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PubMedDate not supplied

Length of stay in the intensive care unit. Effects of practice guidelines and feedback.

We developed consensus management guidelines for patients admitted with chest pain, pulmonary edema, and syncope and used these guidelines to examine practice variation and the effects of physician feedback on decision making in 1145 consecutive admissions to three medical intensive care units. Data collection included a 6-month baseline period and two 6-month physician feedback periods. Hospital length of stay fell from 8.34 days to 7.41 and 7.14 days during feedback; intensive care unit length of stay fell from 2.45 days to 2.23 and 2.07 days. Feedback was associated with an increase in the percentage of patients conforming to the management guidelines. Multiple linear regression showed that feedback correlated with reductions of 0.79 days (confidence interval, 0.12 to 1.46) in hospital length of stay and 0.21 days (confidence interval 0.05 to 0.37) in intensive care unit length of stay. This effect was most apparent in patients not requiring any intervention, but with a major complication. During the 6-month follow-up, mortality, readmission, and urgent readmission rates were similar for patients admitted in baseline and feedback periods.

Boston↗

PubMed1986

Rapid loss of feedback suppressor T-cell activity after priming in vivo.

T cells from antigen-primed mice have a diminished capacity to mediate feedback suppression when compared to T cells from unprimed mice. This was demonstrated using an in vitro model of B-cell induced feedback suppression in which spleen cells from mice primed with sheep erythrocytes (SRBC) activate feedback suppressor T-cell precursors to mediate suppression of the primed spleen cell response. The addition of splenic T cells from unprimed mice to cultures of spleen cells from SRBC-primed mice resulted in suppression of the secondary IgM and IgG anti-SRBC response. In contrast, no suppression was detected when T cells from mice primed with SRBC were added to the primed spleen cell cultures. The loss of suppression by T cells from primed mice was antigen-specific and was detectable by 24 hr after priming, coinciding with the appearance after priming of T-cell enhancing activity. The reduced suppressive activity could be due to changes in the active T-cell subset itself or to the appearance of cells or factors within the T-cell population that block or mask detection of feedback suppression. In either case, the present finding suggests that priming of a host not only activates feedback suppression induction mechanisms, but also rapidly affects the ability of the T-cell population to develop effective feedback suppression.

Animals↗

PubMed1988

Evaluating sources of employee feedback in foodservice.

Foodservice supervisors and employees have different perceptions of the usefulness of sources of employee feedback. Supervisors tend to overestimate the usefulness of feedback to their employees and underestimate the impact of sources of feedback over which they do not have direct control. Supervisors must realize that feedback sources such as coworkers and the work itself are useful to employees and may affect employee performance. Frequent, specific feedback from the supervisor and linkage of formal rewards to performance are feedback strategies that could improve performance in foodservice.

Adult↗

PubMed1986

Feedback reduces test use in a health maintenance organization.

In a cross-over design, three interventions were tested for their impact on the rate of use of 12 commonly ordered blood tests and roentgenograms among internists in a health maintenance organization. Overall use fell by 14.2% in a 16-week period during which physicians received confidential feedback on their individual rates of use compared with peers (cost feedback). Eleven of 12 tests showed some decrease. Similar feedback on rates of abnormal test results (yield feedback) and a program of test-specific education failed to show a consistent effect. Variability in rates of test use among physicians, as measured by the coefficient of variation, fell by 8.3% with cost feedback, by 1.3% with yield feedback, and by 2.3% with education, but these changes were inconsistent across tests.

Boston↗

PubMed1983

Feedback in clinical medical education.

In the setting of clinical medical education, feedback refers to information describing students' or house officers' performance in a given activity that is intended to guide their future performance in that same or in a related activity. It is a key step in the acquisition of clinical skills, yet feedback is often omitted or handled improperly in clinical training. This can result in important untoward consequences, some of which may extend beyond the training period. Once the nature of the feedback process is appreciated, however, especially the distinction between feedback and evaluation and the importance of focusing on the trainees' observable behaviors rather than on the trainees themselves, the educational benefit of feedback can be realized. This article presents guidelines for offering feedback that have been set forth in the literature of business administration, psychology, and education, adapted here for use by teachers and students of clinical medicine.

Attitude↗

PubMed1980

Effects of auditory feedback on velocity extrapolation by mentally retarded and nonretarded groups during rotary pursuit tracking.

Retarded adolescents, CA-matched nonretarded adolescents, and MA-matched nonretarded children stylus-tracked an intermittently disappearing rotary pursuit target with and without auditory feedback. Under the no-feedback condition, all groups demonstrated an almost linear increase in deviation errors over five successive 2-second intervals following disappearance of the target, with the retarded group showing a greater increase than did the CA-matched and MA-matched groups. Under the feedback condition, the CA-matched group reached an asymptote of target proximity 4 seconds after the target disappeared, whereas errors for the retarded and MA-matched groups continued to increase throughout the 10-second sample period. Performance of the retarded group with no feedback was interpreted as evidence for deficient velocity extrapolation, and failure of the retarded and MA-matched groups to stabilize proximity under the feedback condition was attributed to delayed response of the feedback.

Adolescent↗

PubMed1980

Control of unsteady, eccentric fixation in amblyopic eyes by auditory feedback of eye position.

A technique for providing amblyopes with auditory feedback signals of eye position errors is described. With auditory cues, 12 adult eccentrically fixing amblyopes with strabismus and/or anisometropia have been able to maintain steady and foveal fixation with the amblyopic eye. The changes observed in fixation patterns with auditory feedback were both quantitative and qualitative; with such feedback, amblyopes often exhibited sequences of normal-appearing fixation. Some of our subjects have been successful in maintaining steady foveal fixation for short periods of time after feedback is turned off, apparently using visual error signals. For two subjects, feedback also promoted major improvements in smooth tracking performance. We conclude that the use of auditory feedback of eye position has significant value for basic studies of the mechanisms underlying amblyopia and potentially for the clinical treatment of this condition.

Acoustic Stimulation↗

PubMed1994

Rising and sitting down in stroke patients. Auditory feedback and dynamic strength training to enhance symmetrical body weight distribution.

The purpose was to study vertical ground reaction force feedback and dynamic knee extensor training used to enhance stroke patients' symmetrical body weight distribution while rising and sitting down. Sixteen healthy subjects and 51 stroke patients participated in the studies. Two vertical strain gauge force transducers attached to two force-measuring platforms were used to measure body weight distribution over the lower limbs. An auditory feedback device, specially developed for training body weight distribution on the paretic leg, employed two electronic balances sensing vertical forces from each foot, separately. Torque of maximal voluntary eccentric and concentric knee extensor and flexor actions at 30, 60, 120, 180 and 240 deg/s was recorded with an isokinetic dynamometer together with surface electrodes from the quadriceps and hamstring muscles. When instructed to rise with even body weight on each lower limb, the stroke patients loaded the paretic leg more than when rising habitually, indicating that stroke patients have a latent motor capacity. Stroke patients' own estimations on visual analogue scales of body weight distributed on the paretic leg correlated with measured loading of the paretic leg in rising. After six weeks of training with auditory feedback of vertical ground reaction forces in the acute phase after stroke, the patients improved their loading of the paretic leg compared to a control group. The patients distributed body weight over the lower limbs nearly symmetrically while rising and while sitting down. The peak torque was not greater, however, than in the control group, rising with an asymmetrical body weight distribution. This implies that the patients after feedback training were better at using the knee extensor torque of the paretic leg to attain symmetrical body weight distribution over the lower extremities. Changes in improvement of physical performance and sitting to standing were greater than in the control group. No differences between groups were seen in performance of activities of daily living. Body weight distribution over the limbs in rising and in sitting down was re-tested on average 33 months after end of training. The symmetrical weight distribution after feedback training was not maintained over time. Knee extensor strength improved after six weeks of eccentric and concentric training, starting on average 27 months after stroke. The increase in strength was related to enhanced activation of agonist EMG activity. Eccentric training seems to be superior to concentric training with reference to a) improved body weight distribution over the lower limbs in rising, to b) increased knee extension torque and to c) increased agonist EMG activity without a concomitant, augmented EMG activity of the antagonistic knee flexor muscles. It was concluded that stroke patients have a latent motor capacity, that six weeks auditory feedback training promotes symmetrical body weight distribution which, however, is not consistent over time and that isokinetic eccentric training is superior to concentric training with reference to weight distribution in rising, knee extension torque and EMG activity.

Adult↗

PubMed1993

Does feedback improve the quality of cervical smears? A randomized controlled trial.

In a randomized controlled trial three methods of feedback of increasing intensity, directed at 183 doctors taking cervical smears, were compared with respect to their effects on the sampling quality of smears. Overall, feedback was found to have no influence on quality criteria in the crude data analysis. However, a significantly larger decrease in the percentage of smears lacking endocervical cells was found in the groups receiving monthly overviews of their results with peer comparison, when compared with the groups not receiving this type of feedback (odds ratio 0.75). Moreover, feedback appeared to have a clear effect on the presence of endocervical cells among doctors submitting a substantial number of smears in the intervention period, as opposed to those who submitted fewer smears. A positive correlation was also observed between the increase in the group mean of the proportions of smears containing pathological cells and the intensity of the feedback. However, this increase did not reach statistical significance. This study suggests that monthly feedback with peer comparison may have a positive relationship with some aspects of quality improvement in cervical screening.

Adult↗

PubMed1993

Papanicolaou smear quality assurance: providing feedback to physicians.

BACKGROUND: The effective management of Papanicolaou (Pap) smears depends on the reliability and accuracy of obtaining and interpreting the specimen. Provider sampling error is one of the important factors contributing to inadequate specimens. Feedback on provider performance may be an effective way to improve the quality of Pap smears. METHODS: A pilot study in a university-based residency program involving resident and faculty physicians was initiated to assess the impact of feedback on performance of Pap smears. After establishing adequacy and inadequacy criteria and recording adequacy rates for 3 months, individual and group feedback was implemented. No formal educational intervention on Pap smear technique was undertaken. RESULTS: The quality of 836 Pap smears performed by 9 faculty and 13 resident physicians showed continued improvement in both sampling and slide preparation to 90% adequacy over a 9-month period. This improvement, though clinically useful, was not statistically significant owing to the relatively small numbers of smears performed by each physician. This form of feedback may be useful in both practice and educational settings. CONCLUSIONS: Feedback without any formal educational intervention led to a clinically useful trend of improvement in the quality of Pap smears, which has been sustained since the study began. This type of simple feedback may be useful in practice settings and particularly valuable in pinpointing areas for improvement for learners in residency programs.

Academic Medical Centers↗

PubMed1997

[Use of student feedback by preclinical and clinical course directors].

We examined the conceptual and instrumental uses of student feedback on teaching by 2 preclinical and clinical course directors with authority to change structure and content of the courses, assess suitability of instructors and to change methods of teaching. Student feedback questionnaires have been collected systematically for over 2 decades. A report based on this feedback is sent to course directors, the dean, his assistants and the head of the curriculum committee. Course directors from both groups made broad use of the feedback but made greater use of the report than preclinical course directors. Students had greater regard for individual teaching by clinical course directors than by preclinical course coordinators. No relationship was found between the degree of use of feedback by members of either group and their level of teaching. We conclude that senior faculty use student feedback in their decisions regarding the structure and teaching methods of their courses and are not influenced by individual assessments, positive or negative, by their students.

Curriculum↗

PubMed1996

Microcircuitry of forward and feedback connections within rat visual cortex.

Visual cortex in mammals is composed of many distinct areas that are linked by reciprocal connections to form a multilevel hierarchy. Ascending information is sent via forward connections from lower to higher areas and is thought to contribute to the emergence of increasingly complex receptive field properties at higher levels. Descending signals are transmitted via feedback connections from higher to lower areas and are believed to provide information about the context in which a stimulus appears, to contribute to modulation of visual responses by attention, and to play a role in memory processes. To determine whether forward and feedback pathways in rat visual cortex constitute distinct intracortical circuits, we have studied the distribution of reciprocal corticocortical inputs to pyramidal cells and gamma-aminobutyric acid (GABA)ergic interneurons. For this purpose, we chose forward and feedback connections between primary visual cortex and the secondary extrastriate lateromedial (LM) area as a model system. Pathways were traced with the axonal marker phaseolus vulgaris-leucoagglutinin. Labeled terminals were identified in the electron microscope, and GABA immunocytochemistry was used to identify the postsynaptic dendritic shafts of GABAergic interneurons. In both pathways, inputs to pyramidal cells were directed preferentially to dendritic spines and not to shafts. In the forward pathway, 90% of labeled inputs were distributed to pyramidal cells and 10% to interneurons. This proportion was similar to that of nearby unlabeled connections in the neuropil, indicating that forward connections are not selective for pyramidal cells or interneurons. In sharp contrast, feedback connections were significantly different from the unlabeled connections and supplied almost exclusively pyramidal cells (98%). Feedback inputs to GABAergic neurons were five times weaker (2%) relative to the forward direction. These structural differences suggest that disynaptic GABAergic inhibition is much stronger in forward than in feedback pathways. Recent physiological experiments have confirmed this prediction (Shao et al. [1995] Soc. Neurosci. Abstr., 21:1274) and we, therefore, conclude that relatively small anatomical differences in the microcircuitry can have important functional consequences. It remains an open question whether generally reciprocal interareal circuits at all levels of the cortical hierarchy are organized in similar fashion.

Animals↗

PubMed1982

A factorial comparison of schedule and bilateral locus of diastolic blood pressure-contingent feedback.

The purpose of this study was twofold: (a) to compare and determine the effects of a partial and a continuous schedule of feedback on the acquisition and subsequent extinction of bidirectional diastolic blood pressure changes in human subjects; and (b) to examine the result of the administration of response-contingent feedback at specific sites on the bilateral axis between left and right arms on diastolic blood pressure changes at those sites. Subjects were 36 normotensive volunteer college students, ages 18-40 years. A 3 X 3 design was used in which three schedules of feedback (0, 25, and 50%) were factorially compared with three sites of feedback (left arm, both arms, and right arm). The results indicated that varying schedules of feedback differentially affected the acquisition and extinction of diastolic blood pressure response changes. The data also suggested that diastolic blood pressure changes could be produced at specific sites on the bilateral axis, although not completely independent of changes at other sites. Extinction was observed to be rapid in most cases, although a number of subjects with partial feedback schedules showed a somewhat greater resistance to extinction.

Adult↗

PubMed1980

Incentives to enhance the effects of electromyographic feedback training in stroke patients.

The use of monetary incentives to enhance the effects of electromyographic (EMG) feedback training was studied in five stabilized stroke patients with hemiplegia. The study was divided into Baseline, EMG Feedback Training, Feedback Training Plus Incentives, and Follow-up treatment conditions. Integrated EMG activity was recorded simultaneously from the anterior tibialis and medial gastrocnemius muscles during relaxation and dorsiflexion of the affected foot. Patients were instructed to try to increase anterior tibialis EMG activity while decreasing EMG activity in the medial gastrocnemius. Range of motion was measured both prior to and immediately following the Baseline and Feedback Training conditions. Results suggested that (a) EMG feedback training produced greater EMG control and range of motion than did unassisted practice, and (b) the addition of monetary incentives may enhance the effects of feedback training, possibly through its effect on patient motivation.

Adult↗

PubMed1983

Comparisons of high, medium, and low feedback sensitivity for the control of heart-rate acceleration.

Thirty-four student volunteers were randomly assigned to one of three feedback sensitivity conditions: high sensitivity, medium sensitivity, or low sensitivity. Each subject received four sessions of biofeedback training with instructions to accelerate heart rate. In each condition, analogue feedback was provided during heart-rate acceleration trials. In addition to heart rate, frontal EMG and digital skin temperature were also recorded. Results replicated and extended the findings of a previous study in that medium and low sensitivity feedback was found to be superior to high sensitivity feedback during the final training session. These results confirm previous findings that a high sensitivity feedback produces very poor control of heart-rate acceleration. These data were discussed in terms of motor skills theory and in terms of possible effects of feedback sensitivity upon the motivation of subjects.

Adult↗

PubMedDate not supplied

Modification of residents' behavior by preceptor feedback of patient satisfaction.

The authors tested the effect of preceptor feedback to residents of patients' ratings of perceived art and technical quality of care on residents' subsequent performances. New ambulatory patients were asked to complete questionnaires measuring satisfaction with physician behavior during initial encounters. Sixty-eight residents were evaluated by 424 patients over a six-month period. Continuing residents with the lowest scores were assigned to a feedback or a non-feedback group. Residents in the feedback group were individually shown their mean scores on each item, as well as scores for all residents, and were then advised of physicians' behaviors that could increase patient satisfaction. During a subsequent six-month survey of new patients, scores in the feedback group improved more than those in the non-feedback group in art of care, technical quality, and total patient satisfaction (p less than 0.001).

Behavior Therapy↗

PubMed1994

The use of auditory feedback in the design of touch-input devices.

In workspaces with complex displays and controls, and limited space in which to mount them, the use of touchscreen displays as input devices offers significant advantages. To overcome the lack of tactile feedback on touchscreen input devices, auditory feedback has been suggested. This paper examines the results of an experiment looking at the effect of auditory feedback on typing performance. While error rates were not affected by the feedback, the addition of auditory feedback to a typing task did improve typing speeds under all tested conditions. This indicates that the addition of auditory feedback to touchscreen input devices provides a measurable benefit and should be considered, where possible.

Journal Article↗

PubMed1983

Electromyographic (EMG) feedback in chronic musculoskeletal pain: a controlled trial.

The literature regarding the application of EMG feedback training in musculoskeletal pain disorders is reviewed. A within-subject control trial of EMG feedback using a counterbalanced design in patients with chronic musculoskeletal pain is reported here. Eighteen subjects (12 females and 6 males) were studied in terms of subjective reports of pain and EMG activity measurement under standardised conditions. Both EMG feedback and a control condition were active in reducing subjective pain levels, which increased during a waiting list conditions in certain sequences. EMG activity declined during both EMG feedback and control conditions but only EMG feedback resulted in an orderly reduction in EMG baseline measurements with a highly significant linear trend when presented before the control condition in sequence. A significant correlation between subjective pain levels and surface EMG activity was found. These data suggest that EMG feedback is superior to a control condition in training muscle relaxation but not in reducing subjective pain levels despite a high correlation between these two parameters. Non-specific factors may well affect pain scores and further research is required before the specific biofeedback training effect can be accepted as superior to its non-specific effects in reducing subjective pain.

Adolescent↗