PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Observer Variation”

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 55 records · Page 3Linked to original sources
PubMed1978

Observer variation in histologic classification of thyroid cancer.

Histologic slides of 696 cases of thyroid cancer reported to the national cancer registries of Finland, Iceland, Norway and Sweden were reviewed by 5 Nordic pathologists in order to determine the observer variation between the pathologists, as well as the reproducibility of the WHO classification of thyroid tumours. In 58% of the cases all observers agreed upon the diagnosis and in 82% at least three of them agreed. The observer disagreement was lowest for papillary carcinoma (7%) and highest for follicular carcinoma (27%). The corresponding figures for anaplastic and medullary carcinomas were 18% and 23%, respectively. The most common diverging diagnosis for cases finally interpreted as papillary carcinoma was follicular carcinoma, and for cases finally interpreted as follicular carcinoma, a benign thyroid lesion. The results of the present study clearly indicate the necessity of having all cases reviewed by the same pathologist or group of pathologists in order to obtain reliable results for comparative studies.

Adenocarcinoma↗
PubMed1989

Observer variation in histological grading of breast cancer.

A multicentre study was conducted to assess the degree of agreement between pathologists grading breast tumours using the WHO criteria. Satisfactory correlation of grades was found to occur with observer variation of 21.9% on 874 tumours.

Breast Neoplasms↗
PubMed1990

Gastric dysplasia: inter-observer variation, sulphomucin staining and nucleolar organizer region counting.

Gastric dysplasia is regarded as a pre-neoplastic lesion and is generally believed to have higher potential for malignant transformation with increasing grade. To obtain consistency in diagnosis and management, reproducible diagnostic criteria are needed. We have used the classification system of the International Study Group on Gastric Cancer--ISGGC and investigated the interobserver variation in histological diagnosis. A Kappa statistic of 0.579, which reflects moderate agreement, was obtained for variation between two experienced pathologists. The prevalence of type III intestinal metaplasia was studied and found to occur in 55% of dysplastic areas, but in only 9% of hyperplastic areas (P less than 0.01). In addition, the correlation of mean nucleolar organizer region (AgNOR) counts with diagnostic categorization was investigated. A significant inter-observer variation was found between an experienced pathologist and a postgraduate student and only one of the observers obtained statistically significant separation of mean AgNOR counts between the categories of high-grade dysplasia, low-grade dysplasia, atypical hyperplasia, simple hyperplasia and normal.

Adult↗
PubMed1979

Observer variation in the interpretation of lower limb venograms.

After agreeing on diagnostic criteria and after a pilot study, two experienced radiologists twice independently reviewed 40 lower limb venograms performed by a standard technique in patients suspected or known to have venous thrombosis. The observers reviewed 20 examinations at a time, their analysis requiring separate identification of 11 major veins. At each site observers stated whether thrombus was "absent," "doubtful," "presumed," or "definite," or declared "no opinion possible." They then rediscussed criteria of diagnosis and, using the same experimental design, examined another 40 venograms. To correct for agreement expected by chance, data were analyzed by using the kappa statistic. In general, levels of agreement were higher than those reported for many other clinical and radiologic investigations, probably because of refinement of criteria after the pilot study. Nonetheless, observers disagreed about the probable presence or absence of thrombus at some site in the limb in about 10% of examinations. Observer variation should be considered when venography is used as a reference standard to evaluate other methods of diagnosing thrombi.

Adult↗
PubMed1976

Observer variation in the clinical assessment of stroke.

Clinical assessments have to be used in epidemiological studies in the absence of more objective means of establishing diagnosis or recording events in the natural history of disease. This requires the standardization of definition, technique and interpretation as a means of reducing observer variability in clinical examination. The methods used to reduce the observer variation in the clinical assessment of stroke patients are described and results are presented which demonstrate the degree to which this was achieved.

Cerebrovascular Disorders↗
PubMed1987

Inter-observer variation on registration of signals of cancer.

Previous studies have dealt with the role of seven warning signals of cancer in public health education and cancer diagnostics in general practice. Registrations of warning signals from medical records have some inconveniences common to most retrospective record studies. In the present inter-observer variation study it is found that agreement is good for warning signals in cancer patients when the warning signal has a probable connection with the disease. In control patients, and for more incidentally occurring warning signals in cancer patients, agreement is not so good. It seems that reproducible registrations from records are possible when there is a precise definition of what to look for and the data are relevant to the patient's disease. This study stresses the importance of good record keeping in medical practice.

Adolescent↗
PubMed1975

Measuring blood pressure. Training film to illustrate problems of intra- and inter-observer variation.

Some of the errors inherent in the measurement of blood pressure and how they can be overcome have been described. A film has been made consisting of 16 blood pressure readings. This can be used in an attempt to illustrate to a class of students the problems of intra- and inter-observer variation. It is also suggested that the readings act as an easily collected source of data which can be used by students outside the class for further analysis.

Audiovisual Aids↗
PubMed1977

Atrophy of optic nerve fibres in compression of the chiasm. Observer variation in assessment of atrophy.

Different observers' assessment of atrophy according to a semi-quantitative method was analysed. Five observers scored the degree of atrophy on magnified black-and-white fundus photographs from normal controls and from patients with chiasmal lesions of different severity. Four of the five examiners achieved a reasonably uniform assessment of atrophy. The results of the test prompted some modification in the grading system.

Adenoma, Chromophobe↗
PubMed1987

Reflux esophagitis: assessment of therapy effects and observer variation by video documentation of endoscopy findings.

Twenty-eight patients with endoscopically confirmed erosive or ulcerative esophagitis completed an 8-week placebo-controlled trial evaluating the symptomatic and endoscopic improvement obtained with ranitidine, 150 mg twice daily. Twice daily the patients recorded the number of episodes of retrosternal pain, regurgitation, and pyrosis on a diary card during a trial period of 1 week and during the 1st and 5th study week. Video documentation of endoscopy findings was undertaken before and at the end of the trial. The symptomatic relief obtained with ranitidine was significantly better than that obtained with placebo. The videotapes were assessed blindly and independently by three experienced fiberoptic endoscopists. The tapes were also recoded and reassessed by the same endoscopist. No systematic difference between different observers, either before or after treatment, could be detected. The interobserver variation, expressed as Kendall's tau b correlation coefficient, was 0.44 to 0.74. This coefficient was higher in intra-observer variation (0.63 to 0.91). Corresponding kappa-values for inter- and intra-observer variations were 0.12 to 0.30 and 0.27 to 0.85, respectively. The esophagitis, as judged by all observers, improved more in the ranitidine group than in the placebo group, but the difference did not reach statistical significance.

Clinical Competence↗
PubMed1992

Observer variation in functional examination of the temporomandibular joint.

Agreement between observers classifying TMJ sounds from data given in records of nonpatient adolescents was almost perfect in this interobserver study. Intraobserver and interobserver agreement in classifying all specific TMJ sounds at palpation and auscultation was acceptable to moderate (kappa value = 0.49 to 0.74). The agreement was considerably more reliable when classifying only one specific TMJ sound. Measurements of linear jaw opening showed small interobserver differences (coefficient of variation = 2.4 to 3.8). The significant difference found in calculating the angular mandibular opening may be the result of difficulties in maintaining maximum passive opening.

Adolescent↗
PubMed1987

Observer variation in grading sacroiliac radiographs might be a cause of 'sacroiliitis' reported in certain disease states.

Radiological sacroiliitis in Behçet's syndrome (BS) has been a subject of controversy. We have examined pelvic radiographs of 38 patients with BS and 28 age and sex matched controls which we reported previously, and also 17 with ankylosing spondylitis (AS), 27 with non-renal familial Mediterranean fever (FMF), and 33 with primary osteoarthrosis (OA). Initially, five observers assessed radiographs on two different occasions according to the New York criteria for sacroiliitis in a blind protocol. Later, three of them examined the various possible abnormalities of the sacroiliac (SI) joints after training sessions. Although the inter- and intraobserver variation was quite high, all observers found the expected changes in patients with AS. The abnormalities detected in the other diseases were either mild, inconsistent, or both. Erosions were confined to patients with AS, and osteophytes and glenoid sulci to patients with OA. We conclude that high observer variation in interpreting a film of the anteroposterior (AP) view of the pelvis for sacroiliitis may be a major cause of reported 'sacroiliitis' in BS and FMF.

Behcet Syndrome↗
PubMed1990

Inter-observer variation in interpretation of chest X-rays.

139 chest x-rays of children with solid tumours or leukaemia were examined independently by three observers (a radiologist and two physicians) and a consensus report determined. There was total agreement between observers on 40 x-rays (29%). The radiologist agreed with the consensus report on a significantly greater number of x-rays (91%) than both physicians (62% and 46%). There was a high incidence of over-reporting of abnormalities by both physicians. This study reinforces the need for regular dialogue between radiologists and clinicians for optimum interpretation of chest x-rays.

Bronchography↗
PubMedDate not supplied

[Inter- and intra-observer variation in silicosis radiology].

The radiologic criteria are important for the diagnosis of silicosis and must be objective. Initial radiologic changes are nonspecific and sometimes misinterpreted. We asked six Pulmonologists with distinct training in pulmonary disease to interpret 112 chest films according to a simple established protocol. No further information was given. One year later, all the observers analysed the same films over again. Then, we compared the results among the observers and between the two analysis made by the same individual. In 34 cases (30%) there was unanimity in asserting or denying the presence of micronodules and in 74 cases (66%) there was an agreement among the three more experienced observers. The intraobserver variability ranged from 8% to 40% and it was more important in the least trained observers. We concluded that when interpreting early radiologic changes in silicosis inter and intraobserver variability was elevated, more objectivity was achieved by the observers with more experience in epidemiologic studies and that we must be careful in interpreting results of epidemiologic studies concerning this matter.

Adult↗
PubMed1990

Use of screening phase data to evaluate observer variation of sputum cytodiagnosis as an outcome measure in a chemoprevention trial.

Sputum samples obtained during the screening phase of a chemoprevention trial in heavy smokers were evaluated independently by trained cytotechnologists and classified for degree of cellular atypia according to the method of Saccommano et al. (G. Saccommano et al., Cancer (Phila.), 33: 256-270, 1974). The level of agreement within and between Observers A and B was calculated as the percentage of agreement and, in addition, a statistic was used (kappa) to correct for chance-expected agreement. Between observer agreement on 300 specimens from 130 subjects was 68% (204 of 300) (kappa = 0.58). Of the 96 disagreements, only 17 were of more than one category in the six-category classification. Within observer agreement for both Observers A and B was evaluated on a subset of 60 specimens from 49 subjects examined on two separate occasions by each observer. The percentage of within observer agreement was 80% for Observer A (kappa = 0.73) and 62% for Observer B (kappa = 0.49) (P less than 0.04). Altogether, 71% (25 of 35) of within observer discordant readings were confined to only one category. These data, obtained from the screening phase of the study, will allow us to refine the outcome measure for the trial without introducing bias that could result from knowledge of the actual study results. The failure of conventional cancer treatments to impact significantly on overall cancer mortality has led to an emphasis on prevention. If premalignant changes can be reliably detected at a time when the malignant process is reversible, then it may be feasible to intervene to prevent the occurrence of some cancers. The appropriate selection of subjects for such intervention trials and the subsequent demonstration of the efficacy of chemoprevention strategies are therefore crucial.

Etretinate↗