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At least 37 records · Page 2Linked to original sources
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↗
PubMed2006

Inter-observer reliability and intra-observer reproducibility of the Weber classification of ankle fractures.

Our aim was to assess the reproducibility and the reliability of the Weber classification system for fractures of the ankle based on anteroposterior and lateral radiographs. Five observers with varying clinical experience reviewed 50 sets of blinded radiographs. The same observers reviewed the same radiographs again after an interval of four weeks. Inter- and intra-observer agreement was assessed based on the proportion of agreement and the values of the kappa coefficient. For inter-observer agreement, the mean kappa value was 0.61 (0.59 to 0.63) and the proportion of agreement was 78% (76% to 79%) and for intra-observer agreement the mean kappa value was 0.74 (0.39 to 0.86) with an 85% (60% to 93%) observed agreement. These results show that the Weber classification of fractures of the ankle based on two radiological views has substantial inter-observer reliability and intra-observer reproducibility.

Ankle Injuries↗
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↗
PubMedDate not supplied

Admitting a patient "to" observation or "for" observation--what is the difference?

Coding and billing of a patient placed in "observation" status can be confusing, especially in a busy Emergency Department. If physicians know the rules related to observation status, they can avoid denials or accusations of false claims. Documenting either "admit to observation" or "admit for observation" can be interpreted differently for admission status and billing services. From a billing prospective, writing "admit for observation" would be interpreted as an inpatient admission (if the documentation throughout the medical record is consistent with inpatient status). If the order states "admit to observation," this normally would be interpreted as an order for outpatient observation. Physicians are encouraged to write admission orders that clearly state the level of services intended; for example, wording such as "place in outpatient observation" or "admit as inpatient," to clearly convey the physician's intent.

Humans↗
PubMed2006

Amorphous selenium flat panel detectors for digital mammography: validation of a NPWE model observer with CDMAM observer performance experiments.

Model observers have been developed which incorporate a specific imaging task, system performance, and human observer characteristics and can potentially overcome some of the limitations in using detective quantum efficiency for optimization and comparison of detectors. In this paper, a modified nonprewhitening matched filter (NPWE) model observer was developed and validated to predict object detectability for an amorphous selenium (a-Se) direct flat-panel imager (FPI) where aliasing is severe. A preclinical a-Se digital mammography FPI with 85 microm pixel size was used in this investigation. Its physical imaging properties including modulation transfer function (MTF), noise power spectrum, and DQE were fully characterized. An observer performance study was conducted by imaging the CDMAM 3.4 contrast-detail phantom designed specifically for digital mammography and presenting these images to a panel of seven observers. X-ray attenuation and scatter due to the phantom were determined experimentally for use in development of the model observer. The observer study results were analyzed via threshold averaging and signal detection theory (SDT) based techniques to produce contrast-detail curves where threshold contrast is plotted as a function of disk diameter. Validity of the model was established using SDT analysis of the experimental data. The effect of aliasing on the detectability of small diameter disks was determined using the NPWE model observer. The signal spectrum was calculated using the presampling MTF of the detector with and without including the aliased terms. Our results indicate that the NPWE model based on Fourier domain parameters provides reasonable prediction of object detectability for the signal-known-exactly task in uniform image noise for a-Se direct FPI.

Calibration↗
PubMed2005

Sequence learning by action, observation and action observation.

The serial reaction time (SRT) task was used to compare learning of a complex sequence by action (participants responded to sequential stimuli), by observation (participants watched but did not respond to sequential stimuli), and by action-observation (participants watched an expert model responding to sequential stimuli). Each of these groups was compared with an untrained control group. Experiment 1 indicated that both observation and action-observation were sufficient to support learning of a 12-item second-order conditional (SOC) sequence. Experiment 2 confirmed these findings, and showed that, as indexed by reaction time (RT), the extent of learning by observation and by action-observation was comparable to that of action-based learning. Using a recognition test, Experiment 2 and 3 also provided evidence that, whereas learning by stimulus observation was explicit, learning by action-observation was implicit. These findings are consistent with a connection between motor systems and implicit learning, but do not support the hypothesis that overt action is necessary for implicit learning.

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↗
PubMed1994

The 'Ermenonville' classification of observations at coronary angioscopy--evaluation of intra- and inter-observer agreement. European Working Group on Coronary Angioscopy.

A European coronary angioscopy working group has been established to create and evaluate a classification system for angioscopic observation. The 'Ermenonville' classification features items, graded in 3-5 categories, such as lumen diameter, shape of narrowing, colours of surface, atheroma, dissection, thrombus, etc. Inter- and intra-observer agreement on the interpretation of angioscopic images, using this classification system, was studied within the working group. Kappa values for chance-corrected intra-observer agreement of the diagnostic items were 0.51-0.67. The mean kappa values for inter-observer agreement were very low at 0.13-0.29. The important items, such as red thrombus and dissection were studied after recoding as either present or absent. These items proved to have a good intra-observer agreement, and an acceptable inter-observer agreement after recoding. Other angioscopic diagnoses should be made with caution. Multicentre angioscopy studies should make use of an angioscopy core laboratory. A set of definitions for coronary angioscopy is proposed, and this working group will re-evaluate observer agreements using these definitions.

Angioscopy↗
PubMed2003

Inter-observer and intra-observer variability in hepatology.

OBJECTIVES: A determination of the inter-observer variability is an important step before determining diagnostic accuracy and requires a specific methodology and statistical tests. The aim of this study was to report the results, characteristics and methodological quality of agreement studies performed in hepatology. METHODS: A search of published studies yielded 42 that could be used in this evaluation: three were clinical studies, 11 were in the field of endoscopy, 12 in histopathology and 16 in radiology. The studies were described with a grid of 28 items and evaluated with a quality score (QUAS; maximum, 35) including 22 items. RESULTS: The following agreement level was noted: intra-observer > inter-observer > inter-centre. The following signs had good agreement. Endoscopy: size and red signs of oesophageal varices; histopathology: cirrhosis, fibrosis and steatosis; Doppler: mean portal vein and superior mesenteric artery velocities, hepatic artery area and perfusion indexes. Frequent methodological weaknesses were noted. The real agreement (such as the kappa index excluding chance), and the prevalence of signs and biases were rarely assessed. Standardized observations (67% of the studies), blind assessment (48%), simultaneous observations (7%), and the recording technique were not frequently used. The mean QUAS was 13 +/- 6 with 17 +/- 4 in histopathology versus 11 +/- 6 in radiology (P < 0.05). Using multiple regression, four variables independently predicted the QUAS with R2 = 0.77: adapted tests, multiple observations, intra-class correlation coefficient and agreement proportion. CONCLUSIONS: Methodology was often insufficient. Agreement is often measured under biased conditions. Some areas were not or were rarely studied, e.g., biology and ultrasound. The agreement and QUAS were often poor, suggesting the need for studies with improved observation and methodological quality of agreement.

Esophageal and Gastric Varices↗
PubMed1989

[The effects of the viewpoints and observers' traits on the observational learning of altruistic behavior].

This study was to examine the changes of altruistic responses through observational learning (OL) in elementary school children (4th graders) with the conditions of the different viewpoints and observers' traits. The OL was the symbolic modeling of altruistic behavior by presentation of pictures with narration. All the stories had the same situation, but differed whether the actor behaved himself in an altruistic fashion to the object, or not. Observers' viewpoints were determined by the instruction: they were told to observe the story as if they were one of the characters and to pay attention to emotional responses or behavior of the character. The emphasis of each story corresponded to the viewpoint. Out of these eight combined experimental conditions six were performed. Traits were concerned with observers' impression, empathy, and evaluation of the story. The response measure was the change of rating between pre- and post-questionnaires through observation. The effect of OL was higher significantly when the viewpoint directed to the characters' emotion. Observers who reacted strongly to empathy and impression items showed higher altruistic changes.

Altruism↗
PubMed2004

[Grouping of observer's visual characteristics on the basis of difference in the criteria of visual detection and selection of the fittest clustering method:verification of observer's group with radiologist-like visual characteristics].

Various clustering methods are used in cluster analyses, with each clustering method demonstrating unique advantages. Therefore, it is important to make the best use of the advantages each method provides. We have recognized that it is necessary in the evaluation of X-ray images to classify observers quantitatively according to visual characteristics (grouping of observers) and have clustered observers using the UPGMA method, which is one of the clustering methods. We found that the observers were clustered into two different groups, one with radiologist-like characteristics and the other with medical physicist-like characteristics. Furthermore, we suggested that the group with radiologist-like characteristics was suitable for QC of X-ray images. However, it is doubtful whether the UPGMA method is most suitable for the grouping of observers. In this work we clustered observers using various clustering methods and examined the most suitable method for the evaluation of X-ray images. The results showed that the ward method was least suitable for the grouping of observers, and they were distinctly grouped into two different categories by using a further method.

Cluster Analysis↗
PubMed1993

[Cutaneous or subcutaneous calcinosis observed in leprosy patients. 1. Clinical observations].

A roentgenographic examination was made for the limbs of leprosy patients with calcinosis in whom atrophic cutaneous sclerosis and subcutaneous induration or infiltration were observed. The observation results are summarized as follows. 1. Atrophic cutaneous sclerosis was one of a sequela in lepromatous lesion, especially in case of ENL, and it was observed to occur frequently at the extended sides of 1/3distal part from the forearm and the crus mainly. The atrophied cutaneous surface was tinged with lustrous red. It was able to observe calcium deposition directly just under the skin and/or in the shallow subcutaneous region from the roentgenogram of the site. The roentgenographic patterns were demonstrated as if many granules were scattered, and also the dendric and reticular platy-expansions were detected in some cases. The enucleated parts seemed to be similar to the cancellous bone. It might be said that dystrophic calcinosis cutis developed by inducing histological disorder is one of the origin of such a calcinosis, because the skin in these regions is deficient in the mobility and tends to provoke the circulatory disorder in case of chronic inflammation as discerned in lepromatous lesion. 2. An induration in subcutaneous tissue is lipid lump being as it was when chaulmoogra oil was injected and not undergo absorption of the oil. The lipid lumps enveloped in the tunic were observed in the site of lateral upperarm and the front of femur. They seemed to be remained almost all as it was. It was observed that the lipid lumps, as such, were adjacent to the outer layer of fascia, but not in the muscle. And there are some cases where the oil flowed from the injection site through the hypodermis and got the lipid lumps formed in the forearm and/or the crus. Roentgenogram of that showed the existence of calcinosis regardless of size which transmissivity of X-ray had an irregular pattern. The enucleated lipid lumps were easily cut to pieces by scalpel. 3. It may be said that the calcinosis observed in atrophic cutaneous sclerosis due to lepromatous lesion or lipid lump of unabsorbed chaulmoogra oil makes it necessary for its healing to be 10-20 years. 4. Roentgenogram at that time revealed no abnormality as to serum calcium, phosphorous and/or alkaline phosphatase values.

Adult↗
PubMed2004

The effects of conducting behavioral observations on the behavior of the observer.

Behavior-analytic approaches to occupational safety are often effective for improving safety in organizations, and have been successful in a wide variety of settings. The effects of these safety processes are thought to arise primarily from the behavioral observation process and the delivery of feedback. Typically, supervisors or employee observers involved in behavioral safety implementations conduct observations. The present study was an attempt to assess the effects of conducting observations on an observer's safety performance. An ABC multiple baseline counterbalanced across two sets of behaviors was conducted in a simulated office. The target behaviors involved knee and back positions during lifts; back, shoulder, and feet positions while sitting; neck and wrist positions while typing; and neck position during phone use. Substantial improvements in safety performance occurred after participants conducted observations on a videotape of a confederate's performance. The possible behavioral functions responsible for this change, and the implications of these findings for applied settings, are discussed.

Female↗
PubMed1999

Prediction of human observer performance by numerical observers: an experimental study.

Numerical observers are investigated for predicting the outcome of a free-response human observer study involving the detection of simulated pulmonary nodules in images reconstructed from low-dose computed tomography projection data by use of several reconstruction algorithms. A new way of calculating the figure of merit of a numerical observer is proposed wherein the detectability of signals in a particular image depends on the noise properties associated with that image and not the other images in the data set. The resulting variants of numerical observers are found to perform better than their traditional counterparts. In particular, the imagewise variant of the region-of-interest observer is found to predict best the rank ordering of algorithms by human observers for the free-response task.

Algorithms↗
PubMed2000

OBSERVE: a multimedia course on the observational analysis of behavior.

OBSERVE is a preliminary release of a multimedia course for teaching undergraduate and graduate students how and why to study behavior by direct observation. The instructional text and commentary and the self-test and examination materials are built around a series of exercises in which the student observes and categorizes film clips of the behavior of several different species in several different ways. Incorporation of elements from The Observer software for computer recording and video analysis implements fully computerized continuous recording. At present, the text, together with check sheets that the program generates, enables a comparison between one-zero, instantaneous, and continuous sampling of the same behavioral excerpts. Matrices are printed out for an exercise in calculating interobserver reliability. Another section supports carrying out and writing up a small observational project on human behavior in the field. Plans for the future development of OBSERVE are briefly described.

Behavioral Sciences↗