Standardized Patients in Medical Education: A Review of the Literature

The concept of standardized patients (SPs) was first introduced in the 1960s by Dr. Howard Barrows of the University of Southern California and has been applied in medical school education since that time. This practice has allowed medical students to practice skills on live persons who are teachers rather than on real patients, who may be endangered by their emerging skills. Previous studies supported the use of SPs but did not measure whether they improved clinical competence or students’ confidence in their skills. This literature review evaluated whether current medical education literature supports or refutes the use of SPs compared to other modalities such as simulated patients (SiPs) and virtual reality (VR) in the improvement of student confidence, clinical performance, and interpersonal communication skills. The research questions posed for this review were as follows: do medical students in their first two years of education who have practiced skills using SPs have more self-confidence in their ability to perform skills on real patients than those students who did not use SPs, do medical students in their third and fourth years of medical school have higher clinical competency with sensitive patient examinations after using SPs in their first two years of medical education than those students who did not use SPs, and do medical students who have used SPs for discussing sensitive issues have better interpersonal skills when they encounter real patients in the clinical setting than those who have not used SPs? The methodology for this descriptive, systematic review of the literature was organized using a Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) flowchart to describe how articles were collected and synthesized to evaluate the variables under study. The results of this study revealed that students learned the most when SPs were used because they were able to teach students the skills that they needed in a safe learning environment. Medical students performing sensitive patient examinations with SPs learned not only how to perform the examinations but also how to improve their communication with patients. Students and residents reported increased confidence and clinical competence when performing new skills with SPs rather than with peer practice, virtual reality, or real patients in a clinical setting. Although the utilization of SPs has been studied in multiple ways and found to be a powerful tool in the education of undergraduate medical students and interns, there is still much study to be done to address the human needs of real patients. Gaps in this literature included small sample sizes, a lack of standardized assessment tools, and the need to include a multidisciplinary approach that addresses cultural awareness and appreciation. The authors found limited studies analyzing the effect the coronavirus disease 2019 (COVID-19) pandemic had on the use of SPs in medical school education. Continued scientific inquiry in post-pandemic medical education is an essential component for dissemination as most schools have reintroduced the use of SPs, which strengthens the concept that their use is superior to the other simulation methods used when SPs were not available.

Eight out of 195 accredited medical school campuses in the United States (medical doctor (MD) and doctor of osteopathic medicine (DO)) do not advertise the use of standardized patients in their online marketing and web pages [3,4].
In this literature review, the authors will show that the body of literature regarding the use of SPs is overwhelmingly supportive of their use in medical school over the course of a student's education, starting in the first year and extending into residency. The authors found that students expressed increased confidence and less anxiety, demonstrated a higher level of clinical competency, and increased their interpersonal communication skills, after following a medical school curriculum that utilized SPs.  studied how well 163 first-year medical students performed with live patients versus SPs in clinical encounters exploring communication skills. The students reported that SPs provided better feedback than live patients to assist the medical students in learning medical communication concepts [5,6]. Davies et al. (2015) reported that clinical performance and student self-confidence were positively correlated to the use of SPs, as evidenced by increased scores on clinical evaluations and self-reported confidence scores [7]. SP effectiveness was evaluated by Fortin et al. (2002) in a qualitative study with 91 first-year and 36 second-year medical students. The students were questioned on their perceptions of the encounters with the SP. Students reported that the SPs contributed to their learning of communication skills and were helpful in providing knowledge on how to best communicate with patients regarding psychosocial encounters. They reported that the use of the SPs helped them have more confidence in their interpersonal communication [8]. Another study completed by  utilized nine adolescent SPs, in adolescent scenarios with 341 medical students. The purpose of the study was to see if adolescents as SPs could provide meaningful feedback to medical students. Results found from interviews with the medical students revealed that most students found the experience beneficial and helpful using age-appropriate SPs in adolescent case study scenarios, and the adolescent SPs suffered no ill effects [6].
To better understand the role of SPs versus learning from colleagues, Power and Center (2010) looked at peers performing sensitive examinations on each other. The ones that returned the survey stated "this was the worst experience they had during medical school" and showed the need for an SP curriculum to practice skills for genital and breast examinations [9].
In a landmark study, Plauché et al. (1985) studied the effect of using SPs for sensitive patient examinations, particularly gynecologic examinations. This study showed that third-year medical students and resident physicians would rather use gynecologic teaching associates (GTAs) to learn and practice skills because they felt more comfortable and better prepared when they were required to see live patients. This study supported the need for standardized sensitive patient examinations, especially for those students who were not going to go into obstetrics and gynecology [10].
The purpose of this literature review was to look at the body of research and explore the value or detriment of utilizing SPs in medical school education and the effect SP use has on student self-confidence, clinical competence, and interpersonal communication skills in medical students and resident physicians. Additionally, the use of virtual reality and mannequin simulation was also considered. The authors of this paper wanted to determine whether the use of virtual reality and mannequin simulation could replace the use of SPs or if they each served an independent, adjunctive purpose in the student's medical education.
Additionally, an inquiry was made into the traditional role of "real patients" being the primary source of student clinical practice in medical education or whether using SPs in the early medical education of the novice clinician would result in higher levels of clinical competence, interpersonal communication skills, less anxiety, and more self-confidence in these students.
Over the course of looking at the literature, several questions emerged: do medical students in their first two years of education who have practiced skills using SPs have more self-confidence in their ability to perform skills on real patients than those students who did not use SPs, do medical students in their third and fourth years of medical school have higher clinical competency with sensitive patient examinations after using SPs in their first two years of medical education than those students who did not use SPs, and do medical students who have used SPs for discussing sensitive issues have better interpersonal skills when they encounter real patients in the clinical setting than those who have not used SPs?

Review Methods
The aim of this literature review was to evaluate the current body of knowledge on the use of SPs in medical school education. The research questions served to evaluate whether the literature supports or refutes that student confidence, clinical competence, and interpersonal communication skills are more positively related to the use of SPs on these variables than the use of other patient simulation modalities, including real patients, in clinical practice.
To organize the results of the study, the authors grouped these data into the variables under study, which were those included in the research questions for this literature review: variable 1 was student selfconfidence in the performance of skills, variable 2 was the performance of clinical competence by evaluation, and variable 3 was the use of interpersonal communication skills to include sensitive and  difficult topics with patients and their families.   The methodology for this descriptive, systematic review of the literature was organized chronologically in  the literature table to explore trends in the use and benefits of SPs in medical education. The time periods  between 2005 and 2010, and between 2014 and 2018 revealed a surge in the literature regarding the use of  SPs. When the coronavirus disease 2019 (COVID-19) pandemic was emerging and peaking, between the years 2020 and 2022, there were few articles specific to the use of SPs because their use was discontinued during this time of limited face-to-face educational instruction.
Articles were collected with the use of commonly used medical databases such as PubMed Central, EBSCOhost, Cumulative Index to Nursing and Allied Health Literature (CINAHL), Full Text Finder from Lake Erie College of Osteopathic Medicine electronic journal holdings, Medline, and PsycINFO.
The successful keywords selected to obtain articles that were applicable to our research questions and variables under study included "standardized patients," "medical school education," "clinical competence," "interpersonal communication," and "student confidence" or "self-efficacy." To exclude studies that did not fit the research questions of the study, the inclusion criteria were articles written in English, date ranges from 2008 to 2023 (no older than 15 years from publication), and landmark articles for years prior to 2008. Additionally, the literature included from intervention and review articles had to include the use of live SPs during the four years of medical school education or during medical residency and explored the variables under study, as delineated above.
Using these criteria, we finalized 40 articles in total. Of those articles, we had 23 intervention studies, 16 review papers, and one case study review. Within the review articles that were cited, seven of these also had descriptive or informational data related to the use of SPs, which was thought to help the novice reader understand the concept of the use of SPs and the variables under study more clearly.
The variables under study were represented in the 40 articles as follows: variable of student confidence, selfefficacy, or reduction of anxiety (12 articles), variable of clinical competence ratings of students by either SPs or faculty or by student report (15 articles), variable of interpersonal communication skills (20 articles), and variable of problem-based learning (PBL) medical school preparation to clinical (five articles).
The total represented above is over 40 because many of the articles included more than one variable being examined per article. These data are organized into the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) flow diagram presented in Figure 1.

Results
Fifteen articles in this review addressed the variable of clinical competence after using SPs in the four years of medical school. Twelve were focused on student confidence, or self-efficacy, in the ability to perform clinical skills for the breast and gynecologic portions of the examination for females and the genitourinary portions of the examination for males. Self-efficacy and student confidence were also measured and analyzed for communication skills for sensitive and difficult patient interactions. Twenty articles were reviewed to explore interpersonal communication skills using SP encounters. Another seven articles explained the nature of SPs, as well as the gaps in the educational literature on the use of SPs.

Student Self-Confidence
In a landmark study by Plauché et al. (1985), 420 third-year medical students were evaluated for clinical competence and rated for student self-confidence in an intervention using GTAs. The highest-ranked answers from the questionnaire were for increased student comfort, a successful learning experience, and an increase in knowledge. Qualitative data from this study included quotes from students in which graduates of the program felt they would benefit from using GTAs to practice throughout the curriculum. Most of the students in this study strongly disagreed that the use of GTAs was a "waste of time" [10].
Similarly, Beckmann et al. (1986) studied student response to GTAs in 292 second-and third-year medical students and found that almost 100% of the sample reported GTAs to be "outstanding and helped to alleviate anxiety" [11].
In a large 10-year systematic literature review between 1996 and 2005, May et al. (2009) reviewed 866 articles that studied the use of SPs in graduate nursing student education. They found that students reported positive outcomes in knowledge skills and attitudes after having had experiences with SPs prior to seeing real patients in the outpatient setting. Medical students and graduate nursing students have the same type of clinical experience, so results would be appropriate for this review [12].

Student Clinical Competence
Other major studies include interventions aimed at the use of SPs to improve clinical competence. McGraw and O'Connor (1999) performed a quasi-experimental intervention using 75 first-year medical students and found that using SPs helped student learning when utilized in small student groups of four to six early in their medical school education. Additionally, the study supported the conclusion that student clinical competence was not adversely affected when not experiencing real patient encounters [13]. Wånggren et al. (2005) conducted a landmark intervention study to look at the use of GTAs in medical school education, evaluating student skills and feelings. All 48 medical students reported that they felt they were more competent at performing sensitive physical examinations using GTAs. The GTAs were also able to provide appropriate communication to students while performing this sensitive physical assessment to guide them to the correct technique. Additionally, the students highly rated the ability to receive immediate feedback from the SPs in this way. The SP, in this case, was acting in the role of teacher and patient [14].
SPs are commonly used with students to assess their clinical competence. Epstein and Hundert (2002) did a landmark systematic literature review, in which they chose 195 relevant articles and explored professional competence in medical students' assessment skills, interpersonal communication, and professionalism. The results of this study showed a need to standardize the forms used to evaluate clinical competence in medical students, as well as the need to develop a multidisciplinary assessment approach [15]. Theroux and Pearce (2006) completed an intervention study with 28 graduate medical and nursing students, measuring the competence and comfort level they had in performing pelvic examinations after working with SPs. This qualitative, longitudinal study was performed over three years in school and found that those students who utilized SPs expressed more self-efficacy than those who practiced on their peers [16].
More recently, Cifuni et al. (2020) performed an intervention study on first-year emergency medicine interns transitioning to medical practice. The authors wanted to see what the interns felt about using SPs prior to seeing real patients. Of the interns, 90% reported that this experience would change their clinical practice positively. After one year, 75% of residents reported that their experiences with the SPs did in fact change their clinical practice and that they established good habits early in their internship year [17].

Interpersonal Communication Skills
Spencer et al. (2000) explored patient-oriented learning environments with the use of SPs in a landmark study. They focused on the role of standardized patients as teachers in educating medical students on communication skills, empathy, and professional attitudes. This literature review found that using SPs as teachers provided context to their history and physical course content and allowed faculty to evaluate how essential the role of SPs was in the development of strong student interpersonal communication skills [18]. Kneebone et al. (2006) along with several other studies included in this review looked at the use of SPs in contrast to simulation using virtual reality and other simulation methods, such as mannequins and simulators. The overarching conclusion from these studies is that humans, in the form of SPs, can trigger authentic responses from the students that the other modalities do not elicit [19][20][21][22].  used adolescent SPs for teaching communication skills to medical students in their first two years of study; 341 students participated in the study and felt that their communication skills improved due to the use of age-appropriate SPs [6].
Block et al. (2018) completed a systematic literature review and found that students highly rated the feedback they received from SPs. These students expressed that working with SPs improved their communication skills, and they expressed the desire to work with the same SPs to learn communication skills in scenarios over time that supported the concept of continuity of care [23]. of a six-year medical education program, which was their first year in medical school. The purpose of the study was to evaluate clinical skills after doing case-based learning scenarios in class using live SPs. The data collected from three focus groups revealed that the use of SP encounters was very helpful in solidifying concepts they learned in the case [24]. The following year, Diemers et al. (2008) published a second study in which they studied students in the problem-based learning (PBL) track from the Netherlands in their first and second years of medical school. They found that SP encounters reinforced communication skills learned in PBL. The students felt that experiential learning utilizing SPs increased their communication, medical knowledge, and clinical skills [25].

PBL and Communication Skills
Lane and Rollnick (2007) did a systematic literature review, starting with 5,305 references, to study the use of SPs in PBL role-play and compare those to the groups that did not use SPs. The students in these studies more often would report that their communication skills were more improved in the sessions utilizing the SPs [26].
Yoon et al. (2016) studied 99 medical students who were enrolled in a PBL educational curriculum looking at the use of SPs in PBL role-play. They compared role-play using SPs versus video encounters, and most medical students evaluated sessions more positively with the use of standardized patients versus videos [22]. Table 1 presents the entirety of the results of this study . Year

Discussion
The authors of this study reviewed both research intervention and literature review papers that explored the use of an SP curriculum for teaching both clinical skills and interpersonal communication skills in medical school education. The concepts under study included the variables of student self-confidence, ratings from faculty, SPs, and students themselves regarding clinical competence and interpersonal communication skills. This review concluded that the use of SPs prior to working with "real" patients resulted in more student self-confidence and a reduction of student anxiety in performing novice skills. Students demonstrated better clinical skills with sensitive patient examinations using SPs than those who did not use an SP curriculum.

Student Self-Confidence
The concept of using SPs as teachers was explored in this review of the literature. Rethans et al. (2007) [27] and Bokken et al. (2008) [28] reported that the students rated the use of SPs as teachers as highly valuable. They felt that SPs provided a safe learning environment where they could make mistakes and receive feedback, and they revised the method by which they completed the task. Since the SPs were trained, they were aware of what to expect for their examination and could feel free to tell the student the mistakes they had made. In turn, students reported that they could make a mistake without the repercussions of hurting a live patient. Dabson et al. (2014) reported that when students were able to practice the sensitive patient examination with a SP, they reported that they had less anxiety and discomfort because they would be better prepared to perform skills with a live patient and lessen the chance of making a mistake with them. Students also reported that they felt very distressed about having to perform intimate examination skills with their peers, and the use of SPs eliminated that anxiety [29].
Colbert-Getz et al. (2013) examined the attitudes of male and female medical students and their confidence in practicing and performing new skills. Their study revealed that male students tended to feel more confident and rate their performance higher than their female counterparts. This study was included in this review to highlight a possible learning issue that could be present in medical students. The need for further research on this phenomenon could guide medical educators to teach skills in which the student could demonstrate a high competence level, which in turn may increase confidence in some female students [30].

Student Clinical Competence
When looking at a student's ability to perform clinical skills, it was most noted that they felt better prepared to see "live" patients after having utilized SPs to "practice" skills with. Students reported that they were better prepared and more competent for real patient interactions when they practiced their assessment skills with SPs before going into real clinical sessions. Resident physicians who encountered an unknown patient (not knowing whether they were standardized patients or real patients) preferred SPs when revealed, as the SPs acted as teachers, whereas real patients did not [27]. Ramey et al. (2018) showed that SPs increased overall clinical competency in medical students and strengthened their skills. Patients benefited from students who had completed their clinical skill learning with SPs by safeguarding them from the clinical incompetence of a "new" clinician [31]. Marwan et al. (2012) showed that actual clinic patients would refuse to have students perform sensitive patient examinations if the student did not display a level of confidence with this examination. The use of GTAs assured that all students were able to practice these skills regardless of patient refusal [32].
The use of SPs has been shown by this study to enhance the use of psychomotor skills and patient communication. When compared to virtual reality (VR), the use of SPs was seen to support, but not replace, the experience of performing skills with SPs [20]. Kneebone et al. (2006) found similar findings, concluding that "using real humans in an SP role can trigger more authentic responses from trainees on a level that computers and models cannot" [19]. Oh et al. (2015) explored graduate nursing students using SPs and revealed a beneficial effect on self-efficacy, knowledge and skill acquisition, and improved motivation with improved clinical skills in faculty evaluations. The examination skills taught in advanced physical assessment courses in graduate nursing education are comparable to those in medical school; therefore, this study is applicable to medical school education and SPs [33].

Interpersonal Communication Skills
Papanagnou et al. (2021), in one of the descriptive articles, discussed the need to develop protocols for the use of SPs regarding communication skills training in a PBL curriculum. The authors proposed that protocols must include a specific, well-thought-out procedure for the development of the case studies used [34]. Kaplonyi et al. (2017) also demonstrated that the use of SPs early in the curriculum for first-and second-year medical students helped them improve their communication skills [35]. Jones et al. (2022) also noted that the use of SPs early in preclinical education was helpful in integrating pharmacology and basic sciences [36]. Linssen et al. (2007) showcased that medical students in their third year of education who worked with the same SPs over time improved their communication skills more consistently than those who worked sporadically with a different SP each time [37]. Block et al. (2018) corroborated that students and SPs preferred to have the same pairing throughout medical school training as it helped students work on skills longitudinally [23]. Coleman et al. (2013) established that a multidisciplinary approach to sexual healthcare was warranted [38]. Knight et al. (2014) reported that clinicians felt frustrated because they lacked clinical skills specific to the medical approach with the assessment and management of patients from the Lesbian, Gay, Bisexual, Transgender, and Queer plus (LGBTQ+) community, and these clinicians felt that if they had the opportunity to learn and practice this specific skill set with properly trained SPs when they were in their medical education, they would be better prepared and more competent to work with these patients [39].  [41] successfully explored attitudes on the strengths and weaknesses of using SPs in practicing new skills rather than with "real patients." They revealed that students placed greater value on the practical feedback from SP encounters and added that SPs and "real" patients can complement each other without excluding the other. Furthermore, Wilbur et al. (2018) highlighted the need for ongoing studies in medical education using SPs [42].

Conclusions
The reality of medical practice in the United States is based on a productivity model that requires medical providers to see many patients each day to make up for the lack of reimbursement by insurance. This limits the time for teaching or practicing novice skills, making it challenging for medical students to master the decision-making process required for patient care. To overcome this obstacle, medical practice needs an alternative method to better prepare students for clinical training. This review highlighted the rich body of literature that demonstrates the effectiveness of the use of SPs in medical curricula. There is overwhelming evidence to show that using SPs in medical education substantially increases student confidence, clinical competence, and interpersonal communication skills. Moreover, it comprehensively prepares them for the actual clinical encounters on their clinical rotations and beyond. In contrast, there is a lack of meaningful studies on the effectiveness of VR versus SP curriculum and the cost-effectiveness of VR. Newer studies are needed to evaluate more innovative approaches to SP education, as much of the current literature is outdated. Small sample sizes limit the strength of the study conclusions, making it difficult to generalize the findings to other populations of medical students. Studies also lacked reliable instrumentation for measuring positive outcomes that quantify the effectiveness of using SPs. In a post-pandemic environment, it is crucial to study how COVID-19 affected medical students' skills, confidence, and communication.

Conflicts of interest:
In compliance with the ICMJE uniform disclosure form, all authors declare the following: Payment/services info: All authors have declared that no financial support was received from any organization for the submitted work. Financial relationships: All authors have declared that they have no financial relationships at present or within the previous three years with any organizations that might have an interest in the submitted work. Other relationships: All authors have declared that there are no other relationships or activities that could appear to have influenced the submitted work.