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PubMed1990

Observer variation in equine abdominal auscultation.

The reliability of abdominal auscultation was investigated via an observer variation study. Clinicians listened to a variety of minute-long equine gut sound recordings. They evaluated the amount of gut sounds as 'absent', 'decreased', 'normal', or 'increased'. They subsequently evaluated the same recordings replayed in a different order. Intra- and inter-observer agreement was measured by the statistic kappa. There was significant intra-observer (kappa 0.57) agreement, but less agreement between observers (kappa 0.37). The best agreement was on the classification of sound tracks as 'absent' (intra-observer kappa 0.72 and inter-observer kappa 0.55). There was significant correlation between the clinicians' average assessment of the recordings and their acoustic energy levels. In this study abdominal noise was reliably assessed by auscultation. Standardised techniques and definitions would probably enhance the reliability of abdominal auscultation for the evaluation of gastrointestinal disease.

Abdominal Pain↗
PubMed1990

[Observer variation of the radiographic assessment of pulmonary changes caused by asbestos].

Assessment was undertaken of 165 x-ray photographs of the thorax originating from 165 men with varying degrees of exposure to asbestos: 37 were workers in an eternite factory, 65 insulation workers, 42 were plumbers and 21 were patients from the Lung Clinic in Bispebjerg Hospital. Assessment of the x-rays was carried out according to the directives established by the International Workers' Organisation (ILO) by three experienced specialists who had no knowledge of the individual person's exposure to asbestos or smoking habits. In order to investigate not only inter- but also intra observer variation, the three medical specialists described the material on two occasions with an interval of several days. Analysis of the descriptions revealed that there was considerable inter- and intra-observer variation in assessment of the changes caused by asbestos. Description of the parenchymatous changes was associated with slightly greater variation than description of the pleural changes. A partial analysis of smokers who had not had occupational exposure to asbestos showed a not inconsiderable occurrence (5-33%) of parenchymatous changes which could not be differentiated from changes caused by asbestos. It is concluded, that the diagnosis of pulmonary disease caused by asbestos should not be based on radiographic examination alone.

Adolescent↗
PubMed1991

Clinical assessment of ankylosing spondylitis: a study of observer variation in spinal measurements.

Twenty-two measurements repeated non-sequentially on each of 10 patients by five observers were undertaken to determine their reliability for routine clinical use. Measurements without significant inter-observer variation or with a coefficient of reliability greater than 0.70 were cervical rotation, cervical lateral flexion, tragus to wall distance, fingertip to floor distance on sagittal and lateral flexion, C7 to iliac crest line distraction and modified Schober index. It is concluded that many of the currently used measurements are either statistically unreliable or clinically unhelpful in mild or moderate ankylosing spondylitis. The most clinically useful were cervical rotation using a protractor, cervical lateral flexion using a goniometer, thoracolumbar flexion as the C7 to iliac crest line distraction, thoracolumbar lateral flexion as the fingertip to floor distance and the modified Schober index.

Adult↗
PubMed1990

Inter-observer variation in decision-making regarding patients on chronic hemodialysis: a study using the kappa index.

To examine inter-observer variation in the monitoring of patients with chronic disease, four nephrologists independently assessed 62 patients on maintenance hemodialysis. Deviation from normal was determined for adequacy of dialysis, protein intake, and metabolic state. The kappa-index, which allows to adjust for chance agreement, was used to analyze each monitoring diagnosis. Low agreement was found on decisions concerning adequacy of dialysis (kappa 0.12-0.26), while agreement was higher about protein intake (kappa 0.21-0.46), and metabolic state (kappa 0.24-0.52). Two physicians classified no patient as overdialyzed, while 16-18% were thus categorized by the other two. Routines for review of recent medical history also differed significantly between the physicians. Measures are needed to increase the reliability of decisions regarding the monitoring of chronic hemodialysis. A long lasting physician-patient relationship is not a sufficient prerequisite for diminishing decision variation. Medical audit as part of the clinical routine, and use of additional sources of information, exemplified by urea kinetic modeling, are discussed.

Adult↗
PubMed1992

Intra- and inter-observer variation of optic nerve head measurements in glaucoma suspects using disc-data.

The aim of this study was to determine the intra- and inter-observer variation in the use of a system designed for exact measurements from standard optic nerve head photographs. The commercially available system consisted of a colour CCD Videocamera, a dedicated frame grabber and customized software run on a IBM AT compatible computer. Masked measurements were made 3 times by 2 observers, from stereophotographs of the optic nerve head of 56 eyes from 30 glaucoma suspects. The cup was defined on the basis of contour, not pallor and the disc area was defined as the area inside Elschnig's ring. Intra-observer variances were 0.001 +/- 0.001 mm2 for cup area (mean +/- SD), 0.002 +/- 0.002 mm2 for disc area and 0.002 +/- 0.003 mm2 for rim area. These values for intra-observer variance were comparable with the results obtained using manual planimetric techniques. Intra-observer variance for disc area was significantly larger for the less trained of the two experienced observers. Inter-observer variances were 0.004 +/- 0.009 mm2 for cup area, 0.008 +/- 0.013 mm2 for disc area and 0.009 +/- 0.014 mm2 for rim area. These inter-observer variances were significantly larger than those previously reported for manual planimetry. The absolute differences between the two observers ranged from -0.35 to +0.20 mm2 (-0.08 +/- 0.11 mm2) for cup area, from -0.38 to +0.15 mm2 (-0.08 +/- 0.11 mm2) for disc area and from -0.29 to +0.34 mm2 (-0.06 +/- 0.12 mm2) for rim area.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1979

Palpatory estimation of liver size. Within- and between-observer variation.

A study based upon 23 patients revealed substantial within- and between-observer variation, when 14 senior and junior surgeons under blindfold conditions were requested to measure the distance from the thoracic cage to the lower border of the liver in the midclavicular and midsternal lines. Clinical decisions should accordingly not rely heavily upon a palpatory estimate of liver size.

Adult↗
PubMed1990

Global assessment of patients--a bedside study. II. Inter-observer variation and frequency of clinical findings.

Three physicians independently assessed 201 hospital in-patients for the presence of 10 basic physical characteristics, and made an overall assessment of whether or not the patients appeared ill. There were significant differences between the physicians in the average number of observations recorded for each patient (P less than 0.001). There was a significant difference (P less than 0.05) between the physicians regarding the number of positive diagnoses of anaemia, abnormal nutritional state, breathing difficulties and the overall assessment. Inter-observer variation was estimated by a pairwise comparison of the three physicians. Overall agreement rates ranged from 0.65 for abnormal nutritional state to 0.99 for presence of pain. After adjusting for random agreement, kappa values between 0.09 (elevated body temperature) and 0.88 (consciousness impaired) were found. No tendency towards a higher level of agreement in the overall assessment than in the basic findings was observed.

Diagnosis↗
PubMed1975

The definition of radiological signs in gastric ulcer and assessment of their validity by inter-observer variation study.

The initial aim was to program a computer with information on the frequency of radiological signs in benign and malignant gastric ulcers in order to obtain a percentage probability of benignancy or malignancy in succeeding ulcers in clinical practice. However, only four of the many signs described in gastric ulcer were confirmed to be of validity (i.e. reliable existence) by an inter-observer variation study using two observers and the films from 69 barium meal examinations. These were projection or non-projection of the in-profile ulcer, presence or absence of adjacent mucosal folds, good or poor definition of the in-face ulcer's edge, and extension of radiating folds to the in-face ulcer's edge. A few more remained unassessed due to insufficient numbers of relevant cases. It is condluced that: as defined in the literature the majority of radiological signs in this field are of uncertain existence; and the four that were found to be valid do not fully describe the important appearances that may be seen in benign and malignant ulcers and would be inadequate to differentiate them to a sufficiently high degree of probability.

Diagnosis, Computer-Assisted↗
PubMed1979

Sampling error and observer variation in the interpretation of esophageal biopsies.

Esophageal autopsy specimens from 11 subjects were used to determine observer variation and sampling error in assessing alterations attributed to gastroesophageal reflux. Inter- and intraobserver variation exceeded 20% even when the diagnosis was limited to a normal and abnormal reading. Marked differences in basal cell thickness but not in papillary height occurred when specimens were obtained from different levels of the lower esophagus. The differences were less marked in specimens obtained from the same level. Based on these data the reliability of basal cell thickness and papillary height as an index of gastroesophageal reflux appears limited.

Autopsy↗
PubMed1990

Observer variation in mammary thermography: results of a teaching file test carried out in four different centers.

To evaluate observer variation in mammary thermography, a teaching file test of 159 thermographies was worked out by 4 senology centers. The evaluation of accuracy and the K index of variability demonstrated a significant variability among centers. The reliability of thermography in senology seems to be too poor for it to be able to direct any therapeutic decision, either diagnostic or prognostic.

Breast Neoplasms↗
PubMed1990

Observer variation in the radiological measurement of the anorectal angle.

Determination of the anorectal angle (ARA) and the position of the pelvic floor is, theoretically, very important in understanding the mechanisms of anorectal continence and defaecation. The variability in the measurement of the ARA was analyzed. Nine experts drew ther rectal axis either as a line along the posterior wall of the distal rectum or as the central axis of the rectal lumen on the outlines of 18 representative proctographic images. The standard deviations and ranges of the mean values of each ARA were comparable but large in both methods. On average, the S.D. was 8 degrees and the range value about 23 degrees. Inter-observer variation was not related to the magnitude of the ARA, but rather to the anorectal configuration. Drawing a line along the posterior distal rectal wall is difficult when it is irregular or when the puborectalis impression is indistinct. The central rectal axis is difficult to draw when the junction between the upper and lower rectum is ill defined or when the outlines of the distal rectum are asymmetric e.g. by the presence of a rectocele. Thus, the variability of both methods was not strongly interrelated (r = 0.68 for the median values). It is concluded that, in general, radiologic assessment of the ARA is not reliable enough for comparative investigation of the dynamics of the anorectum.

Anal Canal↗
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↗
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↗