Testing for non-inferior mortality: a systematic review of non-inferiority margin sizes and trial characteristics

The impact of a medically directed student registered nurse anesthesia staffing model on Postprocedural patient outcomes

STUDY OBJECTIVE

In 2018, the American Society of Anesthesiologists stated that student registered nurse anesthetists (SRNAs) "are not yet fully qualified anesthesia personnel." It remains unclear, however, whether postprocedural outcomes are affected by SRNAs providing anesthesia care under the medical direction of anesthesiologists, as compared with medically directed anesthesiology fellows or residents, or certified registered nurse anesthetists (CRNAs). We therefore aimed to examine whether medically directed SRNAs serving as in-room anesthesia providers impact surgical outcomes.

DESIGN

Retrospective, matched-cohort analysis.

SETTING

Adult patients (≥18 years old) undergoing inpatient surgery between 2000 and 2017 at a tertiary academic medical center.

PATIENTS

15,365 patients exclusively cared for by medically directed SRNAs were matched to 15,365 cared for by medically directed CRNAs, anesthesiology residents, and/or fellows.

INTERVENTIONS

None.

MEASUREMENTS

The primary composite outcome was postoperative occurrence of in-hospital mortality and six categories of major morbidities (infectious, bleeding, serious cardiac, gastrointestinal, respiratory, and urinary complications). In-hospital mortality was analyzed as the secondary outcome.

MAIN RESULTS

In all, 30,730 cases were matched using propensity score matching to control for potential confounding. The primary outcome was identified in 2295 (7.5%) cases (7.5% with exclusive medically directed SRNAs vs 7.4% with medically directed CRNAs, residents and/or fellows; relative risk, 1.02; 95% CI, 0.94-1.11). Thus, our effort to determine noninferiority (10% difference in relative risk) with other providers was inconclusive (P = .07). However, the medically directed SRNA group (0.8% [118]) was found to be noninferior (P < .001) to the matched group (1.0% [156]) on in-hospital mortality (relative risk, 0.75; 95% CI, 0.59-0.96).

CONCLUSIONS

Among 30,730 patients undergoing inpatient surgery at a single hospital, findings were inconclusive regarding whether exclusive medically directed SRNAs as in-room providers were noninferior to other providers. The use of medically directed SRNAs under this staffing model should be subject to further review. Clinical Trial and Registry URL: Not applicable.

Noninferiority margins exceed superiority effect estimates for mortality in cardiovascular trials in high-impact journals

OBJECTIVES

To determine, in a sample of noninferiority trials, the noninferiority margins (NIMs) and their relation to effect estimates in superiority trials, the rationale being that in general NIMs should be no larger than effects declared important in superiority trials.

STUDY DESIGN AND SETTING

To identify cardiovascular trials published in high-impact journals with a statistically significant primary outcome involving mortality, we systematically searched PubMed, Embase, and MEDLINE databases (January 2015-July 2020). We documented the NIMs and determined the proportion of trials with NIMs larger than the median effect estimates across superiority trials.

RESULTS

From 1,477 screened titles, 65 (39 noninferiority, 26 superiority) trials proved eligible. The NIMs ranged from risk difference of 0.54-10%. The effect estimate across superiority trials was a median risk difference of 2.1% (interquartile range 1.5-4.9); the NIM was larger than 2.1% in 28 (71.8%) noninferiority trials and larger than 1.5%, which was the lower bound of the interquartile range in 32 (82.1%) noninferiority trials.

CONCLUSION

The very wide range of noninferiority margins and the proportion above a threshold that most would consider an important mortality reduction suggest that clinicians and guideline panels should focus on study results, paying little attention to authors' noninferiority margins.

Short-course antibiotic therapy of 5 days in community-acquired pneumonia (CAP5): study protocol for a randomised controlled trial

INTRODUCTION

The optimal duration of antibiotic therapy for community-acquired pneumonia (CAP) is unsettled. Short-course therapy has proved successful in clinical trials but is not yet implemented in everyday clinical practice. Validation of results from randomised controlled trials is crucial to evaluate existing evidence and provide clinicians with assurance of using new treatment strategies. In a pragmatic framework, we aim to assess the use of short-course antibiotic therapy guided by the onset of clinical stability in patients hospitalised with CAP.

METHODS AND ANALYSIS

This study is a randomised controlled trial with a non-inferiority design that will examine the efficacy of short-course antibiotic therapy in patients hospitalised with CAP. From six hospitals across Denmark, we plan to enrol 564 patients between 2019 and 2024. Within 3-5 days after initiating antibiotic therapy, participants will be randomised 1:1 to parallel treatment arms: (1) short-course antibiotic therapy of 5 days or (2) antibiotic therapy of at least 7 days. The primary outcome will be 90-day readmission-free survival and will be estimated as an absolute risk difference with a predefined non-inferiority margin of -6%. Secondary outcomes will comprise other safety measures including new antibiotics, adverse events, length of hospital stay and postdischarge outpatient visits. Both intention-to-treat and per-protocol analyses will be performed.

ETHICS AND DISSEMINATION

This study has been approved by the Health Research Ethics Committee of the Capital Region of Denmark (identifier number: H-19014479). Trial data will be made available in anonymous form when the trial has ended.

TRIAL REGISTRATION NUMBER

NCT04089787, ClinicalTrials.Gov.

Tocilizumab versus baricitinib in hospitalized patients with severe COVID-19: an open label, randomized controlled trial

OBJECTIVE

Randomized controlled trials comparing tocilizumab and baricitinib in patients with coronavirus disease 2019 (COVID-19) are needed. This was an open-label, randomized controlled trial aiming to address this unmet need.

METHODS

To determine whether baricitinib was non-inferior to tocilizumab, we assessed whether the upper boundary of the two-sided 95% CI of the hazard ratio (HR) did not exceed 1.50. The primary outcome was mechanical ventilation or death by day 28. Secondary outcomes included time to hospital discharge by day 28 and change in WHO progression scale at day 10.

RESULTS

We assigned 251 patients with COVID-19 and a PaO_2/FiO₂ ratio of <200 to receive either tocilizumab (n = 126) or baricitinib (n = 125) plus standard of care. Baricitinib was non-inferior to tocilizumab for the primary composite outcome of mechanical ventilation or death by day 28 (mechanical ventilation or death for patients who received baricitinib, 39.2% [n = 49/125]; mechanical ventilation or death for patients who received tocilizumab, 44.4% [n = 56/126]; HR, 0.83; 95% CI, 0.56-1.21; p 0.001 for non-inferiority). Baricitinib was non-inferior to tocilizumab for the time to hospital discharge within 28 days (patients who received baricitinib- discharged alive: 58.4% [n = 73/125] vs. patients who received tocilizumab- discharged alive: 52.4% [n = 66/126]; HR, 0.85; 95% CI, 0.61-1.18; p < 0.001 for non-inferiority). There was no significant difference between the baricitinib and tocilizumab arms in the change in WHO scale at day 10 (0.0 [95% CI, 0.0-0.0] vs. 0.0 [95% CI, 0.0-1.0]; p 0.83).

DISCUSSION

In the setting of this trial, baricitinib was non-inferior to tocilizumab with regards to the composite outcome of mechanical ventilation or death by day 28 and the time to discharge by day 28 in patients with severe COVID-19.

Medial retropharyngeal nodal region sparing radiotherapy versus standard radiotherapy in patients with nasopharyngeal carcinoma: open label, non-inferiority, multicentre, randomised, phase 3 trial

OBJECTIVES

To address whether sparing the medial retropharyngeal lymph node (MRLN) region from elective irradiation volume provides non-inferior local relapse-free survival versus standard radiotherapy in patients with nasopharyngeal carcinoma.

DESIGN

Open-label, non-inferiority, multicentre, randomised, phase 3 trial.

SETTING

Three Chinese hospitals between 20 November 2017 and 3 December 2018.

PARTICIPANTS

Adults (18-65 years) with newly diagnosed, non-keratinising, non-distant metastatic nasopharyngeal carcinoma without MRLN involvement.

INTERVENTIONS

Randomisation was done centrally by the Clinical Trials Centre at Sun Yat-sen University Cancer Center. Eligible patients were randomly assigned (1:1; block size of four) to receive MRLN sparing radiotherapy or standard radiotherapy (both medial and lateral retropharyngeal lymph node groups), and stratified by institution and treatment modality as follows: radiotherapy alone; concurrent chemoradiotherapy; induction chemotherapy plus radiotherapy or concurrent chemoradiotherapy.

MAIN OUTCOME MEASURES

Non-inferiority was met if the lower limit of the one sided 97.5% confidence interval of the absolute difference in three year local relapse-free survival (MRLN sparing radiotherapy minus standard radiotherapy) was greater than -8%.

RESULTS

568 patients were recruited: 285 in the MRLN sparing radiotherapy group; 283 in the standard radiotherapy group. Median follow-up was 42 months (interquartile range 39-45), intention-to-treat analysis showed that the three year local relapse-free survival of the MRLN sparing radiotherapy group was non-inferior to that of the standard radiotherapy group (95.3% v 95.5%, stratified hazard ratio 1.04 (95% confidence interval 0.51 to 2.12), P=0.95) with a difference of -0.2% ((one sided 97.5% confidence interval -3.6 to ∞), P_{non-inferiority}<0.001). In the safety set (n=564), the sparing group had a lower incidence of grade ≥1 acute dysphagia (25.5% v 35.1%, P=0.01) and late dysphagia (24.0% v 34.3%, P=0.008). Patient reported outcomes at three years after MRLN sparing radiotherapy were better in multiple domains after adjusting for the baseline values: global health status (mean difference -5.6 (95% confidence interval -9.1 to -2.0), P=0.002), role functioning (-5.5 (-7.4 to -3.6), P<0.001), social functioning (-6.2 (-8.9 to -3.6), P<0.001), fatigue (7.9 (4.0 to 11.8), P<0.001), and swallowing (11.0 (8.4 to 13.6), P<0.001). The difference in swallowing scores reached clinical significance (>10 points difference).

CONCLUSION

Compared with standard radiotherapy, MRLN sparing radiotherapy showed non-inferiority in terms of risk of local relapse with fewer radiation related toxicity and improved patient reported outcomes in patients with non-metastatic nasopharyngeal carcinoma.

TRIAL REGISTRATION

ClinicalTrials.gov NCT03346109.

Effect of Radiotherapy Alone vs Radiotherapy With Concurrent Chemoradiotherapy on Survival Without Disease Relapse in Patients With Low-risk Nasopharyngeal Carcinoma: A Randomized Clinical Trial

IMPORTANCE

Concurrent chemoradiotherapy has been the standard treatment for stage II nasopharyngeal carcinoma (NPC) based on data using 2-dimensional conventional radiotherapy. There is limited evidence for the role of chemotherapy with use of intensity-modulated radiation therapy (IMRT).

OBJECTIVE

To assess whether concurrent chemotherapy can be safely omitted for patients with low-risk stage II/T3N0 NPC treated with IMRT.

DESIGN, SETTING, AND PARTICIPANTS

This multicenter, open-label, randomized, phase 3, noninferiority clinical trial was conducted at 5 Chinese hospitals, including 341 adult patients with low-risk NPC, defined as stage II/T3N0M0 without adverse features (all nodes <3 cm, no level IV/Vb nodes; no extranodal extension; Epstein-Barr virus DNA <4000 copies/mL), with enrollment between November 2015 and August 2020. The final date of follow-up was March 15, 2022.

INTERVENTIONS

Patients were randomly assigned to receive IMRT alone (n = 172) or concurrent chemoradiotherapy (IMRT with cisplatin, 100 mg/m2 every 3 weeks for 3 cycles [n = 169]).

MAIN OUTCOMES AND MEASURES

The primary end point was 3-year failure-free survival (time from randomization to any disease relapse or death), with a noninferiority margin of 10%. Secondary end points comprised overall survival, locoregional relapse-free survival, distant metastasis-free survival, adverse events, and health-related quality of life (QOL) measured by the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire (QLQ-C30; range, 0-100 points; minimum clinically important difference ≥10 for physical function, symptom control, or health-related QOL; higher score indicates better functioning and global health status or worse symptoms).

RESULTS

Among 341 randomized patients (mean [SD] age, 48 [10] years; 30% women), 334 (98.0%) completed the trial. Median follow-up was 46 months (IQR, 34-58). Three-year failure-free survival was 90.5% for the IMRT-alone group vs 91.9% for the concurrent chemoradiotherapy group (difference, -1.4%; 1-sided 95% CI, -7.4% to ∞; P value for noninferiority, <.001). No significant differences were observed between groups in overall survival, locoregional relapse, or distant metastasis. The IMRT-alone group experienced a significantly lower incidence of grade 3 to 4 adverse events (17% vs 46%; difference, -29% [95% CI, -39% to -20%]), including hematologic toxicities (leukopenia, neutropenia) and nonhematologic toxicities (nausea, vomiting, anorexia, weight loss, mucositis). The IMRT-alone group had significantly better QOL scores during radiotherapy including the domains of global health status, social functioning, fatigue, nausea and vomiting, pain, insomnia, appetite loss, and constipation.

CONCLUSIONS AND RELEVANCE

Among patients with low-risk NPC, treatment with IMRT alone resulted in 3-year failure-free survival that was not inferior to concurrent chemoradiotherapy.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02633202.

Comparison of Outcomes of Ischemic Stroke Initially Imaged With Cranial Computed Tomography Alone vs Computed Tomography Plus Magnetic Resonance Imaging

IMPORTANCE

Patients with acute ischemic stroke often undergo magnetic resonance imaging (MRI) in addition to computed tomography (CT), but its association with clinical outcomes is uncertain.

OBJECTIVE

To assess whether clinical outcomes of patients with acute ischemic stroke with initial CT alone were noninferior to those with additional MRI.

DESIGN, SETTING, AND PARTICIPANTS

A retrospective observational propensity score-matched cohort study of clinical outcomes at discharge and 1 year for patients hospitalized with acute ischemic stroke was conducted at an academic medical center between January 2015 and December 2017. Data collection from an electronic medical record system performed from May 2020 through January 2022 was not completely blinded. Noninferiority margins were based on the designs of previous randomized clinical trials of ischemic stroke treatments. Statistical analysis was performed in January 2022. Participants were adults hospitalized with acute ischemic stroke with admission diagnosis based on CT. Exclusion criteria were primarily missing data. From 508 eligible patients, all 123 cases with additional MRI were propensity-score matched to 123 controls without.

EXPOSURE

MRI after initial diagnosis.

MAIN OUTCOMES AND MEASURES

Death or dependence at hospital discharge (modified Rankin Scale score of 3-6) and stroke or death occurring in survivors within 1 year after discharge.

RESULTS

Among 246 participants, the median age was 68 years (IQR, 58-78.8 years) and 131 (53.0%) were men. Death or dependence at discharge occurred more often in patients with additional MRI (59 of 123 [48.0%]) than in those with CT alone (52 of 123 [42.3%]; absolute difference, 5.7%; 95% CI, -6.7% to 18.1%), meeting the -7.50% criterion for noninferiority. Stroke or death within 1 year after discharge determined for 225 of 235 (96%) survivors occurred more often in patients with additional MRI (22 of 113 [19.5%]) than in those with CT alone (14 of 112 [12.5%]; relative risk, 1.14; 95% CI, 0.86-1.50), meeting the 0.725 relative risk criterion for noninferiority.

CONCLUSIONS AND RELEVANCE

This propensity score-matched cohort study of patients hospitalized with acute ischemic stroke found that a diagnostic imaging strategy of initial CT alone was noninferior to initial CT plus additional MRI with regard to clinical outcomes at discharge and at 1 year. Further research is needed to determine which patients hospitalized with acute ischemic stroke benefit from MRI.

Noninferiority Margin Size and Acceptance of Trial Results: Contingent Valuation Survey of Clinician Preferences for Noninferior Mortality

Objectives

We used modified contingent valuation methodology to determine how noninferiority margin sizes influence clinicians’ willingness to accept clinical trial results that compare mortality in critically ill children.

Methods

We surveyed pediatric infectious diseases and critical care clinicians in Canada, Australia, and New Zealand and randomized respondents to review 1 of 9 mock abstracts describing a noninferiority trial of bacteremic critically ill children assigned to 7 or 14 d of antibiotics. Each scenario showed higher mortality in the 7-d group but met noninferiority criterion. We explored how noninferiority margins and baseline mortality rates influenced respondent acceptance of results.

Results

There were 106 survey respondents: 65 (61%) critical care clinicians, 28 (26%) infectious diseases physicians, and 13 (12%) pharmacists. When noninferiority margins were 5% and 10%, 73% (24/33) and 79% (27/33) respondents would accept shorter treatment, compared with 44% (17/39) when the margin was 20% (P = 0.003). Logistic regression adjusted for baseline mortality showed 5% and 10% noninferiority margins were more likely to be associated with acceptance of shorter treatment compared with 20% margins (odds ratio [OR] 3.5, 95% confidence interval [CI]: 1.3–9.6, P = 0.013; OR 5.1, 95% CI: 1.8–14.6, P = 0.002). Baseline mortality was not a significant predictor of acceptance of shorter treatment.

Conclusions

Clinicians are more likely to accept shorter treatment when noninferiority margins are ≤10%. However, nearly half of respondents who reviewed abstracts with 20% margins were still willing to accept shorter treatment. This is a novel application of contingent valuation methodology to elicit acceptance of research results among end users of the medical literature.

Highlights

Elective upper-neck versus whole-neck irradiation of the uninvolved neck in patients with nasopharyngeal carcinoma: an open-label, non-inferiority, multicentre, randomised phase 3 trial

BACKGROUND

The aim of this trial was to address whether elective ipsilateral upper-neck irradiation (UNI) sparing the uninvolved lower neck provides similar regional relapse-free survival compared with standard whole-neck irradiation (WNI) in patients with nasopharyngeal carcinoma.

METHODS

This open-label, non-inferiority, randomised, controlled, phase 3 trial was done at three Chinese medical centres. Patients aged 18-65 years with untreated, non-keratinising, non-distant metastatic (M0) nasopharyngeal carcinoma; with N0-N1 disease (according to International Union Against Cancer-American Joint Committee on Cancer TNM classification, seventh edition); and a Karnofsky performance status score of 70 or higher were randomly assigned (1:1) to receive elective UNI or WNI of the uninvolved neck. Total radiation doses of 70 Gy (for the primary tumour volume and the enlarged retropharyngeal nodes), 66-70 Gy (for the involved cervical lymph nodes), 60-62 Gy (for the high-risk target volume), and 54-56 Gy (for the low-risk target volume) were administered in 30-33 fractions, five fractions per week. Patients with stage II-IVA disease were recommended to receive combined intravenous cisplatin-based chemotherapy (either induction chemotherapy followed by concurrent chemoradiotherapy or concurrent chemoradiotherapy alone). Randomisation was done centrally by the Clinical Trials Centre of Sun Yat-sen University Cancer Centre by means of a computer-generated random number code with a block size of four. Patients were stratified according to treatment centre and nodal status. Investigators and patients were not masked to treatment allocation. The primary endpoint was regional relapse-free survival in the intention-to-treat population. Non-inferiority was indicated if the upper limit of the 95% CI of the difference in 3-year regional relapse-free survival between the UNI and WNI groups was within 8%. Adverse events were analysed in the safety population (defined as all patients who commenced the randomly assigned treatment). This study is registered with ClinicalTrials.gov, NCT02642107, and is closed.

FINDINGS

Between Jan 22, 2016, and May 23, 2018, 446 patients from 469 screened were randomly assigned to receive UNI (n=224) or WNI (n=222). Median follow-up was 53 months (IQR 46-59). 3-year regional relapse-free survival was similar in the UNI and WNI groups (97·7% [95% CI 95·7-99·7] in the UNI group vs 96·3% [93·8-98·8] in the WNI group; difference -1·4% [95% CI -4·6 to 1·8]; p_{non-inferiority}<0·0001). Although acute radiation-related toxic effects were similar between the groups, the incidence of late toxicity was lower in the UNI group than in the WNI group, including any-grade hypothyroidism (66 [30%] of 222 patients vs 87 [39%] of 221), skin toxicity (32 [14%] vs 55 [25%]), dysphagia (38 [17%] vs 71 [32%]), and neck tissue damage (50 [23%] vs 88 [40%]). No patients died during treatment. After treatment, one patient in the WNI group died from a non-cancer-related cause (dermatomyositis).

INTERPRETATION

Elective UNI of the uninvolved neck provides similar regional control and results in less radiation toxicity compared with standard WNI in patients with N0-N1 nasopharyngeal carcinoma.

FUNDING

Sun Yat-sen University Clinical Research 5010 Program, the Natural Science Foundation of Guangdong Province, and the Overseas Expertise Introduction Project for Discipline Innovation.

TRANSLATION

For the Chinese translation of the abstract see Supplementary Materials section.

Effect of Concurrent Chemoradiotherapy With Nedaplatin vs Cisplatin on the Long-term Outcomes of Survival and Toxic Effects Among Patients With Stage II to IVB Nasopharyngeal Carcinoma: A 5-Year Follow-up Secondary Analysis of a Randomized Clinical Trial

IMPORTANCE

Nedaplatin-based concurrent chemoradiotherapy (CCRT) regimen at 2 years was noninferior to cisplatin-based regimen in patients with locoregional, stage II to IVB nasopharyngeal carcinoma (NPC) and was associated with fewer late adverse events, but longer-term outcomes and toxicity are unclear.

OBJECTIVE

To evaluate the 5-year outcomes and late toxicity profile of nedaplatin-based CCRT in patients with locoregional, stage II to IVB NPC.

DESIGN, SETTINGS, AND PARTICIPANTS

This 5-year follow-up secondary analysis of an open-label, noninferiority, multicenter randomized clinical trial enrolled patients with nonkeratinizing stage II to IVB NPC between January 16, 2012, and July 16, 2014, with a median follow-up duration of 78 months (IQR, 3-99 months). Data analysis was conducted from November 10, 2020, to July 8, 2021.

INTERVENTIONS

Patients were randomly assigned (1:1) to receive nedaplatin (100 mg/m2)- or cisplatin (100 mg/m2)-based chemotherapy every 3 weeks for 3 cycles concurrently with intensity-modulated radiotherapy.

MAIN OUTCOMES AND MEASURES

The primary end point was progression-free survival (PFS). Secondary end points were overall survival, distant metastasis-free survival, and locoregional relapse-free survival.

RESULTS

A total of 402 eligible participants were enrolled (median [IQR] age, 45 [18-65] years; 302 [75.1%] male). Patients were randomly assigned to receive nedaplatin- or cisplatin-based CCRT (n = 201 for each): 196 patients (97.5%) started nedaplatin-based CCRT and 197 patients (98.0%) started cisplatin-based CCRT. Intention-to-treat analysis demonstrated a 5-year progression-free survival rate of 81.4% (95% CI, 75.9%-86.9%) for the cisplatin group and 79.8% (95% CI, 74.1%-85.5%) for nedaplatin group, with a difference of 1.6% (95% CI, -6.3% to 9.5%; P = .002 for noninferiority). No significant survival differences were observed between the cisplatin and nedaplatin groups for 5-year overall survival (89.4% vs 88.8%, P = .63), distant metastasis-free survival (85.9% vs 90.4%, P = .17), and locoregional relapse-free survival (92.6% vs 89.6%, P = .17) rates. The cisplatin group had a higher incidence of grade 3 and 4 auditory toxic effects than the nedaplatin group (35 [17.7%] vs 21 [10.5%], P = .04).

CONCLUSIONS AND RELEVANCE

In this secondary analysis of a randomized clinical trial, long-term analysis confirmed that nedaplatin-based CCRT could be regarded as an alternative doublet treatment strategy to cisplatin-based CCRT in stage II to IVB NPC.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT01540136.