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At least 19 recordsLinked to original sources
PubMed2002

Motor facilitation while observing hand actions: specificity of the effect and role of observer's orientation.

Action observation enhances cortico-spinal excitability. Here we tested the specificity of this effect and the role played by the orientation of the observer. Ten normal subjects observed video clips of right hand performing three different finger movements (thumb ab-/adduction, index ab-/adduction, index extens-/flexion) in two different orientations (Away, i.e., natural hand-orientation facing out from the observer; or Toward, i.e., unnatural hand-orientation facing toward the observer). Motor-evoked potentials (MEPs) induced by transcranial magnetic stimulation (TMS) were recorded from the abductor pollicis brevis (APB) and the first dorsal interosseus (FDI) muscles. Movement direction of the index finger was recorded using force transducers. Facilitation of MEP size was significantly greater for APB during observation of thumb movements and for FDI during observation of index finger movements. Facilitation of MEP size was significantly greater when the hand presented on screen was facing out from and corresponding to that of the observer (Away orientation). The direction of the index finger movement evoked by TMS shifted toward extension/flexion versus ab-/adduction matching the observed movement. Our results give further evidence that observation of a movement enhances motor output to the muscles involved in the movement and facilitates the observed action. In addition, we provide novel evidence about the high degree of specificity of this observation-induced motor cortical modulation. The degree of modulation depends on hand orientation. The modulation is maximal when the observed action corresponds to the orientation of the observer.

Adult↗
PubMed2001

Intra-observer, inter-observer and inter-scanner variations in brain MRI volume measurements in multiple sclerosis.

INTRODUCTION: Measurement of brain volume on magnetic resonance imaging (MRI) scans is regarded as an objective marker of multiple sclerosis (MS) severity with the potential to monitor treatment efficacy accurately. This study was performed to assess the variability of brain MRI volume measurements. PATIENTS AND METHODS: We studied nine patients with relapsing-remitting MS, who were imaged on two occasions (separated by an interval of 24 h) using two different MR scanners and fast fluid-attenuated inversion recovery (fast-FLAIR) sequences. The whole brain volume computed from each image was measured three times by three observers using a seed-growing technique based on signal intensity thresholding. Intra-observer, inter-observer and inter-scanner variabilities were expressed as coefficients of variations (COVs). The inter-scanner variability included not only the intra-observer variation but also the repositioning variability and the variation in observed brain volume caused by different scanner hardware and sequence implementations. RESULTS: There was no statistically significant difference in patients' brain volume values between observers (P=0.82) or between scanners (P=0.30). The mean intra-observer COV was 1.2% (s.e.=0.4%), the mean inter-observer COV was 1.8% (s.e.=0.8%) and the mean inter-scanner COV was 2.4% (s.e.=1.2%). The intra-observer variance was not statistically different from those found between observers (P=0.83) or scanners (P=0.44). CONCLUSION: The intra-observer variability in brain volume measurements found in this study was within the range of intra-observer variability found in previous studies. This study shows that the use of different observers and MR scanners has only a small influence on the measured brain volume and does not affect the reproducibility of this measurement greatly.

Adult↗
PubMed2000

Reliability of radiographic observations recorded on a proforma measured using inter- and intra-observer variation: a preliminary study.

AIM: The aim of this preliminary study was to test the reliability of radiographic evaluation of features of endodontic interest using a newly devised data collection system. METHODOLOGY: Twelve endodontic MSc postgraduate students and one specialist endodontist examined sample radiographs derived from a random selection of 42 patients seen previously on an Endodontic New Patient Clinic (EDI). Each student examined a random selection of 8-9 roots on periapical radiographs of single- and multirooted teeth, with and without previous root canal therapy and 3-4 dental panoramic tomograms (DPTs). A total of 100 roots were examined. A proforma was used to record observations on 67 radiographic features using predefined criteria. Intra-observer agreement was tested by asking the students to re-examine the radiographs. The principle investigator and the specialist endodontist examined the same radiographs and devised a Gold Standard using the same criteria. This was compared with the student assessments to determine inter-observer variation. The postgraduates then attended a revision session on the use of the form. Each student subsequently examined 8-9 different roots from the pool of radiographs. A further assessment of inter-observer variation was made by comparing these observations with the Gold Standard. RESULTS: Of the 67 radiographic features, only 25 had sufficient response to allow statistical analysis. Kappa values for intra- and inter-observer variation were estimated. These varied depending on the particular radiographic feature being assessed. Fifteen out of 25 intra-observer recordings showed 'good' or 'very good' Kappa agreement, but only three out of 25 inter-observer observations achieved 'good' or 'very good' values. Inter-observer variation was improved following the revision session with 16 out of 25 observations achieving 'good' or 'very good' Kappa agreement. CONCLUSIONS: Modification to the proforma, the criteria used, and training for radiographic assessment were considered necessary to improve the accuracy and reproducibility of the observations entered.

Data Collection↗
PubMed1988

Inter-observer and intra-observer variability of the Oxford clinical cataract classification and grading system.

Intra-observer (within observers) and inter-observer (between observers) variability of the Oxford Clinical Cataract Classification and Grading System were studied. Twenty cataracts were examined and scored independently by four observers. On a separate occasion two of the observers repeated the assessments of the same cataracts in the absence of information from the initial observations. The chance corrected and weighted kappa statistics for observer agreement, both for inter-observer and intra-observer variability demonstrated satisfactory repeatability of the cataract grading system. The overall intra-observer mean weighted kappa was kappa w = +0.68 (range SE kappa = 0.012-0.052) and the overall inter-observer mean weighted kappa was kappa w = +0.55 (range SE kappa = 0.011-0.043).

Cataract↗
PubMed2001

Directly observed therapy for treating tuberculosis.

BACKGROUND: Up to half the people with tuberculosis do not complete their treatment. Strategies to improve adherence to diagnostic and treatment regimens are therefore important. OBJECTIVES: To assess the effects of directly observed therapy by an appointed agent (health worker, community volunteer, or family member) on cure and treatment completion in people on treatment for tuberculosis. SEARCH STRATEGY: We searched The Cochrane Controlled Trials Register, the Cochrane Infectious Diseases Group specialized trials register, MEDLINE, EMBASE, LILACS, and reference lists of articles. We also contacted experts in the field. SELECTION CRITERIA: Randomized and quasi-randomized trials of direct observation of tablet swallowing compared with self treatment for tuberculosis. DATA COLLECTION AND ANALYSIS: Two reviewers independently assessed trial quality and extracted data. MAIN RESULTS: Four studies (n = 1603 participants) included. There was no difference detected between direct observation and self treatment for cure (Relative Risk [RR] 1.06, 95% confidence interval [CI] 0.98 to 1.14); and for cure plus treatment completion (RR 1.06, 95% CI 1.00 to 1.13). A stratified analysis by the appointed agent (health professional, lay health worker, or family/community member) did not reveal any important differences. One study conducted in an optimal setting in which patients were given a choice of supervisor did show modest benefit: cure (RR 1.13, 95% CI 1.04 to 1.24); cure plus treatment completion (RR 1.11, 95% CI 1.03 to 1.18). REVIEWER'S CONCLUSIONS: Randomized trials provide no evidence that directly observed therapy in low and middle income country settings improves cure or treatment completion rates in patients with tuberculosis.

Antitubercular Agents↗
PubMed1986

Inter-observer and intra-observer variation in bone histomorphometry.

Inter-observer variation has been examined for a number of histomorphometric indices in 20 normal human iliac crest biopsies. Quantitation was performed using an eye-piece graticule and eye-piece micrometer. The same sections were examined by two observers and the methodology was identical. Intra-observer variation was also assessed. Significant inter-observer differences were found for the measurement of total trabecular bone volume, osteoid volume and surface, double plus single and double tetracycline labeled surfaces, and the mean osteoid seam width. The percentage variance due to inter-observer variation was highest for osteoid surface and volume, total resorption surface, and mean osteoid seam width. Intra-observer variation in both observers was small. We conclude that a large inter-observer variation may occur in the measurement of a number of histomorphometric indices, even when section preparation and methodology are identical. Caution should be used in basing the diagnosis of metabolic bone disease on strictly defined control data from other observers, particularly when this has been obtained from centers where the effects of inter-observer variation may be magnified by differences in methodology.

Bone Resorption↗
PubMed2001

Imitative learning in Japanese quail (Coturnix japonica) depends on the motivational state of the observer quail at the time of observation.

The 2-action method was used to examine whether imitative learning in Japanese quail (Coturnix japonica) depends on the motivational state of the observer quail at the time of observation of the demonstrated behavior. Two groups of observers were fed before observation (satiated groups), whereas 2 other groups of observers were deprived of food before observation (hungry groups). Quail were tested either immediately following observation or after a 30-min delay. Results indicated that quail in the hungry groups imitated, whereas those in the satiated groups did not, regardless of whether their test was immediate or delayed. The results suggest that observer quail may not learn (through observation) behavior that leads to a reinforcer for which they are unmotivated at the time of test. In addition, the results show that quail are able to delay the performance of a response acquired through observation (i.e., they show deferred imitation).

Animals↗
PubMed2002

Kappa statistics in the assessment of observer variation: the significance of multiple observers classifying ankle fractures.

Studies using kappa statistics have been conducted with a varied but limited number of observers. The aim of this study was to evaluate the significance of multiple observers on kappa as a measure of observer variation. One hundred orthopedic specialists were asked to assess a random sample of ten sets of standard radiographs of 94 consecutive patients with ankle fractures. The observers were randomly allocated into four groups, which again were divided into subgroups with an increasing number of observers. Random subgroups of three observers revealed kappa values from 0.20 to 0.64 in the Lauge-Hansen and 0.27 to 0.90 in the Weber classification system. With an increasing number of observers in the subgroups, kappa stabilizes around a mean value, indicating that the sampling variation and standard error decrease. The standard error found in this study makes kappa questionable as a measure for agreement among a small number of observers. Thus, kappa values obtained for a given diagnostic tool at one department are not directly comparable with results from other departments. We conclude that kappa cannot stand alone as a simple measure of observer variation.

Ankle Injuries↗
PubMed2000

Methodological issues in the direct observation of parent-child interaction: do observational findings reflect the natural behavior of participants?

This review examines evidence for the utility and validity of direct observational techniques for answering particular research and clinical questions. Observational techniques often involve recording behavior in settings that are relatively unnatural for families. However, it is argued that construct validity of observational methods depends partly on whether the findings are representative of participants' typical everyday behavior. Evidence is reviewed concerning whether observational findings are affected by the presence of the observer, and by two factors which have been neglected in the literature, namely the type of task imposed by the observer (e.g., directing parent and child to play rather than observing spontaneous interaction) and the location of the observations (e.g., clinic or laboratory rather than home). The review suggests that the presence of an observer does not necessarily distort the nature of interactions. However, the small number of studies in this area suggest that interactions in structured or artificial settings are not necessarily representative of those normally taking place at home.

Child↗
PubMed1997

Inter-observer and intra-observer agreement in the interpretation of visual fields in glaucoma.

Visual field changes are one of the main parameters used to monitor progression of glaucoma. This study assesses the degree of intra-observer and inter-observer agreement among nine observers in grading visual fields in glaucoma patients using a visual field system previously described by Jay. The results show a median inter-observer agreement of 61% (median kappa = 0.52) and a median intra-observer agreement of 72% (median kappa = 0.65). This system for grading fields in glaucoma has a high degree of intra-observer agreement, suggesting it is a useful system for longitudinal follow-up of patients by a single observer. The higher degree of disagreement between observers points to the need for careful pretraining of observers in clinical management and research where the results from visual field examinations are to be graded by more than one clinician.

Cohort Studies↗
PubMed1993

Intra-observer and inter-observer reliability of the pulsatility index calculated from pulsed Doppler flow velocity waveforms in three fetal vessels.

OBJECTIVE: Study of the intra observer and inter observer reliability of the pulsatility index, calculated from pulsed Doppler recordings of three fetal vessels. DESIGN: Flow velocity waveforms (FVW) were recorded from the umbilical artery, the fetal descending aorta and the fetal internal carotid artery. Intra-observer reliability was assessed in six fetuses; ten repeated measurements were performed by one observer. Inter-observer reliability was studied in 14 fetuses; two observers performed two repeated measurements in each fetus. SETTING: A tertiary referral hospital. SUBJECTS: High risk pregnancies with a gestational age ranging from 29 to 42 weeks. MAIN OUTCOME MEASURES: Analysis of variance with repeated measurements and a graphical method were used for data analysis. Intra-observer repeatability was expressed as Intraclass Correlation Coefficient (IntraCC). Inter-observer agreement was expressed as Interclass Correlation Coefficient (InterCC). RESULTS: IntraCC for umbilical artery, descending aorta and internal carotid artery were 0.91, 0.78, and 0.54, respectively. InterCC values for these vessels were 0.39, 0.45 and 0.34, respectively. No systematic differences between the two observers except for the fetal descending aorta, were apparent. IntraCC decreased remarkable when fetuses with absent end diastolic velocities were excluded from the analysis. CONCLUSION: The pulsatility index (PI) used for fetal measurements has a poor reliability. This is of serious concern when clinical use of FVW measurements is considered as a diagnostic tool.

Aorta, Thoracic↗
PubMed2002

Practice of directly observed treatment (DOT) for tuberculosis in southern Thailand: comparison between different types of DOT observers.

SETTING: A government health system in southern Thailand where the directly observed treatment, short-course (DOTS) strategy has been implemented. OBJECTIVE: To compare the practice of actual directly observed treatment (DOT) and the observer sustainability for different types of observer. METHODS: During 1999-2000, 411 patients with new smear-positive pulmonary tuberculosis were followed up. The patients and/or their observers were interviewed about the presence of any person with the patient during drug intake and the practice of watching the patient swallowing the medicine (actual DOT). Data were recorded monthly and analysed by Cox and logistic regression models. RESULTS: For health personnel (HP), community member (CM), and family member (FM) observers, the proportions who did not practise actual DOT were respectively 11%, 23%, and 35%, and the proportions who changed to no observer or self administration were respectively 11%, 1%, and 2%, during the first 9 months of treatment. Health personnel had the lowest risk of not practising actual DOT (odds ratio HP/FM 0.1, 95%CI 0.1-0.2; CM/FM 0.9, 95%CI 0.5-1.6) but the highest risk for change to self administration. CONCLUSION: To increase the coverage of actual DOT, strategies are needed to maintain health personnel as the DOT observers and to promote actual DOT among family member observers.

Adolescent↗
PubMed2001

Reproducibility of the WHO/IASLC grading system for pre-invasive squamous lesions of the bronchus: a study of inter-observer and intra-observer variation.

AIMS: Although many workers have graded pre-invasive squamous lesions arising in the bronchus, there has been no consensus classification system until the latest edition of the WHO/IASLC histological classification of pulmonary and pleural tumours. Because the value of any such system is dependent on its reproducibility, we have circulated a series of such lesions to a panel of histopathologists to assess interobserver and intra-observer variation when the WHO/IASLC classification was applied. METHODS AND RESULTS: Colour transparencies of 28 pre-invasive squamous lesions were assessed by six histopathologists (two with a special interest in pulmonary pathology, two generalists and two trainees) on three separate occasions over a period of 3 months, using the criteria of the WHO/IASLC (mild, moderate and severe dysplasia, and in-situ carcinoma). An additional category of metaplasia was added for those cases that showed no dysplasia. Weighted kappa coefficents of agreement (K(w)) were used to evaluate paired observations with a standard quadratic weighting being employed, such that kappa coefficients corresponded to intra-class correlation coefficients. Wilcoxon's sign-ranked test was used to measure the statistical significance of group trends, when comparing kappa values for the three grading systems. Various 3-point systems were also assessed, through combination of the above groups. Intra-observer agreement was substantially better than interobserver variation (mean: 0.71 vs. 0.55). Between the various pathologist groups, inter-observer variation was relatively minor, although intra-observer variation was higher within the trainee pathologist group. Using weighted kappa values, there was no significant difference in either inter-observer or intra-observer agreement between the five point grading system and a 3-point system of metaplasia/mild, moderate and severe/in-situ grades. However, there was a significant increase in variation when a 3-point system of metaplasia/mild, moderate/severe and in-situ carcinoma was used. CONCLUSION: This study shows levels of interobserver and intra-observer variation similar to those found in other grading systems in histopathology, with no significant decrease in variability found by abridging the system. The WHO/IASLC system is therefore recommended for future use in both clinical and research fields.

Bronchial Neoplasms↗
PubMed2000

Intra-observer repeatability and inter-observer agreement of the Smith method of measuring the anterior chamber depth.

The Smith (1979) method provides a means of estimating the anterior chamber depth without additional attachments to the slit lamp [Smith, R. J. H. (1979). A new method of estimating the depth of the anterior chamber. Br. J. Ophthalmol. 63, 215-220]. In this study, the 95% intra-observer limits of repeatability and the 95% inter-observer limits of agreement of this method have been determined. The intra-observer limits of repeatability were determined by plotting the difference vs the mean of the estimated anterior chamber depth obtained in two different sessions by each of two examiners, while the inter-observer limits of agreement are represented by a plot of the difference vs the mean estimated anterior chamber depth between the two examiners. For one examiner, the 95% intra-observer limits of repeatability was -0.36 to 0.58 mm, while for the other examiner the 95% intra-observer limits of repeatability was -0.25 to 0.37 mm. The 95% inter-observer limits of agreement were -0.31 to 0.23 mm and -0.41 to 0.25 mm for the first and second sessions respectively. The intra-observer limits of repeatability are comparable with those reported for A-scan ultrasonographic measures of the anterior chamber depth. These results imply that the Smith method can be used with a high degree of repeatability and agreement to clinically monitor longitudinal changes in anterior chamber depth.

Adult↗
PubMed1987

[Modeled events and observers' traits underlying observational learning of altruistic behavior].

The present experiments investigated the changes of altruistic responses through observational learning (OL) in elementary school children (ages 10 and 11) with relation to the characteristics of the modeled events and the observers' traits. The former included certain categories of observed materials and the methods of presentation. The latter included subject's impression, empathy for, and evaluation of these materials. The OL was the symbolic modeling of altruistic behavior by presentation of pictures with narration. The response measures were the rating of pre- and post-questionnaires on the altruistic stories. The main result of Experiment I showed that subjects responded selectively to each pretest questionnaire, and that the observational learning was most effective on the similar kind of behavior type. The generalization of OL to other items of categories was also observed. In Experiment II, the combined effect of a pair of observed materials (positive or negative altruistic content) was examined. The effect of OL was highest when the material presented was a P-N pair, lowest when it was a N-N pair. The observers' traits in empathy, impression, and evaluation on observed materials were positively correlated to the effect of OL.

Altruism↗
PubMed1995

Intra-observer and inter-observer variability in scoring laparoscopic diagnosis of pelvic adhesions.

The objective of this study was to investigate intra-observer as well as inter-observer variability in the assessment of laparoscopic scoring of adhesive disease. Patients with suspected pelvic adhesions underwent a laparoscopic examination and surgical correction, using a standardized adhesion scoring system for severity as well as for extent of the adhesive process. An active agent or placebo was placed in the peritoneal cavity to discourage reformation of adhesions on a double-blind basis. A second laparoscopy was performed in 6-10 weeks and patients were re-scored. The videotapes were viewed and re-scored by the operator and four other gynaecological surgeons on two occasions, 3 months apart. Both adhesion severity and extent scores were lower following laparoscopic intervention. Reliability coefficients as defined by intra-class correlations were large indicating good reliability (0.778 and 0.758 for severity and extent respectively). Intra-observer (replication) variability was 12% of the total versus 19% for inter-observer variability of adhesion severity. These values were 15.4 and 22.3% of the total respectively, for adhesion extent. Individual observers tended to up-grade severity and minimize extent of adhesions when comparing the second with the first videotape views. The surgeon recorded greater adhesion score differences between the two procedures than the other observers. Though two physicians consistently had higher scores than two others, the intra-observer and interobserver variabilities were acceptable. Consultant review of high quality videotaped laparoscopic procedures is a valid method of independent assessment of operative findings.

Adnexal Diseases↗
PubMed2002

An evaluation of the inter-observer and intra-observer variability of the ultrasound diagnosis of polycystic ovaries.

BACKGROUND: This prospective observational study was undertaken to evaluate the reliability and consistency of ultrasound diagnosis of polycystic ovarian syndrome (PCOS). METHODS: Eighteen women with clinical and biochemical features suggestive of PCOS and nine normal control women underwent transvaginal ultrasound scan by a single ultrasonographer. The 27 ovarian scans were video-recorded and the recordings were later edited and arranged randomly so that each record appeared twice at random on the tape producing a total of 54 ovarian scans. Four experienced observers independently reviewed the recordings. The observers scored each case as follows: normal, possible polycystic ovary (PCO) and definite PCO. RESULTS: The mean intra-observer agreement was 69.4% (kappa = 0.54) and the mean inter-observer agreement was 51% (kappa = 0.28). CONCLUSION: The results suggest that the currently used ultrasonographic criteria for the diagnosis of polycystic ovaries do have significant intra-observer and inter-observer variability and as such must be considered subjective. Transvaginal ultrasonography alone may not therefore be a reliable method of diagnosing or excluding PCOS.

Adult↗