Learning Curve Cumulative Summation Research Articles

EVALUATING THE LEARNING CURVE OF A NOVICE OPTOMETRY STUDENT IN SCLERAL LENS FITTING: A PROSPECTIVE QUANTITATIVE STUDY USING DELIBERATE PRACTICE AND CUMULATIVE SUMMATION (LC-CUSUM)

Background and Objective: To evaluate the learning curve of a novice optometry student in scleral lens fitting through deliberate practice and to objectively quantify the learning process using the LearningCurve-Cumulative Summation (LC-CUSUM) test, ensuring accurate and unbiased results. Method: The complexity of scleral contact lens fittings was assessed by categorizing subjects into regular and irregular cornea groups. A student enrolled in the Master of Optometry program conducted the fittings using a dedicated scleral lens record form (rubrics) designed to quantify the lens management approach. Prior to performing fittings independently, the student received four weeks of training from a contact lens expert, who also served as her guide for the study. This training period and the subsequent fittings were structured based on the principles of deliberate practice, with the student performing repeated diagnostic trials. A maximum of three diagnostic trials were performed for each subject to achieve the optimal fit. After each trial, the student completed a self-efficacy scale questionnaire to assess her perceived diffi-culty and clinical judgement skills, recording “FIRST trial scores” following the initial trial and ‘LAST trial scores’ after achieving the optimal fit. The guide consistently provided verbal feedback after each case throughout the fitting process as part of the deliberate practice methodology to enhance the student’s understanding of the fitting procedure while keeping the scores confidential to ensure unbiased self-as-sessment. Following the complete supervision of the fitting procedure, the guide evaluated the student’s clinical skills using a specially designed observation scale questionnaire, referred to as the ‘GUIDE scores.’ A seven-point Likert scale was used to rate the judgement for both the self-efficacy scale and observation scale questionnaire. The student’s LAST trial scores were subsequently compared with the GUIDE scores. Results: A total of 80 scleral lens fittings were evaluated. The Intraclass Correlation Coefficient (ICC) demonstrated excellent agreement between student-reported self-efficacy scores and guide-reported observation scores. The difference in self-efficacy scores between the initial and final lens fittings was statistically significant (p < 0.05), as determined by the Wilcoxon signed-rank test. The Learning Curve-Cumulative Summation (LC-CUSUM) chart revealed that learning stabilized after 26 fittings, marking a consolidation phase where minimal further improvement was observed beyond this point, and additional practice primarily helped to maintain proficiency. The average number of trials required per eye was higher in patients with irregular corneas than those with regular corneas. Conclusion: This study evaluated the learning curve of a novice optometry student in scleral lens fitting through deliberate practice, utilizing the LC-CUSUM test to quantify progress and assess skill acquisition objectively. Proficiency was achieved after 26 fittings, with additional trials needed for irregular corneas, underscoring the influence of patient characteristics on learning. These findings emphasize the importance of structured training, personalized feedback, and self-assessment in developing clinical competence. The insights contribute to advancing education and research in contact lens science by providing practical guid-ance for designing effective programs focused on planning, teaching, and learning about scleral lens fittings.

225 Learning Curve Cumulative Summation in Emergency Medicine Residents Performing Ocular Ultrasound

225 Learning Curve Cumulative Summation in Emergency Medicine Residents Performing Ocular Ultrasound

The learning curve of transoral condylectomy; a retrospective analysis of 100 consecutive cases of unilateral condylar hyperplasia

In this study, 100 consecutive scheduled transoral condylectomies for unilateral condylar hyperplasia were included. The safety and surgical performances were assessed, using the operating time, conversion rate and complication rate. The conversion rate learning curve was evaluated with a learning curve cumulative summation (LC-CUSUM).The total conversion rate was 8.0%. The LC-CUSUM for conversion signaled at the 53th procedure, indicating sufficient evidence had accumulated that the surgeon had achieved competence. For procedures 54–100, the conversion rate was 4.0%. The operating time for the transoral condylectomy was 41.5 ± 15.3 min; when a conversion was necessary, the operating time was 101.4 ± 28.3 min (p < 0.05). The estimated operating time in the post-learning phase was 37 min, this was reached after approximately 47 procedures. There was 1 major complication of a permanent inferior alveolar nerve hypoesthesia. The complication rate was not significantly decreased after the learning curve.Within the limitations of the study, it seems that transoral condylectomy for UCH is a safe procedure with several advantages over the traditional preauricular approach. Surgeons starting this procedure should be aware of the potential complications and of the learning curve of approximately 53 procedures.

The learning curve for a novel, fluoroscopy-based robotic-assisted total hip arthroplasty system.

Adoption of robotic-assisted total hip arthroplasty (RA-THA) systems can improve the accuracy of acetabular cup placement, but no group has reported the learning curve of novel, fluoroscopy-based RA-THA systems. A learning-curve cumulative summation (LC-CUSUM) analysis was performed on a consecutive series of the first 100 patients who received fluoroscopy-based RA-THA by the study surgeon. Operative times and specific robotic timepoints were compared between learning and proficiency phases. Implementation of fluoroscopy-based RA-THA was associated with a learning curve of 12 cases. A 6-min increase in operative time was seen during the learning phase compared to the proficiency phase (44.3±4.4 vs. 38.0±7.1min; p<0.001), with a 3-min longer robotic cup impaction sequence during the learning phase (7.8±1.9 vs. 4.8±1.3min; p<0.001). Adoption of fluoroscopy-based RA-THA is associated with a brief learning curve of 12 cases, with the most significant improvements in surgical efficiency realised during acetabular cup placement.

Learning curve for biportal endoscopic posterior cervical foraminotomy determined using the cumulative summation test

BackgroundLearning curves describe the rate of performance improvements corresponding to the surgeon’s caseload, followed by a plateau where limited further improvements are observed. This study aimed to determine the learning curve for biportal full-endoscopic posterior cervical foraminotomy (BE-PCF) for the unilateral cervical foraminal disc.MethodsThe learning curve was evaluated using a learning curve cumulative summation test (LC-CUSUM). The goal for the operation time was set to 78 min, which is the mean operation time (mOT) of percutaneous full-endoscopic posterior cervical foraminotomy (PE-PCF) performed by a senior surgeon. Moreover, clinical outcomes and post-operative complications were compared between the early and late learning periods 1 year post-operatively.ResultsThis study enrolled the first 50 patients who underwent single-level BE-PCF, performed by a single surgeon. The LC-CUSUM signalled competency for surgery at the 20th operation, indicating that sufficient evidence was obtained to prove that the surgeon was competent. The mOT was 71.29 ± 11.69 min in BE-PCF, 71.84 ± 12.61 min in the early learning period, and 67.83 ± 10.31 min in the late learning period (p = 0.254). There was no statistical difference in clinical outcomes, visual analogue scale scores, and neck disability index between both periods (p > 0.05). Four complications were recorded throughout the whole period, with three in the early period and one in the late period (p = 0.285).ConclusionOur study shows that BE-PCF has a learning curve of 20 caseloads to achieve 90% proficiency, and it significantly reduces the operation time based on the performance of a senior surgeon proficient in PE-PCF.

Learning curve for microscopic unilateral laminectomy for bilateral decompression surgery using the cumulative summation test for learning curve.

A retrospective observational study The purpose of this study was to characterize the learning curve for a single level unilateral laminectomy and bilateral decompression in lumbar spinal stenosis using a learning curve cumulative summation test. Unilateral laminectomy and bilateral decompression for lumbar spinal stenosis proposes a potential benefit with minimizing surgery-related instability compared to traditional bilateral laminectomy, by preserving posterior stabilizing structures and contralateral facet joint and neural arch. Due to a narrow surgical corridor, it is considered to exhibit a steep learning curve as other types of minimally invasive procedures. However, there are few reports available regarding learning curve of unilateral laminectomy and bilateral decompression. The learning curve of a single surgeon performing single level unilateral laminectomy and bilateral decompression was assessed using learning curve cumulative summation test analysis. The surgeon had minimal experience in open decompressive laminectomy but no previous experience in unilateral laminectomy and bilateral decompression. Procedure success was defined as an operation time less than 75 minutes. Surgery related complications were recorded. Total 194 consecutive patients, who underwent primary single level unilateral laminectomy and bilateral decompression by a single spine surgeon, were included. The mean operative time for unilateral laminectomy and bilateral decompression was 64.6 ± 23.6 minutes. The mean operative time in the early learning period (≤29th case) was 80.6 ± 20.9 minutes, and that in the late learning period (after 29th case) was 61.8 ± 22.7 minutes, respectively. The overall complication rate was 13.9%. Majority of complications occurred in the early learning period. The learning curve cumulative summation test signaled competency for unilateral laminectomy and bilateral decompression at the 29th operation, indicating that the surgeon reached the competent level. In addition, based on the cumulative summation test, the surgeon seemed to maintain his competency for the procedure. This study showed that surgical experience reduced the operation time and surgery related complications. For inexperienced surgeon to achieve an acceptable outcome in unilateral laminectomy and bilateral decompression, minimum 30 cases of unilateral laminectomy and bilateral decompression are required to reach competent level of surgery.

An implementation of the learning curve cumulative summation test to evaluate a practicum for endometrial cancer ultrasound staging.

The learning curve cumulative summation (LC-CUSUM) test is commonly used as a quantitative assessment of the individual learning process. This study aimed to evaluate the skill acquisition process for performing ultrasound staging of endometrial cancer using the LC-CUSUM test. Sixty-seven ultrasound examinations performed by two operators were evaluated using the LC-CUSUM test according to their rate of success or failure to correctly stage myometrial invasion, serosa involvement, and pelvic and para-aortic lymph node involvement. The reference standard was the pathologic result. After the learning phase, the cumulative summation (CUSUM) test was applied to assess performance maintenance. The processes achieved satisfactory performance in the majority of the cases according to the established definitions. Operator 1 reached adequate performance within the 30th procedure for all the locations considered, while operator 2 performed fewer than 30 ultrasound examinations by the audit time. The CUSUM test confirmed that the target quality was preserved after the learning phase. Moreover, the ultrasound staging for endometrial cancer was highly accurate. Using the LC-CUSUM test made it possible to monitor the achievement and maintenance of a satisfactory performance quantitatively. The LC-CUSUM test could be a valuable instrument to survey diagnostic pathways in gynecological ultrasonography quantitatively.

Learning Curve for the Detection of Deep Infiltrating Endometriosis and Adenomyosis with 3-D Transvaginal Water Contrast Sonography.

Three-dimensional rectosonography (RSG) is a transvaginal sonography technique using rectal water contrast and 3-D acquisitions. The main points of interest of 3-D RSG could be its easy accessibility and its quick learning curve, especially with respect to rectosigmoid lesions. The objective of this prospective observational study was to assess the learning curve of 3-D RSG for the diagnosis of rectosigmoid lesions and for various other locations of deep endometriosis (DE), endometriomas and adenomyosis. From April 2017 to November 2017, 116 patients with suspected pelvic endometriosis were referred to the Croix-Rousse University Hospital, and those who underwent 3-D RSG were included in our study. After a short training period, four residents were asked to perform 3-D RSG by themselves. Each procedure was systematically controlled immediately afterward by a single expert sonographer. The success of the procedure involved the correct identification of various locations of endometriosis (rectosigmoid, uterosacral ligament, retrocervical space, vagina, bladder and ovaries) and adenomyosis, using the expert sonographer's examination as the reference technique. The learning curve was generated using these data and assessed using the Learning Curve Cumulative Summation Test (LC-CUSUM) method. The pooled LC-CUSUM revealed that the required level of achievement was reached after 24 3-D RSGs were performed for the diagnosis of rectosigmoid lesions. All four residents were significantly competent in diagnosing rectosigmoid lesions at the end of their training period, with an α risk <0.05 (T1, p=0.03; T2, p=0.0002; T3, p=0.05; T4, p=0.02). The LC-CUSUM analysis confirmed that competency was achieved for vaginal DE, torus uterinum DE, US DE, bladder DE, endometriomas and adenomyosis within 17, 27, 38, 19, 17 and 33 scans, respectively. This study provides evidence that the skills required to diagnose endometriosis lesions and adenomyosis with 3-D RSG can be acquired after a brief learning period in an expert center.

Ultrasound Block of the Medial Branch: Learning the Technique Using CUSUM Curves.

Background:Blocking the medial branch of the lumbar facet joints plays a fundamental diagnostic and therapeutic role in the treatment of lumbar pain. Attempts to replace the typical guided X-ray techniques with ultrasound-guided techniques have also involved treating the lumbar medial branches. By applying the cumulative sum control chart (CUSUM method), we sought to evaluate the learning curve associated with ultrasound-guided block of the lumbar medial branches in operators experienced in locoregional anesthesia but without expertise in pain therapy.Aim:This study aimed to use a repeatable method to identify the learning curve of the ultrasound-guided medial branch block.Settings and Design:This study was a prospective application of over forty consecutive procedures of ultrasound lumbar medial branch block.Materials and Methods:The ultrasound medial branch blocks were performed under ultrasound guidance with confirmation of correct positioning using fluoroscopy on a population of patients with low back pain with any body mass index (BMI).Statistical Analysis:The operator's performance was assessed using the learning curve cumulative summation test (LS-CUSUM).Results and Conclusions:The correct target was reached in 29 procedures out of a total of 40 (72.5%) and in 29 out of 36 procedures performed on patients with BMI <30 (80.5%). According to the CUSUM algorithm, 11 further consecutive successes would have been necessary (47 procedures in total) to achieve a proven learning of the technique in the group with only patients with a BMI <30, with a further 22 consecutive successes (62 procedures in total) in the general group. Ultrasound-guided block of the lumbar medial branch appears not to be optimal for training beginner/intermediate operators seeking to replace guided X-ray procedures with guided ultrasound.

Learning Curve For Lateral Meniscal Allograft Transplantation: Preventing Meniscal Extrusion

This study analyzes the large number of lateral meniscal allograft transplantation (LMAT) procedures conducted by a single surgeon over 23 years to determine whether the absolute amount of graft subluxation and the incidence of extrusion are different at the present time compared to the early MAT era. We reviewed 320 cases of LMAT performed by a single surgeon between 1996 and 2019. This cohort was chronologically divided into 8 groups (of 40 subjects). The absolute amount of subluxation was measured by the coronal sections of magnetic resonance images taken 1 year after operation. Subluxation by more than 3 mm was considered as extrusion. The graft extrusion learning curve was plotted in each series using the learning curve cumulative summation test (LC-CUSUM). Extrusion incidence was 41.6%, and the mean absolute amount of graft subluxation was 3.4 ± 2.2 mm for all subjects. There were significant between-group differences in extrusion incidence and absolute amount of graft subluxation (extrusion incidence, P < .001; absolute amount of graft subluxation, P < .001), and the extension incidence and graft subluxation decreased from Group I (72.5%, 4.6 ± 1.7) to Group VIII (27.5%, 2.5 ± 2.1). LC-CUSUM analysis signaled that the surgeon had achieved predefined acceptable outcomes in avoiding extrusion after 128 cases. The incidence of extrusion and absolute amount of graft subluxation decreased significantly over a period of 23 years, and the surgeon achieved a certain level of proficiency after 128 cases. Level IV, Case series.

Assessment of operator performance during oocyte retrievals: residents\u2019 learning curve and continuous monitoring of senior physicians

BackgroundThe learning curve cumulative summation test (LC CUSUM test) allows to define an individualized learning curve and determine the moment when clinical proficiency is attained. After acquisition of the skills, the cumulative summation test (CUSUM test) allows to monitor the maintenance of the required level over time. The LC CUSUM test has been frequently used in the field of Obstetrics and Gynecology (Ob/Gyn) for several procedures, but only once for OR.MethodsWe performed a retrospective study at Angers university hospital between May 2017 and September 2018. Seven Ob/Gyn residents and 5 senior physicians were included, and all OR performed during that time (n = 690) were analyzed. The performance index assessed was the oocyte retrieval rate (ORR), defined as the ratio of oocytes retrieved to follicles aspirated. We used the LC CUSUM test to analyze the learning curves of residents, and the CUSUM test to monitor the performance of senior physicians. An ORR ≥50% in 60% of retrievals was defined as the threshold for clinical proficiency.ResultsSix hundred seventy-four oocyte retrieval (OR) were included: 315 were performed by residents, 220 by senior physicians, and 139 by both residents and physicians (mixed retrievals). Four residents (57%) reached the threshold after aspirating 82, 67, 53 and 46 ovaries, respectively. The mean number of ovaries aspirated in order to reach clinical proficiency was 62, and the mean number of weeks needed was 21. The duration of the learning period varied between 26 and 80 days. Two senior physicians (40%) remained proficient across the duration of the study, while two physicians (40%) had one statistically “suboptimal” OR, and one physician (20%) had two suboptimal retrievals.ConclusionThere is a large variability in the duration of the learning period and the number of procedures needed for a resident to master OR. Senior physicians maintain an adequate performance.

Quantitative and individualized assessment of the learning curve in preoperative planning of the acetabular cup size in primary total hip arthroplasty

IntroductionThe aim of the present study was to investigate the learning curves of 2 trainees with different experience levels to reach proficiency in preoperative planning of the cup size based on learning curve cumulative summation (LC-CUSUM) statistics and a cumulative summation (CUSUM) test.Materials and methodsOne-hundred-twenty patients who had undergone primary total hip arthroplasty with a cementless cup were selected. Preoperative planning was performed by an experienced orthopedic surgeon. Trainee 1 (student) and trainee 2 (resident) planned the cup size. The trainees were blinded to the preoperative plan and the definitive cup size. Only after a cup size was chosen, the trainees were unblinded to the preoperative plan of the surgeon. LC-CUSUM was applied to both trainees to determine when proficiency in determining the appropriate cup size was reached. A CUSUM test was applied to ensure retention of proficiency.ResultsWith reference to the preoperative plan of the surgeon, LC-CUSUM indicated proficiency after 94 planning attempts for trainee 1 and proficiency after 66 attempts for trainee 2, respectively. Trainee 1 and 2 maintained proficiency thereafter. With reference to the definitive cup size, LC-CUSUM did not signal competency within the first 120 planning attempts for trainee 1. Trainee 2 was declared competent after 103 attempts and retained competency thereafter.ConclusionsLC-CUSUM/CUSUM allow for an individualized, quantitative and continuous assessment of planning quality. Based on LC-CUSUM statistics, the two trainees of this study gain proficiency in planning of the acetabular cup size after 50–100 attempts when an immediate feedback is provided. Previous experience positively influences the performance. The study serves as basis for the medical education of students and residents in joint replacement procedures.

Point-of-Care Ultrasound to Confirm Umbilical Line Placement: Impact of a Simulation Enhanced Curriculum on Neonatal Intensive Care Unit Provider Competency.

Neonatal intensive care unit (NICU) provider point-of-care ultrasound (POCUS) procedural competency for umbilical line placement confirmation has not been defined, and the necessary training to achieve competency has not been previously studied. This study's objective was to test the hypothesis that a simulation-enhanced curriculum will improve NICU providers' POCUS competency to confirm umbilical line placement. Neonatal intensive care unit providers without prior ultrasound experience were randomized to a curriculum with or without simulation-based training. Competency for catheter detection, tip localization, and scan interpretation on patients was determined using learning curve-cumulative summation, a specific statistical tool designed to indicate when a predefined level of performance is reached. Differences in success rates were analyzed by χ2 test. Two thirds (22/33) of participants completed 10 scans. Three (simulation) and 1 (control) attained catheter detection competency (P = 0.28). The simulation group was more successful for catheter detection (81% vs. 69%, P = 0.04) and scan interpretation (61% vs. 48%, P = 0.04). Success did not differ by umbilical vessel location, provider role, or duration of NICU experience. A simulation-enhanced POCUS curriculum improved catheter detection rate and scan interpretation, but there was no difference in procedural competency between groups on ultrasound scans performed on patients with umbilical catheters. We speculate that more than 10 scans may be needed for NICU providers to obtain POCUS competency.

Minimizing Individual Learning Curves in a Mature Endoscopic Fetal Surgery Program

Introduction: Twin-to-twin transfusion syndrome affects monochorionic twin pregnancies and can result in fetal death. Endoscopic laser treatment remains a relatively infrequent procedure for this condition. This presents difficulties for maintaining proficiency and for training new personnel. Objective: The dual mentoring program at our institution allows for continuous mentoring of new providers. We hypothesize that this approach stabilizes program proficiency despite the addition of new practitioners. Methods: Query of the fetal treatment program database returned 146 cases of laser ablation between 2000 and 2019. Patient and pregnancy characteristics as well as operative time and outcomes were recorded. The learning curve-cumulative summation method and rolling averages were used to analyze outcomes. Results: Overall survival was 69%, and survival of at least 1 twin was 89%. Mean operative time was 53.6 ± 20.9 min. Overall twin survival stabilized after the first 40 cases. Rolling averages for operative time decreased from 71 to 49 min for the most recent cases. These results were not affected by the introduction of new surgeons. Conclusions: Creative mentoring can maintain stable overall program outcomes despite changes in team composition. This training approach may be applicable to other rare procedures in fetal surgery.

HipSim — hip fracture surgery simulation utilizing the Learning Curve–Cumulative Summation test (LC-CUSUM)

Background and purpose — Virtual reality simulation of hip fracture surgery is available for orthopedic residents nationwide in Denmark. Summative assessment of learning applying the learning curve cumulative summation test (LC-CUSUM) has not been utilized in orthopedic simulation training. The strength of the LC-CUSUM is that it assumes incompetency and signals competency based on solid statistics. We investigated the LC-CUSUM characteristics of novices stepwise mastering the simulated dynamic hip screw (DHS) procedure. Material and methods — 32 1st-year orthopedic residents participated in HipSim and its 3 subsequent LC-CUSUM evaluations: placing a Kirschner wire, placing a Kirschner wire in different patients, and performing the entire DHS procedure in different patients. The career status of the participants, i.e., still working in orthopedics or in another specialty was recorded ≥ 2 years after participation and associated with the simulation performance (passed/failed). Results — 13/14 participants passing HipSim according to LC-CUSUM were still working in orthopedics, while 9/18 participants failing HipSim had quit orthopedics at ≥ 2 years follow-up. The simulator-generated feedback did not statistically significantly differ between the groups. Interpretation — LC-CUSUM and its summative pass/fail assessment of each simulation was feasible in this formative simulation program. Clinical educators can be reassured that participants passing HipSim are likely to continue to 2nd–5th year of residency, while failing HipSim should raise concerns and trigger career counselling and clinical supervision. The motivational aspect of LC-CUSUM pass/fail assessment when designing formative simulation training warrants further research.

Learning Curve Analyses for Achieving Satisfactory Procedural Completion Rates in Paediatric Oesophagogastroduodenoscopy.

The learning curve in paediatric oesophagogastroduodenoscopy (OGD) is unknown. Using ≥95% D2 (second part of the duodenum) intubation rates as a marker of technical competency, we conducted learning curve analyses to identify when trainees achieve competency in paediatric OGD. Factors associated with competency were also evaluated. This nationwide study analysed data from paediatric OGD procedures prospectively entered into the UK endoscopy training e-portfolio between 2014 and 2018. Moving average and learning curve cumulative summation analyses were performed to determine procedural numbers required to achieve ≥95% D2 intubation rates. Factors associated with D2 intubation were assessed using a multivariable binary logistic regression approach. A total of 8929 procedures performed by 61 trainees were identified. These 61 trainees had recorded a mean of 124.6 procedures (range 22-571, interquartile range 165). By moving average analysis, 95% D2 intubation was achieved after 79 procedures. By learning curve cumulative summation analysis, 81.6% of trainees were competent after 100 procedures. Multivariable factors associated with unassisted procedural completion included: lifetime procedure count (P < 0.001), higher trainee seniority (P < 0.001), patient age (P = 0.002), outpatient status (P < 0.001), and attendance at a national Basic Skills OGD course (P = 0.011). This study demonstrates that, on average, 79 procedures in paediatric OGD are required to attain the competency outcome of ≥95% D2 intubation rates. By 100 procedures, 81.6% of our sample had achieved ≥95% D2 intubation. The minimum procedural count of 100 set by the UK and international training programmes can be used alongside existing objective assessment measures to safeguard competency within a training cohort.

Learning curve for detection of pelvic parts of ureters by transvaginal sonography: feasibility study.

To investigate how many examinations it takes to be able to identify the pelvic parts of the ureters on transvaginal sonography (TVS). This was a prospective study including consecutive women attending a gynecological outpatient clinic in a tertiary referral setting. Prior to commencement of the study, three trainees, with a focus on gynecological surgery and TVS but with no experience in identifying ureters, each observed an expert examiner performing 10 routine TVS examinations, including identification of both ureters. All were standardized gynecological TVS examinations, with visualization of the pelvic part of both ureters. Consecutive women were then examined, first by the expert, unobserved by the trainees, and then by one of the three trainees, in the presence of the expert. To ensure that identification of the pelvic parts of the ureters could be incorporated feasibly into routine gynecological TVS in a tertiary referral setting, a time limit of 150 s was set for successful identification of each ureter. A successful examination was defined by identifying both ureters within the time limit. The number of women examined by each trainee was determined by how quickly they achieved proficiency, which was evaluated using the learning curve cumulative summation (LC-CUSUM) score. Between January 2017 and June 2017, a total of 140 women were recruited for the study, with 135 patients being included in the final analysis. The three trainees were able to identify the right ureter after a maximum of 48 (range, 34-48) TVS examinations, and the left ureter after a maximum of 47 (range, 27-47) TVS examinations. Sonographers and/or gynecologists who are familiar with gynecological TVS should be able to become proficient in identifying both ureters after 40-50 TVS examinations. Detection of the ureters is a feasible part of the TVS workup of patients attending a clinic in a tertiary referral center. © 2019 the Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of the International Society of Ultrasound in Obstetrics and Gynecology.

Simulation-based fetal shunting training.

To develop a simulation model and assess the learning curve of fetal shunting. Three staff and three trainees performed fetal shunting on a model using the fetal bladder stent. The model was evaluated according to various sources of validity evidence. The number of procedures to reach competency was determined by the learning curve-cumulative summation (LC-CUSUM) and CUSUM analysis. The learning and control phases were defined as the periods before and after passing the level of competency, respectively. The model was validated to be constructive in the educational process. A total of 600 procedures were carried out with an overall success rate of 94.2% and no significant difference between staff and trainees. The average number of procedures to reach competency was 47. Total procedural time decreased after passing the level of competency. Although the trainees required a longer procedural time in the learning phase than the staff did, there was no significant between-group difference in the control phase. Using this model, the estimated number of procedures to achieve competency was 47, as substantiated by the increased procedural success and reduced procedural time in the control phase. Training on this simulation model may improve technical performance.

Learning curve for ultrasonographic diagnosis of deep infiltrating endometriosis using structured offline training program.

To assess the learning curves of trainees during a structured offline/hands-on training program for the ultrasonographic diagnosis of deep infiltrating endometriosis (DIE). Four trainees (all Ob/Gyn postgraduates with at least 5 years' experience in ultrasonography in obstetrics and gynecology, but with no experience of sonographic examination of DIE) participated in the study. They underwent a 2-week training program with a single trainer. Day 1 was devoted to theoretical issues and guided offline analysis of 10 three-dimensional ultrasound volumes. During the following days, four sessions of real-time sonographic examinations were performed in a DIE referral center ultrasound unit. In between these sessions, the trainees analyzed four datasets offline, each containing 25 volumes. At the end of each set, misinterpreted volumes were reassessed with the trainer. Presence or absence of DIE at surgery was considered the gold standard. The trainees' learning process was evaluated by learning-curve cumulative summation (LC-CUSUM) and the deviations of the trainees' level of performance at the control stage was assessed by CUSUM (standard CUSUM), for different locations of DIE. The trainees reached competence after an average of 17 (range, 14-21)evaluations for bladder, 40 (range, 30-60)for rectosigmoid, 25 (range, 14-34)for forniceal, 44 (range, 25-66)for uterosacral ligament (USL) and 21 (range, 14-43)for rectovaginal septum (RVS) locations of DIE, and then kept the process under control, with error levels of less than 4.5% until the end of the test. The overall accuracy for each trainee in diagnosis of DIE at the different locations ranged from 0.91 to 0.98 for bladder DIE, from 0.80 to 0.94 for rectosigmoid DIE, from 0.90 to 0.94 for forniceal DIE, from 0.79 to 0.82 for USL DIE and from 0.89 to 0.98 for RVS DIE. The suggested 2-week training program, based on a mixture of offline and live scanning sessions, is feasible and apparently provides effective training for the ultrasonographic diagnosis of DIE. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.

Learning curve-cumulative summation analysis of visual estimation of left ventricular function in novice practitioners: A STROBE-compliant article.

The aim of the present study was to determine the value of cumulative summation (CUSUM) analysis in assessing the proficiency of novice practitioners in estimating the left ventricular ejection fraction (EF).Seven novice practitioners with no echocardiography experience were recruited in this observational study. Each practitioner assessed EF from echocardiographic video files of 100 cases, one by one, and received feedback and teaching. We obtained a CUSUM score through comparison of the gold standard values of EF and the EF values determined by the practitioners. Then, the practitioners underwent the same test 4 weeks later, except without feedback and teaching, using echocardiographic video files from 100 other cases.The mean number of visual estimation cases required to pass the learning curve (LC)-CUSUM test was 56.3 ± 9.1 (95% CI 47.8–64.7). The LC-CUSUM average of the 7 novice practitioners showed improvement in visual estimation skill, with an average acceptable level achieved after a mean experience of 55 cases. In the test performed after 4 weeks, 5 of the 7 novice practitioners showed significantly good overall agreement. All novice practitioners had a kappa coefficient greater than .8, and significant and almost perfect agreement was observed. All the participants exhibited a percentage of correct answers greater than 81%.We found that the novice practitioners could acquire an acceptable level of skill for estimating EF with short-term, self-learning-focused echocardiographic training.