SEARCH · PubMed Health

Results for “performance”

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 631 records · Page 35Linked to original sources

PubMed2005

Complex interactions between tutor performance, tutorial group productivity and the effectiveness of PBL units as perceived by students.

AIM: Tutor performance and tutorial group productivity interact with each other in a complex manner. The aim of this study was to investigate how tutor performance, tutorial group productivity and the effectiveness of a PBL unit interact with each other. Three hypotheses were tested: (1) Does the tutor performance score differ across different levels of group productivity? (2) Does the group productivity score differ across different levels of tutor performance? and (3) Is the learning effectiveness score of a PBL unit related to tutor performance and group productivity? METHOD: Students rated the tutor performance, the tutorial group productivity and the effectiveness of the PBL unit. In total 287 unique tutors were involved and were categorized as having a relatively low, average or relatively high score on tutor performance. This was also done for the group productivity score. For each combination, average effectiveness score were computed. Furthermore, partial correlation coefficients were computed. RESULTS: The results demonstrated that the average tutor performance score was higher if the productivity score was higher (hypothesis 1). The results also demonstrated that the average productivity score was higher if the tutor performance score was higher (hypothesis 2). Furthermore it was found that the effectiveness score was higher if the productivity score was higher. The effectiveness score was also higher if the tutor score was higher. The results furthermore demonstrated that the correlation coefficient between tutor performance and effectiveness of the PBL unit is 0.01 (n.s.) if the correlation between the two variables was controlled for group productivity (was 0.36). In addition, the correlation coefficient between group productivity and effectiveness became 0.39 if the correlation between these two variables was controlled for tutor performance (was 0.51) (hypothesis 3). CONCLUSION: It is concluded that tutor performance differs across different levels of group productivity and that the group productivity score differs across different levels of tutor performance. In addition, it is concluded that both group productivity and the tutor's performance have an impact on the effectiveness of a PBL unit, although the correlation between group productivity and effectiveness is higher than the correlation between tutor performance and effectiveness. This finding illustrates the importance of the group's productivity in PBL and the tutor's importance and implies that schools should put more efforts in improving tutorial group functioning as well as in improving a tutor's performance.

Education, Medical, Undergraduate↗

PubMed2004

Factors affecting the performance of maternal health care providers in Armenia.

BACKGROUND: Over the last five years, international development organizations began to modify and adapt the conventional Performance Improvement Model for use in low-resource settings. This model outlines the five key factors believed to influence performance outcomes: job expectations, performance feedback, environment and tools, motivation and incentives, and knowledge and skills. Each of these factors should be supplied by the organization in which the provider works, and thus, organizational support is considered as an overarching element for analysis. Little research, domestically or internationally, has been conducted on the actual effects of each of the factors on performance outcomes and most PI practitioners assume that all the factors are needed in order for performance to improve. This study presents a unique exploration of how the factors, individually as well as in combination, affect the performance of primary reproductive health providers (nurse-midwives) in two regions of Armenia. METHODS: Two hundred and eighty-five nurses and midwives were observed conducting real or simulated antenatal and postpartum/neonatal care services and interviewed about the presence or absence of the performance factors within their work environment. Results were analyzed to compare average performance with the existence or absence of the factors; then, multiple regression analysis was conducted with the merged datasets to obtain the best models of "predictors" of performance within each clinical service. RESULTS: Baseline results revealed that performance was sub-standard in several areas and several performance factors were deficient or nonexistent. The multivariate analysis showed that (a) training in the use of the clinic tools; and (b) receiving recognition from the employer or the client/community, are factors strongly associated with performance, followed by (c) receiving performance feedback in postpartum care. Other - extraneous - variables such as the facility type (antenatal care) and whether observation was on simulated vs. real patients (postpartum care) also had a role in observed performance. CONCLUSION: This study concludes that the antenatal and postpartum care performance of health providers in Armenia is strongly associated with having the practical knowledge and skills to use everyday tools of the trade and with receiving recognition for their work, as well as having performance feedback. The paper recognized several limitations and expects further studies will illuminate this important topic further.

Journal Article↗

PubMed2006

Papanicolaou tests with mixed high-grade and low-grade squamous intraepithelial lesion features: distinct performance in the College of American Pathologists Interlaboratory Comparison Program in Cervicovaginal Cytopathology.

CONTEXT: Previous studies have shown that in gynecologic cytology, cases of low-grade squamous intraepithelial lesion (LSIL) and high-grade squamous intraepithelial lesion (HSIL) perform differently on interpretive review. The performance of cases with mixed LSIL and HSIL features is unknown. OBJECTIVE: To compare the performance of gynecologic cytology cases of "pure" LSIL and HSIL with cases showing mixed LSIL and HSIL features. DESIGN: We compiled performance data from the College of American Pathologists Interlaboratory Comparison Program in Cervicovaginal Cytopathology from the years 2003 and 2004, and compared the performance of slides showing relatively pure LSIL and HSIL (< or = 10% misclassification as HSIL and LSIL, respectively) with slides showing mixed LSIL or HSIL features (cases misclassified as LSIL or HSIL > 10% of the time). RESULTS: Interpretations from a total of 4508 cases (2452 HSIL and 2056 LSIL) were analyzed. Overall, the sensitivity of participants on slides with a reference diagnosis of HSIL was 97.3%, and of LSIL was 95.9%. Performance trends for pure versus mixed cases varied by slide type and reference diagnosis. For conventional slides, participant sensitivity on pure HSIL cases was greatest (98.0%) and on pure LSIL cases was least (95.2%), while participant performance on cases with mixed features was intermediate (97.0% for mixed HSIL and 96.7% for mixed LSIL). In contrast, participant performance on ThinPrep slides showed the greatest sensitivity for mixed LSIL slides (97.9%), while performance on mixed HSIL slides showed the lowest sensitivity (95.7%); slides with pure features had intermediate sensitivity levels (96.3% for both HSIL and LSIL). Further evaluation demonstrated that conventional pure HSIL slides performed significantly better than mixed HSIL slides (P = .006), whereas mixed LSIL slides performed better than pure LSIL slides (P = .01). For ThinPrep slides, pure HSIL cases performed similarly to mixed HSIL cases (P = .43), while mixed LSIL cases performed better than pure LSIL cases (P = .04). CONCLUSION: Slides with mixed LSIL and HSIL features have measurably distinct performance characteristics in comparison to slides with pure LSIL or HSIL features. Participant performance on conventional mixed cases is distinctly different from performance on ThinPrep mixed cases.

Diagnosis, Differential↗

PubMed2003

The ability to self-monitor performance during a week of simulated night shifts.

STUDY OBJECTIVES: Research has indicated that individuals are able to accurately monitor the performance decrements they experience during unitary periods of acute sleep deprivation. The aim of the current study was to investigate the ability to self-monitor performance during a week of simulated night shifts. DESIGN: Subjects completed 7 consecutive 8-hour night shifts (11 pm-7 am). SETTING: University sleep laboratory. SUBJECTS: Fifteen young (7 men, 8 women, 19-25 years) healthy volunteers. INTERVENTIONS: During the night shifts, performance was measured hourly on 4 performance parameters: psychomotor vigilance test (PVT), tracking, and grammatical reasoning (GRG) accuracy and response latency. Before and after each test, subjects completed visual analogue scales, which required them to rate their alertness and their performance speed and/or accuracy. RESULTS: Analysis indicated that GRG response latency and tracking were significantly impaired (P<0.05) during the first 2 shifts only. The PVT performance displayed consistent impairment, with significant (P<0.05) declines during all but the final shift. The pattern of deterioration in subjective ratings of alertness was similar to that of the PVT data. Correlations between subjective alertness and self-ratings of performance were significant (P<0.01) for all parameters (r=0.39-0.69). Significant (P<0.05) correlations were found across the week between pretest performance ratings and actual performance for all parameters except GRG accuracy (r=0.29-0.58) and between posttest ratings and actual performance for all parameters (r=0.52-0.75). Correlations between pretest ratings and actual performance were also conducted separately for each shift. Highest correlations were found during the first shift, with r-values that were low for GRG accuracy (r=0.32) and GRG response latency (r=0.20), moderate for tracking (r=0.41), and high for PVT (r=0.82). In general, lower correlations were found later in the week. CONCLUSIONS: Overall, results indicate that individuals have only a moderate ability to predict performance impairment during a week of night shifts. It is likely that performance ratings are based, at least to a certain extent, on subjective alertness levels. Furthermore, it seems that rating accuracy is improved on tasks providing performance feedback, such as the PVT. Finally, it appears that after testing, individuals have a more accurate perception of their performance.

Acute Disease↗

PubMed1990

Goal or near miss! Movement potential differences between adults and children in skilled performance.

In this study, the performances and the movement-related brain macropotentials of a group of adults and 10-year-old children were analyzed to test whether and how they were correlated to the success or failure in the performance. Bereitschaftspotential (BP), motor cortex potential (MCP) and skilled performance positivity (SPP) related to preparation, execution and evaluation of performance respectively showed a significant relationship to the performance outcome. The BP area in the left precentral decreased significantly with increasing performance time. The amplitude of the MCP was maximum during target performances and decreased with increasing range of error of performance. There was a difference in trend between adults and children in the SPP latency. During target performances, SPP latency in Pz was maximum in children and minimum in adults. In children, the SPP amplitude was greater in frontal and precentral areas during target performance and decreased with increasing inaccuracy of performance. This trend was not evident in adults. The results seem to indicate that the SPP latency does not seem to depend on the performance time but on the evaluation of information conveyed by the stimulus. How this evaluation takes place seems to be different in children and adults; this evaluation process is also reflected in the SPP amplitude of children during target performances. For the adults who have already developed formal thinking, the probability that any outcome is possible exists and so the significant relationship between SPP amplitude and performance is not seen.

Adolescent↗

PubMed1997

Circadian rhythms in human performance and mood under constant conditions.

UNLABELLED: This study explored the relationship between circadian performance rhythms and rhythms in rectal temperature, plasma cortisol, plasma melatonin, subjective alertness and well-being. Seventeen healthy young adults were studied under 36 h of 'unmasking' conditions (constant wakeful bedrest, temporal isolation, homogenized 'meals') during which rectal temperatures were measured every minute, and plasma cortisol and plasma melatonin measured every 20 min. Hourly subjective ratings of global vigour (alertness) and affect (well-being) were obtained followed by one of two performance batteries. On odd-numbered hours performance (speed and accuracy) of serial search, verbal reasoning and manual dexterity tasks was assessed. On even-numbered hours, performance (% hits, response speed) was measured at a 25-30 min visual vigilance task. Performance of all tasks (except search accuracy) showed a significant time of day variation usually with a nocturnal trough close to the trough in rectal temperature. Performance rhythms appeared not to reliably differ with working memory load. Within subjects, predominantly positive correlations emerged between good performance and higher temperatures and better subjective alertness; predominantly negative correlations between good performance and higher plasma levels of cortisol and melatonin. Temperature and cortisol rhythms correlated with slightly more performance measures (5/7) than did melatonin rhythms (4/7). Global vigour correlated about as well with performance (5/7) as did temperature, and considerably better than global affect (1/7). IN CONCLUSION: (1) between-task heterogeneity in circadian performance rhythms appeared to be absent when the sleep/wake cycle was suspended; (2) temperature (positively), cortisol and melatonin (negatively) appeared equally good as circadian correlates of performance, and (3) subjective alertness correlated with performance rhythms as well as (but not better than) body temperature, suggesting that performance rhythms were not directly mediated by rhythms in subjective alertness.

Adult↗

PubMed2006

Relationship between Medicare's hospital compare performance measures and mortality rates.

CONTEXT: In response to concerns about the quality of care in US hospitals, the Centers for Medicare & Medicaid Services began measuring hospital performance and reporting this performance on their Web site, Hospital Compare. It is unknown whether these process performance measures are related to hospital-level outcomes. OBJECTIVE: To determine whether quality measured with the process measures used in Hospital Compare are correlated with and predictive of hospitals' risk-adjusted mortality rates. DESIGN, SETTING, AND PARTICIPANTS: Cross-sectional study of hospital care between January 1 and December 31, 2004, for acute myocardial infarction, heart failure, and pneumonia at acute care hospitals in the United States included on the Hospital Compare Web site. Ten process performance measures included in Hospital Compare were compared with hospital risk-adjusted mortality rates, which were measured using Medicare Part A claims data. MAIN OUTCOME MEASURES: Condition-specific inpatient, 30-day, and 1-year risk-adjusted mortality rates. RESULTS: A total of 3657 acute care hospitals were included in the study based on their performance as reported in Hospital Compare. Across all acute myocardial infarction performance measures, the absolute reduction in risk-adjusted mortality rates between hospitals performing in the 25th percentile vs those performing in the 75th percentile was 0.005 for inpatient mortality, 0.006 for 30-day mortality, and 0.012 for 1-year mortality (P<.001 for each comparison). For the heart failure performance measures, the absolute mortality reduction was smaller, ranging from 0.001 for inpatient mortality (P = .03) to 0.002 for 1-year mortality (P = .08). For the pneumonia performance measures, the absolute reduction in mortality ranged from 0.001 for 30-day mortality (P = .05) to 0.005 for inpatient mortality (P<.001). Differences in mortality rates for hospitals performing in the 75th percentile on all measures within a condition vs those performing lower than the 25th percentile on all reported measures for acute myocardial infarction ranged between 0.008 (P = .06) and 0.018 (P = .008). For pneumonia, the effects ranged between 0.003 (P = .09) and 0.014 (P<.001); for heart failure, the effects ranged between -0.013 (P = .06) and -0.038 (P = .45). CONCLUSIONS: Hospital performance measures predict small differences in hospital risk-adjusted mortality rates. Efforts should be made to develop performance measures that are tightly linked to patient outcomes.

Benchmarking↗

PubMed2002

A comparison of sleep deprivation and narcolepsy in terms of complex cognitive performance and subjective sleepiness.

OBJECTIVES: (i) To expose 'normal sleepers' to a 32-h sleep deprivation protocol and evaluate the impact of this deprivation on a complex performance task i.e. the paced auditory serial addition test (PASAT). (ii) To compare these sleep deprivation performance findings with historical data on the impact of sleepiness secondary to narcolepsy on PASAT performance measures. (iii) To investigate the recuperative effects of a brief nap period on both sleepiness and PASAT performance for the sleep-deprived subjects. (iv) To compare these post-nap effects with historical data relating to the impact of napping on both sleepiness and PASAT performance for subjects with narcolepsy. BACKGROUND: Previous research has demonstrated that sleepiness induced by sleep deprivation in normal sleepers may lead to cognitive impairment across a range of performance tasks. Sleepiness secondary to narcolepsy has also been noted to impair cognitive function especially for complex processing tasks. Direct comparison of the effects of sleepiness on performance between non-pathological and pathological sleepiness states is confounded, however, by methodological differences in research design especially in relation to levels of induced sleepiness and performance task selection. The purpose of the current study was to undertake a sleep deprivation study that achieved a methodological match with published data evaluating the impact of sleepiness on cognitive performance for subjects with narcolepsy. This methodological matching allowed for a more precise comparison of the impact of sleepiness on performance between non-pathological and pathological sleepiness groups. RESULTS: Normal sleepers required a 32-h deprivation protocol to develop a subjective level of sleepiness that equated with that identified by subjects with narcolepsy. This induced sleepiness in normal sleepers did not result in any significant decrement in complex performance, a finding that was in contrast to the performance decrement previously found in subjects with narcolepsy with equivalent subjective sleepiness ratings. A 20-min nap produced more improvement in both arousal and cognitive processing performance for the subjects with narcolepsy than for the current sleep-deprivation cohort. CONCLUSION: This study identified significant differences in the impact of sleepiness on complex performance between non-pathological sleep-deprived subjects and subjects with narcolepsy. This paper explores these differences in relation to the potential for both quantitative and qualitative differences that exist in the nature of sleepiness between non-pathological and pathological sleepiness states.

Journal Article↗

PubMed1994

Learning, experience, and self-assessment of competence of third-year medical students in performing bedside procedures.

BACKGROUND: Third-year medical students are expected to perform common bedside procedures as part of their daily ward activities, but there are few programs to teach these skills or document students' abilities to perform them. PURPOSE: In addition to describing the clinical procedures course at the Medical College of Georgia School of Medicine, the purpose of this paper is to report how often students perform common bedside procedures during the third year of medical school, whether the number of times a procedure has been performed is indicative of self-perceived level of competence, and how useful the students find the procedures course for learning how to perform common procedures. METHOD: In June 1991, the 163 entering third-year students participated in a two-day course in which they were taught universal precautions and provided specific step-by-step instructions for performing 16 clinical procedures. One year later, after the students had completed their third-year clerkships, they were asked to report the numbers of times they had performed the procedures during their clerkships, to provide self-assessments of their competency, and to indicate how helpful the course had been for learning clinical procedures. The association between the number of times the students reported performing a procedure and how competent they felt to perform the procedure was assessed using Kendall's tau coefficient. RESULTS: A total of 100 students returned completed questionnaires. Most of the students reported performing venipuncture, obtaining blood cultures, and scrubbing surgically more than five times, but they reported performing other procedures less frequently. For most procedures, self-assessment of competency correlated with frequency of performance. The procedures course was well received by students and instructors, based on both written evaluations and informal verbal feedback. CONCLUSION: Surprisingly, the students' self-reports indicated that many students performed procedures on patients infrequently. As expected, for most procedures there was a significant association between frequency of performance and self-assessed competency.

Academic Medical Centers↗

PubMed1999

Distortion product otoacoustic emission test performance for a priori criteria and for multifrequency audiometric standards.

OBJECTIVES: 1) To describe distortion product otoacoustic emission (DPOAE) test performance when a priori response criteria are applied to a large set of DPOAE data. 2) To describe DPOAE test performance when multifrequency definitions of auditory function are used. 3) To determine DPOAE test performance when a single decision regarding auditory status is made for an ear, based on DPOAE data from several frequencies. 4) To compare univariate and multivariate test performance when multifrequency gold standard definitions and response criteria are applied to DPOAE data. DESIGN: DPOAE and audiometric data were analyzed from 1267 ears of 806 subjects. These data were evaluated for three different frequency combinations (2, 3, 4 kHz; 2, 3, 4, 6 kHz; 1.5, 2, 3, 4, 6 kHz). DPOAE data were collected for each of the f2 frequencies listed above, using primary levels (L1/L2) of 65/55 dB SPL and a primary ratio (f2/f1) of 1.22. Sensitivity and specificity were evaluated for signal to noise ratios (SNRs) of 3, 6, and 9 dB, which are in common clinical use. In addition, test performance was evaluated using clinical decision theory, following the convention we have used in previous reports on otoacoustic emission test performance. Both univariate and multivariate analyses techniques were applied to the data. In addition to evaluating DPOAE test performance for the case when audiometric and f2 frequency were equal, multifrequency gold standards and multifrequency criterion responses were evaluated. Three new gold standards were used to assess test performance: average pure-tone thresholds, extrema thresholds that took into account both the magnitude of the loss and the number of frequencies at which hearing loss existed, and a combination of the two. These new gold standards were applied to each of the three frequency groups described above. RESULTS: As expected, SNR criteria of 3, 6, and 9 dB never resulted in perfect DPOAE test performance. Even the most stringent of these criteria (9 dB SNR) did not result in a sensitivity of 100%. This result suggests that caution should be exercised in the interpretation of DPOAE test results when these a priori criteria are used clinically. Excellent test performance was achieved when auditory status was classified on the basis of the new gold standards and when either SNR or the output of multivariate logistic regressions (LRs) were used as criterion measures. Invariably, the LR resulted in superior test performance compared with what was achieved by the SNR. For SNR criteria of 3, 6, and 9 dB and (by definition) for the LR, specificity, in general, exceeded 80% and often was greater than 90%. Sensitivity, however, depended on the magnitude of hearing loss. Diagnostic errors, when they occurred, were more common for patients with mild hearing losses (21 to 40 dB HL); sensitivity approached 100% once the hearing loss exceeded 40 dB HL. The largest differences between test performance based on SNR or LR occurred for the ears with mild hearing loss, where the LR resulted in more accurate diagnoses. CONCLUSIONS: It should not be assumed that the use of a priori response criteria, such as SNRs of 3, 6, or 9 dB, will identify all ears with hearing loss. Test performance when multifrequency gold standards are used to define an ear as normal or impaired and when data from multiple f2 frequencies are used to make a diagnosis, resulted in excellent test performance, especially when the LR was used. When predicting auditory status with multifrequency gold standards, the LR resulted in relative operating characteristic curve areas of 0.95 or 0.96. An output from the LR can be selected that results in a specificity of 90% or better. When the loss exceeded 40 dB HL, the same output from the LR resulted in test sensitivity of nearly 100%. These were the best test results that were achieved. (ABSTRACT TRUNCATED)

Acoustic Stimulation↗

PubMed2005

The changes in running performance and maximal oxygen uptake after long-term training in elite athletes.

AIM: The relationship between VO2max (mL x kg(-1) x min(-1)) and running performance has been assessed in cross-sectional studies. Follow-up studies of the long-term effects of running training on the changes in performance and VO2max have not been undertaken. METHODS: Twenty-five male endurance-trained (MET) and 8 female endurance-trained (FET) athletes were tracked over 4 years. In each event the athletes were divided into Class A, including half the number of athletes with the best performances, and Class B. VO2max, examined at the end of the competitive season, and the best performance was chosen each year. RESULTS: After 3 years of training, in MET and FET athletes the performance improved by 1.77% and 0.69% (P<0.01 and P=0.579), respectively. In Class A runners, training resulted in non-significant increase in performance (-0.04%) (P=0.982) and in Class B runners, performance increased by 3.16% (P=0.001). In all groups VO(2max) remained essentially unchanged. Longitudinal changes in the VO2max were not related with the changes in running performance in any group. CONCLUSIONS: This study show than in older runners with more years of training, heavy training does not produce improvements in running performance neither changes in the VO2max. It is possible that these elite athletes have reached the plateau in their performance; although unlikely, some improvement in training techniques may happen and break the present limit. In younger runners with less years of training, heavy training produce improvements in running performance without changes in the VO2max. These athletes that had not attained his biological limits at the beginning of study improved the performance in competition and it is quite probable that this improvement be due to training. The changes in performance were not related to changes in VO2max. Consequently, another physiological or psychological variables must be studied by longitudinal form to explain the variability of performance in competition.

Adaptation, Physiological↗

PubMed2001

The implications of linking the dynamic performance and turnover literatures.

This article examines how the literatures of dynamic performance and the performance-turnover relationship inform each other. The nonrandom performance turnover relationship suggests that dynamic performance studies may be biased by their elimination of participants who do not remain for the entire study period. The authors demonstrated that the performance slopes of those who leave an organization differ from the performance slopes of those who remain. This finding suggests that studies of the performance-turnover relationship need to consider employee performance trends when predicting turnover. Replicating and extending the research of D. A. Harrison, M. Virick, and S. William (1996), the authors found that performance changes from the previous month and performance trends measured over a longer time period explained variance in voluntary turnover beyond current performance. Finally, the authors showed that performance trends interacted with current performance in the prediction of voluntary turnover.

Employee Performance Appraisal↗

PubMed2006

Upper alpha ERD and absolute power: their meaning for memory performance.

A variety of studies have shown that EEG alpha activity in the upper frequency range is associated with different types of cognitive processes, memory performance, perceptual performance and intelligence, but in strikingly different ways. For semantic memory performance we have found that resting or reference power is positively associated with performance, whereas during actual processing of the task, small power--reflected by a large extent of event-related desynchronization (ERD)--is related to good performance. We also have shown that the induction of large alpha reference power by neurofeedback training or repetitive transcranial magnetic stimulation (rTMS) at individual alpha frequency mimicked exactly the situation which is typical for good memory performance under normal situations: increased alpha reference power is associated with large ERD and good performance. Recent studies have demonstrated that this relationship holds true only for memory and not perceptual tasks that require the identification of simple visual stimuli under difficult conditions. In contrast to good memory performance, good perceptual performance is related to small pre-stimulus alpha power and a small ERD. We interpret this finding in terms of cortical inhibition vs. activation preceding task performance by assuming that large rhythmic alpha activity reflects inhibition. We assume that small reference alpha enhances perceptual performance because the cortex is activated and prepared to process the stimulus, whereas memory performance is enhanced if the cortex is deactivated before a task is performed because in typical memory tasks selective processing can start only after the to-be-remembered item or cue is presented. We also suggest that conflicting results about alpha ERD and the neural efficiency hypothesis (which assumes that highly intelligent exhibit a small ERD) can also be interpreted in terms of inhibition. Only if an intelligence test actually requires the activation of (semantic) memory, a large (because task specific) ERD can be observed. If other processing systems are required, the semantic memory system may even become suppressed, which is reflected by alpha event-related synchronization (ERS) or at least a largely decreased ERD.

Alpha Rhythm↗

PubMed2001

Perceived and actual performance of daily tasks: relationship to visual function tests in individuals with retinitis pigmentosa.

PURPOSE: To investigate the functioning in daily task performance of individuals with retinitis pigmentosa (RP). Goals were (1) to quantify the relationships among clinical tests of vision, self-reports, and evaluations of actual task performance to predict difficulty in these tasks; and (2) to validate self-report questionnaire data about daily task performance with observations and measurements of actual task performance conducted by a certified low-vision specialist. DESIGN: A cross-sectional study and survey. PARTICIPANTS: Sixty-two individuals with RP (mean age, 37 years) participated in the study. METHODS: We obtained data about task performance from subjects' reports about their daily performance as assessed by a 53-item questionnaire and from a specialist's rating about actual ability on a 64-item battery of tasks, including ones similar to those assessed with the questionnaire. MAIN OUTCOME MEASURES: Clinical measures of vision included visual acuity, visual fields using Goldmann perimetry, letter contrast sensitivity, and cone and rod electroretinogram (ERG) function. The questionnaire and functional tasks were clustered into three categories: "reading," "mobility," and "peripheral detection." RESULTS: Self-report was correlated significantly with actual task performance. Task performance was correlated significantly with clinical test performance. Moderate or worse difficulty in performance was observed only for visual acuity worse than 20/40; log contrast sensitivity less than 1.4; a visual field area smaller than 2000 deg(2) (area equivalent to a 50-degree diameter of visual field to the Goldmann II-4-e target); and ERG amplitudes less than 10 microvolts for 32-Hz light-adapted white flicker. CONCLUSIONS: Despite the significant correlations, there remains variability in task performance that is unaccounted for in some individuals with low levels of clinical test performance. The assessment of actual task performance validated the use of self-reports in individuals with RP.

Activities of Daily Living↗

PubMed2000

The ability to self-monitor performance when fatigued.

The present study aimed to systematically investigate the effects of elevated fatigue levels on the ability to self-monitor performance. Eighteen participants, aged 19-26 y, remained awake for a period of 28 h. Neurobehavioural performance was measured at hourly intervals using four tests from a standardized computer test battery. From these four tests, six measures of performance were obtained: grammatical reasoning (accuracy and response latency); vigilance (accuracy and response latency); simple sensory comparison and tracking. In addition, before and after each test, participants completed visual analogue scales which required them to rate their alertness level and the speed and accuracy of their performance. Individual test results for both self-ratings and neurobehavioural performance were converted to z-scores. Planned comparison analysis indicated that scores on four of the six performance measures decreased significantly as hours of wakefulness increased. Similarly, predicted performance scores for all six measures of performance decreased significantly. Analysis revealed moderate correlations between predicted and actual performance for the four parameters affected by fatigue. Furthermore, moderate to high correlations were found between all six performance parameters and their respective post-test self-ratings. In addition, moderate to high correlations were found between predicted performance and alertness. Taken together, these findings suggest that as fatigue levels increase, subjects globally assess performance decrements. Results suggest that subjective alertness may in part mediate an individual's global assessment of performance.

Adult↗

PubMed2003

Kinetic analysis of complex training rest interval effect on vertical jump performance.

Complex training has been recommended as a method of incorporating plyometrics with strength training. Some research suggests that plyometric performance is enhanced when performed 3-4 minutes after the strength training set, whereas other studies have failed to find any complex training advantage when plyometrics are performed immediately after the strength training portion of the complex. The purpose of this study was to determine if there is an ergogenic advantage associated with complex training and if there is an optimal time for performing plyometrics after the strength training set. Subjects were 21 NCAA Division I athletes who performed a countermovement vertical jump, a set of 5 repetitions maximum (5 RM) squats, and 5 trials of countermovement vertical jump at intervals of 10 seconds and 1, 2, 3, and 4 minutes after the squat. Jump height and peak ground reaction forces were acquired via a force platform. The pre-squat jump performance was compared with the post-squat jumps. Repeated measures ANOVA determined a difference (p </= 0.05) between genders and that jump performance immediately following the squat exercise was hindered (0.66 m), but no effect (p > 0.05) was found comparing subsequent jumps (0.72-0.76 m) to the pre-squat condition (0.74 m). When comparing high to low strength individuals, there was no effect on jump performance following the squat (p > 0.05). In conclusion, complex training does not appear to enhance jumping performance significantly and actually decreases it when the jump is performed immediately following the strength training set; however, a nonsignificant trend toward improvement seemed to be present. Therefore to optimize jump performance it appears that athletes should not perform jumps immediately following resistance training. It may be possible that beyond 4 minutes of recovery performance could be enhanced; however, that was not within the scope of the current study.

Adolescent↗

PubMed2005

Impact of educational intervention on confidence and competence in the performance of a simple surgical task.

BACKGROUND: Many complex new procedures involve a learning curve, and patients treated by individuals who are new to a procedure may have more complications than those treated by a practitioner who has performed the intervention more frequently. Still, at some point on the learning curve, each individual must decide that he or she is qualified to perform a procedure, presumably on the basis of his or her level of confidence, background, education, and skill. To evaluate the interrelationship of these factors, we designed a study in which we assessed the performance of a simulated knee joint injection. METHODS: Ninety-three practitioners attending a continuing medical education session on knee injection were randomized to receive skills instruction through the use of a printed manual, a video, or hands-on instruction; each performed one injection before and after instruction. The participants completed pre-instruction and post-instruction questionnaires gauging confidence and also provided self-assessments of their performances of injections before and after instruction. Self-assessments were compared with objective performance standards measured by custom-designed knee models with electronic sensors that detected correct needle placement. RESULTS: Before instruction, the participants' confidence was significantly but inversely related to competent performance (r = -0.253, p = 0.02); that is, greater confidence correlated with poorer performance. Both men and physician-practitioners displayed higher pre-instruction confidence (p < 0.01), which was not correlated with better performance. After instruction, performance improved significantly in all three training groups (p < 0.001), with no significant differences in efficacy detected among the three groups (p = 0.99). After instruction, confidence correlated with objective competence in all groups (r = 0.24, p = 0.04); however, this correlation was weaker than the correlation between the participants' confidence and their self-assessment of performance (r = 0.72, p = 0.001). CONCLUSIONS: Even low-intensity forms of instruction improve individuals' confidence, competence, and self-assessment of their skill in performing the fairly straightforward psychomotor task of simulated knee injection. However, men and physicians disproportionately overestimated their skills both before and after training, a finding that worsened as confidence increased. The inverse relationship between confidence and competence that we observed before the educational intervention as well as the demographic differences that we noted should raise questions about how complex new procedures should be introduced and when self-trained practitioners should begin to perform them.

Clinical Competence↗

PubMed2001

Improving cycling performance: how should we spend our time and money.

Cycling performance is dependent on physiological factors which influence mechanical power production and mechanical and environmental factors that affect power demand. The purpose of this review was to summarize these factors and to rank them in order of importance. We used a model by Martin et al. to express all performance changes as changes in 40 km time trial performance. We modelled the performance of riders with different ability ranging from novice to elite cyclists. Training is a first and most obvious way to improve power production and was predicted to have the potential to improve 40 km time trial performance by 1 to 10% (1 to 7 minutes). The model also predicts that altitude training per se can cause a further improvement of 23 to 34 seconds. Carbohydrate-electrolyte drinks may decrease 40 km time by 32 to 42 seconds. Relatively low doses of caffeine may improve 40 km time trial performance by 55 to 84 seconds. Another way of improving time trial performance is by reducing the power demand of riding at a certain velocity. Riding with hands on the brake hoods would improve aerodynamics and increase performance time by approximately 5 to 7 minutes and riding with hands on the handlebar drops would increase performance time by 2 to 3 minutes compared with a baseline position (elbows on time trail handle bars). Conversely, riding with a carefully optimised position could decrease performance time by 2 to 2.5 minutes. An aerodynamic frame saved the modelled riders 1:17 to 1:44 min:sec. Furthermore, compared with a conventional wheel set, an aerodynamic wheel set may improve time trial performance time by 60 to 82 seconds. From the analysis in this article it becomes clear that novice cyclists can benefit more from the suggested alterations in position, equipment, nutrition and training compared with elite cyclists. Training seems to be the most important factor, but sometimes large improvements can be made by relatively small changes in body position. More expensive options of performance improvement include altitude training and modifications of equipment (light and aerodynamic bicycle and wheels). Depending on the availability of time and financial resources cyclists have to make decisions about how to achieve their performance improvements. The data presented here may provide a guideline to help make such decisions.

Bicycling↗