Table 3 lists all statements in Domains 1–3 with references that were considered as evidence for each statement, the median appropriateness score for Round 2, the degree of consensus, the level of evidence, and the strength of the recommendation. Table 4 lists all Domain 4 content items considered for an undergraduate medical student ultrasound curriculum.

There were a total of 332 consensus conference statements and curricular content items in Domains 1–4. Of these, 145 were recommended, 126 were strongly recommended, and 61 were not recommended. Relevant conference discussion, written survey comments of participants, and more recent references have been included in the discussion of the final consensus recommendations.

Of the 28 statements in Domains 1–3 covering the scope, the rationale, and the characteristics of an undergraduate ultrasound curriculum, 19 statements were recommended and 9 were strongly recommended. As anticipated, GRADE evaluation of the literature did not demonstrate a high level of evidence for the statements, confirming the need for an emphasis on expert opinion.

These 28 consensus statements can serve as a guide for medical school curriculum directors and their institutions in the planning, development, and expansion of ultrasound medical student education. Details including statements, rationales and relevant references of all 28 statements can be found in Additional file 1: Appendix S1. The nine statements that the expert panelists strongly recommended are highlighted here as well as one of the recommended statements of particular significance related to non-physician ultrasound education.

Domain 1: scope of consensus conference curriculum

D1.1: The ICC will produce consensus recommendations on “An integrated ultrasound curriculum” (“curriculum”) for undergraduate medical education (medical school).

The overall structure of the medical student curriculum should be that of an integrated curriculum across concurrent courses horizontally and across courses and clinical clerkships vertically for each year of medical school. Integration can be broadly defined operationally as deliberately unifying separate areas of knowledge [26]. Globally, medical education accrediting bodies have encouraged and even required that medical school curricula be integrated [27,28,29]. The Carnegie Foundation Report in 2010 Educating Physicians: A Call for Reform of Medical School and Residency calls for more integration throughout medical education [31]. Various levels of integrated ultrasound curricula have been successfully implemented in medical schools internationally varying in size, school mission, and integration format [33,34,35,36,37,38, 157, 173].

D1.2: The curriculum forms the foundation for ultrasound as a core clinical competency for all graduates regardless of specialty choice.

Over the past two decades, competency-based medical education (CBME) has become the standard for medical education. Competency can be defined as an observable, measurable, and assessable ability of a health professional. Competencies can be broken down into milestones that are observable steps used to assess and document a learner’s progress toward a given competency along a developmental continuum [39, 40].

General Physician Competencies have been clustered into domains of competence which are broad but distinguishable areas of competence that constitute a general descriptive framework for a profession [41]. From the work on competencies and domains have come Entrustable Professional Activities (EPAs). EPAs are units of professional practice, defined as tasks or responsibilities that trainees are entrusted to perform unsupervised once they have attained sufficient specific competence [42, 43].

Ultrasound is well suited for a competency-based model of medical education and EPAs. Ultrasound can directly serve as a competency component for a number of the core EPAs such as performing a quality physical examination (EPA 1), prioritizing a differential diagnosis following a clinical encounter (EPA 2), recommending and interpreting common diagnostic and screening tests (EPA 3), recognizing a patient requiring urgent or emergent care and initiating evaluation and management (EPA 10), and performing general procedures of a physician (EPA 12) [3, 44,45,46,47,48,49,50,51,52].

In addition to these direct roles that ultrasound can play in these EPAs, it can also play important indirect roles in several other core EPAs such as being more knowledgeable about ordering imaging studies (EPA 4), forming clinical questions (EPA 7), collaborating on an inter-professional team (EPA 9), understanding informed consent (EPA 11), and contributing to a culture of safety and improvement (EPA 13).

Patient safety is an important aspect of EPAs as it has been proclaimed as “the primary motivation for the work on EPAs” [42]. Because ultrasound does not use ionizing radiation like X-rays and computed tomography, it is a particularly safe imaging modality. In addition, the Agency for Healthcare Research and Quality (AHRQ) has identified the use of real-time ultrasound guidance during central line insertion as a top ten patient safety practice. The AHRQ also recommends that providers not delay in adopting this practice of using ultrasound guidance [53].

Domain 2: rationale for the curriculum

D2.8: The curriculum enhances the overall educational experience.

Early POCUS research on medical student exposure to ultrasound focused primarily on student satisfaction and found that students enjoy having ultrasound in the curriculum and feel it enhances their education [33, 70, 82, 84, 116,117,118,119]. However, some evidence suggests that students can feel overconfident in their POCUS skills or image interpretation at a time when they have limited understanding of the underlying core principles of patient management leading to the consideration that POCUS might best be considered as a supplemental skill [120]. POCUS has been described as motivating students to delve deeper into matters of interest while not appearing to adversely impact the time necessary to learn the content that already exist in overcrowded undergraduate curricula [35, 121]. Although there is some suggestion that ultrasound improves basic science knowledge and clinical skill, future educational research will need to focus more on objective outcomes that show that ultrasound enhances learning of content and prepares students for advanced training and clinical practice.

D2.9: Medical students can learn basic ultrasound.

There is ample evidence that students can learn basic ultrasound and ultrasound applications, including both image acquisition and image interpretation [35, 70,71,72, 75, 122,123,124,125,126,127,128,129,130,131,132,133,134,135,136,137,138,139,140,141,142]. Image integration into clinical practice still requires clinical knowledge that exposure to ultrasound anatomy and physiology alone does not confer. Once a standardized ultrasound curriculum is established, more individual and collaborative research efforts will be needed to further define the best methods of ultrasound instruction and assessment of student ultrasound knowledge and skill.

Domain 3: characteristics of the curriculum

D3.1: The ultrasound curriculum forms the foundation for ultrasound training along a continuum of medical education from undergraduate through graduate to continuing medical education.

Point-of-care ultrasound at the patient's bedside represents a new tool for the practicing physician. Originally introduced by those caring for emergency and critical care patients to rapidly evaluate and manage their patients, its use has spread throughout hospital services and outpatient care settings. As many as 20 US medical and surgical specialties now require competency and/or experience in ultrasound applications at the completion of their graduate medical education training [152].

Because POCUS is rapidly diffusing into medical practice, it is essential that there be a structured and well-organized program to facilitate ultrasound training in schools of medicine and a smooth transition to postgraduate training.

A recent scoping review of the literature on ultrasound in medical school education and a consensus of ultrasound education directors support the need for a standardized point-of-care ultrasound curriculum that would lead to the development of common standards for milestones and competency-based assessments [19, 155]. Hence, a standardized foundational curriculum delineated by experts in the field of ultrasonography, by those experienced in its use in diverse clinical settings and at the point of patient care, and by educators knowledgeable about the trajectory of physician development can provide guidance as this new skill is integrated into the profession throughout the world.

D3.8: The ultrasound curriculum enhances the learning of clinical sciences through the integration of ultrasound into clinical problem solving.

Along with the integration of the patient history, the physical exam, and laboratory data, point-of-care ultrasound can provide additional information readily available at the time of the patient encounter leading to a more rapid and accurate guide to diagnosis and treatment [3, 163]. Thus, the introduction of ultrasound into the medical school curriculum, likewise, may provide additional accuracy in the accumulation of patient information that fosters improved understanding of underlying pathophysiology. Such improved understanding can aid in the development of a student’s rational diagnostic or therapeutic plan. Ultrasound in undergraduate medical education has been shown to improve the accuracy of the student physical examination. For example, students with limited ultrasound training were more accurate than cardiologists in cardiac exams [44]; than faculty in estimating the size of the liver [45]; and in locating the femoral artery with than without ultrasound [99]. Integration of ultrasound has the potential to improve other aspects of the physical exam, including evidence of professionalism [154]. Use of ultrasound by students may enhance their ability to assess patients with critical presentations, such as hypotension [100]. Accurate patient assessment during physical examination allows the student to better integrate findings into their overall clinical problem solving.

The following recommendations are clustered for discussion as all three relate to the value and validity of the recommended curriculum in the context of organized medical ultrasound.

D3.12: The ultrasound curriculum is based on evidence and expert opinion.

D3.13: The ultrasound curriculum is consistent with recommendations and guidelines of well-established specialty organizations.

D3.14: The ultrasound curriculum is consistent with recommendations and guidelines of regulatory bodies with significant experience in ultrasound.

Point-of-care ultrasound represents a new clinical skill with much information now accumulating on its applicability to many areas of medicine. As such, a burgeoning literature along with expert opinion is becoming widely accessible to guide the development of an international curriculum. A number of professional societies have developed or are developing guidelines and/or curricula in the area of ultrasound [5, 106, 164,165,166,167,168,169,170,171,172]. The International Consensus Curriculum aligns with these societal guidelines to prepare early learners with the necessary foundation to use POCUS in their future chosen area of medicine, as supported by the guidelines of these national and international societies.

In addition to these strong recommendations from Domains 1–3, recommended statement D1.4 concerning the role of the consensus conference curriculum in non-physician education warrants some clarification based on considerable conference meeting discussion and survey comments.

D1.4: The curriculum can serve as a valuable resource for the development of ultrasound training programs for non-physician healthcare providers such as advanced nurse practitioners and physician assistants.

Considering the overlap in medical student educational content and skill with that of other healthcare professionals as set by their accrediting bodies such as nurse practitioners, nurses, physician assistants, and emergency medicine technicians, an integrated ultrasound curriculum for medical students should prove to be a valuable and appropriate resource for the education of these and other healthcare professionals [27, 59,60,61,62]. It has been demonstrated that non-physician providers can learn and competently use ultrasound in the clinical setting [63,64,65,66]. In addition, a common clinical skill like ultrasound offers excellent opportunities for inter-professional training.

There was agreement in conference discussions that a standardized ultrasound curriculum for medical students determined by this consensus conference could be a valuable resource for non-physician healthcare providers. However, it was emphasized that the curriculum should not be considered a recommended curriculum; it should only serve as a resource for curricular development. Other healthcare providers will need to determine the specifics of their ultrasound curricula based on their accreditation and clinical practice standards as determined by their own professional organizations.

Domain 4: curricular content

Domain 4 focused on the content of a medical student ultrasound curriculum. Of the 304 Domain 4 content items, 126 (41.4%) were recommended, 117 (38.5%) were strongly recommended, and 61 (20.1%) were not recommended. All recommended content would be considered appropriate for a medical student ultrasound curriculum, but should not be considered as required content. Content used within an individual medical student curriculum should be based on a number of factors including how well the specific content items fulfill the needs and objectives of the courses and clinical clerkships in the curriculum, the availability of adequate resources to implement the specific ultrasound components, and the faculty expertise available to teach the specific components of the ultrasound curriculum.

It should also be noted that for those medical educational systems that have medical school graduates immediately engaged in various levels of independent clinical practice, assessment of medical student ultrasound competency at graduation would need particular attention. Completion of the recommended ultrasound curricular content does not ensure independent clinical ultrasound competency. The decision of practice competency directly after medical school graduation will need to be made by the individual medical school and/or the appropriate accrediting body in accordance with established clinical practice standards.

Medical schools with successful ultrasound programs have generally started by introducing a small number of basic ultrasound components into the curriculum and have then expanded the number of ultrasound components over time [