Optic Nerve Sheath Diameter Point-of-Care Ultrasonography Quality Criteria Checklist: An International Consensus Statement on Optic Nerve Sheath Diameter Imaging and Measurement.

OBJECTIVES: To standardize optic nerve sheath diameter (ONSD) point-of-care ultrasonography (POCUS) and improve its research and clinical utility by developing the ONSD POCUS Quality Criteria Checklist (ONSD POCUS QCC). DESIGN: Three rounds of modified Delphi consensus process and three rounds of asynchronous discussions. SETTING: Online surveys and anonymous asynchronous discussion. SUBJECTS: Expert panelists were identified according to their expertise in ONSD research, publication records, education, and clinical use. A total of 52 panelists participated in the Delphi process. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Three Delphi rounds and three asynchronous discussion rounds generated consensus on quality criteria (QC). This started with 29 QC in addition to other QC proposed by expert panelists. The QC items were categorized into probe selection, safety, body position, imaging, measurement, and research considerations. At the conclusion of the study, 28 QC reached consensus to include in the final ONSD POCUS QCC. These QC were then reorganized, edited, and consolidated into 23 QC that were reviewed and approved by the panelists. CONCLUSIONS: ONSD POCUS QCC standardizes ONSD ultrasound imaging and measurement based on international consensus. This can establish ONSD ultrasound in clinical research and improve its utility in clinical practice.

Individualized empirical null estimation for exact tests of healthcare quality.

United States federal agencies evaluate healthcare providers to identify, flag, and potentially penalize those that deliver low-quality care compared to national expectations. In practice, evaluation metrics are inevitably impacted by unobserved confounding factors, which reduce flagging accuracy and cause the statistics to be overdispersed relative to the theoretical null distributions. In response to this issue, several authors have proposed individualized empirical null (IEN) methods to estimate an appropriate null distribution for each provider's evaluation statistic while taking into account the provider's effective size. However, existing IEN methods require that the statistics asymptotically follow normal distributions, which often does not hold in applications with small providers or misspecified models. In this article, we develop an IEN framework for exact hypothesis tests that accounts for the impact of unobserved confounding without making any asymptotic assumptions. Simulations show that the proposed IEN method has greater flagging accuracy compared to conventional approaches. We apply these methods to evaluate dialysis facilities and transplant centers that are monitored by the Centers for Medicare and Medicaid Services.

Optimal survival analyses with prevalent and incident patients.

Period-prevalent cohorts are often used for their cost-saving potential in epidemiological studies of survival outcomes. Under this design, prevalent patients allow for evaluations of long-term survival outcomes without the need for long follow-up, whereas incident patients allow for evaluations of short-term survival outcomes without the issue of left-truncation. In most period-prevalent survival analyses from the existing literature, patients have been recruited to achieve an overall sample size, with little attention given to the relative frequencies of prevalent and incident patients and their statistical implications. Furthermore, there are no existing methods available to rigorously quantify the impact of these relative frequencies on estimation and inference and incorporate this information into study design strategies. To address these gaps, we develop an approach to identify the optimal mix of prevalent and incident patients that maximizes precision over the entire estimated survival curve, subject to a flexible weighting scheme. In addition, we prove that inference based on the weighted log-rank test or Cox proportional hazards model is most powerful with an entirely prevalent or incident cohort, and we derive theoretical formulas to determine the optimal choice. Simulations confirm the validity of the proposed optimization criteria and show that substantial efficiency gains can be achieved by recruiting the optimal mix of prevalent and incident patients. The proposed methods are applied to assess waitlist outcomes among kidney transplant candidates.

Concordance indices with left-truncated and right-censored data.

In the context of time-to-event analysis, a primary objective is to model the risk of experiencing a particular event in relation to a set of observed predictors. The Concordance Index (C-Index) is a statistic frequently used in practice to assess how well such models discriminate between various risk levels in a population. However, the properties of conventional C-Index estimators when applied to left-truncated time-to-event data have not been well studied, despite the fact that left-truncation is commonly encountered in observational studies. We show that the limiting values of the conventional C-Index estimators depend on the underlying distribution of truncation times, which is similar to the situation with right-censoring as discussed in Uno et al. (2011) [On the C-statistics for evaluating overall adequacy of risk prediction procedures with censored survival data. Statistics in Medicine 30(10), 1105-1117]. We develop a new C-Index estimator based on inverse probability weighting (IPW) that corrects for this limitation, and we generalize this estimator to settings with left-truncated and right-censored data. The proposed IPW estimators are highly robust to the underlying truncation distribution and often outperform the conventional methods in terms of bias, mean squared error, and coverage probability. We apply these estimators to evaluate a predictive survival model for mortality among patients with end-stage renal disease.

Pitfalls of the concordance index for survival outcomes.

Prognostic models are useful tools for assessing a patient's risk of experiencing adverse health events. In practice, these models must be validated before implementation to ensure that they are clinically useful. The concordance index (C-Index) is a popular statistic that is used for model validation, and it is often applied to models with binary or survival outcome variables. In this paper, we summarize existing criticism of the C-Index and show that many limitations are accentuated when applied to survival outcomes, and to continuous outcomes more generally. We present several examples that show the challenges in achieving high concordance with survival outcomes, and we argue that the C-Index is often not clinically meaningful in this setting. We derive a relationship between the concordance probability and the coefficient of determination under an ordinary least squares model with normally distributed predictors, which highlights the limitations of the C-Index for continuous outcomes. Finally, we recommend existing alternatives that more closely align with common uses of survival models.

Assessing clinical competence: a multitrait-multimethod matrix construct validity study.

Education in Doctor of Medicine programs has moved towards an emphasis on clinical competency, with entrustable professional activities providing a framework of learning objectives and outcomes to be assessed within the clinical environment. While the identification and structured definition of objectives and outcomes have evolved, many methods employed to assess clerkship students' clinical skills remain relatively unchanged. There is a paucity of medical education research applying advanced statistical design and analytic techniques to investigate the validity of clinical skills assessment. One robust statistical method, multitrait-multimethod matrix analysis, can be applied to investigate construct validity across multiple assessment instruments and settings. Four traits were operationalized to represent the construct of critical clinical skills (professionalism, data gathering, data synthesis, and data delivery). The traits were assessed using three methods (direct observations by faculty coaches, clinical workplace-based evaluations, and objective structured clinical examination type clinical practice examinations). The four traits and three methods were intercorrelated for the multitrait-multimethod matrix analysis. The results indicated reliability values in the adequate to good range across the three methods with the majority of the validity coefficients demonstrating statistical significance. The clearest evidence for convergent and divergent validity was with the professionalism trait. The correlations on the same method/different traits analyses indicated substantial method effect; particularly on clinical workplace-based assessments. The multitrait-multimethod matrix approach, currently underutilized in medical education, could be employed to explore validity evidence of complex constructs such as clinical skills. These results can inform faculty development programs to improve the reliability and validity of assessments within the clinical environment.

Determinants of medical specialty competitiveness.

BACKGROUND: Although the concept of medical specialty competitiveness may seem intuitive, there are very little existing empirical data on the determinants of specialty competitiveness in USA. An understanding of the determinants of specialty competitiveness may inform career choices among students and their advisors. Specialty competitiveness correlates with availability and appeal. METHODS: This narrative review examines 2019 National Resident Matching Program (NRMP) data and the existing literature to define the determinants of specialty competitiveness. A statistical analysis of key elements of the 2019 NRMP data was performed. RESULTS: Using US senior applicant fill rate as a measure of competitiveness, medical specialty competitiveness follows general principles of supply and demand. The demand, or appeal, of a specialty correlates with several factors, including salary, prestige and lifestyle. Salary correlates strongly with US senior fill rate (r=0.78, p=0.001). Relatively few positions are available for the most competitive specialties in the NRMP match. The negative correlation between US senior fill rate and position availability is also strong (r=-0.85; p<0.0001). CONCLUSION: A 'competitive specialty' correlates strongly with high earnings potential and limited position availability. In an ideal world, a student's pursuit of a medical specialty should be guided by interest, qualifications and ability to succeed in that field. However, students must contend with the realities of competition created by the residency matching system.

Validation of a performance checklist for ultrasound-guided internal jugular central lines for use in procedural instruction and assessment.

PURPOSE OF THE STUDY: Tools created to measure procedural competency must be tested in their intended environment against an established standard in order to be validated. We previously created a checklist for ultrasound-guided internal jugular central venous catheter (US IJ CVC) insertion using the modified Delphi method. We sought to further validate the checklist tool for use in an educational environment. STUDY DESIGN: This is a cohort study involving 15 emergency medicine interns being evaluated on their skill in US IJ CVC placement. We compared the checklist tool with a modified version of a clinically validated global rating scale (GRS) for procedural performance. RESULTS: The correlation between the GRS tool and the checklist tool was excellent, with a correlation coefficient (Pearson's r) of 0.90 (p<0.0001). CONCLUSIONS: This checklist represents a useful tool for measuring procedural competency.

Derivation of a Performance Checklist for Ultrasound-Guided Arthrocentesis Using the Modified Delphi Method.

OBJECTIVES: Arthrocentesis is an important skill for physicians in multiple specialties. Recent studies indicate a superior safety and performance profile for this procedure using ultrasound guidance for needle placement, and improving quality of care requires a valid measurement of competency using this modality. METHODS: We endeavored to create a validated tool to assess the performance of this procedure using the modified Delphi technique and experts in multiple disciplines across the United States. RESULTS: We derived a 22-item checklist designed to assess competency for the completion of ultrasound-guided arthrocentesis, which demonstrated a Cronbach's alpha of 0.89, indicating an excellent degree of internal consistency. CONCLUSIONS: Although we were able to demonstrate content validity for this tool, further validity evidence should be acquired after the tool is used and studied in clinical and simulated contexts.

Video-augmented feedback for procedural performance.

BACKGROUND: Resident programs must assess residents' achievement of core competencies for clinical and procedural skills. AIMS: Video-augmented feedback may facilitate procedural skill acquisition and promote more accurate self-assessment. METHODS: A randomized controlled study to investigate whether video-augmented verbal feedback leads to increased procedural skill and improved accuracy of self-assessment compared to verbal only feedback. Participants were evaluated during procedural training for ultrasound guided internal jugular central venous catheter (US IJ CVC) placement. All participants received feedback based on a validated 30-point checklist for US IJ CVC placement and validated 6-point procedural global rating scale. RESULTS: Scores in both groups improved by a mean of 9.6 points (95% CI: 7.8-11.4) on the 30-point checklist, with no difference between groups in mean score improvement on the global rating scale. In regards to self-assessment, participant self-rating diverged from faculty scoring, increasingly so after receiving feedback. Residents rated highly by faculty underestimated their skill, while those rated more poorly demonstrated increasing overestimation. CONCLUSIONS: Accuracy of self-assessment was not improved by addition of video. While feedback advanced the skill of the resident, video-augmented feedback did not enhance skill acquisition or improve accuracy of resident self-assessment compared to standard feedback.

A Novel Tool for Assessment of Emergency Medicine Resident Skill in Determining Diagnosis and Management for Emergent Electrocardiograms: A Multicenter Study.

BACKGROUND: Reading emergent electrocardiograms (ECGs) is one of the emergency physician's most crucial tasks, yet no well-validated tool exists to measure resident competence in this skill. OBJECTIVES: To assess validity of a novel tool measuring emergency medicine resident competency for interpreting, and responding to, critical ECGs. In addition, we aim to observe trends in this skill for resident physicians at different levels of training. METHODS: This is a multi-center, prospective study of postgraduate year (PGY) 1-4 residents at five emergency medicine (EM) residency programs in the United States. An assessment tool was created that asks the physician to identify either the ECG diagnosis or the best immediate management. RESULTS: One hundred thirteen EM residents from five EM residency programs submitted completed assessment surveys, including 43 PGY-1s, 33 PGY-2s, and 37 PGY-3/4s. PGY-3/4s averaged 74.6% correct (95% confidence interval [CI] 70.9-78.4) and performed significantly better than PGY-1s, who averaged 63.2% correct (95% CI 58.0-68.3). PGY-2s averaged 69.0% (95% CI 62.2-73.7). Year-to-year differences were more pronounced in management than in diagnosis. CONCLUSIONS: Residency training in EM seems to be associated with improved ability to interpret "critical" ECGs as measured by our assessment tool. This lends validity evidence for the tool by correlating with a previously observed association between residency training and improved ECG interpretation. Resident skill in ECG interpretation remains less than ideal. Creation of this sort of tool may allow programs to assess resident performance as well as evaluate interventions designed to improve competency.

Faculty Prediction of In-Training Examination Scores of Emergency Medicine Residents: A Multicenter Study.

BACKGROUND: The Emergency Medicine In-Training Examination (EMITE) is one of the few validated instruments for medical knowledge assessment of emergency medicine (EM) residents. The EMITE is administered only once annually, with results available just 2 months before the end of the academic year. An earlier predictor of EMITE scores would be helpful for educators to institute timely remediation plans. A previous single-site study found that only 69% of faculty predictions of EMITE scores were accurate. OBJECTIVE: The goal of this article was to measure the accuracy with which EM faculty at five residency programs could predict EMITE scores for resident physicians. METHODS: We asked EM faculty at five different residency programs to predict the 2014 EMITE scores for all their respective resident physicians. The primary outcome was prediction accuracy, defined as the proportion of predictions within 6% of the actual scores. The secondary outcome was prediction precision, defined as the mean deviation of predictions from the actual scores. We assessed faculty background variables for correlation with the two outcomes. RESULTS: One hundred and eleven faculty participated in the study (response rate 68.9%). Mean prediction accuracy for all faculty was 60.0%. Mean prediction precision was 6.3%. Participants were slightly more accurate at predicting scores of noninterns compared to interns. No faculty background variable correlated with the primary or secondary outcomes. Eight participants predicted scores with high accuracy (>80%). CONCLUSIONS: In this multicenter study, EM faculty possessed only moderate accuracy at predicting resident EMITE scores. A very small subset of faculty members is highly accurate.

COMPOSITE SCORES FOR TRANSPLANT CENTER EVALUATION: A NEW INDIVIDUALIZED EMPIRICAL NULL METHOD.

Risk-adjusted quality measures are used to evaluate healthcare providers with respect to national norms while controlling for factors beyond their control. Existing healthcare provider profiling approaches typically assume that the between-provider variation in these measures is entirely due to meaningful differences in quality of care. However, in practice, much of the between-provider variation will be due to trivial fluctuations in healthcare quality, or unobservable confounding risk factors. If these additional sources of variation are not accounted for, conventional methods will disproportionately identify larger providers as outliers, even though their departures from the national norms may not be "extreme" or clinically meaningful. Motivated by efforts to evaluate the quality of care provided by transplant centers, we develop a composite evaluation score based on a novel individualized empirical null method, which robustly accounts for overdispersion due to unobserved risk factors, models the marginal variance of standardized scores as a function of the effective sample size, and only requires the use of publicly-available center-level statistics. The evaluations of United States kidney transplant centers based on the proposed composite score are substantially different from those based on conventional methods. Simulations show that the proposed empirical null approach more accurately classifies centers in terms of quality of care, compared to existing methods.

Limitations of the Inter-Unit Reliability: A Set of Practical Examples.

Healthcare quality measures are statistics that serve to evaluate healthcare providers and identify those that need to improve their care. Before using these measures in clinical practice, developers and reviewers assess measure reliability, which describes the degree to which differences in the measure values reflect actual variation in healthcare quality, as opposed to random noise. The Inter-Unit Reliability (IUR) is a popular statistic for assessing reliability, and it describes the proportion of total variation in a measure that is attributable to between-provider variation. However, Kalbfleisch, He, Xia, and Li (2018) [Health Services and Outcomes Research Methodology, 18, 215-225] have argued that the IUR has a severe limitation in that some of the between-provider variation may be unrelated to quality of care. In this paper, we illustrate the practical implications of this limitation through several concrete examples. We show that certain best-practices in measure development, such as careful risk adjustment and exclusion of unstable measure values, can decrease the sample IUR value. These findings uncover potential negative consequences of discarding measures with IUR values below some arbitrary threshold.

Foundations of Emergency Medicine: Impact of a Standardized, Open-access, Core Content Curriculum on In-Training Exam Scores.

Introduction: Learners frequently benefit from modalities such as small-group, case-based teaching and interactive didactic experiences rather than passive learning methods. These contemporary techniques are features of Foundations of Emergency Medicine (FoEM) curricula, and particularly the Foundations I (F1) course, which targets first-year resident (PGY-1) learners. The American Board of Emergency Medicine administers the in-training exam (ITE) that provides an annual assessment of EM-specific medical knowledge. We sought to assess the effect of F1 implementation on ITE scores. Methods: We retrospectively analyzed data from interns at four EM residency programs accredited by the Accreditation Council for Graduate Medical Education. We collected data in 2021. Participating sites were geographically diverse and included three- and four-year training formats. We collected data from interns two years before (control group) and two years after (intervention group) implementation of F1 at each site. Year of F1 implementation ranged from 2015-2018 at participating sites. We abstracted data using a standard form including program, ITE raw score, year of ITE administration, US Medical Licensing Exam Step 1 score, Step 2 Clinical Knowledge (CK) score, and gender. We performed univariable and multivariable linear regression to explore differences between intervention and control groups. Results: We collected data for 180 PGY-1s. Step 1 and Step 2 CK scores were significant predictors of ITE in univariable analyses (both with P < 0.001). After accounting for Step 1 and Step 2 CK scores, we did not find F1 implementation to be a significant predictor of ITE score, P = 0.83. Conclusion: Implementation of F1 curricula did not show significant changes in performance on the ITE after controlling for important variables.

Perceptions of the current and future emergency medicine workforce.

Objective: The objectives of the study were to assess emergency medicine (EM) physician perceptions of the EM job market 2 years after "The Emergency Medicine Physician Workforce: Projections for 2030" was published in Annals of Emergency Medicine and to examine how the workforce report may have influenced perceptions about job prospects. Methods: A cross-sectional survey was conducted in 2022 of EM residents, fellows, and attendings at 21 practice sites. Main outcomes were perceptions of the likelihood of currently finding any job, currently finding a desirable job, and confidence in the future EM job market. Results: Note that 831 of 1938 physicians (42.9%) responded. A total of 92.4% reported a high likelihood of finding any job currently, 49.8% reported a high likelihood of finding a desirable job currently, and 44.4% reported future confidence. Workforce report familiarity was associated with greater likelihood of finding a desirable job. Fellows were least confident in the future. Residents with desired Midwest location were twice as confident in the future job market; those with desired West location were less confident. Attendings 20 or more years post-training were more than twice as likely to report a high likelihood of finding a desirable job and almost twice as likely to report future confidence. Attendings in leadership were nearly three times as likely to report high a likelihood of finding a desirable job and future confidence. Conclusion: EM trainees and attendings have favorable perceptions of the current job market but are less confident in future prospects. As the projected surplus of EM physicians appears to have had an impact, updated projections are needed for more accurate assessments of the future of the specialty.

Video self-instruction for police officers in cardiopulmonary resuscitation and automated external defibrillators.

INTRODUCTION: Police officers often serve as first responders during out-of-hospital cardiac arrests (OHCA). Current knowledge and attitudes about resuscitation techniques among police officers are unknown. Hypothesis/problem This study evaluated knowledge and attitudes about cardiopulmonary resuscitation (CPR) and automated external defibrillators (AEDs) among urban police officers and quantified the effect of video self-instruction (VSI) on these outcomes. METHODS: Urban police officers were enrolled in this online, prospective, educational study conducted over one month. Demographics, prior CPR-AED experience, and baseline attitudes were queried. Subjects were randomized into two groups. Each group received a slightly different multiple-choice test of knowledge and crossed to the alternate test after the intervention, a 10-minute VSI on CPR and AEDs. Knowledge and attitudes were assessed immediately before and after the intervention. The primary attitude outcome was entering "very likely" (5-point Likert) to do chest compressions (CC) and use an AED on a stranger. The primary knowledge outcomes were identification of the correct rate of CC, depth of CC, and action in an OHCA scenario. RESULTS: A total of 1616 subjects responded with complete data (63.6% of all electronic entries). Randomization produced 819 participants in group 1, and 797 in group 2. Groups 1 and 2 did not differ significantly in any background variable. After the intervention, subjects "very likely" to do CC on a stranger increased by 17.2% (95% CI, 12.5%-21.8%) in group 1 and 21.2% (95% CI, 16.4%-25.9%) in group 2. Subjects "very likely" to use an AED on a stranger increased by 20.0% (95% CI, 15.3%-24.7%) in group 1 and 25.0% (95% CI, 20.2%-29.6%) in group 2. Knowledge of correct CC rate increased by 59.0% (95% CI, 55.0%-62.8%) in group 1 and 64.8% (95% CI, 60.8%-68.3%) in group 2. Knowledge of correct CC depth increased by 44.8% (95% CI, 40.5%-48.8%) in group 1 and 54.4% (95% CI, 50.3%-58.3%) in group 2. Knowledge of correct action in an OHCA scenario increased by 27.4% (95% CI, 23.4%-31.4%) in group 1 and 27.2% (95% CI, 23.3%-31.1%) in group 2. CONCLUSION: Video self-instruction can significantly improve attitudes toward and knowledge of CPR and AEDs among police officers. Future studies can assess the impact of VSI on actual rates of CPR and AED use during real out-of-hospital cardiac arrests.

Reconceptualizing the emergency medicine resident scholarly requirement: Proposed framework and rubric.

Background: The completion of a scholarly project is a common program requirement by the Accreditation Council for Graduate Medical Education (ACGME) for all residency training programs. However, the implementation can vary significantly between programs. Lack of generalizable standards for scholarly projects required of all trainees within ACGME-accredited residencies has led to a large range of quality and effort put forth to complete these projects. Our goal is to introduce a framework and propose a corresponding rubric for application to resident scholarship to quantify and qualify the components of scholarship to better measure resident scholarly output across the graduate medical education (GME) continuum. Methods: Eight experienced educators and members of the Society for Academic Emergency Medicine Education Committee were selected to explore the current scholarly project guidelines and propose a definition that can be universally applied to diverse training programs. Following a review of the current literature, the authors engaged in iterative, divergent, and convergent discussions via meetings and asynchronous dialogue to develop a framework and associated rubric. Results: The group proposes that emergency medicine (EM) resident scholarship should (1) involve a structured process, (2) generate outcomes, (3) be disseminated, and (4) be peer reviewed. These components of resident scholarly activity are achieved whether this is a single project encompassing all four domains, or multiple smaller projects that sum to the whole. To assist residency programs in assessing a given individual resident's achievement of the standards set forth, a rubric is proposed. Conclusion: Based on current literature and consensus, we propose a framework and rubric for tracking of resident scholarly project achievement in an effort to elevate and advance EM scholarship. Future work should explore the optimal application of this framework and define minimal scholarship goals for EM resident scholarship.

The more things change the more they stay the same: Factors influencing emergency medicine residency selection in the virtual era.

Background: Interviews for emergency medicine (EM) residency positions largely transitioned to a virtual-only format in 2020-2021. The impact of virtual interview factors on applicants' rank of programs is unknown. Objective: We sought to assess the impact of modifiable factors in virtual interviews on applicants' rank of EM residency programs. Methods: We conducted a cross-sectional mixed-methods survey of students applying to at least one of seven study authors' EM residency programs in the United States during the 2020-2021 application cycle. The survey was developed using an interactive Delphi process and piloted prior to implementation. The survey was administered from May to June 2021 with up to four email reminders. Quantitative analysis included descriptive statistics. Three authors performed a thematic qualitative analysis of free-text responses. Results: A total of 664 of 2281 (29.1%) students completed the survey, including 335 (50.5%) male, 316 (47.7%) female, and six (0.9%) nonbinary. A total of 143 (21.6%) respondents identified as underrepresented in medicine and 84 (12.7%) identified as LGBTQIA+. Respondents participated in a median of 14 interviews and ranked a median of 14 programs. Most respondents (335, 50.6%) preferred a choice of in-person or virtual, while 183 (27.6%) preferred all in-person, and 144 (21.8%) preferred all virtual. The program website and interview social were the most important factors influencing respondent ranking. Qualitative analysis revealed several positive aspects of virtual interviews including logistical ease and comfort. Negative aspects include technical issues, perceived interview hoarding, and barriers to applicant assessment and performance. Demonstrated effort by the program, effective information delivery, communication of resident culture, and a well-implemented interview day positively influenced respondents' rank of programs. Conclusions: This study identified characteristics of the virtual interview format that impact applicants' rank of programs. These results can inform future recruitment practices.

Quality assessment of optic nerve sheath diameter ultrasonography: Scoping literature review and Delphi protocol.

BACKGROUND AND PURPOSE: The optic nerve is surrounded by the extension of meningeal coverings of the brain. When the pressure in the cerebrospinal fluid increases, it causes a distention of the optic nerve sheath diameter (ONSD), which allows the use of this measurement by ultrasonography (US) as a noninvasive surrogate of elevated intracranial pressure. However, ONSD measurements in the literature have exhibited significant heterogeneity, suggesting a need for consensus on ONSD image acquisition and measurement. We aim to establish a consensus for an ONSD US Quality Criteria Checklist (ONSD US QCC). METHODS: A scoping systematic review of published ultrasound ONSD imaging and measurement criteria was performed to guide the development of a preliminary ONSD US QCC that will undergo a modified Delphi study to reach expert consensus on ONSD quality criteria. The protocol of this modified Delphi study is presented in this manuscript. RESULTS: A total of 357 ultrasound studies were included in the review. Quality criteria were evaluated under five categories: probe selection, safety, positioning, image acquisition, and measurement. CONCLUSIONS: This review and Delphi protocol aim to establish ONSD US QCC. A broad consensus from this process may reduce the variability of ONSD measurements in future studies, which would ultimately translate into improved ONSD clinical applications. This protocol was reviewed and endorsed by the German Society of Ultrasound in Medicine.