Significant Learning Effect Research Articles

Learning Curve and Fatigue Effect of Flicker Defined Form Perimetry

To evaluate the learning curve and fatigue effect of flicker defined form (FDF) perimetry. Prospective cross-sectional study. One hundred forty-one eyes of 75 healthy subjects were included in the study. Every subject was measured 3 times on 3 different days within 3 months. Differences among the tests were analyzed for mean sensitivity (MS), mean deviation (MD), pattern standard deviation (PSD), reliability indices, test duration, and test points <5% and <0.5% in 75 right eyes on the basis of linear mixed models for repeated measurements. To assess the effect of fatigue, differences of MS, MD, and PSD values between 66 left and right eyes were evaluated regarding alterations between these 3 examinations. After 3 test sessions, significant improvements were found in MS and MD among all 3 tests (P ≤ .01), and in PSD between test 1 and test 3 (P = .02). Test duration decreased significantly between tests 1 and 3 (P = .01); fixation-loss errors decreased significantly between tests 2 and 3 and between tests 1 and 3 (P = .02, respectively). Test points with p < 0.5% decreased significantly between tests 1 and 2 (P = .04) and 1 and 3 (P = .01) When comparing both eyes, MS, MD, and PSD were significantly better in first than in second eyes examined. There exist significant learning and fatigue effects for repeated flicker defined form perimetry. For good and reliable results on FDF perimetry, at least 3 tests should be performed in an individual. Between the tests of both eyes, a rest should be offered.

Efectos de la aplicación del Kinesio taping™ en el diafragma en el resultado la cicloergoespirometría y la prueba marcha de 6 minutos

Objective The aim of the study was to verify whether the application of the anterior diaphragmatic technique of Kinesio™ taping (KT) improves the performance in sports in healthy subjects. Design Repeated measures with randomization in order of tests, with or without KT. Material and methods The study sample included 17 subjects, 10 men and 7 women, 21 to 38 years old. A cycloergospirometric or graded exercise test (bike test with spirometry) and 6 minute walk test were performed. The subjects came on two separate days, 7 days apart, performing the KT tests on one of the days and the tests without the KT on the other. In the first place, muscle weight was calculated through anthropometry and bioimpedance. During the cycloergospirometric test, variables that included the maximal oxygen consumption per kg of muscle achieved on the graded exercise test were measured. The results analyzed from the 6 minute walk test included distance covered and work performed (distance per kg of muscle mass). Results The KT did not produce any significant changes in the variables measured during the graded exercise test or the 6 minute walk test. A significant learning effect was observed only for the 6 minute walking test results, both for the distance covered (Distance 1st test = 834.69 ± 107.03 m; 2nd test = 891.12 ± 93.91 m; p = .007) and for the work achieved ( P = .008). Conclusions There was no significant effect of diaphragmatic KT on results of the graded exercise test and 6 minute walk test. There is a learning effect for the 6 minute walk test.

Decision making under ambiguity in temporal lobe epilepsy: Does the location of the underlying structural abnormality matter?

Previous studies have reported decision-making deficits in patients affected by mesial temporal lobe epilepsy (TLE). The aim of the study described here was to assess the specificity of these deficits by comparing performance of patients with neocortical TLE, patients with mesial TLE, and healthy controls. The mesial TLE group performed lower than healthy controls and the neocortical TLE group in decision making under initial ambiguity. Although patients with neocortical TLE and controls showed a significant learning effect over the blocks of the Iowa gambling task, performance of patients with mesial TLE did not improve from the first to the last block of trials. Results suggest that TLE associated with neocortical brain abnormalities does not have deleterious effects on decision making as is found for epilepsy caused by mesial temporal lobe pathologies. The present findings highlight the specificity of the mesial temporal lobes in reward-based, adaptive learning and decision making.

Balance ability of 7 and 10 year old children in the population: Results from a large UK birth cohort study

Objective The literature contains many reports of balance function in children, but these are often on atypical samples taken from hospital-based clinics and may not be generalisable to the population as a whole. The purpose of the present study is to describe balance test results from a large UK-based birth cohort study. Methods Data from the Avon Longitudinal Study of Parents and Children (ALSPAC) were analysed. A total of 5402 children completed the heel-to-toe walking test at age 7 years. At age 10 years, 6915 children underwent clinical tests of balance including beam-walking, standing heel-to-toe on a beam and standing on one leg. A proportion of the children returned to the clinic for retesting within 3 months allowing test–retest agreement to be measured. Results Frequency distributions for each of the balance tests are given. Correlations between measures of dynamic balance at ages 7 and 10 years were weak. The static balance of 10 year old children was found to be poorer with eyes closed than with eyes open, and poorer in boys than in girls for all measures. Balance on one leg was poorer than heel-to-toe balance on a beam. A significant learning effect was found when first and second attempts of the tests were compared. Measures of static and dynamic balance appeared independent. Consistent with previous reports in the literature, test–retest reliability was found to be low. Conclusions This study provides information about the balance ability of children aged 7 and 10 years and provides clinicians with reference data for balance tests commonly used in the paediatric clinic.

Adaptive feedback and student behaviour in computer-assisted instruction

Two packages of adaptive computer-assisted instruction (CAIs), both offering questions and subsequent feedback, were compared in terms of amount of feedback offered, learning efficiency and appreciation. Feedback was either barely more than knowledge of result ('minimal') or consisted of a complete additional learning path ('elaborate'). The CAIs differed in the way the type of feedback given was triggered. A total of 97 Bachelor of Science students were stratified based on a pre-test before the experiment and were allocated randomly to two groups to receive either a 'programme-assessed' or a 'student-assessed' treatment. In the former, the feedback provided by the CAI (either elaborate or minimal) was completely determined by the objective correctness of the student's response. In the student-assessed treatment, elaborate feedback was provided only to students who stated explicitly that they did not know the answer. Afterwards, students completed a post-test and an appreciation questionnaire. Both CAIs resulted in a significant learning effect, but overall the effect was significantly higher in the programme-assessed treatment. Students using the student-assessed CAI hardly ever used the 'I don't know' option and therefore received mostly minimal feedback. There was no difference in students' appreciation between treatments. An interaction between the learner's prior knowledge and treatment was found: for learners with a high level of prior knowledge the programme-assessed treatment resulted in significantly higher learning effectiveness compared with the student-assessed treatment, whereas for learners with a low level of prior knowledge there was no significant difference. Our results demonstrate that learners achieved a significantly higher learning effectiveness in the programme-assessed treatment in which the received feedback was fully controlled by the correctness of the answer, compared with the student-assessed treatment. In the latter, students hardly ever admitted to not knowing the answer. Therefore, student-initiated use of the tool in a student-assessed CAI requires to be improved.

Working with distant researchers—Distance and content in university–industry interaction

This paper studies the role of geographic proximity for interaction on R&D, by exploring the special case of formalised university–industry interaction in the engineering sector. While numerous studies find that geographic proximity facilitates spillover effects between university and industry by utilising evidence from e.g. patenting and publishing activities, the geographical dimension is largely understudied in studies that report evidence from direct interaction. A series of interviews with R&D managers suggests that linkages in geographical proximity are more likely than distant linkages to generate impulses to innovation and create significant learning effects at the firm. Similarly, geographic proximate interaction is more likely to successfully contribute to R&D projects with short time to market. For long-term R&D projects, geographic proximity is generally seen as a less critical factor. A survey to 425 R&D managers in Swedish engineering firms provides evidence that supports these hypotheses.

Mild Learning Effect of Short-wavelength Automated Perimetry Using SITA Program

To evaluate the learning effect at Short-wavelength Automated Perimetry (SWAP) using the Swedish Interactive Threshold Algorithm (SITA) program over the central 24 degrees on patients with ocular hypertension experienced with standard automated perimetry. Twenty-seven patients underwent 5 SITA SWAP tests at intervals of 5+/-2 days in a randomized eye. Learning effect was defined as an improvement in results for duration, perimetric indices, foveal sensitivity, Glaucoma Hemifield Test, number of points with a P<5% and <1% in the total, and pattern deviation maps, total, central, paracentral, peripheral, and quadrant sensitivity. Learning effect was shown for foveal sensitivity (P=0.006, analysis of variance), which was significantly different only between the first (23.0 dB+/-4.1 dB) and the last test (24.7 dB+/-3.8 dB, P=0.003, t test) and was not affected by any demographic or ophthalmic characteristics of the population. All the other parameters did not show any significant learning effect. SITA SWAP is affected by a small learning effect interfering only with the first test, as opposite to full-threshold SWAP program, which previously showed severe learning artefacts. This fact may induce reconsideration of the clinical utilization of SWAP for the early diagnosis of glaucoma.

Learning Effect of Humphrey Matrix Frequency Doubling Technology Perimetry in Patients with Open-Angle Glaucoma

To evaluate the learning effect of frequency doubling technology (FDT) perimetry using the Humphrey Matrix perimeter in patients with open-angle glaucoma with no perimetric experience. One eye each of 30 glaucoma patients who had no history of visual field testing underwent 3 Matrix tests using 24-2 program with full-threshold strategy. The parameters investigated to detect learning effect were test duration, reliability indexes, mean deviation (MD), pattern standard deviation (PSD), and the number of points with a p of <5% and <1% in the total and pattern deviation maps. MD showed a larger defect at the first test (-13.64 +/- 1.63 dB) than at the second (-12.68 +/- 1.45 dB) and third (-11.69 +/- 1.48 dB) tests (p<0.05). A statistically significant reduction (p<0.05) in the number of points with a p <5% and <1% in the total deviation map was observed when repeating the examination. The values of test duration, PSD, fixation losses, false-positive rate, false-negative rate, and number of points with a p <5% and <1% in the pattern deviation map were not changed significantly (p>0.05). Humphrey Matrix FDT perimetry showed a statistically significant learning effect on MD and the number of significantly depressed points of the total deviation map in glaucoma patients with no perimetric experience. It is probably necessary to obtain at least 3 repetitions to rule out the presence of a learning effect in such patients before providing useful results.

Lesion isolation by circumferential submucosal incision prior to endoscopic mucosal resection (CSI-EMR) substantially improves en bloc resection rates for 40-mm colonic lesions

En bloc resection is preferred for colonic laterally spreading tumors, but is limited to 20 mm with endoscopic mucosal resection (EMR) using normal saline submucosal injection. Our aims were to compare the efficacy and safety of circumferential submucosal incision prior to EMR (CSI-EMR) versus conventional EMR for en bloc resection of artificial lesions 40 x 40 mm in size using submucosal injection of succinylated gelatin in a porcine colon model. Two areas of normal rectosigmoid mucosa measuring 40 x 40 mm were marked with soft coagulation for en bloc resection in each of 10 pigs. By alternate allocation, one was removed with conventional snare-based EMR following submucosal injection of succinylated gelatin. The other was circumferentially incised using an insulated-tip knife, followed by submucosal succinylated gelatin injection followed by EMR of the isolated area. All procedures were performed by a single endoscopist with significant experience of EMR but none of endoscopic submucosal dissection (ESD). Euthanasia and colectomy were performed on day 10. Specimens and ex vivo colon resection sites were examined by a specialist gastrointestinal histopathologist blinded to the technique used. En bloc excision rates were 70 % for CSI-EMR vs. 0 % for conventional EMR ( P = 0.016). The median number of resections was 1 (interquartile range, IQR: 1-2) for CSI-EMR vs. 4 (3 - 6) for EMR ( P < 0.001). Mean specimen dimensions were 50 x 43 mm for CSI-EMR vs. 37 x 32 mm for EMR ( P = 0.001). Overall procedure duration (mean +/- SD) was 30.3 +/- 19.8 minutes for CSI-EMR vs. 12.4 +/- 6.8 minutes ( P = 0.003) for EMR. The mean duration of the final 5 CSI-EMRs was 17 minutes, with a statistically significant learning effect R = -0.7, P = 0.025. No perforations or bleeding occurred. All animals were euthanased on day 10. Histologically, CSI-EMR resulted in larger specimens and deeper submucosal resections. CSI-EMR with submucosal injection of succinylated gelatin is safe and superior to conventional EMR, consistently resulting in en bloc resections larger than 50 x 40 mm. With experience, total procedure duration is comparable.

The Effect of Pitch, Rhythm, and Familiarity on Working Memory and Anxiety as Measured by Digit Recall Performance

The purpose of this study was to isolate and quantitatively evaluate the effects of pitch and rhythm of unfamiliar and familiar melodies on working memory and anxiety as measured by sequential digit recall performance. Participants (N = 60) listened to 6 treatment conditions each consisting of 9 randomized monosyllabic digits. The digits were paired with (a) a familiar melody and pitch only, (b) a familiar melody and rhythm only, (c) a familiar melody with both pitch and rhythm, (d) an unfamiliar melody with pitch only, (e) an unfamiliar melody with rhythm only, and (f) an unfamiliar melody with both pitch and rhythm. The 6 different treatments were counterbalanced using a Latin square design in an attempt to control for order effects. Participants rated their state anxiety on a Likert-type scale before, midway through, and after the digits test. No statistically significant order, learning, or practice effects were found. A 3-way repeated-measures ANOVA indicated a statistically significant difference in digit recall performance across musical element conditions and groups. Results indicated that music majors outperformed nonmusic majors on the digit recall task. Participants were able to recall digits from the rhythm condition most accurately while recalling digits from pitch only and both pitch and rhythm conditions the least accurately. Graphic analysis of treatment as a function of sequential position indicated digit recall was best during conditions of primacy and recency. No main effects were found for the familiarity condition. Additionally, no main effects or interactions were found for the anxiety variable. The results of this study are congruent with existing working memory and music literature suggesting that pairing information with rhythm can facilitate recall, music majors outperform non-music majors, and recall accuracy is best in positions of primacy and recency. Implications for practice in therapy and education are made as well as suggestions for future research.

Feasibility of exhaled nitric oxide measurements at various flow rates in children with asthma

Measurement of bronchial and alveolar exhaled nitric oxide (NO) levels could be of clinical importance for the treatment of asthma. To discriminate between alveolar and bronchial NO, measurements need to be assessed at various flow rates. To study the feasibility, linearity, and long-term repeatability of NO measurements at four different exhalation flow rates in children with asthma. Twenty-one children with moderate persistent asthma, aged 6-12 yrs, were included in the study. NO was measured according to the ATS/ERS guidelines, using the NIOX analyzer with flow restrictors of 30, 50, 100, and 200 ml/s. Duration of the measurements ranged from 6-10 s, depending on the flow rate. The tests were repeated 3 and 6 months after the first NO measurement. Feasibility of NO measurements at these four flow rates increased from 67% to 91% and 95% at the first, second and third visit, respectively. A significant learning effect was present. Age and lung function indices did not influence success or failure of the tests. At the first measurements occasions, no problems occurred during the NO analysis at a 100 ml/s flow rate. There was a 75-90% success rate when performing the test using flow rates of 30, 50, and 200 ml/s. However, repeating the tests resulted in a 100% success rate. Measurements were not successful if: (i) children ran out of air; (ii) NO concentration exceeded 200 ppb; (iii) the measured NO flow was unstable; and (iv) the NO plateau was not formed. This study showed good feasibility and linearity of NO measurements in asthmatic children of 6 yrs and over at flow rates between 50-200 ml/s. A significant learning effect was present. The long-term reproducibility of alveolar and bronchial NO values during 6 months was moderate.

The Influence of Approach and Avoidance Behavior on Visual Selective Attention

ABSTRACT Recent findings indicate that enactment of approach behavior broadens the focus of perceptual attention. The aim of the present study was to examine how approach and avoidance behavior influence visual selective attention. To achieve this, the authors combined approach and avoidance manipulations with a visual precueing task (local vs. global cues preceding either local or global targets). The authors hypothesized that participants with an enactment of approach behavior would show faster attentional orienting with compatible cue-target-relations than in incompatible trials. The results support that enactment of approach behavior leads to faster attentional orienting in compatible trials compared with incompatible trials. Although participants showed significant attentional learning effects across blocks, learning was not enhanced by approach and avoidance manipulations.

Functional but not structural changes associated with learning: An exploration of longitudinal Voxel-Based Morphometry (VBM)

Voxel-Based Morphometry (VBM) has been used for several years to study differences in brain structure between populations. Recently, a longitudinal version of VBM has been used to show changes in gray matter associated with relatively short periods of training. In the present study we use fMRI and three different standard implementations of longitudinal VBM: SPM2, FSL, and SPM5 to assess functional and structural changes associated with a simple learning task. Behavioral and fMRI data clearly showed a significant learning effect. However, initially positive VBM results were found to be inconsistent across minor perturbations of the analysis technique and ultimately proved to be artifactual. When alignment biases were controlled for and recommended statistical procedures were used, no significant changes in grey matter density were found. This work, initially intended to show structural and functional changes with learning, rather demonstrates some of the potential pitfalls of existing longitudinal VBM methods and prescribes that these tools be applied and interpreted with extreme caution.

Influence of 5 Hz repetitive transcranial magnetic stimulation on motor learning

The aim of our study was to assess a possible improvement in motor learning induced by 5Hz repetitive transcranial magnetic stimulation (rTMS) of human motor cortex. The same stimulation protocol previously enhanced perceptual learning as assessed by tactile discrimination performance when applied to the human primary somatosensory cortex. We applied 1250 pulses of 5Hz “real” rTMS at 90% of resting motor threshold to the motor hotspot of the abductor pollicis brevis (APB) muscle in 15 healthy subjects before 1h of motor training. Furthermore, 15 subjects received 5Hz “sham” rTMS and served as control group. The motor task consisted of a synchronized co-contraction of the right APB and deltoid muscle. The latency between the onsets of muscle contractions was measured during training and served as a parameter for motor learning. MEP amplitudes were assessed in a subgroup of 10 subjects before and after rTMS as a parameter of corticospinal excitability. We found a significant learning effect in both groups as indicated by a reduction of latencies between the onsets of muscle contractions in the course of the training. Corticospinal excitability increased after “real”, but not after “sham” rTMS. However, “real” rTMS did not significantly influence motor learning as compared to “sham” rTMS. We conclude that 5Hz rTMS of human primary motor cortex is not able to improve motor learning in healthy subjects, which might be due to the higher complexity of motor learning as compared to perceptual learning in the tactile domain.

Tracheal intubation and alternative airway management devices used by healthcare professionals with different level of pre‐existing skills: a manikin study*

The classic Laryngeal Mask Airway (cLMA), ProSeal Laryngeal Mask Airway (PLMA), Intubating Laryngeal Mask Airway (ILMA), Combitube (CT), Laryngeal Tube (LT) and tracheal intubation (TI) were compared in a manikin study. Nurses, anaesthetic nurses, paramedics, physicians and anaesthetists inserted the devices three times in a randomised sequence. Time taken for successful insertion, success rates and ease of insertion were evaluated. Anaesthetists performed tracheal intubation significantly faster than other healthcare professionals (p < 0.05). Insertion times for the cLMA, PLMA, LT and CT were not significantly different between the groups. Insertion of the CT, ILMA and TI was associated with a significant learning effect in all groups. This was not observed with the cLMA, PLMA or LT. All non-anaesthetists were able to insert the cLMA, PLMA and LT within two attempts with a > 90% success rate on the first attempt. The ILMA and TI were the only devices where more than one subject experienced some difficulty in insertion. The cLMA, PLMA and LT should be evaluated for use in situations where only limited airway training is possible.

Designing technology for emergent literacy: The PictoPal initiative

PictoPal is the name of a technology-supported intervention designed to foster the development of emergent reading and writing skills in four and five year old children. Following the theoretical underpinnings and a brief description of PictoPal, this article describes how children worked with the technology; how the intervention elicited their engagement with literacy concepts both on the computer and off; and effects on early literacy learning. Observation results indicate that children are able to work independently with the program after a few instruction sessions. Observation data yield insight in the nature of adult guidance and the way the results of computer activities were implemented in off-computer classroom activities, as well as areas where this could be improved. Comparison of the four pre–post test experiments used to assess learning effects, suggest that the on-computer activities in PictoPal can yield a statistically significant learning effect, but only when integration with off-computer activities is present.

A Study of Inherent Pen Input Modalities for Precision Parameter Manipulations during Trajectory Tasks

Adjustment of a certain parameter in the course of performing a trajectory task such as drawing or gesturing is a common manipulation in pen-based interaction. Since pen tip information is confined to x-y coordinate data, such concurrent parameter adjustment is not easily accomplished in devices using only a pen tip. This paper comparatively investigates the performance of inherent pen input modalities (Pressure, Tilt, Azimuth, and Rolling) and Key Pressing with the non-preferred hand used for precision parameter manipulation during pen sliding actions. We elaborate our experimental design framework here and conduct experimentation to evaluate the effect of the five techniques. Results show that Pressure enabled the fastest performance along with the lowest error rate, while Azimuth exhibited the worst performance. Tilt showed slightly faster performance and achieved a lower error rate than Rolling. However, Rolling achieved the most significant learning effect on Selection Time and was favored over Tilt in subjective evaluations. Our experimental results afford a general understanding of the performance of inherent pen input modalities in the course of a trajectory task in HCI (human computer interaction).

Diagnostic accuracy and reliability of muscle strength and endurance measurements in patients with chronic low back pain

Dynamometric trunk muscle strength and endurance tests are performed widely within the rehabilitation management of chronic low back pain. The aim of this study was to examine the accuracy and long-term reliability of these measurements in patients with chronic low back pain. Cross-sectional study. Thirty-two patients with chronic low back pain, 19 healthy controls and 15 patients with chronic headache matched for age, sex and body mass index. Both patient groups and healthy controls performed isokinetic and isometric trunk extensor and flexor tests on a Biodex 2000 dynamometer. The Biering-Sørensen test served to examine back muscle endurance. Borg-Category-Ratio-Scales CR-10 rated participants' body experience immediately before and after the testing. Patients with chronic low back pain repeated measurements after 3 weeks. Among dynamometric tests, isokinetic measurements revealed the best area under the curve (AUC = 0.89) for the discrimination between patients with chronic low back pain and healthy controls. Reliability testing revealed highly significant learning effects for isometric trunk flexion and isokinetic measurements. The Biering-Sørensen test demonstrated excellent accuracy (AUC = 0.93) and no learning effects. Borg-category-ratio-scale ratings were not associated with the observed changes. In chronic low back pain dynamometric trunk muscle measures are limited to muscle function assessment purposes. Monitoring treatment outcome in these patients with these measures appears to be problematic because of learning effects. Based on our findings, we recommend the Biering-Sørensen test for management of chronic low back pain rehabilitation.

Learning Effect of Humphrey Matrix Frequency Doubling Technology Perimetry in Patients With Ocular Hypertension

To evaluate the learning effect of Frequency Doubling Technology (FDT) perimetry using the Humphrey Matrix-FDT perimetry (Matrix) 24-2 full-threshold program on patients with ocular hypertension experienced with standard automated perimetry. Twenty-four patients with ocular hypertension underwent 5 full-threshold Matrix tests at intervals of 5+/-2 days. Learning effect was defined as an improvement at results for duration, perimetric indices, foveal sensitivity, Glaucoma Hemifield Test, and the number of points with a P<5% and <1% in the total and pattern deviation maps. Eccentricity, hemifield, and quadrant sensitivities were also addressed as sources of differences in learning effect. Test-retest variability was also calculated for each repetition as the mean of the point-to-point interindividual standard deviations. A learning effect was demonstrated for mean defect (P=0.031, analysis of variance) and foveal sensitivity (P=0.009) and it only affected the first test for both parameters. All the other parameters did not show any significant learning effect. The effect was independent from eccentricity and quadrant or hemifield sensitivities. The results of this study demonstrate that the learning effect for Matrix-FDT is mild and it may affect only the first test. Caution is needed in the analysis of the first Matrix-FDT examination and retest may be advisable in the presence of low mean defect.

Positive surgical margins during robotic radical prostatectomy: a contemporary analysis of risk factors

To determine the risk factors (clinical, pathological and technical) for positive surgical margins (PSMs) after robotically assisted radical prostatectomy (RARP), as a PSM is associated with an increased risk of biochemical recurrence and often responsible for significant patient anxiety. Between November 2003 and March 2007, 216 consecutive patients had an RARP by one fellowship-trained urological oncologist. The surgical pathological specimens were fixed and processed using standard techniques, and assessed by a pathologist at the same institution. A PSM was defined as the presence of cancer adjacent to the inked margin. The clinical charts were reviewed retrospectively under an approved institutional review board protocol. Univariable and multivariable methods, including logistic regression models, were used to analyse the clinical, pathological and technical risk factors for PSM. The overall prevalence of PSM was 14.8% (32/216), and 5.4% (8/149) for pT2 cancers. The only preoperative factor that was associated with a greater risk of a PSM was the serum prostate-specific antigen (PSA) level (P = 0.012) and PSA density (P = 0.005). Age, clinical stage and clinical Gleason grade were not predictors of a PSM. The overall and pT2 PSM rate remained constant throughout the series of 216 patients (P = 0.371), indicating that the initial experience for RARP was not associated with a significantly greater risk of a PSM. However, there was a small independent 'learning curve' effect, with a lower rate of PSM associated with each increment of 25 patients (odds ratio 0.8, 95% confidence interval 0.6-1.0), supported by the significantly decreasing trend in PSM for pT3 cancers over time (P = 0.031) Although there was no significant increase over time in PSM with the use of an endostapler to control the dorsal venous complex (DVC), there was a significant learning effect, with a decrease in the PSM rate specifically in pT3 cancers using the suture technique (P = 0.005). A nerve-sparing procedure increased the risk of PSM in multivariable analysis (P = 0.03). As expected, pathological stage and pathological Gleason grade were the strongest predictors of PSM (P < 0.001). The most important risk factors for a PSM after RARP are the preoperative PSA level, PSA density, pathological stage and Gleason grade. PSM rates for a surgeon in their initial experience can be comparable to that of a surgeon experienced in RARP. Using a stapling device to control the DVC does not appear to increase the risk of a PSM, although nerve-sparing increases the rates of PSM in extraprostatic prostate cancer.