Challenges in the Design and Interpretation of Noninferiority Trials

Non-inferiority trials in clinical ophthalmology: a systematic review

PURPOSE

To summarize the characteristics and methodology of non-inferiority trials in ophthalmology, aiding researchers in understanding the applications and limitations of such trials in ophthalmic diseases.

METHODS

PubMed, Web of Science, Embase and Scopus were searched for literature on non-inferiority randomized trials in ophthalmology published between 2000 and November 5 2023. Data on the basic characteristics were extracted and summarized. The Risk of Bias 2's was used to assess the bias risk.

RESULTS

A total of 294 papers were included, with 77.6% of the trials conducted in the last 10 years, and more than 2/3 (72.1%) were multicenter studies, and 79.9% were registered on platforms. The majority of trials were applied in the researches of glaucoma, cataract, age macular degeneration, macular edema, dry eye, myopia, or refractive error. Non-inferiority thresholds were reported in 88.4% of the trials. Intent-to-treat analysis was the primary outcome analysis method in only 21.8% of trials, while both intent-to-treat and per-protocol analyses were used in 29.6%. Last observation carried forward method was used to address missing values in 23.5%. However, 56.5% of the articles did not report how missing values were handled, leaving uncertainty regarding whether missing data was considered in the analysis. About 20.7% of the studies were at high risk of bias, mainly due to outcome measures and missing value treatments.

CONCLUSION

Non-inferiority trials are commonly used in ophthalmologic research to assess the effectiveness, safety, cost-effectiveness of treatments or surgical methods, but the quality of implementation and reporting needs to be improved.

Clinical vs. statistical significance: considerations for clinical laboratories

Amongst the main perspectives when evaluating the results of medical studies are statistical significance (following formal statistical testing) and clinical significance. While statistical significance shows that a factor's observed effect on the study results is unlikely (for a given alpha) to be due to chance, effect size shows that the factor's effect is substantial enough to be clinically useful. The essence of statistical significance is "negative" - that the effect of a factor under study probably did not happen by chance. In contrast, effect size and clinical significance evaluate whether a clinically "positive" effect of a factor is effective and cost-effective. Medical diagnoses and treatments should never be based on the results of a single study. Results from numerous well-designed studies performed in different circumstances are needed, focusing on the magnitude of the effects observed and their relevance to the medical matters being studied rather than on the p-values. This paper discusses statistical inference and its relevance to clinical importance of quantitative testing in clinical laboratories. To achieve this, we first pose questions focusing on fundamental statistical concepts and their relationship to clinical significance. The paper also aims to provide examples of using the methodological approaches of superiority, equivalence, non-inferiority, and inferiority studies in clinical laboratories, which can be used in evidence-based decision-making processes for laboratory professionals.

Barrett's Oesophagus Surveillance Versus Endoscopy at Need Study (BOSS): A Randomized Controlled Trial

BACKGROUND & AIMS

Barrett's esophagus (BE) is a precursor lesion for esophageal adenocarcinoma (EAC). Surveillance endoscopy aims to detect early malignant progression; although widely practiced, it has not previously been tested in a randomized trial.

METHODS

BOSS (Barrett's Oesophagus Surveillance Versus Endoscopy at Need Study) was a randomized controlled trial at 109 centers in the United Kingdom. Patients with BE were randomized to 2-yearly surveillance endoscopy or "at-need" endoscopy, offered for symptoms only. Follow-up was a minimum of 10 years. The primary outcome was overall survival in the intention-to-treat population. Secondary outcomes included cancer-specific survival, time to diagnosis of EAC, stage of EAC at diagnosis, frequency of endoscopy, and serious adverse events related to interventions.

RESULTS

There were 3453 patients recruited; 1733 patients were randomized to surveillance and 1719 to at-need endoscopy. Median follow-up time was 12.8 years for the primary outcome. There was no evidence of a difference in overall survival between the surveillance arm (333 deaths among 1733 patients) and the at-need arm (356 deaths among 1719 patients; hazard ratio, 0.95; 95% CI, 0.82-1.10; stratified log-rank P = .503). There was no evidence of a difference for surveillance vs at-need endoscopy in cancer-specific survival (108 vs 106 deaths from any cancer; hazard ratio, 1.01; 95% CI, 0.77-1.33; P = .926), time to diagnosis of EAC (40 vs 31 patients had a diagnosis of EAC; hazard ratio, 1.32; 95% CI, 0.82-2.11; P = .254), or cancer stage at diagnosis. Eight surveillance patients (0.46%) and 7 at-need patients (0.41%) reported serious adverse events.

CONCLUSIONS

Surveillance did not improve overall survival or cancer-specific survival. At-need endoscopy may be a safe alternative for low-risk patients. (ClinicalTrials.gov, Number: NCT00987857.).

Noninferiority Study Design: Application to Clinical Trials

SUMMARY

The noninferiority trial, a distinct category within randomized controlled trials, is garnering increased attention in medical research. Its unique and evolving role comes to the forefront in scenarios where new treatments, despite not surpassing the efficacy of an existing standard, bring additional benefits such as reduced side effects, enhanced compliance, or cost savings. As the field of surgery witnesses a growing number of published noninferiority trials, it becomes imperative for surgeons to grasp the intricacies of this trial type to accurately decipher and interpret their outcomes.

Mechanical or biological prosthesis for aortic valve replacement in patients aged 45 to 74 years

OBJECTIVE

The selection of valve prostheses for patients undergoing surgical aortic valve replacement remains controversial. In this study, we compared the long-term outcomes of patients undergoing aortic valve replacement with biological or mechanical aortic valve prostheses.

METHODS

We evaluated late results among 5762 patients aged 45 to 74 years who underwent biological or mechanical aortic valve replacement with or without concomitant coronary artery bypass from 1989 to 2019 at 4 medical centers. The Cox proportional hazards model was used to compare late survival; the age-dependent effect of prosthesis type on long-term survival was evaluated by an interaction term between age and prosthesis type. Incidences of stroke, major bleeding, and reoperation on the aortic valve after the index procedure were compared between prosthesis groups.

RESULTS

Overall, 61% (n = 3508) of patients received a bioprosthesis. The 30-day mortality rate was 1.7% (n = 58) in the bioprosthesis group and 1.5% (n = 34) in the mechanical group (P = .75). During a mean follow-up of 9.0 years, the adjusted risk of mortality was higher in the bioprosthesis group (hazard ratio, 1.30, P < .001). The long-term survival benefit associated with mechanical prosthesis persisted until 70 years of age. Bioprosthesis (vs mechanical prosthesis) was associated with a similar risk of stroke (P = .20), lower risk of major bleeding (P < .001), and higher risk of reoperation (P < .001).

CONCLUSIONS

Compared with bioprostheses, mechanical aortic valves are associated with a lower adjusted risk of long-term mortality in patients aged 70 years or less. Patients aged less than 70 years undergoing surgical aortic valve replacement should be informed of the potential survival benefit of mechanical valve substitutes.

Early vs Delayed Bypass Surgery in Patients With Acute Coronary Syndrome Receiving Ticagrelor: The RAPID CABG Randomized Open-Label Noninferiority Trial

Importance

Perioperative bleeding is a major concern in patients receiving ticagrelor for acute coronary syndromes (ACS) when coronary artery bypass graft (CABG) surgery is required.

Objective

To evaluate whether early CABG surgery at 2 to 3 days after ticagrelor cessation is noninferior to waiting 5 to 7 days.

Design, Setting, and Participants

RAPID CABG was a noninferiority, open-label randomized trial with 6 months of follow-up. Participants were patients with ACS who had received ticagrelor and required CABG. Patients were enrolled in tertiary centers in Canada between January 2016 and March 2021. Data were analyzed from March 2021 to December 2023.

Intervention

Early or delayed CABG.

Main Outcomes and Measures

The primary outcome was based on noninferiority comparison of class 3 or 4 universal definition of perioperative bleeding (UDPB). Noninferiority was prespecified as 8% between groups. Twelve-hour chest tube drainage was reported as a noninferiority comparison. Other bleeding, ischemic, and length-of-stay outcomes were assessed for superiority.

Results

Among 143 randomized patients, the median (IQR) age was 65 (58-72) years; there were 117 male patients (82%) and 26 female (18%). Of these, 123 patients (86.0%) underwent surgery in the allocated time frame (per protocol). The median (IQR) time to surgery was 3 (2-3) days in the early group and 6 (5-7) days in the delayed group (P < .001). In a per-protocol analysis, severe or massive UDPB occurred in 3 of 65 early-group patients (4.6%) and 3 of 58 patients (5.2%) in the delayed group (between-group difference, -0.6%; 95% CI, -8.3% to 7.1%; P = .03 for noninferiority). Median (IQR) chest tube drainage was 470 (330-650) mL vs 495 (380-610) mL (between-group difference -25 mL; 95% CI, -111.25 to 35; P = .01 for noninferiority). Median (IQR) hospital stay was 9 (7-13) days and 12 (10-15) days for the early and delayed groups (P < .001).

Conclusion and Relevance

This study found that an early surgical strategy, 2 to 3 days after ticagrelor cessation, was noninferior in incurring perioperative bleeding. The data support a reduction in the delay between ticagrelor cessation and CABG surgery and may decrease hospital length of stay.

Trial Registration

ClinicalTrials.gov Identifier: NCT02668562.

Six-Week Problem Area-Concordant vs 8-Week Problem Area-Discordant Group Interpersonal Psychotherapy: A Randomized Clinical Trial

Importance

Depression is a prevalent mental health condition contributing to morbidity worldwide. The World Health Organization (WHO) recommends group-based interpersonal psychotherapy (IPT-G) for first-line depression treatment in resource-constrained settings. Standard of care in the study context is 8 to 12 weekly sessions in groups with a mix of depression problem areas (eg, grief, life changes, loneliness, conflict).

Objective

To investigate whether grouping participants with a common depression problem area (problem area-concordant) using shortened IPT-G (6 sessions) is noninferior to grouping participants with a mix of problem areas (problem area-discordant) using standard IPT-G (8 sessions) in Uganda.

Design, Setting, and Participants

This noninferiority randomized clinical trial included adults 18 years or older in central Uganda with 9-item Patient Health Questionnaire (PHQ-9) scores of 10 or greater, indicating symptoms consistent with probable depression. Assessors were masked to treatment arm. Data were accrued from October 31, 2022, to March 24, 2023.

Interventions

Participants were randomized 1:1 to 6-session problem area-concordant or 8-session problem area-discordant IPT-G.

Main Outcome and Measures

The primary outcome was PHQ-9 score reduction at 3 months. Secondary outcomes were treatment response (PHQ-9 5-point, 10-point, and 50% score reduction), reduction in disability (WHO Disability Assessment Schedule 2.0), and improvement in subjective quality of life (WHO Quality of Life tool).

Results

Among 328 enrolled participants (303 [92.4%] female; mean [SD] age, 42.3 [15.2] years), retention was high, with 321 [97.9%] undergoing assessment at the end of therapy and 292 [89.0%] at 3-month follow-up. From baseline to the end of therapy, PHQ-9 scores dropped a mean (SD) of 15.2 (5.1) points in the problem area-concordant arm and 13.3 (5.3) points in the problem area-discordant arm. Problem area-concordant 6-week IPT-G was noninferior (P < .001) at end of therapy and 3 months post therapy. Compared with the 8-week problem area-discordant arm, posttherapy PHQ-9 scores in the 6-week problem area-concordant arm were 1.86 (95% CI, 0.74-3.00) points lower (P = .001). At 3 months, PHQ-9 scores were 1.98 (95% CI, 0.60-3.36) points lower (P = .005). Disability score reduction was significantly larger post therapy in the 6-week arm compared with the 8-week arm (2.70 [95% CI, 0.95-4.44] points) but not significantly different between arms after 3 months. Quality of life scores across all domains were not significantly different between arms at end of therapy and 3 months post therapy.

Conclusions and Relevance

In this randomized clinical trial, 6-week problem area-concordant IPT-G was noninferior to 8-week problem area-discordant IPT-G for reducing depression symptoms, with similar to larger improvements in disability and quality of life. Problem area-concordant group therapy appears to be a promising approach to increase efficiency and scalability of depression treatment.

Trial Registration

Pan African Clinical Trials Registry Identifier: PACTR202306771120632.

Rectal diclofenac versus indomethacin for prevention of post-ERCP pancreatitis (DIPPP): a multicentre, double-blind, randomised, controlled trial

BACKGROUND

Recent meta-analyses suggested diclofenac may be superior to indomethacin in preventing post-endoscopic retrograde cholangiopancreatography (ERCP) pancreatitis (PEP). The aim of our study was to compare the efficacy of 100 mg rectal indomethacin versus diclofenac on PEP incidences.

DESIGN

This multicentre, double-blinded, randomised controlled trial was conducted in nine tertiary centres in China. Patients with low and high risk for PEP and native papilla were randomly allocated (1:1) to receive 100 mg diclofenac or 100 mg indomethacin rectally before ERCP. The primary outcome was the occurrence of PEP defined by the Cotton consensus. The intention-to-treat principle was conducted for the analysis.

RESULTS

The trial was terminated early for futility after the predetermined first interim analysis. Between June 2023 and May 2024, 1204 patients were randomised into the diclofenac group (n=600) or indomethacin group (n=604). Baseline characteristics were balanced. The primary outcome occurred in 53 patients (8.8%) of 600 patients allocated to the diclofenac group and 37 patients (6.1%) of 604 patients allocated to the indomethacin group (relative risk 1.44; 95% CI 0.96 to 2.16, p=0.074). PEP occurred in 35 (14.2%) of 247 high-risk patients in the diclofenac group and 26 (9.8%) of 266 high-risk patients in the indomethacin group (p=0.124). PEP incidences were also comparable in low-risk patients between the two groups (18/353 (5.1%) vs 11/338 (3.3%), p=0.227). Other ERCP-related complications did not differ between the two groups.

CONCLUSION

Pre-procedure 100 mg rectal diclofenac was not superior to the same dose of rectal indomethacin regarding preventing PEP. These findings supported current clinical practice guidelines of 100 mg indomethacin or diclofenac for PEP prophylaxis in patients without contraindications.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov (NCT05947461).

Oral fluid supplementation for the prevention of post-dural puncture headache: A noninferiority randomized controlled trial

AIM(S)

To investigate the impact of the absence of specific advice for oral fluid intake, compared to supplementation water intake on the occurrence of post-dural puncture headache.

DESIGN

A prospective, open-label, non-inferiority, multicenter trial including hospitalized patients requiring a diagnostic lumbar puncture in seven hospitals in France.

METHODS

Patients were randomly allocated (1:1) either to receive no specific advice on oral fluid intake (FREE-FLUID), or to be encouraged to drink 2 liters of water (CONTROL) within the 2 hours after lumbar puncture. The primary outcome was the post-dural puncture headache rate within the 5 days after lumbar puncture, with a non-inferiority margin of 10%. The secondary outcome was the time-to-post-dural puncture headache onset between Day 0 and Day 5.

RESULTS

From November 2016 and July 2019, we have included 554 participants. The primary outcomes occurs in 33.1% patients in the FREE-FLUID group, versus 38.0% in the CONTROL group with adjusted difference of 3.7%.

CONCLUSION

Among patients who had lumbar puncture, our study shows the noninferiority of the absence of specific advice on water intake after a lumbar puncture, compared with advice to increase oral fluid to prevent a post-dural puncture headache.

IMPACT

The value of questioning the appropriateness of non-evidence-based nursing care may allow time to be devoted to more relational and comforting care.

REPORTING METHOD

The study adheres to the CONSORT reporting guidelines.

PATIENT OR PUBLIC CONTRIBUTION

No patient or public contribution.

TRIAL REGISTRATION

Clinical Trials.gov (NCT02859233, August 9, 2016).

Innovation in the Design of Clinical Trials for Infectious Diseases: Focusing on Patients Over Pathogens

Much infectious disease research focuses on the interaction of microorganisms and drugs in the laboratory, assuming biological activity of inhibiting organism growth in vitro directly translates to improving patient outcomes in the clinic. Yet in vitro testing does not consider the important role of the human immune system in causing and response to disease. Research shows that patient outcomes are still suboptimal even with disease due to organisms that maintain in vitro susceptibility to currently available drugs. Resources and discussions have focused on "antimicrobial resistance" yet the majority of deaths are with susceptible organisms. Studies of new interventions do not address the questions that patients and clinicians in practice ask in order to improve patient outcomes regardless of causative pathogen in patients who would receive the drugs in the real-world setting. Research in infectious diseases should shift to refocus on improving patient outcomes. This would result in changes in the research questions evaluated, the types of patients enrolled, the comparisons made, the interventions studied, the outcomes evaluated, and the types of statistical evaluations used. In turn this would provide patients and clinicians with better evidence for patient care and justify payment for new interventions.

Dose optimisation to improve access to effective cancer medicines

Access to many cancer medicines on WHO's Essential Medicines List (EML) is restricted because of price, especially in low-income and middle-income countries (LMICs). Other cancer medicines that have been shown to improve survival, such as immune checkpoint inhibitors for lung cancer, are not included on the EML because approved doses and schedules exceed affordable prices in LMICs. Multiple strategies are therefore needed to reduce medicine costs or circumvent these problems, such as optimising doses and schedules. Cancer medicines are approved by regulatory agencies, such as the US Food and Drug Administration and the European Medicines Agency, following rigorous clinical trials. However, these approvals can involve dosing regimens and treatment schedules that, although effective in showing statistically significant benefits in trials, can be higher in intensity, frequency, or duration than is necessary to achieve meaningful improved survival. In clinical practice, these regimens can lead to concerns about balancing optimal therapeutic outcomes with the risk of side-effects, patient quality of life, and long-term health effects. Various types of evidence can, and should, be used to explore and show near-equivalence of beneficial outcomes from reduced-intensity treatments, including randomised clinical trials, dose-finding phase 1 and 2 studies, and pharmacokinetic and pharmacodynamic studies. The positive effects of proving that lower doses or less intensive schedules retain therapeutic activity include reduced toxicity and large price reductions, leading to better cost-effectiveness and greater access to treatments that improve survival. Beyond regulatory approvals, identification of regimens that have similar outcomes with reduced doses and less intense schedules should be a priority for clinicians and policy makers in the selection process to identify effective medicines at national and global levels.

Factors influencing the adoption of innovation in spine surgery: An international survey of AO spine network

INTRODUCTION

Knowledge translation from research to clinical practice can often be challenging, and practice modification patterns among surgeons may stem from a variety of sources, including personal experience, peer influence, ongoing education, and evolving research findings.

RESEARCH QUESTION

This study aimed to investigate the adoption patterns amongst surgeons for newer innovations and to analyse the factors affecting the implementation of the same in clinical practice. We used the adoption of osteobiologics as a case example.

METHODS

An international expert survey was conducted among AO Spine users and members. The survey, comprising 30 items, explored surgeons' demographics, risk aversion, and factors influencing practice change. We categorized the innovation-adoptive nature of the surgeons and scored their risk-adoptive behaviour.

RESULTS

A total of 458 responses were received from surgeons across 81 countries including 433 male (95%), orthopaedic surgeons (n = 263; 57%) from university-affiliated hospitals (n = 185; 40%). Most were in the early majority phase of the innovation-adoption cycle (n = 174; 38%) with a majority in the 'high-moderate' risk-adoption category (n = 396; 86%). This risk adoption behaviour had a significant correlation with their appetite for innovation (r = 0.182,p=<0.001). About 67.9% of respondents preferred scientific literature and conference presentations showcasing solid clinical evidence to be the most influential factor in driving change in their clinical practice. Material logistics (55%) is considered an important barrier to practice modification followed by familiarity (50%) and financial reimbursements (25%).

DISCUSSION & CONCLUSION

A complex interplay exists between risk-adoptive behaviour amongst surgeons and the factors influencing a change in their clinical practice. Although most surgeons were in the early adoptive phase in accepting the innovations into their clinical practice, they were also equally noted to be risk tolerant. Hence, a successful adoption of practice-changing innovation hinges on addressing not only logistical and financial challenges but also on providing robust scientific evidence to drive the necessary change in clinical practice.

The clinical journey of belantamab mafodotin in relapsed or refractory multiple myeloma: lessons in drug development

Patients with relapsed/refractory multiple myeloma (RRMM) have a poor prognosis and a need remains for novel effective therapies. Belantamab mafodotin, an anti-B-cell maturation antigen antibody-drug conjugate, was granted accelerated/conditional approval for patients with RRMM who have received at least 4 prior lines of therapy, based on response rates observed in DREAMM-1/DREAMM-2. Despite the 41% response rate and durable responses observed with belantamab mafodotin in the Phase III confirmatory DREAMM-3 trial, the marketing license for belantamab mafodotin was later withdrawn from US and European markets when the trial did not meet its primary endpoint of superiority for progression-free survival compared with pomalidomide and dexamethasone. This review reflects on key lessons arising from the clinical journey of belantamab mafodotin in RRMM. It considers how incorporating longer follow-up in DREAMM-3 may have better captured the clinical benefits of belantamab mafodotin, particularly given its multimodal, immune-related mechanism of action with responses deepening over time. A non-inferiority hypothesis may have been more appropriate rather than superiority in the context of a monotherapy versus an active doublet therapy. Further, anticipation of, and planning for, non-proportional hazards arising from response heterogeneity may have mitigated loss of statistical power. With the aim of improving the efficacy of belantamab mafodotin, other Phase III trials in the RRMM development program (DREAMM-7 and DREAMM-8) proceeded to evaluate the synergistic potential of combination regimens in earlier lines of treatment. The aim was to increase the proportion of patients responding to belantamab mafodotin (and thus the likelihood of seeing a clear separation of the progression-free survival curve versus comparator regimens). Protocol amendments reflecting DREAMM-3 learnings could also be implemented prospectively on the combinations trials to optimize the follow-up duration and mitigate risk. The wider implications of the lessons learned for clinical research in RRMM and in earlier treatment settings are discussed.

Challenges in designing a randomized, double-blind noninferiority trial for treatment of acne: The SD-ACNE trial

BACKGROUND/AIMS

Excessive use of antibiotics has led to development of antibiotic resistance and other antibiotic-associated complications. Dermatologists prescribe more antibiotics per clinician than any other major specialty, with much of this use for acne. Alternative acne treatments are available but are used much less often than antibiotics, at least partially because dermatologists feel that they are less effective. Spironolactone, a hormonal therapy with antiandrogen effects that can address the hormonal pathogenesis of acne, may represent a therapeutic alternative to oral antibiotics for women with acne. However, the comparative effects of spironolactone and oral antibiotics in the treatment of acne have not been definitively studied. The Spironolactone versus Doxycycline for Acne: A Comparative Effectiveness, Noninferiority Evaluation (SD-ACNE) trial aims to answer whether spironolactone, in addition to standard topical therapy, is noninferior to doxycycline (an oral antibiotic) for women with acne. Several interesting challenges arose in the development of this study, including determining acceptability of the comparative regimens to participating dermatologists, identifying data to support a noninferiority margin, and establishing a process for unblinding participants after they completed the study while maintaining the blind for study investigators.

METHODS

We present the scientific and clinical rationale for the decisions made in the design of the trial, including input from key stakeholders through a Delphi consensus process.

RESULTS

The Spironolactone versus Doxycycline for Acne: A Comparative Effectiveness, Noninferiority Evaluation trial (NCT04582383) is being conducted at a range of community and academic sites in the United States. To maximize external validity and inform clinical practice, the study is designed with broad eligibility criteria and no prohibition of use of topical medications. Participants in the trial will be randomized to receive either spironolactone 100 mg/day or doxycycline hyclate 100 mg/day for 16 weeks. The primary outcome is the absolute decrease in inflammatory lesion count, and we have established a noninferiority margin of four inflammatory lesions. Secondary outcomes include the percentage of participants achieving Investigator Global Assessment success, change in quality of life, and microbiome changes and diversity.

CONCLUSIONS

The Spironolactone versus Doxycycline for Acne: A Comparative Effectiveness, Noninferiority Evaluation trial will have substantial implications for the treatment of acne and antibiotic stewardship. In addition, this study will provide important information on the effect of these systemic agents on the development of changes to the microbiome and antibiotic resistance in a healthy population of patients.

Understanding Noninferiority Trials: What Stroke Specialists Should Know

Noninferiority trials aim to prove that the efficacy, defined in terms of a key clinical outcome, of a new treatment is not meaningfully worse than that of an established active control. Noninferiority trials are important when other aspects of care can be improved, such as convenience, toxicity, costs, and safety (nonefficacy benefits). While the motivation for a noninferiority trial is straightforward, the design, execution, and interpretation of these trials is not a trivial task. Several safeguards that protect superiority trials from incorrect conclusions do not apply or even work in reverse for noninferiority trials. This review aims to provide stroke clinicians and researchers with a general overview of noninferiority trials and a deeper understanding of 10 pitfalls they should consider when designing and interpreting such trials.

Effectiveness of sequential bilateral repetitive transcranial stimulation versus bilateral theta burst stimulation for patients with treatment-resistant depression (BEAT-D): A randomized non-inferiority clinical trial

BACKGROUND

Bilateral repetitive transcranial magnetic stimulation (BL-rTMS) over the dorsolateral prefrontal cortex is effective for treatment-resistant depression (TRD). Owing to a shorter treatment time, bilateral theta burst stimulation (BL-TBS) can be more efficient protocol. The non-inferiority of BL-TBS to BL-rTMS was established in late-life TRD; however, this has not been determined in adults of other age groups. Therefore, we investigated the non-inferiority in efficacy of BL-TBS versus BL-rTMS for TRD across a wide range of ages in a randomized, single-blind, multicenter trial.

METHODS

The study included 180 participants with major depressive disorder (moderate or greater severity) who were unresponsive to at least one antidepressant treatment between September 2018 and July 2022. Following venlafaxine treatment, patients were randomly assigned to BL-rTMS or BL-TBS (1:1 ratio). The primary outcome was baseline-adjusted Montgomery-Åsberg Depression Rating Scale scores at 6 weeks. The non-inferiority margin of -3.86 was compared against the baseline-adjusted difference. Secondary outcomes included other depression rating scales.

RESULTS

Seventy-seven patients were randomly assigned to BL-rTMS and 81 to BL-TBS, of whom 73 and 76 were assessed for the primary outcome, respectively. There was a -2.44 point difference, favoring BL-rTMS (one-tailed lower 95 % CI = -4.19, p = 0.091 for non-inferiority), and non-inferiority of BL-TBS was not established. However, non-inferiority was observed for secondary outcomes. The all-cause dropout rates and number of adverse effects were similar between them.

CONCLUSION

Our study could not establish the non-inferiority of BL-TBS compared to BL-rTMS in terms of efficacy for patients with TRD across the adult lifespan.

Some superiority trials with nonsignificant results published in high impact factor journals correspond to noninferiority situations: a research-on-research study

OBJECTIVES

Many negative randomized controlled trials (RCTs) report spin in their conclusions to highlight the benefits of the experimental arm, which could correspond to a noninferiority (NI) objective. We aimed to evaluate whether some negative superiority RCTs comparing 2 active interventions could correspond to an NI situation and to explore associated trial characteristics.

STUDY DESIGN AND SETTING

We searched PubMed for superiority RCTs comparing 2 active interventions with non-statistically significant results for the primary outcome that were published in 2021 in the 5 journals with the highest impact factor in each medical specialty. Three reviewers independently evaluated whether trials could correspond to an NI situation (ie, an evaluation of efficacy as the primary outcome, with the experimental intervention presenting advantages including better safety profile, ease of administration, or decreased cost as compared with the control intervention).

RESULTS

Of the 147 trials included, 19 (12.9%, 95% CI [7.9%, 19.4%]) corresponded to a potential NI situation. As compared with trials not in a potential NI situation, they were published in a journal with a lower impact factor (median impact factor 8.7 vs 15.6), were more frequently rated at high or some concerns regarding risk of bias (n = 14, 73.7% vs n = 69, 53.9%) and reported spin in the article conclusions (n = 11, 57.9% vs n = 24, 18.8%).

CONCLUSION

A non-negligible proportion of superiority negative trials comparing 2 active interventions could correspond to an NI situation. These trials seemed at increased risk of bias and frequently reported spin in the conclusions, which may distort the interpretation of results.

PLAIN LANGUAGE SUMMARY

Noninferiority trials are designed to show that a new intervention is not worse in terms of efficacy than the reference intervention. It is adapted when the new intervention has an advantage in terms of safety, ease of use or cost over the reference one. However, the literature displayed some superiority negative trials comparing 2 active interventions that could correspond to a potential noninferiority situation. Our study aimed to assess whether some superiority trials with nonsignificant results for the primary outcome could correspond to an NI situation and to explore associated trial characteristics. Our findings indicate that a non-negligible proportion of superiority negative trials could correspond to a noninferiority situation. Moreover, those trials seemed at increased risk of bias and frequently reported spin in the conclusions.

Perception and acquaintance of stroke specialists on non-inferiority trials: An international survey

INTRODUCTION

The adoption of non-inferiority trial designs for assessing new interventions in stroke treatment is on the rise. We designed a survey to assess stroke specialists' understanding and familiarity with non-inferiority trials and margins.

METHODS

A brief web-based questionnaire was sent to the members of the World Stroke Organization (WSO). The median acceptable non-inferiority margins in different research settings provided by responders were summarized and reported according to the acquaintance of responders with non-inferiority trials.

RESULTS

A total of 120 WSO members from 42 countries responded to the survey. Thirty-two percent (32 %) of respondents self-identified as being very familiar with non-inferiority trials, while 6 % identified as extremely familiar. When asked about the impact of non-inferiority trials on improving stroke patient care, 42 % rated it as high and 45 % as moderate. 83 % of responders reported that the findings of non-inferiority trials affect their clinical practice. Ease of administration, relative effect of the standard treatment, clinical implications of inappropriately introducing the new treatment, availability, price, ease of storage and shipping were all considered as factors that should influence the size of the non-inferiority margin. The magnitude and variability of acceptable non-inferiority margins were seen to decrease as the acquaintance of responders with non-inferiority trials increased.

CONCLUSION

Although responders acknowledge the importance of non-inferiority trials, most have limited acquaintance with this research design. Educational activities are needed to enhance literacy in non-inferiority trials and the interpretation of non-inferiority margins.

A review of UK publicly funded non-inferiority trials: is the design more inferior than it should be?

BACKGROUND

The number of non-inferiority (NI) trials, those aiming to show a new treatment is no worse than a comparator, is increasing. However, their added complexity over superiority trials can create confusion. Most guidance and reviews to date have an industry focus with research suggesting these trials may differ from publicly funded NI trials. The aim of this work is to review the design and reporting characteristics of UK publicly funded NI trials. This assessment will show how well recommendations from industry are translating to publicly funded trials.

METHODS

The International Standard Randomised Controlled Trial Number web registry and the National Institute for Health and Care Research's Funding and Awards Library and Journals Library were searched using the term non-inferiority and logical synonyms. Inclusion requirements were a UK publicly funded NI randomised controlled trial. Characteristics of the design, analyses and results as available were recorded on a dedicated data extraction spreadsheet. Appropriate summary statistics were used to present the results.

RESULTS

Searches completed on the 14th of January 2022 identified 477 potential trials which after exclusions resulted in a database of 114 NI trials to be summarised. Non-inferiority margins were defined for most trials with a median of 8% (IQR: 3-10%) used for risk differences (n = 58) and 0.35 (IQR: 0.26-0.43) standardised mean difference for continuous outcomes (n = 30). Justifications for the margin chosen (n = 62) were more commonly based on the clinical importance (49/62) and less commonly using statistical considerations (13/62). The most prevalent primary analysis population was solely on an intention-to-treat basis (49/114). The superiority of the treatment was well described but not always included as an outcome and only powered for in about a third of cases.

CONCLUSIONS

Aspects of NI trial design are well described but not always in line with current recommendations. Of particular note, is the absence of statistical considerations when setting the non-inferiority margin, which eliminates the ability to confirm indirect superiority over placebo for the new treatment. Additionally, despite suggestions that it can increase the type 1 error in NI trials, the use of the intention-to-treat alone is the most common analysis population.

TRIAL REGISTRATION

Research on Research ID: 3171 (registration date: 31st May 2023).

Cold and vibration for children undergoing needle-related procedures: A non-inferiority randomized clinical trial

The use of a rapid, easy-to-use intervention could improve needle-related procedural pain management practices in the context of the Emergency Department (ED). As such, the Buzzy device seems to be a promising alternative to topical anesthetics. The aim of this study was to determine if a cold vibrating device was non-inferior to a topical anesthetic cream for pain management in children undergoing needle-related procedures in the ED. In this randomized controlled non-inferiority trial, we enrolled children between 4 and 17 years presenting to the ED and requiring a needle-related procedure. Participants were randomly assigned to either the cold vibrating device or topical anesthetic (4% liposomal lidocaine; standard of care). The primary outcome was the mean difference (MD) in adjusted procedural pain intensity on the 0-10 Color Analogue Scale (CAS), using a non-inferiority margin of 0.70. A total of 352 participants were randomized (cold vibration device n = 176, topical anesthetic cream n = 176). Adjusted procedural pain scores' MD between groups was 0.56 (95% CI:-0.08-1.20) on the CAS, showing that the cold vibrating device was not considered non-inferior to topical anesthetic. The cold vibrating device was not considered non-inferior to the topical anesthetic cream for pain management in children during a needle-related procedure in the ED. As topical anesthetic creams require an application time of 30 min, cost approximately CAD $40.00 per tube, are underused in the ED setting, the cold vibrating device remains a promising alternative as it is a rapid, easy-to-use, and reusable device.

Effect of a Reduced PCV10 Dose Schedule on Pneumococcal Carriage in Vietnam

BACKGROUND

After pneumococcal disease and colonization have been controlled through vaccination campaigns, a reduced pneumococcal conjugate vaccine (PCV) schedule may be sufficient to sustain that control at reduced costs.

METHODS

We investigated whether a single primary dose and booster dose (1p+1) of the 10-valent PCV (PCV10) would be noninferior to alternative dose schedules in sustaining control of carriage of pneumococcal serotypes included in the vaccine. In Nha Trang, Vietnam, an area in which PCV had not been used previously, a PCV10 catch-up campaign was conducted in which the vaccine was offered to children younger than 3 years of age, after which a cluster-randomized trial was conducted in which children received PCV10 at 2, 3, and 4 months of age (3p+0 group); at 2, 4, and 12 months of age (2p+1 group); at 2 and 12 months of age (1p+1 group); or at 12 months of age (0p+1 group). Annual carriage surveys in infants (4 to 11 months of age) and toddlers (14 to 24 months of age) were conducted from 2016 through 2020. The primary end point was protection against carriage of vaccine serotypes, evaluated in a noninferiority analysis in the 1p+1 group as compared with the 2p+1 and 3p+0 groups, 3.5 years after vaccine introduction (noninferiority margin, 5 percentage points). Noninferiority of the 0p+1 schedule was also evaluated.

RESULTS

In 2016, before the introduction of PCV10, vaccine-serotype carriage was found in 160 of 1363 infants (11.7%); in 2020, vaccine-serotype carriage was found in 6 of 333 (1.8%), 5 of 340 (1.5%), and 4 of 313 (1.3%) infants in the 1p+1, 2p+1, and 3p+0 groups, respectively, indicating noninferiority of 1p+1 to 2p+1 (difference, 0.3 percentage points; 95% confidence interval [CI], -1.6 to 2.2) and to 3p+0 (difference, 0.5 percentage points; 95% CI, -1.4 to 2.4). Similarly, 1p+1 was noninferior to 2p+1 and 3p+0 for protection against vaccine-serotype carriage among toddlers. In 2016, carriage of serotype 6A was found in 99 of 1363 infants (7.3%); in 2020, it was found in 12 of 333 (3.6%), 10 of 340 (2.9%), and 3 of 313 (1.0%) infants in the 1p+1, 2p+1, and 3p+0 groups, respectively. The 0p+1 schedule was also noninferior to the other three dose schedules among infants and toddlers, although cross-protection against serotype 6A was less common than with the other vaccination schedules. No PCV10-associated severe adverse effects were observed.

CONCLUSIONS

A reduced vaccination schedule involving a single primary dose and booster dose of PCV10 was noninferior to alternative schedules in protecting against vaccine-serotype carriage in infants and toddlers. (Funded by the Bill and Melinda Gates Foundation and others; ClinicalTrials.gov number, NCT02961231.).

Changing Landscape of Randomized Clinical Trials in Stroke: Explaining Contemporary Trial Designs and Methods

Evidence generated from randomized clinical trials (RCTs) plays an indispensable role in advancing clinical stroke care. Although the number of stroke-related RCTs published every year has grown exponentially over the past 25 years, the execution and completion of RCTs, particularly those conducted in a hyperacute setting, have grown more complicated and challenging over the years. In addition to the practical challenges associated with conducting a clinical trial, like obtaining human subjects approval, identifying clinical sites, training trial personnel, and enrolling the target number of patients within the available funding and timeline, the complexity of contemporary RCT designs and analyses has become much more exacting. It is no longer sufficient to have a decent understanding of the 2-arm, placebo-controlled RCT, combined with a rudimentary grasp of the P value; things are now much more complicated. Innovations in trial design and analysis, including adaptive, Bayesian, platform, and noninferiority designs, have occurred to address the problems of poor trial efficiency. However, these advances require the end user to have a much greater level of understanding regarding the rationale, conduct, analysis, and interpretation of each design. While these newer designs seek greater efficiency, there are inevitably tradeoffs that need to be understood. In this month's edition of Stroke, we introduce a new series designed to help fill in these knowledge gaps. Over the next few months, 4 papers will be published that address major design innovations (adaptive, Bayesian, platform, and noninferiority) with the aim of illustrating how these approaches can make trials more efficient (where efficiency is defined as getting to the right answer, sooner, with a potentially lower sample size). In addition to introducing this series, this current article also reviews traditional hypothesis testing and the common misinterpretations of the P value; fortunately, new philosophical schools of inference are beginning to vanquish the overreliance on the P value. We are excited about the opportunity to educate the Stroke readership about these new trial designs and the profound implications that they bring.

Femoral prosthesis alignment of augmented reality-assisted versus accelerometer-based navigation in total knee arthroplasty: A noninferiority analysis

INTRODUCTION

The purpose of this study was to examine the comparative precision of the augmented reality (AR)-assisted navigation system and the accelerometer-based navigation system in total knee arthroplasty (TKA).

MATERIALS AND METHODS

We performed noninferiority analysis in a retrospective cohort. The coronal alignment of femoral prosthesis was compared between 109 TKAs performed using the AR-assisted navigation system and 118 TKAs performed using the accelerometer-based navigation system. All femoral prostheses were planned to be positioned perpendicular to the mechanical axis of the femur. The primary outcome was the success rate of coronal alignment of the femoral prosthesis defined as alignment error relative to neutral alignment <3°. We calculated the noninferiority margin as 7%-points using the 95%-95 % method and also confirmed the validity of the noninferiority margin using the fixed margin method. Noninferiority would be shown if the lower boundary of the 95 % confidence interval (CI) for the between-group difference in percentage of the success rate was not less than 0.93 (i.e., 1.00 - 0.07).

RESULTS

Treatment success was achieved in 104 of 109 patients (95.4 %) in the AR-assisted navigation group and 110 of 118 (93.2 %) in the accelerometer-based navigation group. The risk ratio of success between the AR-assisted navigation group versus accelerometer-based navigation group was 1.02 (95 % CI, 0.96 to 1.09): the CIs did not include the noninferiority margin of 0.93.

CONCLUSION

The AR-assisted navigation system was noninferior to the accelerometer-based navigation system in terms of coronal alignment of the femoral prosthesis in TKA.

Pulmonary hypertension associated with left heart disease

Left heart disease (LHD) is the most common cause of pulmonary hypertension (PH), which may be classified further as isolated post-capillary (ipcPH) or combined post- and pre-capillary PH (cpcPH). The 7th World Symposium on Pulmonary Hypertension PH-LHD task force reviewed newly reported randomised clinical trials and contemplated novel opportunities for improving outcome. Results from major randomised clinical trials reinforced prior recommendations against the use of pulmonary arterial hypertension therapy in PH-LHD outside of clinical trials, and suggested possible harm. Greater focus on phenotyping was viewed as one general strategy by which to ultimately improve clinical outcomes. This is potentially achievable by individualising ipcPH versus cpcPH diagnosis for patients with pulmonary arterial wedge pressure within a diagnostic grey zone (12-18 mmHg), and through a newly developed PH-LHD staging system. In this model, PH accompanies LHD across four stages (A=at risk, B=structural heart disease, C=symptomatic heart disease, D=advanced), with each stage characterised by progression in clinical characteristics, haemodynamics and potential therapeutic strategies. Along these lines, the task force proposed disaggregating PH-LHD to emphasise specific subtypes for which PH prevalence, pathophysiology and treatment are unique. This includes re-interpreting mitral and aortic valve stenosis through a contemporary lens, and focusing on PH within the hypertrophic cardiomyopathy and amyloid cardiomyopathy clinical spectra. Furthermore, appreciating LHD in the profile of PH patients with chronic lung disease and chronic thromboembolic pulmonary disease is essential. However, engaging LHD patients in clinical research more broadly is likely to require novel methodologies such as pragmatic trials and may benefit from next-generation analytics to interpret results.

Systemic lidocaine versus erector spinae plane block for improving quality of recovery after laparoscopic cholecystectomy: A randomized controlled trial

STUDY OBJECTIVE

To compare intravenous lidocaine, ultrasound-guided erector spinae plane block (ESPB), and placebo on the quality of recovery and analgesia after laparoscopic cholecystectomy.

DESIGN

A prospective, triple-arm, double-blind, randomized, placebo-controlled non-inferiority trial.

SETTING

A single tertiary academic medical center.

PATIENTS

126 adults aged 18-65 years undergoing elective laparoscopic cholecystectomy.

INTERVENTIONS

Patients were randomly allocated to one of three groups: intravenous lidocaine infusion (1.5 mg/kg bolus followed by 2 mg/kg/h) plus bilateral ESPB with saline (25 mL per side); bilateral ESPB with 0.25% ropivacaine (25 ml per side) plus placebo infusion; or bilateral ESPB with saline (25 ml per side) plus placebo infusion.

MEASUREMENTS

The primary outcome was the 24-h postoperative Quality of Recovery-15 (QoR-15) score. The non-inferiority of lidocaine versus ESPB was assessed with a margin of -6 points and 97.5% confidence interval (CI). Secondary outcomes included 24-h area under the curve (AUC) for pain scores, morphine consumption, and adverse events.

MAIN RESULTS

124 patients completed the study. Median (IQR) 24-h QoR-15 scores were 123 (117-127) for lidocaine, 124 (119-126) for ESPB, and 112 (108-117) for placebo. Lidocaine was non-inferior to ESPB (median difference  -1, 97.5% CI: -4 to ∞). Both lidocaine (median difference 9, 95% CI: 6-12, P < 0.001) and ESPB (median difference 10, 95% CI: 7-13, P < 0.001) were superior to placebo. AUC for pain scores and morphine use were lower with lidocaine and ESPB versus placebo (P < 0.001 for all), with no significant differences between lidocaine and ESPB. One ESPB patient reported a transient metallic taste; no other block-related complications occurred.

CONCLUSIONS

For patients undergoing laparoscopic cholecystectomy, intravenous lidocaine provides a non-inferior quality of recovery compared to ESPB without requiring specialized regional anesthesia procedures. Lidocaine may offer a practical and accessible alternative within multimodal analgesia pathways.

Optimal Duration of High-Fidelity Simulator Training for Bronchoscope-Guided Intubation: A Noninferiority Randomized Trial

INTRODUCTION

The optimal simulator training duration for flexible optical bronchoscopic (FOB) intubation is unknown. This study aimed to determine whether a learning curve-based training modality was noninferior to a fixed training time modality in terms of clinical FOB intubation time.

METHODS

This multicenter, randomized, noninferiority study was conducted from May to August 2022. Anesthesiology residents or interns were enrolled. Eligible participants were randomized in a 1:1 ratio to receive new learning curve-based simulator training (individualized training time based on performance, group New) or reference fixed training time simulator training (1 hour, group Reference). The primary outcome was the time to complete FOB intubation in patients, which was defined as the time from the introduction of the FOB into the mouth until the first capnography visualization. The margin for detecting clinical significance was defined as 10 seconds.

RESULTS

A total of 32 participants were included in the analysis (16 in each group). All trainees successfully intubated the patients. The mean intubation time (95% confidence interval [CI]) was 81.9 (65.7-98.1) seconds in group New and 97.0 (77.4-116.6) seconds in group Reference. The upper bound of the 1-sided 97.5% CI for the mean difference of clinical intubation time between groups was 9.3 seconds. Noninferiority was claimed. The mean duration of the training in group New was 28.4 (95% CI, 23.5-33.4) minutes. The total number of training procedures on simulators in group New was significantly less than that in group Reference ( P < 0.01).

CONCLUSIONS

The clinical FOB intubation time in group New was noninferior to that in group Reference.

The tyranny of non-inferiority trials

Opportunities to decrease the toxicity and cost of approved treatment regimens with lower dose, less frequent, or shorter duration alternative regimens have been limited by the perception that alternatives must be non-inferior to approved regimens. Non-inferiority trials are large and expensive to do, because they must show statistically that the alternative and approved therapies differ in a single outcome, by a margin far smaller than that required to demonstrate superiority. Non-inferiority's flaws are manifest: it ignores variability expected to occur with repeated evaluation of the approved therapy, fails to recognise that a trial of similar design will be labelled as superiority or non-inferiority depending on whether it is done prior to or after initial registration of the approved treatment, and relegates endpoints such as toxicity and cost. For example, while a less toxic and less costly regimen of 3 months duration would typically be required to demonstrate efficacy that is non-inferior to that of a standard regimen of 6 months to displace it, the longer duration therapy has no such obligation to prove its superiority. This situation is the tyranny of the non-inferiority trial: its statistics perpetuate less cost-effective regimens, which are not patient-centred, even when less intensive therapies confer survival benefits nearly identical to those of the standard, by placing a disproportionately large burden of proof on the alternative. This approach is illogical. We propose that the designation of trials as superiority or non-inferiority be abandoned, and that randomised, controlled trials should henceforth be described simply as "comparative".

A multicenter randomized trial to compare automatic versus as-needed follow-up for children hospitalized with common infections: The FAAN-C trial protocol

INTRODUCTION

Physicians commonly recommend automatic primary care follow-up visits to children being discharged from the hospital. While automatic follow-up provides an opportunity to address postdischarge needs, the alternative is as-needed follow-up. With this strategy, families monitor their child's symptoms and decide if they need a follow-up visit in the days after discharge. In addition to being family centered, as-needed follow-up has the potential to reduce time and financial burdens on both families and the healthcare system. As-needed follow-up has been shown to be safe and effective for children hospitalized with bronchiolitis, but the extent to which hospitalized children with other common conditions might benefit from as-needed follow-up is unclear.

METHODS

The Follow-up Automatically versus As-Needed Comparison (FAAN-C, or "fancy") trial is a multicenter randomized controlled trial. Children who are hospitalized for pneumonia, urinary tract infection, skin and soft tissue infection, or acute gastroenteritis are eligible to participate. Participants are randomized to an as-needed versus automatic posthospitalization follow-up recommendation. The sample size estimate is 2674 participants and the primary outcome is all-cause hospital readmission within 14 days of discharge. Secondary outcomes are medical interventions and child health-related quality of life. Analyses will be conducted in an intention-to-treat manner, testing noninferiority of as-needed follow-up compared with automatic follow-up.

DISCUSSION

FAAN-C will elucidate the relative benefits of an as-needed versus automatic follow-up recommendation, informing one of the most common decisions faced by families of hospitalized children and their medical providers. Findings from FAAN-C will also have implications for national quality metrics and guidelines.

Unilateral biportal endoscopic versus microscopic transforaminal lumbar interbody fusion for degenerative lumbar spinal stenosis in China: study protocol for a prospective, randomised, controlled, non-inferiority trial

INTRODUCTION

Degenerative lumbar spinal stenosis is a common cause of low back or leg pain and disability in the elderly population. Patients with spinal stenosis who fail to respond to conservative treatment often require surgical interventions. Minimally invasive transforaminal lumbar interbody fusion (TLIF) with microscopic tubular technique (MT-TLIF) is a well-established procedure for lumbar spinal stenosis. Recently, a novel MIS technique, unilateral biportal endoscopic TLIF (UBE-TLIF), has been frequently performed to treat spinal stenosis. However, the efficacy and safety of using UBE-TLIF in this population have not been well examined.

METHODS AND ANALYSIS

A total of 96 patients with lumbar spinal stenosis will be randomly assigned to the UBE-TLIF group or the MT-TLIF group at a 1:1 ratio to receive UBE-TLIF or MT-TLIF treatment respectively. The primary outcome is the Oswestry Disability Index (ODI) score at 1 year after receiving the surgery. Secondary outcomes include the ODI scores at additional time points, Visual Analogue Scale score, 36-Item Short Form Survey questionnaire, EuroQol 5 Dimensions questionnaire, radiological measurements (disc height, lumbar lordosis angles and vertebral fusion rate) and general condition during hospitalisation.

ETHICS AND DISSEMINATION

This protocol is approved by the Medical Ethics Committee of the Third Affiliated Hospital of Sun Yat-sen University. All participants of the study will be well informed and written informed consent will be requested. Findings from this trial will be published in peer-reviewed publications, specifically in orthopedic and spinal journals. The completion of this study will not only examine the use of UBE-TLIF in lumbar spinal stenosis but also provide helpful clinical references.

TRIAL REGISTRATION NUMBER

ChiCTR2300069333.

Optimal sample size allocation for two-arm superiority and non-inferiority trials with binary endpoints

The sample size of a clinical trial has to be large enough to ensure sufficient power for achieving the aim the study. On the other side, for ethical and economical reasons it should not be larger than necessary. The sample size allocation is one of the parameters that influences the required total sample size. For two-arm superiority and non-inferiority trials with binary endpoints, we performed extensive computations over a wide range of scenarios to determine the optimal allocation ratio that minimizes the total sample size if all other parameters are fixed. The results demonstrate, that for both superiority and non-inferiority trials the optimal allocation may deviate considerably from the case of equal sample size in both groups. However, the saving in sample size when allocating the total sample size optimally as compared to balanced allocation is typically small.

Pragmatic Trial Design to Compare Real-world Effectiveness of Different Treatments for Inflammatory Bowel Diseases: The PRACTICE-IBD European Consensus

BACKGROUND AND AIMS

Pragmatic studies designed to test interventions in everyday clinical settings can successfully complement the evidence from registration and explanatory clinical trials. The European consensus project PRACTICE-IBD was developed to identify essential criteria and address key methodological issues needed to design valid, comparative, pragmatic studies in inflammatory bowel diseases [BDs].

METHODS

Statements were issued by a panel of 11 European experts in IBD management and trial methodology, on four main topics: [I] study design; [II] eligibility, recruitment and organisation, flexibility; [III] outcomes; [IV] analysis. The consensus process followed a modified Delphi approach, involving two rounds of assessment and rating of the level of agreement [1 to 9; cut-off ≥7 for approval] with the statements by 18 additional European experts in IBD.

RESULTS

At the first voting round, 25 out of the 26 statements reached a mean score ≥7. Following the discussion that preceded the second round of voting, it was decided to eliminate two statements and to split one into two. At the second voting round, 25 final statements were approved: seven for study design; six for eligibility, recruitment and organisation, flexibility; eight for outcomes; and four for analysis.

CONCLUSIONS

Pragmatic, randomised, clinical trials can address important questions in IBD clinical practice, and may provide complementary, high-level evidence, as long as they follow a methodologically rigorous approach. These 25 statements intend to offer practical guidance in the design of high-quality, pragmatic, clinical trials that can aid decision making in choosing a management strategy for IBDs.

Key insights and challeneges in noninferiority trials

Noninferiority clinical trials are crucial for evaluating the effectiveness of new interventions compared to standard interventions. By establishing statistical and clinical comparability, these trials can be conducted to demonstrate that a new intervention is not significantly inferior to the standard intervention. However, selecting appropriate noninferiority margins and study designs are essential to ensuring valid and reliable results. Moreover, employing the Consolidated Standards of Reporting Trials (CONSORT) statement for reporting noninferiority clinical trials enhances the quality and transparency of research findings. This article addresses key considerations and challenges faced by investigators in planning, conducting, and interpreting the results of noninferiority clinical trials.

Clinical and cost-effectiveness of remote-delivered, online lifestyle therapy versus psychotherapy for reducing depression: results from the CALM non-inferiority, randomised trial

Background

We conducted the first non-inferiority, randomised controlled trial to determine whether lifestyle therapy is non-inferior to psychotherapy with respect to mental health outcomes and costs when delivered via online videoconferencing.

Methods

An individually randomised, group treatment design with computer-generated block randomisation was used. Between May 2021-April 2022, 182 adults with a Distress Questionnaire-5 score = ≥8 (indicative depression) were recruited from a tertiary mental health service in regional Victoria, Australia and surrounds. Participants were assigned to six 90-min sessions over 8-weeks using group-based, online videoconferencing comprising: (1) lifestyle therapy (targeting nutrition, physical activity) with a dietitian and exercise physiologist (n = 91) or (2) psychotherapy (Cognitive Behavioural Therapy) with psychologists (n = 91). The primary outcome was Patient Health Questionnaire-9 (PHQ-9) depression at 8-weeks (non-inferiority margin ≤2) using Generalised Estimating Equations (GEE). Cost-minimisation analysis estimated the mean difference in total costs from health sector and societal perspectives. Outcomes were assessed by blinded research assistants using Computer Assisted Telephone Interviews. Results are presented per-protocol (PP) and Intention to Treat (ITT) using beta coefficients with 95% Confidence Intervals (CIs).

Findings

The sample was 80% women (mean: 45-years [SD:13.4], mean PHQ-9:10.5 [SD:5.7]. An average 4.2 of 6 sessions were completed, with complete data for n = 132. Over 8-weeks, depression reduced in both arms (PP: Lifestyle (n = 70) mean difference:-3.97, 95% CIs:-5.10, -2.84; and Psychotherapy (n = 62): mean difference:-3.74, 95% CIs:-5.12, -2.37; ITT: Lifestyle (n = 91) mean difference:-4.42, 95% CIs: -4.59, -4.25; Psychotherapy (n = 91) mean difference:-3.82, 95% CIs:-4.05, -3.69) with evidence of non-inferiority (PP GEE β:-0.59; 95% CIs:-1.87, 0.70, n = 132; ITT GEE β:-0.49, 95% CIs:-1.73, 0.75, n = 182). Three serious adverse events were recorded. While lifestyle therapy was delivered at lower cost, there were no differences in total costs (health sector adjusted mean difference: PP AUD$156 [95% CIs -$182, $611, ITT AUD$190 [95% CIs -$155, $651] ]; societal adjusted mean difference: PP AUD$350 [95% CIs:-$222, $1152] ITT AUD$ 408 [95% CIs -$139, $1157].

Interpretation

Remote-delivered lifestyle therapy was non-inferior to psychotherapy with respect to clinical and cost outcomes. If replicated in a fully powered RCT, this approach could increase access to allied health professionals who, with adequate training and guidelines, can deliver mental healthcare at comparable cost to psychologists.

Funding

This trial was funded by the Australian Medical Research Future Fund (GA133346) under its Covid-19 Mental Health Research Grant Scheme.

Assessment of Noninferiority Margins in Cardiovascular Medicine Trials

Background

Noninferiority trials are increasingly common in cardiovascular medicine, but their reporting and interpretation are challenging, particularly when an absolute risk difference is used as noninferiority margin.

Objectives

This study aimed to investigate the effect of using absolute rather than relative noninferiority margins in cardiovascular trials.

Methods

We reviewed noninferiority trials presented at major cardiovascular conferences from 2015 to 2022 and published within the same period. Based on the actual versus anticipated event rates in the control group, we recalculated the absolute noninferiority margin and re-assessed the trial results. The primary outcome of interest was the proportion of trials with a different interpretation after recalculation. Additionally, we analyzed the conclusion statements of these trials to determine if cautionary notes for the interpretation of study results were included.

Results

We analyzed a total of 768 trials, of which 88 had a noninferiority design and 66 used an absolute noninferiority margin. Of 48 comparisons from 45 trials qualifying for the analysis, 11 (22.9%) had divergent results after recalculation of the absolute noninferiority margin based on the observed rather than anticipated event rate. Ten trials originally claiming noninferiority, did not meet it after the margin recalculation. All of them did not include statements suggesting cautionary interpretation of the study results in the conclusion section. Compared with the other trials, these displayed a larger median difference between anticipated and recalculated noninferiority margins (44.7% [IQR: 38.6%-56.7%] vs 15.3% [IQR: -1.5% to 28.9%]; P < 0.001).

Conclusions

Recalculating noninferiority margins based on actual event rates, rather than anticipated ones, led to different outcomes in approximately 1 out of 4 cardiovascular trials, with most divergent trials lacking cautionary interpretation. These findings emphasize the importance of using or supplementing the relative noninferiority margin, particularly in studies with significant deviations between observed and expected event rates. This underscores the critical need for enhanced methodological and reporting standards in noninferiority trials, especially those employing absolute margins.

A Randomized Controlled Trial of Animal-assisted Activities for Pediatric Oncology Patients: Psychosocial and Microbial Outcomes

INTRODUCTION

Evidence about the effectiveness and safety of dog visits in pediatric oncology is limited.

METHOD

We conducted a randomized controlled trial (n=26) of dog visits versus usual care among pediatric oncology inpatients. Psychological functioning and microbial load from hand wash samples were evaluated. Parental anxiety was a secondary outcome.

RESULTS

We did not observe a difference in the adjusted mean present functioning score (-3.0; 95% confidence interval [CI], -12.4 to 6.4). The difference in microbial load on intervention versus control hands was -0.04 (95% CI, -0.60 to 0.52) log10 CFU/mL, with an upper 95% CI limit below the prespecified noninferiority margin. Anxiety was lower in parents of intervention versus control patients.

DISCUSSION

We did not detect an effect of dog visits on functioning; however, our study was underpowered by low recruitment. Visits improved parental anxiety. With hand sanitization, visits did not increase hand microbial levels.

CLINICAL TRIAL REGISTRATION

Clinicaltrials.gov NCT03471221.

Fusing trial data for treatment comparisons: Single vs multi-span bridging

While randomized controlled trials (RCTs) are critical for establishing the efficacy of new therapies, there are limitations regarding what comparisons can be made directly from trial data. RCTs are limited to a small number of comparator arms and often compare a new therapeutic to a standard of care which has already proven efficacious. It is sometimes of interest to estimate the efficacy of the new therapy relative to a treatment that was not evaluated in the same trial, such as a placebo or an alternative therapy that was evaluated in a different trial. Such dual-study comparisons are challenging because of potential differences between trial populations that can affect the outcome. In this article, two bridging estimators are considered that allow for comparisons of treatments evaluated in different trials, accounting for measured differences in trial populations. A "multi-span" estimator leverages a shared arm between two trials, while a "single-span" estimator does not require a shared arm. A diagnostic statistic that compares the outcome in the standardized shared arms is provided. The two estimators are compared in simulations, where both estimators demonstrate minimal empirical bias and nominal confidence interval coverage when the identification assumptions are met. The estimators are applied to data from the AIDS Clinical Trials Group 320 and 388 to compare the efficacy of two-drug vs four-drug antiretroviral therapy on CD4 cell counts among persons with advanced HIV. The single-span approach requires weaker identification assumptions and was more efficient in simulations and the application.

Follow-Up of Patients With Axial Spondyloarthritis in Specialist Health Care With Remote Monitoring and Self-Monitoring Compared With Regular Face-to-Face Follow-Up Visits (the ReMonit Study): Protocol for a Randomized, Controlled Open-Label Noninferiority Trial

BACKGROUND

Patients with chronic inflammatory joint diseases such as axial spondyloarthritis have traditionally received regular follow-up in specialist health care to maintain low disease activity. The follow-up has been organized as prescheduled face-to-face visits, which are time-consuming for both patients and health care professionals. Technology has enabled the remote monitoring of disease activity, allowing patients to self-monitor their disease and contact health care professionals when needed. Remote monitoring or self-monitoring may provide a more personalized follow-up, but there is limited research on how these follow-up strategies perform in maintaining low disease activity, patient satisfaction, safety, and cost-effectiveness.

OBJECTIVE

The Remote Monitoring in Axial Spondyloarthritis (ReMonit) study aimed to assess the effectiveness of digital remote monitoring and self-monitoring in maintaining low disease activity in patients with axial spondyloarthritis.

METHODS

The ReMonit study is a 3-armed, single-site, randomized, controlled, open-label noninferiority trial including patients with axial spondyloarthritis with low disease activity (Ankylosing Spondylitis Disease Activity Score <2.1) and on stable treatment with a tumor necrosis factor inhibitor. Participants were randomized 1:1:1 to arm A (usual care, face-to-face visits every sixth month), arm B (remote monitoring, monthly digital registration of patient-reported outcomes), or arm C (patient-initiated care, self-monitoring, no planned visits during the study period). The primary end point was disease activity measured with the Ankylosing Spondylitis Disease Activity Score, evaluated at 6, 12, and 18 months. We aimed to include 240 patients, 80 in each arm. Secondary end points included other measures of disease activity, patient satisfaction, safety, and cost-effectiveness.

RESULTS

The project is funded by the South-Eastern Norway Regional Health Authority and Centre for the treatment of Rheumatic and Musculoskeletal Diseases (REMEDY), Diakonhjemmet Hospital, Norway. Enrollment started in September 2021 and was completed with 242 patients by June 2022. The data collection will be completed in December 2023.

CONCLUSIONS

To our knowledge, this trial will be among the first to evaluate the effectiveness, safety, and cost-effectiveness of remote digital monitoring and self-monitoring of patients with axial spondyloarthritis compared with usual care. Hence, the ReMonit study will contribute important knowledge to personalized follow-up strategies for patients with axial spondyloarthritis. These results may also be relevant for other patient groups with inflammatory joint diseases.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05031767; hpps://www.clinicaltrials.gov/study/NCT05031767.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/52872.

Effect of a Social Care Intervention on Health Care Experiences of Caregivers of Hospitalized Children: A Randomized Clinical Trial

Importance

Health-related social risks (HRSRs), like food and housing insecurity, are stigmatized conditions that, when addressed in clinical settings, could inadvertently compromise health care experiences.

Objective

To test the noninferiority hypothesis that a low-intensity, high-scale social care intervention does not promote experiences of discrimination or diminish satisfaction with care compared to usual care.

Design, Setting, and Participants

This was a double-blind randomized clinical trial conducted from November 2020 to June 2022 with 12-month follow-up analyzing data obtained 1 week after baseline intervention at a 155-bed academic urban children's hospital with 5300 annual admissions. Participants were recruited from their children's hospital rooms during their children's inpatient hospital stays. Inclusion criteria were identifying as the primary caregiver of a child younger than 18 years who was hospitalized in the general, intensive care, or transplant units; living in 1 of 42 target zip codes; and consenting to receive text messages. Caregivers of healthy newborns and caregivers of children expected to be hospitalized for less than 24 hours or greater than 30 days were excluded. A total of 637 eligible parents and caregivers were enrolled.

Interventions

Participants were randomized to usual care or usual care plus CommunityRx, a low-intensity, universally delivered, electronic medical record-integrated social care assistance intervention providing personalized information about local resources alongside education about HRSRs and how to access additional support. Usual care included an admission brochure about hospital-based free food options and nonsystematic provision of resource information.

Main Outcomes and Measures

Experiences of discrimination, measured using the Discrimination in Medical Settings Scale (range 7-35; higher scores indicate more frequent discrimination) and satisfaction with hospital discharge 1 week postdischarge using Child HCAHPS (range 0-100; higher scores indicate higher satisfaction). The a priori noninferiority margins (control minus intervention) were -0.9 (discrimination) and 1.6 (satisfaction).

Results

Of 637 eligible caregiver participants, most identified as female (n = 600 [94.3%]), Black (n = 505 [79.4%]), and had household income less than $50 000 per year (n = 488 [78.5%]). One-third were experiencing food insecurity (n = 223). Half of participants reported discrimination experiences during the pediatric hospitalization (n = 259). Discrimination experiences among the intervention group were noninferior to those among the control group (mean [SD] score: control, 10.3 [4.7] vs intervention, 10.0 [4.6]; difference, 0.2; 90% CI, -0.5 to 0.9). Mean (SD) satisfaction with discharge was high (control, 84.2 [23.8] vs intervention, 81.9 [24.8]), but evidence was insufficient to support intervention noninferiority for this end point (difference, 2.3; 90% CI, -1.2 to 5.8). Food security status did not moderate the relationship between intervention and either outcome.

Conclusions and Relevance

The findings suggest that a universally delivered social care assistance intervention did not promote caregiver experiences of discrimination during a child's hospitalization but were inconclusive regarding satisfaction.

Trial Registration

ClinicalTrials.gov Identifier: NCT04171999.