Individual Learning Curves Research Articles

The Accuracy of the Learning-Curve Cumulative Sum Method in Assessing Brachial Plexus Block Competency.

The learning-curve cumulative sum method (LC-CUSUM) and its risk-adjusted form (RA-LC-CUSUM) have been proposed as performance-monitoring methods to assess competency during the learning phase of procedural skills. However, scarce data exist about the method's accuracy. This study aimed to compare the accuracy of LC-CUSUM forms using historical data consisting of sequences of successes and failures in brachial plexus blocks (BPBs) performed by anesthesia residents. Using historical data from 1713 BPB performed by 32 anesthesia residents, individual learning curves were constructed using the LC-CUSUM and RA-LC-CUSUM methods. A multilevel logistic regression model predicted the procedure-specific risk of failure incorporated in the RA-LC-CUSUM calculations. Competency was defined as a maximum 15% cumulative failure rate and was used as the reference for determining the accuracy of both methods. According to the LC-CUSUM method, 22 residents (84.61%) attained competency after a median of 18.5 blocks (interquartile range [IQR], 14-23), while the RA-LC-CUSUM assigned competency to 20 residents (76.92%) after a median of 17.5 blocks (IQR, 14-25, P = .001). The median failure rate at reaching competency was 6.5% (4%-9.75%) under the LC-CUSUM and 6.5% (4%-9%) for the RA-LC-CUSUM method ( P = .37). The sensitivity of the LC-CUSUM (85%; 95% confidence interval [CI], 71%-98%) was similar to the RA-LC-CUSUM method (77%; 95% CI, 61%-93%; P = .15). Identical specificity values were found for both methods (67%; 95% CI, 29%-100%, P = 1). The LC-CUSUM and RA-LC-CUSUM methods were associated with substantial false-positive and false-negative rates. Also, small lower limits for the 95% CIs around the accuracy measures were observed, indicating that the methods may be inaccurate for high-stakes decisions about resident competency at BPBs.

Cumulative sum learning curve for cordocentesis among maternal-fetal medicine fellows in a low-cost simulation model.

To determine the individual learning curves for cordocentesis in a low-cost simulator for maternal-fetal medicine (MFM) fellows. This observational, descriptive, educational, and prospective study was performed from July through November 2022. After an introductory course based on a standardized technique for cordocentesis, each second-year MFM fellow who accepted to participate in the study performed this procedure using a low-cost simulation model, and experienced operators supervised the cordocenteses. Learning curves were then created using cumulative sum analysis (CUSUM). Seven second-year MFM fellows with no previous experience in cordocentesis accepted to participate in the study. A total of 2676 procedures were assessed. On average, residents performed 382 ± 70 procedures. The mean number of procedures to achieve proficiency was 369 ± 70, the overall success rate was 84.16%, and the corresponding failure rate was 15.84%. At the end of the study, all fellows were considered competent in cordocentesis. One fellow required 466 attempts to achieve competency, performing a total of 478 procedures, but the resident with the fewest attempts to reach competency required 219 procedures, completing 232 procedures. Some of the most frequent reasons for failed attempts included not reaching the indicated point for vascular access (20.99%) and being unable to retrieve the sample (69.10%). CUSUM analysis to assess learning curves, in addition to using low-cost simulation models, helped to appraise individualized learning, allowing an objective demonstration of competency for cordocentesis among MFM fellows.

Learning curves for itinerant nurses to master the operation skill of Ti-robot-assisted spinal surgery equipment by CUSUM analysis: A pilot study.

This study aimed to investigate the minimum number of operations required for itinerant nurses in the operating room to master the skills needed to operate the Ti-robot-assisted spinal surgery equipment. Additionally, we aimed to provide a corresponding basis for the development of qualification admission criteria and skill training for nurses who cooperate with this type of surgery. Nine operating room itinerant nurses independently performed Ti-robot equipment simulations using a spine model as a tool, with 16 operations per trainee. Four evaluation indices were recorded: time spent on equipment preparation and line connections, time spent on image acquisition and transmission, time spent on surgical spine screw placement planning, and time spent on robot arm operation. Individual and general learning curves were plotted using cumulative sum analysis. The number of cases in which the slope of the individual learning curves began to decrease was 3-11 cases, and the number of cases in which the slope of the general learning curve began to decrease was 8 cases. The numbers of cases in which the learning curves began to decrease in the four phases were the 5th, 8th, 11th, and 3rd cases. Itinerant nurses required at least eight cases to master the equipment operation skills of Ti-robot-assisted spinal surgery. Among the four phases, the image acquisition and transmission phases and the surgical spine screw placement planning phase were the most difficult and must be emphasized in future training.

Capturing learning curves with the multiday Boston Remote Assessment of Neurocognitive Health (BRANCH): Feasibility, reliability, and validity.

Unsupervised remote digital cognitive assessment makes frequent testing feasible and allows for measurement of learning over repeated evaluations on participants' own devices. This provides the opportunity to derive individual multiday learning curve scores over short intervals. Here, we report feasibility, reliability, and validity, of a 7-day cognitive battery from the Boston Remote Assessment for Neurocognitive Health (Multiday BRANCH), an unsupervised web-based assessment. Multiday BRANCH was administered remotely to 181 cognitively unimpaired older adults using their own electronic devices. For 7 consecutive days, participants completed three tests with associative memory components (Face-Name, Groceries-Prices, Digit Signs), using the same stimuli, to capture multiday learning curves for each test. We assessed the feasibility of capturing learning curves across the 7 days. Additionally, we examined the reliability and associations of learning curves with demographics, and traditional cognitive and subjective report measures. Multiday BRANCH was feasible with 96% of participants completing all study assessments; there were no differences dependent on type of device used (t = 0.71, p = .48) or time of day completed (t = -0.08, p = .94). Psychometric properties of the learning curves were sound including good test-retest reliability of individuals' curves (intraclass correlation = 0.94). Learning curves were positively correlated with in-person cognitive tests and subjective report of cognitive complaints. Multiday BRANCH is a feasible, reliable, and valid cognitive measure that may be useful for identifying subtle changes in learning and memory processes in older adults. In the future, we will determine whether Multiday BRANCH is predictive of the presence of preclinical Alzheimer's disease. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

First Series of Free Flap Reconstruction Using a Dedicated Robotic System in a Multidisciplinary Microsurgical Center.

Robotic microsurgery is a novel technology for microsurgical free flap transplantation in reconstructive surgery. Recently, the first free flap transplantation using a dedicated robotic system for microsurgery (Symani Surgical System; Medical Microinstruments) was published for a single reconstructive case. For broader future application, evaluating its potential benefits in different anatomical regions, anastomotic configurations, and clinical scenarios is necessary. In this world-wide first free flap series using this robotic system, we describe our experience with this new technology in a multidisciplinary microsurgical center. The robotic system was used for different free flaps in a range of reconstructive applications in plastic surgery, oral and maxillofacial surgery, and head and neck surgery. A total of 23 flaps were performed, with all 23 arterial and a selection of two venous anastomoses being performed with the robotic system. Time for anastomoses was significantly longer than commonly. Five of the arterial robotic anastomoses had to be redone. All but one flap survived. We could show that this new dedicated microsurgical robotic system is feasible for carrying out robot-assisted anastomoses in end-to-end, as well as end-to-side fashion under varying clinical conditions and in different microsurgical subspecialties. However, some drawbacks still need to be overcome, which are partly related to individual and institutional learning curves, to finally estimate the potential benefit for robotic free flap surgery. Multidisciplinary application of the robotic system may accelerate this process by putting together different microsurgical backgrounds, while economic burden of establishing this new technology is spread among several departments.

Low-cost model for pancreatojejunostomy simulation in minimally invasive pancreatoduodenectomy.

Minimally invasive pancreatoduodenectomy (MIS PD) is a well reported technique with several advantages over conventional open pancreatoduodenectomy. In comparison to distal pancreatectomy, the adoption of MIS PD has been slow due to the technical challenges involved, particularly in the reconstruction phase of the pancreatojejunostomy (PJ) anastomosis. Hence, we introduce a low-cost model for PJ anastomosis simulation in MIS PD. We fashioned a model of a cut pancreas and limb of jejunum using economical and easily accessible materials comprising felt fabric and the modelling compound, Play-Doh. Surgeons can practice MIS PJ suturing using this model to help mount their individual learning curve for PJ creation. Our video demonstrates that this model can be utilized in simulation practice mimicking steps during live surgery. Our model is a cost-effective and easily replicable tool for surgeons looking to simulate MIS PJ creation in preparation for MIS PD.

Exploring Learning Curves in Acupuncture Education Using Vision-Based Needle Tracking

Measuring learning curves allows for the inspection of the rate of learning and competency threshold for each individual, training lesson, or training method. In this work, we investigated learning curves in acupuncture needle manipulation training with continuous performance measurement using a vision-based needle training system. We tracked the needle insertion depth of 10 students to investigate their learning curves. The results show that the group-level learning curve was fitted with the Thurstone curve, indicating that students were able to improve their needle insertion skills after repeated practice. Additionally, the analysis of individual learning curves revealed valuable insights into the learning experiences of each participant, highlighting the importance of considering individual differences in learning styles and abilities when designing training programs.

Transition from transperitoneal to retroperitoneal approach in laparoscopic living donor nephrectomy: team-based and individual learning curve: a cross-sectional study

Background: Laparoscopic living donor nephrectomy (LLDN) is a standard practice for kidney donor transplantation due to fewer complications associated with the treatment. Retroperitoneal approach to LLDN is thought to be more advantageous in preventing injuries to various abdominal organs. However, the transition process from transperitoneal to retroperitoneal LLDN is important to ensure the best outcome for the patients. The aim of this study was to investigate the learning curve for retroperitoneal approach in LLDN among urologists in an individual and team-based approach Methods: A retrospective analysis of retroperitoneal LLDN was performed on procedures performed by a kidney donor team consisting of four urologists from January 2019 to January 2022 at Cipto Mangunkusumo National General Hospital, Indonesia. The data were taken from pre-existing medical records. The learning curve for the operation time, warm ischemic time, and estimated blood loss was analyzed using cumulative sum (CUSUM) analysis. Phase 1 represents the initial learning curve, the phase 2 plateau represents the period of proficiency, while phase 3 represents the mastery period. Results: A total of 127 retroperitoneal LLDN procedures were done during the study period by four operators with various experience. The average procedure needed to achieve proficiency was 16.5 procedures. Meanwhile, the average procedure needed to achieve mastery was 28 procedures. Shorter learning curve was achieved by operators with more experience in other laparoscopic procedures. Conclusions: The learning curve for transition from transperitoneal to retroperitoneal approach to LLDN is relatively short and feasible for both individuals and teams of urologists. Therefore, transition to retroperitoneal approach is a feasible option to reduce the complication rate of LLDN.

Repetition learning is neither a continuous nor an implicit process

Learning advances through repetition. A classic paradigm for studying this process is the Hebb repetition effect: Immediate serial recall performance improves for lists presented repeatedly as compared to nonrepeated lists. Learning in the Hebb paradigm has been described as a slow but continuous accumulation of long-term memory traces over repetitions [e.g., Page & Norris, Phil. Trans. R. Soc. B 364, 3737-3753 (2009)]. Furthermore, it has been argued that Hebb repetition learning requires no awareness of the repetition, thereby being an instance of implicit learning [e.g., Guérard etal., Mem. Cogn. 39, 1012-1022 (2011); McKelvie, J. Gen. Psychol.114, 75-88 (1987)]. While these assumptions match the data from a group-level perspective, another picture emerges when analyzing data on the individual level. We used a Bayesian hierarchical mixture modeling approach to describe individual learning curves. In two preregistered experiments, using a visual and a verbal Hebb repetition task, we demonstrate that 1) individual learning curves show an abrupt onset followed by rapid growth, with a variable time for the onset of learning across individuals, and that 2) learning onset was preceded by, or coincided with, participants becoming aware of the repetition. These results imply that repetition learning is not implicit and that the appearance of a slow and gradual accumulation of knowledge is an artifact of averaging over individual learning curves.

Assessing the learning curve of robot-assisted total mesorectal excision: a multicenter study considering procedural safety, pathological safety, and efficiency

PurposeEvidence regarding the learning curve of robot-assisted total mesorectal excision is scarce and of low quality. Case-mix is mostly not taken into account, and learning curves are based on operative time, while preferably clinical outcomes and literature-based limits should be used. Therefore, this study aims to assess the learning curve of robot-assisted total mesorectal excision.MethodsA retrospective study was performed in four Dutch centers. The primary aim was to assess the safety of the individual and institutional learning curves using a RA-CUSUM analysis based on intraoperative complications, major postoperative complications, and compound pathological outcome (positive circumferential margin or incomplete TME specimen). The learning curve for efficiency was assessed using a LC-CUSUM analysis for operative time. Outcomes of patients before and after the learning curve were compared.ResultsIn this study, seven participating surgeons performed robot-assisted total mesorectal excisions in 531 patients. Learning curves for intraoperative complications, postoperative complications, and compound pathological outcome did not exceed predefined literature-based limits. The LC-CUSUM for operative time showed lengths of the learning curve ranging from 12 to 35 cases. Intraoperative, postoperative, and pathological outcomes did not differ between patients operated during and after the learning curve.ConclusionThe learning curve of robot-assisted total mesorectal excision based on intraoperative complications, postoperative complications, and compound pathological outcome did not exceed predefined limits and is therefore suggested to be safe. Using operative time as a surrogate for efficiency, the learning curve is estimated to be between 12 and 35 procedures.

Summative Entrustment Decision-Making in a National Entrustable Professional Activity-Based Residency Training Programme: Where theory meets practice

Introduction: The Entrustable Professional Activity (EPA) framework was introduced to operationalise and translate competency-based medical education into daily practice. Adoption of EPAs is recommended and supported in guidelines by educational research on trust and entrustment decision-making. However, systematic field studies evaluating the experiences of medical professionals (residents and supervisors) working with an EPA framework in daily practice are lacking. Still these evaluations are necessary to support the design and implementation of new EPA-based residency training programmes. This study provides an in-depth insight and a more comprehensive understanding of the experiences of professionals working in an EPA-based residency training programme. Methods: We conducted a qualitative study using a constructivist approach. Focus groups were used for separate interviews with residents and supervisors assessing their experiences with the first national EPA-based residency training programme in the Netherlands. Thematic analysis was used to analyse the results of the focus groups and to define relevant themes. Results: The EPA framework enabled residents to enhance and individualise their training programme. Personal leadership proved to be essential for finding a balance between the requirements of the national training programme and exploration of residents’ individual talents, experience and learning curve. Supervisors’ supportive and guiding role is crucial throughout the process of EPA acquirement. Independent from each other, supervisors and residents indicated that trust (and not exhaustive testing) is essential in the summative assessment by a Clinical Competence Committee (CCC). Supervisors see added value in the mandatory portfolio that residents compile to help them prepare for the CCC meeting. Starting to work without supervision is an important but challenging goal once an EPA has been acquired. The ability to further individualise the training programme after an EPA has been acquired, varies among residents. Discussion: We found that residents and supervisors see added value in working and learning in an EPA-based residency training programme. Awareness and encouragement of self-regulated learning skills could potentially help create a balance between programme requirements and individualisation. When discussing a portfolio, trust and gut-feelings during CCC meetings is fundamental and helpful for supervisors to get a comprehensive view of the resident’s performance. An autonomy-supportive supervision strategy could encourage and improve residents’ autonomy and practice of working without direct supervision after acquiring an EPA.

Learning laparoscopic hysterectomy: analysis of different surgeons' individual learning curves.

The aim of this study was to examine the development of surgical skills among surgeons learning total laparoscopic hysterectomy (TLH), using differences in complication rates between surgeons with different levels of experience and analyzing the development of individual operating times. This retrospective, single-center cohort study included 576 total laparoscopic hysterectomy procedures conducted between January 2015 and December 2019 at the municipal hospital in Karlsruhe, Germany. All TLHs were performed by eight surgeons, two of whom were experienced and six inexperienced. Complications were graded using the Clavien-Dindo classification. No differences in complication rates were seen between experienced and inexperienced surgeons. With growing numbers of procedures, most surgeons quickly became faster, leading to reduced operating times. However, experienced surgeons who had performed more than 100 procedures also became faster, not reaching a time plateau after adjustment for weight of the uterus, presurgery score, and adnexal score. Learning laparoscopic hysterectomy in routine practice is safe for patients, and surgeons rapidly become faster as growing numbers of procedures are performed. Operating times for experienced surgeons who have carried out more than 100 operations also improve, and a time plateau is not reached.

Robotic major and minor hepatectomy: critical appraisal of learning curve and its impact on outcomes.

Robotic hepatectomy has gained increasing acceptance across the US. Although the robotic approach offers significant technical advantages, it is still bound by the individual surgeon's learning curve. Proficiency in this approach should theoretically lead to improved peri-operative outcomes. Between 2017 and 2020, data on 148 consecutive robotic hepatectomies performed by a single surgeon was retrospectively analyzed. Using cumulative sum (CUSUM) method, intraoperative blood loss (EBL) and operative time were used to assess learning curves for robotic major (n = 58) and minor (n = 90) hepatectomy patients. Perioperative outcomes were compared in regards with proficiency. Proficiency for robotic major and minor hepatectomy was achieved after 22 cases and 34 cases, respectively. No significant differences were observed in patient demographics or tumor characteristics. For robotic major hepatectomy, when compared to early experience, proficiency was associated with a significant improvement in mean EBL (242mL vs 118mL, p = 0.0004), operative time (330min vs 247min, p = 0.0002), decreased overall complication rate (23% vs 3%, p = 0.039), and length of hospital stay (5.7days vs 4.1days, p = 0.004). No difference in conversion rate, mortality or 30day readmission was seen. For robotic minor hepatectomy, proficiency was associated with significantly decreased mean EBL (115mL vs 54mL, p = 0.005), operative time (168 vs 125min, p = 0.014), and length of hospital stay (2.8days vs 2.1days, p = 0.021). No difference was observed in conversion rate, overall complications, mortality or 30day readmission. In the modern era, robotic hepatectomy offers a safe approach with excellent perioperative outcomes. Post learning curve proficiency is associated with significant improvements in perioperative outcomes in both major and minor hepatectomy. Results from our study can serve as a guide to surgeons and programs looking to adopt this technique.

A novel episodic memory test optimized for smart phone high‐frequency assessments

AbstractBackgroundDecline in episodic memory is a strong marker of neurodegenerative diseases, making it an important target for cognitive assessment. We present a new remote, repeatable, and brief assessment of episodic memory and visual short‐term memory (VSTM) for smart phone deployment. We evaluated this task for sensitivity to age and established cognitive measures of memory and attention.MethodThe task consists of a learning phase where participants see a sequence of items, then are asked to replicate the item order and location by dragging and dropping these items on‐screen. A recall phase follows a minimum 12‐hour delay, with replication of the earlier response. Each session takes less than 2 minutes. The first phase supplies metrics of spatial and order precision VSTM, with the second phase characterising long‐term episodic memory.Experiment 1 (n = 133) compares the task with CANTAB assessments of visuospatial memory. In Experiment 2 (n = 80) the novel task was repeated twice daily for a week, alongside momentary mood ratings, and a more comprehensive battery of CANTAB tasks at baseline.In Experiment 1, multiple regression and dominance analyses explore the independent and shared variance of measures in explaining age. In Experiment 2, clustering and multivariate autoregressive models outline differences in timeseries relationships between mood and memory, and age.ResultExperiment 1 revealed that CANTAB measures and novel spatial and order metrics were correlated with age (r = .20 to r = .37, adjusted P = <.05). Multiple regression showed models with CANTAB Paired Associate Learning (PAL) score, and delayed novel spatial metrics were significantly predictive of age (t = ‐4.08, 3.17, p <.005). The dominance analysis revealed novel immediate precision overlapped with existing measures in predicting Age, while delayed precision had more unique variance (4.6% vs 0.62% unique sample variance explained in Age, accounting for PAL).Experiment 2 characterised variance in individual learning curves over time and differing autoregressive processes associated with age and CANTAB measures.ConclusionWe present a brief novel episodic memory task that can be deployed remotely, with delayed spatial precision significantly predictive of healthy Ageing. Additionally, we show this test’s suitability as a repeated assessment, compatible with high‐frequency study designs in older populations.

A novel episodic memory test optimized for smart phone high-frequency assessments.

Decline in episodic memory is a strong marker of neurodegenerative diseases, making it an important target for cognitive assessment. We present a new remote, repeatable, and brief assessment of episodic memory and visual short-term memory (VSTM) for smart phone deployment. We evaluated this task for sensitivity to age and established cognitive measures of memory and attention. The task consists of a learning phase where participants see a sequence of items, then are asked to replicate the item order and location by dragging and dropping these items on-screen. A recall phase follows a minimum 12-hour delay, with replication of the earlier response. Each session takes less than 2 minutes. The first phase supplies metrics of spatial and order precision VSTM, with the second phase characterising long-term episodic memory. Experiment 1 (n=133) compares the task with CANTAB assessments of visuospatial memory. In Experiment 2 (n=80) the novel task was repeated twice daily for a week, alongside momentary mood ratings, and a more comprehensive battery of CANTAB tasks at baseline. In Experiment 1, multiple regression and dominance analyses explore the independent and shared variance of measures in explaining age. In Experiment 2, clustering and multivariate autoregressive models outline differences in timeseries relationships between mood and memory, and age. Experiment 1 revealed that CANTAB measures and novel spatial and order metrics were correlated with age (r=.20 to r=.37, adjusted P= <.05). Multiple regression showed models with CANTAB Paired Associate Learning (PAL) score, and delayed novel spatial metrics were significantly predictive of age (t= -4.08, 3.17, p <.005). The dominance analysis revealed novel immediate precision overlapped with existing measures in predicting Age, while delayed precision had more unique variance (4.6% vs 0.62% unique sample variance explained in Age, accounting for PAL). Experiment 2 characterised variance in individual learning curves over time and differing autoregressive processes associated with age and CANTAB measures. We present a brief novel episodic memory task that can be deployed remotely, with delayed spatial precision significantly predictive of healthy Ageing. Additionally, we show this test's suitability as a repeated assessment, compatible with high-frequency study designs in older populations.

Characterizing individual trainee learning curves in surgical training: Challenges and opportunities

The surgical learning curve is an observable and measurable phenomenon. In the era of competency-based approaches to surgical training, monitoring the trajectory of individual trainee competence attainment could represent a meaningful method of formative and summative assessment. While technology can assist this approach, a number of significant barriers to the implementation of such assessment methods remain, including: accurate data collection, standard setting, and reliable assessment. Translating individual learning curve data into quantifiable case minimum targets in training poses further difficulties, and may not be possible for all procedures, particularly those that are less frequently performed and assessed. In spite of these challenges, significant benefits could be realized through an individualized approach to competency assessment using trainee learning curve data. Tracking competence acquisition against criterion-referenced standards could allow for targeted training and remediation, conforming with modern theories of adult education and empowering trainees to take control of their own learning. Learning curve data could also be used to assess the effects of educational interventions such as simulation-based training on subsequent competence acquisition rates. Ultimately, the individual learning curves of trainees could be used to inform personalised decisions regarding entrustment, credentialing, and certification, allowing training programmes to move beyond minimum operative experience targets as a crude proxy measure of competence.

Multidisciplinary perceptions on robotic surgical training: the robot is a stimulus for surgical education change.

It is unclear how to best establish successful robotic training programs or if subspecialty robotic program principles can be adapted for general surgery practice. The objective of this study is to understand the perspectives of high-volume robotic surgical educators on best practices in robotic surgery training and to provide recommendations transferable across surgical disciplines. This multi-institutional qualitative analysis involved semi-structured interviews with high-volume robotic educators from academic general surgery (AGS), community general surgery (CGS), urology (URO), and gynecology (GYN). Purposeful sampling and snowballing ensured high-volume status and geographically balanced representation across four strata. Interviews were transcribed, deidentified, and independently, inductively coded. A codebook was developed and refined using constant comparative method until interrater reliability kappa reached 0.95. A qualitative thematic, framework analysis was completed. Thirty-four interviews were completed: AGS (n = 9), CGS (n = 8), URO (n = 9), and GYN (n = 8) resulting in 40 codes and four themes. Theme 1: intangibles of culture, resident engagement, and faculty and administrative buy-in are as important as tangibles of robot and simulator access, online modules, and case volumes. Theme 2: robotic OR integration stresses the trainee-autonomy versus patient-safety balance. Theme 3: trainees acquire robotic skills along individual learning curves; benchmark assessments track progress. Theme 4: AGS can learn from URO and GYN through multidisciplinary collaboration but must balance pre-existing training program use with context-specific curricular needs. Robotic surgical experts emphasize the importance of universal training paradigms, such as a strong educational culture that balances autonomy and patient safety, collaboration between disciplines, and routine assessments for continuous growth. Often, introduction and acceptance of the robot serves as a stimulus to discuss broader surgical education change.

Age-Related Learning and Working Memory Impairment in the Common Marmoset.

Aging is the greatest risk factor for the development of neurodegenerative diseases, yet we still do not understand how the aging process leads to pathologic vulnerability. The research community has relied heavily on mouse models, but the considerable anatomic, physiological, and cognitive differences between mice and humans limit their translational relevance. Ultimately, these barriers necessitate the development of novel aging models. As a nonhuman primate (NHP), the common marmoset (Callithrix jacchus) shares many features in common with humans and yet has a significantly shorter lifespan (10 years) than other primates, making it ideally suited to longitudinal studies of aging. Our objective was to evaluate the marmoset as a model of age-related cognitive impairment. To do this, we used the Delayed Recognition Span Task (DRST) to characterize age-related changes in working memory capacity in a cohort of sixteen marmosets, of both sexes, varying in age from young adult to geriatric. These monkeys performed thousands of trials over periods of time ranging up to 50% of their adult lifespan. To our knowledge, this represents the most thorough cognitive profiling of any marmoset aging study conducted to date. By analyzing individual learning curves, we found that aged animals exhibited delayed onset of learning, slowed learning rate after onset, and decreased asymptotic working memory performance. These findings are not accounted for by age-related impairments in motor speed and motivation. This work firmly establishes the marmoset as a model of age-related cognitive impairment.SIGNIFICANCE STATEMENT Understanding the normal aging process is fundamental to identifying therapeutics for neurodegenerative diseases for which aging is the biggest risk factor. Historically, the aging field has relied on animal models that differ markedly from humans, constraining translatability. Here, we firmly establish a short-lived nonhuman primate (NHP), the common marmoset, as a key model of age-related cognitive impairment. We demonstrate, through continuous testing over a substantial portion of the adult marmoset lifespan, that aging is associated with both impaired learning and working memory capacity, unaccounted for by age-related changes in motor speed and motivation. Characterizing individual cognitive aging trajectories reveals inherent heterogeneity, which could lead to earlier identification of the onset of impairment, and extended timelines during which therapeutics are effective.

A method for identifying the learning curve for the surgical stabilization of rib fractures.

Surgical stabilization of rib fractures (SSRF) is an accepted efficacious treatment modality for patients with severe chest wall injuries. Despite increased adoption of SSRF, surgical learning curves are unknown. We hypothesized intraoperative duration could define individual SSRF learning curves. Consecutive SSRF operations between January 2017 and December 2021 at a single institution were reviewed. Operative time, as measured from incision until skin closure, was evaluated by cumulative sum methodology using a range of acceptable "missteps" to determine the learning curves. Misstep was defined by extrapolation of accumulated operative time data. Eighty-three patients underwent SSRF by three surgeons during this retrospective review. Average operative times ranged from 135 minutes for two plates to 247 minutes for seven plates. Using polynomial regression of average operative times, 75 minutes for general procedural requirements plus 35 minutes per plate were derived as the anticipated operative times per procedure. Cumulative sum analyses using 5%, 10%, 15%, and 20% incident rates for not meeting expected operative times, or "missteps" were used. An institutional learning curve between 15 and 55 SSRF operations was identified assuming a 90% performance rate. An individual learning curve of 15 to 20 operations assuming a 90% performance rate was observed. After this period, operative times stabilized or decreased for surgeons A, B, and C. The institutional and individual surgeon learning curves for SSRF appears to steadily improve after 15 to 20 operations using operative time as a surrogate for performance. The implementation of SSRF programs by trauma/acute care surgeons is feasible with an attainable learning curve. Therapeutic/Care Management; Level IV.

Modeling Technical Skills Learning Curves of Incoming Surgical Trainees

Not all trainees reach technical competency even after completing surgical training. While assessment of technical skill is not part of the residency interview process, identifying under-performers early on may help identify opportunities for individualized, targeted training. The objectives of this study were to (1) create predictive learning curve (LC) models for each of 3 basic laparoscopic tasks to identify performers versus underperformers and (2) evaluate the use of LCs to identify underperformers during selection into surgical training. Predictive LC models were created for laparoscopic pattern cutting (PC), peg transfer (PT) and intra-corporeal knots (IC) over 40 repetitions by 65 novice trainees in 2014. Trainees were categorized as performers and underperformers. Receiver operator characteristic analysis determined the minimum number of repetitions required to predict individual LCs, which were then used to determine the proportion of underperformers. Technical performance was assessed onsite at the Canadian Residence Matching Service (CaRMS) interviews, after interview completion (January 2015). Applicants to general surgery (GS) and gynecology (OBGYN) participated in a skills assessment during. The PC, PT and IC tasks required a minimum of 8, 10, and 5 repetitions respectively, to predict overall performance. Predictive values for each task had excellent sensitivity and specificity: 1.00, 1.00 (PC); 1.00, 1.00 (PT); and 0.94, 1.00 (IC). Eighty applicants completed 8 PC repetitions; 16% were identified as underperformers. Individual LCs for three different laparoscopic tasks can be predicted with excellent sensitivity and specificity based on 10 repetitions or less. This information can be used to identify trainees who may have difficulty with laparoscopic technical skills early on.