are frequently employed for these purposes, formalizing this assessment as a test of multiple regression parameters. But, the presence of multiple variables of primary interest and correlation between covariates can complicate sample size/power calculation. Given the paucity of available sample size formulas for this context, these calculations are often performed via simulation, which can be both time-consuming as well as demanding extensive probability modeling. We propose a simpler, general approach to sample size and power determination that may be applied when testing multiple parameters in commonly used regression models, including generalized linear models as well as ordinary and stratified versions of the Cox and Fine-Gray models. Through both rigorous simulations and theoretical derivations, we demonstrate the formulas' accuracy in producing sample sizes that will meet the type I error rate and power specifications of the study design.

Defining the Cynomolgus Macaque (Macaca fascicularis) Animal Model for Aerosolized Venezuelan Equine Encephalitis: Importance of Challenge Dose and Viral Subtype

Venezuelan equine encephalitis virus (VEEV) outbreaks occur sporadically. Additionally, VEEV has a history of development as a biothreat agent. Yet, no FDA-approved vaccine or therapeutic exists for VEEV disease. The sporadic outbreaks present a challenge for testing medical countermeasures (MCMs) in humans; therefore, well-defined animal models are needed for FDA Animal Rule licensure. The cynomolgus macaque (CM) model has been studied extensively at high challenge doses of the VEEV Trinidad donkey strain (>1.0 × 108 plaque-forming units [PFU]), doses that are too high to be a representative human dose. Based on viremia of two subtypes of VEEV, IC, and IAB, we found the CM infectious dose fifty (ID50) to be low, 12 PFU, and 6.7 PFU, respectively. Additionally, we characterized the pattern of three clinical parameters (viremia, temperature, and lymphopenia) across a range of doses to identify a challenge dose producing consistent signs of infection. Based on these studies, we propose a shift to using a lower challenge dose of 1.0 × 103 PFU in the aerosol CM model of VEEV disease. At this dose, NHPs had the highest viremia, demonstrated a fever response, and had a measurable reduction in complete lymphocyte counts-biomarkers that can demonstrate MCM efficacy.

Where are caregivers in the clinical trial? Evaluation of caregiver responsibilities in Alzheimer's disease and related dementias clinical trials

INTRODUCTION

Family caregivers of persons with Alzheimer's disease and related dementias (ADRD) have significant responsibilities within health care. They may identify relevant clinical trials and support decision-making about their relative's participation. The objectives of this study were to (a) evaluate the responsibilities of caregivers related to their relative's participation in ADRD clinical trials and (b) examine how these responsibilities are communicated on clinicaltrials.gov.

METHODS

We reviewed ADRD clinical trials completed between 1990 and 2021 using clinicaltrials.gov.

RESULTS

Less than half of clinical trial study information pages included caregiver responsibilities. Nine caregiver responsibilities were provided among those with information (e.g., giving consent, caregiver training and education, monitoring patient's response to intervention, communicating with study team).

DISCUSSION

ADRD clinical trial study information pages should consistently include caregiver responsibilities to help caregivers better prepare for trial responsibilities. This enhanced engagement with caregivers could also facilitate recruitment and retention, including participants from diverse communities.

HIGHLIGHTS

Alzheimer's disease and related dementias (ADRD) clinical trial study information does not consistently include caregiver responsibilities. Caregiver responsibilities in clinical trials span communication, monitoring, and transportation. Robust information provision to caregivers could support participant recruitment and retention. Meaningfully engaging caregivers could support recruitment of diverse participants.

Clinical Performance Evaluation of Continuous Glucose Monitoring Systems: A Scoping Review and Recommendations for Reporting

The use of different approaches for design and results presentation of studies for the clinical performance evaluation of continuous glucose monitoring (CGM) systems has long been recognized as a major challenge in comparing their results. However, a comprehensive characterization of the variability in study designs is currently unavailable. This article presents a scoping review of clinical CGM performance evaluations published between 2002 and 2022. Specifically, this review quantifies the prevalence of numerous options associated with various aspects of study design, including subject population, comparator (reference) method selection, testing procedures, and statistical accuracy evaluation. We found that there is a large variability in nearly all of those aspects and, in particular, in the characteristics of the comparator measurements. Furthermore, these characteristics as well as other crucial aspects of study design are often not reported in sufficient detail to allow an informed interpretation of study results. We therefore provide recommendations for reporting the general study design, CGM system use, comparator measurement approach, testing procedures, and data analysis/statistical performance evaluation. Additionally, this review aims to serve as a foundation for the development of a standardized CGM performance evaluation procedure, thereby supporting the goals and objectives of the Working Group on CGM established by the Scientific Division of the International Federation of Clinical Chemistry and Laboratory Medicine.

Career development in pragmatic clinical trials to improve care for people living with dementia

The growing number of people living with dementia (PLWD) requires a coordinated clinical response to deliver pragmatic, evidence-based interventions in frontline care settings. However, infrastructure to support such a response is lacking. Moreover, there are too few researchers conducting rigorous embedded pragmatic clinical trials (ePCTs) to make the vision of high quality, widely accessible dementia care a reality. National Institute on Aging (NIA) Imbedded Pragmatic Alzheimer's disease and Related Dementias Clinical Trials (IMPACT) Collaboratory seeks to improve the pipeline of early career researchers qualified to lead ePCTs by funding career development awards. Even with support from the Collaboratory, awardees face practical and methodological challenges to success, recently exacerbated by the COVID-19 pandemic. We first describe the training opportunities and support network for the IMPACT CDA recipients. This report then describes the unique career development challenges faced by early-career researchers involved in ePCTs for dementia care. Topics addressed include challenges in establishing a laboratory, academic promotion, mentoring and professional development, and work-life balance. Concrete suggestions to address these challenges are offered for early-career investigators, their mentors, and their supporting institutions. While some of these challenges are faced by researchers in other fields, this report seeks to provide a roadmap for expanding the work of the IMPACT Collaboratory and initiating future efforts to recruit, train, and retain talented early-career researchers involved in ePCTs for dementia care.

Enhancing Enrollment in Acute Stroke Trials: Current State and Consensus Recommendations

The Stroke Treatment Academic Industry Roundtable (STAIR) convened a session and workshop regarding enrollment in acute stroke trials during the STAIR XII meeting on March 22, 2023. This forum brought together stroke physicians and researchers, members of the National Institute of Neurological Disorders and Stroke, industry representatives, and members of the US Food and Drug Administration to discuss the current status and opportunities for improving enrollment in acute stroke trials. The workshop identified the most relevant issues impacting enrollment in acute stroke trials and addressed potential action items for each. Focus areas included emergency consent in the United States and other countries; careful consideration of eligibility criteria to maximize enrollment and representativeness; investigator, study coordinator, and pharmacist availability outside of business hours; trial enthusiasm/equipoise; site start-up including contractual issues; site champions; incorporation of study procedures into standard workflow as much as possible; centralized enrollment at remote sites by study teams using telemedicine; global trials; and coenrollment in trials when feasible. In conclusion, enrollment of participants is the lifeblood of acute stroke trials and is the rate-limiting step for testing an exciting array of new approaches to improve patient outcomes. In particular, efforts should be undertaken to broaden the medical community's understanding and implementation of emergency consent procedures and to adopt designs and processes that are easily incorporated into standard workflow and that improve trials' efficiencies and execution. Research and actions to improve enrollment in ongoing and future trials will improve stroke outcomes more broadly than any single therapy under consideration.

Capturing red squirrels (Sciurus vulgaris) on camera: A cost-effective approach for monitoring relative abundance and habitat preference

Effective methods for monitoring animal populations are crucial for species conservation and habitat management. Motion-activated cameras provide an affordable method for passively surveying animal presence across the landscape but have mainly been used for studying large-bodied mammals. This paper explores the relative abundance and habitat preferences of red squirrels (Sciurus vulgaris) in coniferous forests using cameras and live trapping. The study was conducted in two forests (Newborough and Pentraeth) on Anglesey, North Wales, with a total of 50 sampling locations across four habitat categories. Detailed woodland structure and composition data were gathered around each sampling location. We found a strong positive correlation between the number of individual red squirrels live trapped over 10 days with the number of camera images of squirrels recorded during a previous 5-day period. The time interval between camera deployment and the first recorded image of a red squirrel showed a significant negative correlation with the number of individuals live trapped. Red squirrel relative abundance was negatively related to forest canopy openness, while the presence of Scots pine and increased tree species diversity were positively associated with the relative abundance of squirrels. There was also a strong site difference with lower relative abundance at Newborough compared with Pentraeth, which likely reflects the heavy thinning of mature forest at Newborough reducing tree crown connectivity. The results show that remotely activated cameras are an effective method for monitoring red squirrel populations across varying animal densities. The cameras also provided crucial information on red squirrel habitat preferences that can aid in woodland management and conservation efforts. Cameras have great potential to collect data on the population status of other small mammals, but it is essential that these methods are validated on a species-by-species basis.

Sample Size, Replicability, and Pre-Test Likelihoods-Essential, Overlooked, and Critical Components of Statistical Inference: A Journal of Neurotrauma Guide to Statistical Methods and Study Design

Perhaps one of the most overlooked components of statistical inference is the sample size. While in randomized controlled trials, power analysis is common and sample size justification is an integral component of the core statistical analysis plan, observational and laboratory research studies often rely on convenience samples and/or underpowered analyses. Insufficiently powered studies increase uncertainty associated with the results and limit interpretability. Moreover, they increase the likelihood that the findings might be disproved in future replication studies. A scientific study can be compared with a diagnostic test for the "truth"- i.e., whether a certain effect exists or whether a relationship is actually true. In this diagnostic analogy, the positive predictive value is dependent not only on the statistical power of the study in question, but also on the pre-test likelihood that any true relationship exists at all. The concept of using an estimate of the pre-test likelihood to interpret observed results is another critical and often overlooked component of statistical inference. Even if a statistically significant relationship or an effect is found, however, such finding alone may be insufficient. It often must be replicated, ideally in a more generalizable setting. Further, if the effect size is small, replication often requires sample sizes that are substantially larger than the original study. For most neurotrauma research, thousands of subjects are usually not required, but many studies do require substantially larger sample sizes than are typically presented in published research to increase replicability. In this methodological tutorial, choice of sample size, pre-test probability, and the concept of positive predictive value for scientific findings will be discussed, together with suggestions to improve replicability of neurotrauma research in the future.

Common methodological pitfalls in ICI pneumonitis risk prediction studies

Background

Pneumonitis is one of the most common adverse events induced by the use of immune checkpoint inhibitors (ICI), accounting for a 20% of all ICI-associated deaths. Despite numerous efforts to identify risk factors and develop predictive models, there is no clinically deployed risk prediction model for patient risk stratification or for guiding subsequent monitoring. We believe this is due to systemic suboptimal approaches in study designs and methodologies in the literature. The nature and prevalence of different methodological approaches has not been thoroughly examined in prior systematic reviews.

Methods

The PubMed, medRxiv and bioRxiv databases were used to identify studies that aimed at risk factor discovery and/or risk prediction model development for ICI-induced pneumonitis (ICI pneumonitis). Studies were then analysed to identify common methodological pitfalls and their contribution to the risk of bias, assessed using the QUIPS and PROBAST tools.

Results

There were 51 manuscripts eligible for the review, with Japan-based studies over-represented, being nearly half (24/51) of all papers considered. Only 2/51 studies had a low risk of bias overall. Common bias-inducing practices included unclear diagnostic method or potential misdiagnosis, lack of multiple testing correction, the use of univariate analysis for selecting features for multivariable analysis, discretization of continuous variables, and inappropriate handling of missing values. Results from the risk model development studies were also likely to have been overoptimistic due to lack of holdout sets.

Conclusions

Studies with low risk of bias in their methodology are lacking in the existing literature. High-quality risk factor identification and risk model development studies are urgently required by the community to give the best chance of them progressing into a clinically deployable risk prediction model. Recommendations and alternative approaches for reducing the risk of bias were also discussed to guide future studies.

Field and laboratory guidelines for reliable bioinformatic and statistical analysis of bacterial shotgun metagenomic data

Shotgun metagenomics is an increasingly cost-effective approach for profiling environmental and host-associated microbial communities. However, due to the complexity of both microbiomes and the molecular techniques required to analyze them, the reliability and representativeness of the results are contingent upon the field, laboratory, and bioinformatic procedures employed. Here, we consider 15 field and laboratory issues that critically impact downstream bioinformatic and statistical data processing, as well as result interpretation, in bacterial shotgun metagenomic studies. The issues we consider encompass intrinsic properties of samples, study design, and laboratory-processing strategies. We identify the links of field and laboratory steps with downstream analytical procedures, explain the means for detecting potential pitfalls, and propose mitigation measures to overcome or minimize their impact in metagenomic studies. We anticipate that our guidelines will assist data scientists in appropriately processing and interpreting their data, while aiding field and laboratory researchers to implement strategies for improving the quality of the generated results.

Applying hybrid effectiveness-implementation studies in equity-centered policy implementation science

Policy implementation science (IS) is complex, dynamic, and fraught with unique study challenges that set it apart from biomedical or clinical research. One important consideration is the ways in which policy interacts with local contexts, such as power and social disadvantage (e.g., based on ability, race, class, sexual identity, geography). The complex nature of policy IS and the need for more intentional integration of equity principles into study approaches calls for creative adaptations to existing implementation science knowledge and guidance. Effectiveness-implementation hybrid studies were developed to enhance translation of clinical research by addressing research questions around the effectiveness of an intervention and its implementation in the same study. The original work on hybrid designs mainly focused on clinical experimental trials; however, over the last decade, researchers have applied it to a wide range of initiatives and contexts, including more widespread application in community-based studies. This perspectives article demonstrates how effectiveness-implementation hybrid studies can be adapted for and applied to equity-centered policy IS research. We draw upon principles of targeted universalism and Equity in Implementation Research frameworks to guide adaptations to hybrid study typologies, and suggest research and engagement activities to enhance equity considerations; for example, in the design and testing of implementing strategies. We also provide examples of equity-centered policy IS studies. As the field of policy IS rapidly evolves, these adapted hybrid type studies are offered to researchers as a starting guide.

The one-way ANOVA test explained

BACKGROUND

Quantitative methods and statistical analysis are essential tools in nursing research, as they support researchers testing phenomena, illustrate their findings clearly and accurately, and provide explanation or generalisation of the phenomenon being investigated. The most popular inferential statistics test is the one-way analysis of variance (ANOVA), as it is the test designated for comparing the means of a study's target groups to identify if they are statistically different to the others. However, the nursing literature has identified that statistical tests are not being used correctly and findings are being reported incorrectly.

AIM

To present and explain the one-way ANOVA.

DISCUSSION

The article presents the purpose of inferential statistics and explains one-way ANOVA. It uses relevant examples to examine the steps needed to successfully apply the one-way ANOVA. The authors also provide recommendations for other statistical tests and measurements in parallel to one-way ANOVA.

CONCLUSION

Nurses need to develop their understanding and knowledge of statistical methods, to engage in research and evidence-based practice.

IMPLICATIONS FOR PRACTICE

This article enhances the understanding and application of one-way ANOVAs by nursing students, novice researchers, nurses and those engaged in academic studies. Nurses, nursing students and nurse researchers need to familiarise themselves with statistical terminology and develop their understanding of statistical concepts, to support evidence-based, quality, safe care.