SEARCH · PubMed Health

Results for “Learning Curve”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 973 records · Page 54Linked to original sources

PubMed1998

[Risks and benefits of laparoscopic hernia-plasty (TAPP). 5 years experiences with 3,400 hernia repairs].

In the present study, for the first time the aspects of risk, benefit and the costs of laparoscopic hernioplasty in the transabdominal technique with preperitoneal placement of a polypropylene mesh are examined prospectively in a very large group of patients with 3,400 hernia repairs. The median operation time was 45 min for unilateral primary hernias, 50 min for unilateral recurrent hernias and 76 min for bilateral hernias. The frequency of complications showed a significant dependence on the individual steps in the development of the method and the individual learning curve. The same is true for the rate of recurrency. Whereas initially the rate of serious complications was 2.75%, the rate of minor complications 11% and the rate of recurrences 4.5% the corresponding figures are at present 0.4%, 4.4% and 0.5%. Laparoscopic hernioplasty proved to be equally as effective in the treatment of primary hernias, recurrent hernias and bilateral hernias. The large number of 11 surgeons participating proves that laparoscopic hernioplasty can be learned and that even in a teaching hospital it can be performed safely, efficiently and cost-effectively.

Adolescent↗

PubMed2003

Predicting conversion in laparoscopic colorectal surgery. Fellowship training may be an advantage.

BACKGROUND: Laparoscopic colorectal surgery has clear advantages over open surgery; however, the effectiveness of the approach depends on the conversion rate. The objective of this work was to prospectively validate a model that would predict conversion in laparoscopic colorectal surgery. METHODS: A simple clinical model for predicting conversion in laparoscopic colorectal surgery was previously developed based on a multivariable logistic regression analysis of 367 procedures. This model was applied prospectively to a follow-up group of 248 procedures by the same team, including 54 procedures performed by one new fellowship-trained surgeon. RESULTS: Patients in the follow-up group were more likely to have cancer (56% vs 44%, p = 0.007) and were more obese (median, 71.0 vs 66.0 kg; p < 0.001). The rate of conversion in the follow-up group was unchanged (8.9% vs 9.0%, p > 0.05). Despite expected trends toward increasing risk of conversion with weight level (<60 kg, 6.8%; 60-<90 kg, 9.0%; >90 kg, 12.1%; p > 0.05) and malignancy (10.1% vs 7.3%, p > 0.05), the model did not distinguish well between groups at risk for conversion. Contrary to the model, however, the fellowship-trained surgeon had a conversion rate that was not higher than that of the other, more experienced surgeons (7.3% vs 9.3%, p > 0.05) even though he was less experienced, and operating on patients who were more obese (median, 75.0 vs 70 kg; p = 0.02) and more likely to have cancer (59% vs 55%, p > 0.05). Recalculated conversion scores that excluded the inexperience point for the fellowship-trained surgeon showed a good fit for the model. Considering the original and follow-up experience together (615 cases), the model clearly stratifies patients into low (0 points), medium (1-2 points), and high risk (3-4 points) for conversion, with respective rates of 2.9%, 8.1%, and 20% ( p = 0.001). CONCLUSION: This model appears to be a valid predictor of conversion to open surgery. Fellowship training may provide sufficient experience so that learning curve issues are redundant in early practice. This model now requires validation by other centers.

Body Weight↗

PubMed1998

Early experience with stenting for iliac occlusive disease.

OBJECTIVES: To review our experience of iliac artery stenting for occlusive disease. DESIGN: Prospective study of 50 consecutive patients with iliac occlusive disease, November 1993-November 1996. The indications for stenting were complete iliac occlusion (37) restenosis (four), donor site inflow for bypass grafting (four) and difficult stenoses (> 90% and/or > 5 cm) (five). The majority of patients (41) presented with intermittent claudication. RESULTS: All 13 stenoses were successfully stented. One occluded but the rest remain patent. There were no other complications. By contrast, it was not possible to place a stent across 10 of the 37 complete iliac occlusions. In this group there were nine major complications, including five patients who required early embolectomy (four femoral, one brachial) and one patient who developed a false aneurysm at the site of the stent. The "intention to treat" primary cumulative patency for iliac occlusions was 65% at 2 years but after excluding technical failures was 88%. CONCLUSIONS: There is a sharp learning curve and significant complication rate associated with stenting complete occlusions. However, following successful stenting patency rates are around 90% for both iliac stenoses and occlusions.

Aged↗

PubMedDate not supplied

The practice-makes-perfect hypothesis in the context of other production concepts in health care.

Many studies have found a significant relationship between the volume of specific diagnoses and procedures and patient outcomes. Often, these studies have cited the "practice-makes-perfect" hypothesis as a potential explanation. However, the expression "practice-makes-perfect" hypothesis is inappropriate in most circumstances. This article suggests using the expression "routine" hypothesis instead. In addition, this article compares the routine hypothesis with other familiar concepts from industrial production, which also aim at explaining the relationship between factor input and output in health care: economies of scale, economies of scope, the learning curve, and the focused factory. To point out subtle differences among the concepts, this article suggests a taxonomy organized by type of output and outcome. This taxonomy may help ensure the appropriate use of terminology when applying these concepts.

Health Care Sector↗

PubMed2006

Robotic radical prostatectomy: the Vattikuti Urology Institute training experience.

Robotic radical prostatectomy is increasingly becoming a popular surgical treatment modality for men with clinically localized prostate cancer. Establishing a robotic prostatectomy program is a tremendous undertaking for any institution requiring both financial support and a dedicated operating room team. A structured approach to learning robotics is paramount in order to successfully start a program while optimizing the learning curve to master the technique and minimize peri-operative complications. We describe our own experience in establishing a robotics program to accomplish a safe and effective operation. In addition, we describe the steps utilized in order to teach our structured approach to other practitioners and institutions around the world. Robotic surgery can be taught to experienced open, as well as, laparoscopic surgeons, and incorporated into residency and fellowship training using this structured approach to learning.

Clinical Competence↗

PubMed2003

Toward totally endoscopic coronary artery surgery.

BACKGROUND: Here we explore a method of using robotics to reduce morbidity and mortality in conventional coronary surgery. METHODS: Using a robotic surgical system two surgeons completed five steps: (1) 80 synthetic suture exercises; (2) 76 left internal thoracic artery to left anterior descending (LIMA-to-LAD) on porcine hearts; (3) cadaveric port placement for assessing optimal access; (4) endoscopic stabilization in the live porcine model; and, finally (5) eight clinical LIMA-to-LADs performed robotically. RESULTS: After 70 hours training, mean dry lab times fell from 7.0 and 5.8 min to 5.7 and 5.1 min in the two surgeonstab series. Wet lab times fell from 40.1 and 28.5 min to 28.8 and 19.2 min. In the clinical series of eight patients there were no mortalities; all had uncomplicated postoperative recovery and all were angina free at 6-week follow-up. CONCLUSION: The learning curve for robotic training is short, and reproducible results can be achieved clinically, after appropriate training, resulting in real patient benefit.

Animals↗

PubMed2005

A prospective randomized study to test the transfer of basic psychomotor skills from virtual reality to physical reality in a comparable training setting.

OBJECTIVE: To test whether basic skills acquired on a virtual endoscopic surgery simulator are transferable from virtual reality to physical reality in a comparable training setting. SUMMARY BACKGROUND DATA: For surgical training in laparoscopic surgery, new training methods have to be developed that allow surgeons to first practice in a simulated setting before operating on real patients. A virtual endoscopic surgery trainer (VEST) has been developed within the framework of a joint project. Because of principal limitations of simulation techniques, it is essential to know whether training with this simulator is comparable to conventional training. METHODS: Devices used were the VEST system and a conventional video trainer (CVT). Two basic training tasks were constructed identically (a) as virtual tasks and (b) as mechanical models for the CVT. Test persons were divided into 2 groups each consisting of 12 novices and 4 experts. Each group carried out a defined training program over the course of 4 consecutive days on the VEST or the CVT, respectively. To test the transfer of skills, the groups switched devices on the 5th day. The main parameter was task completion time. RESULTS: The novices in both groups showed similar learning curves. The mean task completion times decreased significantly over the 4 training days of the study. The task completion times for the control task on Day 5 were significantly lower than on Days 1 and 2. The experts' task completion times were much lower than those of the novices. CONCLUSIONS: This study showed that training with a computer simulator, just as with the CVT, resulted in a reproducible training effect. The control task showed that skills learned in virtual reality are transferable to the physical reality of a CVT. The fact that the experts showed little improvement demonstrates that the simulation trains surgeons in basic laparoscopic skills learned in years of practice.

Clinical Competence↗

PubMed1995

Paradoxical effects of practice of fast single-joint movements.

We studied the effects of extensive practice of fast, unidirectional, single-joint elbow flexions against a small extending torque bias upon the kinematic and electromyographic (EMG) characteristics of the movements as well as upon the reconstructed hypothetical control patterns (equilibrium trajectories). The subjects were tested at different distances, both with and without the bias torque prior to and after the practice sessions. The basic finding was paradoxical: The subjects did not improve their performance at the practiced task (against the bias) and at other distances in the same condition; however, they showed an increase in movement speed and a decrease in movement time at all distances in unpracticed conditions (without the bias). Changes in the EMG patterns were similar in both conditions. We hypothesize that the principle of learning the dynamics of interaction with the experimental setup in combination with a very steep learning curve form the basis for the observed paradoxical effects of practice. The equilibrium-point hypothesis of movement control provides the least controversial description of these effects as compared to the force-control and EMG-control approaches.

Adult↗

PubMed2005

Prevention of alcohol-induced developmental delays and learning abnormalities in a model of fetal alcohol syndrome.

OBJECTIVE: Prenatal alcohol exposure results in fetal death and neurobehavioral complications including learning impairment. Previously synthetic peptides derived from activity-dependent neurotrophic factor have been shown to prevent aspects of alcohol-induced damage in pregnancy. The objective of this work was to evaluate whether activity-dependent neurotrophic factor-12 could prevent alcohol-induced damage in a model of fetal alcohol syndrome. STUDY DESIGN: Using a well-characterized model, C57Bl6/J mice on gestational day 8 were treated with placebo, alcohol (30% volume/volume alcohol 0.03 mL/kg), alcohol plus activity-dependent neurotrophic factor-12 30 minutes prior to alcohol, or activity-dependent neurotrophic factor-12 alone. Fetal death was assessed on gestational day 18 (25 litters were evaluated: alcohol, n = 5; placebo, n = 9; alcohol plus activity-dependent neurotrophic factor-12, n = 11). Neonatal behavior tests were performed on postnatal days 1 through 21 with the offspring of 12 dams (alcohol, n = 16; placebo, n = 46; alcohol plus activity-dependent neurotrophic factor-12, n = 23; and activity-dependent neurotrophic factor-12, n = 35). Adult males were tested in the Morris water maze for learning assessment and with the hole punch activity test for exploratory activity. Statistical analysis included Kruskal-Wallis and analysis of variance. RESULTS: Fetal death was greater in alcohol (67% +/- 13%) vs placebo (8.4% +/- 3%, P < .001). Pretreatment with activity-dependent neurotrophic factor-12 prevented the alcohol-induced fetal death (2.2% +/- 8.1%) with levels similar to control (P = .12). Alcohol exposure caused a delay in achieving developmental milestones, with alcohol achieving milestones later than all other groups (all P < .001). Pretreatment with activity-dependent neurotrophic factor-12 prevented the alcohol-induced milestone delays. In the Morris water maze, the placebo learned, decreasing their latency to find the hidden platform over 70% (P < .01). Alcohol plus activity-dependent neurotrophic factor-12 also significantly learned, with a learning curve not different from placebo (all P > .5) and significantly better than alcohol on days 4, 6, and 7 (all P < .05). Alcohol exposure resulted in significantly less time in hole punch activity (P < .02) than control. Activity-dependent neurotrophic factor-12 pretreatment prevented the alcohol-induced decline, with levels the same as control (P = .1). CONCLUSION: The novel peptide activity-dependent neurotrophic factor-12 prevents alcohol-induced fetal death and developmental and learning abnormalities in a model of fetal alcohol syndrome. This demonstrates that a single treatment with a peptide is efficacious and may be of value in the prevention of alcohol-induced damage.

Animals↗

PubMed2005

Neural mechanisms underlying probabilistic category learning in normal aging.

Probabilistic category learning engages neural circuitry that includes the prefrontal cortex and caudate nucleus, two regions that show prominent changes with normal aging. However, the specific contributions of these brain regions are uncertain, and the effects of normal aging have not been examined previously in probabilistic category learning. In the present study, using a blood oxygenation level-dependent functional magnetic resonance imaging block design, 18 healthy young adults (mean age, 25.5 +/- 2.6 years) and 15 older adults (mean age, 67.1 +/- 5.3 years) were assessed on the probabilistic category learning "weather prediction" test. Whole-brain functional images acquired using a 1.5T scanner (General Electric, Milwaukee, WI) with gradient echo, echo planar imaging (3/1 mm; repetition time, 3000 ms; echo time, 50 ms) were analyzed using second-level random-effects procedures [SPM99 (Statistical Parametric Mapping)]. Young and older adults displayed equivalent probabilistic category learning curves, used similar strategies, and activated analogous neural networks, including the prefrontal and parietal cortices and the caudate nucleus. However, the extent of caudate and prefrontal activation was less and parietal activation was greater in older participants. The percentage correct and reaction time were mainly positively correlated with caudate and prefrontal activation in young individuals but positively correlated with prefrontal and parietal cortices in older individuals. Differential activation within a circumscribed neural network in the context of equivalent learning suggests that some brain regions, such as the parietal cortices, may provide a compensatory mechanism for healthy older adults in the context of deficient prefrontal cortex and caudate nuclei responses.

Adult↗

PubMed1998

Long-term rail stance training in healthy young adult women.

Daily rail stance training was performed for no longer than 3 months on 12 healthy Japanese women volunteers with eyes open and closed. Rail width conditions were varied, during which time rail stance was repeated 30 times every day until volunteers could stand for 60 s in at least half the trials. Prolongation of stance time and retention of training effects were investigated. The rate of progress depended on the difficulty of the stance and was determined by rail width and visual conditions. However, marked differences were seen among subjects even under the same training conditions. The faster the progress, the better preserved was the training effect during the post-training period. There was no obvious difference in the learning curve between narrow rails with eyes open and wide rails with eyes closed. We concluded that the retention of the training effect parallels the rate of progress, and this is determined by the difficulty of action relative to the inherent ability of the subjects.

Adult↗

PubMedDate not supplied

Learning "what" and "how" in a human motor task.

We studied the development of implicit and of verbally declared knowledge for normal human subjects who learned an unfamiliar motor task in one learning session. The exploratory nature of motor learning and a special period for optimizing skill were followed in real time. Subjects understood the goal for task success, but they had to learn a motor strategy of what pattern of serial movements to make and the tactics of how much to scale their amplitudes and timing. We compared the time course for acquiring tactical skill with that for acquiring knowledge of strategy and of tactics, and their necessary cues. Implicit and declarative knowledge were distinguished from one another by correlating subjects' verbal self-reports with movement kinematics and their results. Implicit generation of the correct strategy and of the tactics developed in an exploratory manner from the beginning of the learning session. Implicit strategy learning soon gave way to conscious efforts, but tactical learning remained implicit until its first unambiguous verbal declaration (with one exception). First strategy declarations were voiced before those for tactics, during trial-and-error learning that did not require task success, and referred to reversing the direction of hand movements (one exception). In contrast, first declarations of tactics almost always required actual or imminent success, referred to when direction was to be reversed, and it was achieved near the top of a sigmoid learning curve that rose to tactical skill (with one exception). During the sigmoid rise, movement amplitudes and timing were optimized in a distinct manner, although tactics usually adapted thereafter to movements of more moderate speed that could still be successful.

Adult↗

PubMed2003

Laparoscopic sutured anastomosis of the bowel.

BACKGROUND: Even though the safety and efficacy of sutured anastomosis have been proved in open surgery, laparoscopic sutured anastomosis is rarely performed because it is difficult and time-consuming. We aim at description of a standardized technique for laparoscopic sutured anastomosis of the bowel and definition of its learning curve. METHODS: Fifty-six laparoscopic sutured anastomoses of cow small intestine were performed in a laparoscopic simulator. In a survival animal trial, 10 end-to-end, 2 gastrojejunostomy, 2 cholecystojejunostomy, 2 colocolic, and one side-to-side anastomoses were performed, using the same technique. RESULTS: In the survival cases, we had no leaks or obstruction, minimal adhesions, and only one stenotic gastrojejunostomy. The mean end-to-end anastomotic time was 50 min. The technique was suitable for most sites in the GIT. The learning phase required 40 anastomoses in the simulator. CONCLUSIONS: The described technique seems relatively fast, safe, and universal, and it needs about 40 anastomoses to be mastered.

Anastomosis, Surgical↗

PubMed1989

Clinical competence in the performance of fiberoptic laryngoscopy and endotracheal intubation: a study of resident instruction.

Anesthesiologists must be competent in the technique of fiberoptic laryngoscopy and intubation in airway management. The goal of this study was to test the hypothesis that an acceptable level of technical expertise in fiberoptic laryngoscopy and intubation may be acquired within 10 intubations while maintaining patient safety. The learning objectives were an intubation time of 2 minutes or less and greater than 90% success on the first intubation attempt. Ninety-one ASA physical status I-II patients with normal laryngeal anatomy had general anesthesia and were intubated orally with an Olympus LF-1 fiberoptic scope; the mean (+/- SD) time for intubation was 1.92 +/- 1.45 minutes. Four residents with no prior experience with fiberoptic laryngoscopy intubated at least 15 patients each. A learning curve was generated using logarithmic analysis of the mean (+/- SD) time for intubation of patients 1 to 15 for all residents combined. The curve showed that the mean (+/- SD) intubation time decreased from 4.00 +/- 2.91 to 1.53 +/- 0.76 minutes within the first 10 intubations. After the tenth intubation, the mean time was 1.53 minutes and the percent success on the first attempt at intubation was greater than 95%. There were no clinically important changes in O2 saturation, mean arterial pressure (MAP), or heart rate (HR) as a consequence of fiberoptic intubation. The results suggest that an acceptable level of technical expertise in fiberoptic intubation can be obtained (as defined by the learning objectives) by the tenth intubation, and patient safety is maintained.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1985

Hippocampectomy disrupts the topography of conditioned nictitating membrane responses during reversal learning.

The effects of bilateral hippocampectomy on the topography, or shape, of conditioned nictitating membrane (NM) responses were examined during four learning tasks: one-tone delay conditioning, unpaired extinction, two-tone discrimination, and reversal of two-tone discrimination. Results showed that hippocampal ablation altered conditioned NM response topography only during reversal learning and not during the other training paradigms. In addition, the shapes of learning curves for hippocampectomized animals were different from those of control animals during reversal conditioning but not during the other paradigms. The implications of these findings with respect to unit-recording studies of hippocampal cellular activity during classical conditioning of the NM response are discussed.

Animals↗

PubMed2001

Dis-oriented?

To reduce the learning curve as much as possible, new trustees need to go through a thorough orientation right off the bat. Opinions may differ on curriculum and techniques, but experienced trustees and governance experts offer a wealth of practical advice on what's worked for them and where to get help.

Competency-Based Education↗

PubMed2006

[Implementation of sentinel node biopsy for breast cancer in the North of France].

OBJECTIVE: To assess how surgeons in the Region Nord-Pas-de-Calais are incorporating sentinel lymph node biopsy (SLNB) into practice, before publication of official guidelines for this procedure. METHODS: Five hundred thirty five general or gynecologic surgeons were mailed a questionnaire, with 81 performed breast cancer operations responding. RESULTS: Forty five surgeons (55%) performed fewer than 20 breast cancer operations per year (group A), 19 (23%) between 20 and 50 cancers (group B), 17 (21%) more than 50 breast cancers per year (group C). Forty nine (60%) performed SLNB: 38% in group A, 79% in group B, 100% in group C. Fifty seven p. cent used a combination of blue dye and sulfure colloide radioisotope, 22% use only radioisotope, 20% only blue dye. Eighty eight p. cent performed a learning curve, but with fewer than 20 procedures for 37%. Surgical training included scientific publications lecture (61%), formal training course (53%), or practical stage (41%). CONCLUSIONS: Surgeon with a high exposure to breast disease seemed to be most involved in the development of SLNB.

Breast Neoplasms↗

PubMed2004

Image is everything: pearls and pitfalls of digital photography and PowerPoint presentations for the cosmetic surgeon.

BACKGROUND: Cosmetic surgery and photography are inseparable. Clinical photographs serve as diagnostic aids, medical records, legal protection, and marketing tools. In the past, taking high-quality, standardized images and maintaining and using them for presentations were tasks of significant proportion when done correctly. Although the cosmetic literature is replete with articles on standardized photography, this has eluded many practitioners in part to the complexity. A paradigm shift has occurred in the past decade, and digital technology has revolutionized clinical photography and presentations. Digital technology has made it easier than ever to take high-quality, standardized images and to use them in a multitude of ways to enhance the practice of cosmetic surgery. PowerPoint presentations have become the standard for academic presentations, but many pitfalls exist, especially when taking a backup disc to play on an alternate computer at a lecture venue. OBJECTIVE: Embracing digital technology has a mild to moderate learning curve but is complicated by old habits and holdovers from the days of slide photography, macro lenses, and specialized flashes. Discussion is presented to circumvent common problems involving computer glitches with PowerPoint presentations. CONCLUSION: In the past, high-quality clinical photography was complex and sometimes beyond the confines of a busy clinical practice. The digital revolution of the past decade has removed many of these associated barriers, and it has never been easier or more affordable to take images and use them in a multitude of ways for learning, judging surgical outcomes, teaching and lecturing, and marketing. Even though this technology has existed for years, many practitioners have failed to embrace it for various reasons or fears. By following a few simple techniques, even the most novice practitioner can be on the forefront of digital imaging technology. By observing a number of modified techniques with digital cameras, any practitioner can take high-quality, standardized clinical photographs and can make and use these images to enhance his or her practice. This article deals with common pitfalls of digital photography and PowerPoint presentations and presents multiple pearls to achieve proficiency quickly with digital photography and imaging as well as avoid malfunction of PowerPoint presentations in an academic lecture venue.

Documentation↗