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Results for “Observer Variation”

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PubMed1984

Growth rate and life span in Drosophila. III. Effect of body size and developmental temperature on the biphasic relationship between growth rate and life span.

The previous finding of a biphasic relationship between life span and growth rate of Drosophila, developed at 25 degrees C, was confirmed at other temperatures in the usual range (19-28 degrees C) and for development in either a standard medium or one deprived of nutrients but with varying amounts of yeast added on the medium. The role of body size in this relationship was studied by developing flies in a nutrient-less medium with a constant, submaximal amount of added yeast and varying temperature. It was found that under these conditions, which abolished the usual inverse relationship between body size and developmental temperature, body size variations did not account for the observed variations in life span. Thus, corroborating previous studies from this laboratory, body size was ruled out as a causative factor in the life span-growth rate relationship.

Animals↗

PubMed1982

Cholesterol esterification and lipids in blood plasma of the char (Salmo alpinus L.) during sexual maturation.

1. The initial rate of cholesterol esterification and the concentration of triacylglycerols in plasma were generally lower in prespawning than in immature chars. No typical pattern of variation of plasma cholesterol could be observed. 2. The observed variations in plasma cholesterol esterification and lipids may be caused by reduced feeding in the prespawning period. 3. The initial rate of cholesterol esterification in plasma was positively correlated with the concentrations of triacylglycerols and unesterified cholesterol in plasma, respectively.

Animals↗

PubMed2001

[Risk factors and prevention of the acquisition and transmission of glycopeptide resistant enterococci].

We reviewed the literature concerning the role of antibiotic use as a risk factor for glycopeptide-resistant enterococci (VRE) infection/colonisation, to enable us to develop measures for preventing the acquisition and transmission of VRE. We found that the length of stay, the number of stays in hospital and the transfer of patients between hospitals and units were all risk factors for acquiring VRE infection. However, analysis of group and individual data showed that there was also a clear link between vancomycin and third-generation cephalosporin use and the prevalence of VRE colonisation/infection. Evidence for this link was provided by the consistent association and dose-effect relationship observed, and from the frequently consistent variations observed over time. However, it is difficult to give precise recommendations because very few studies have investigated both intrinsic bacterial factors making specific strains more epidemic and the precise characteristics of the conditions determining antibiotic selection pressure. In the absence of this information, and maintaining the prevention measures against cross-contamination which remain a priority, these results suggest that programs aimed at improving the prescription of antibiotics should be initiated in hospitals.

Anti-Bacterial Agents↗

PubMed1980

A study in the measurement of corneal endothelial cell density using the specular microscope.

Six subjects who never wore contact lenses underwent six determinations of corneal cell density using each of two measurement modes: Mode A: the eye was applanted once and pairs of photographs were taken; Mode B: the eye was applanated and a single photograph was taken. For each measurement mode data were collected on two separate sessions (Test, Retest). Chi-square analysis revealed a significantly larger proportion of uncountable photographs from the first measurement session, and analysis of variance revealed that Mode A was less reliable than Mode B upon retesting. It was concluded that Mode B was the preferred measurement mode, and that many more than six determinations be made on the initial session in order to obtain six readable photographs. Finally, estimates of inter and intra-session variation, intra-pair variation, and inter and intra-observer variation are given.

Cell Count↗

PubMed1989

Doppler ultrasonography of the fetoplacental circulation--normal reference values.

Normal reference values for the resistance index, A/B ratio and pulsatility index of the umbilical artery obtained by Doppler ultrasonography are presented. The resistance index and A/B ratio values are very similar to those previously published, indicating no need to formulate normal values for different populations. The pulsatility index differed from other published values, probably reflecting different calculation methods built into the spectrum analysers rather than differences in waveforms. The resistance index had the lowest coefficient of variation and showed least inter-observer variation. For routine use the resistance index is preferable to other indices.

Adult↗

PubMed2006

Large scale evaluation of WHO's ultrasonographic staging system of schistosomal periportal fibrosis in Ethiopia.

OBJECTIVES: To evaluate the recent WHO's ultrasonographic diagnostic staging system of schistosomal periportal thickening/fibrosis and to assess intra/inter-observer variation associated with its use. METHODS: Local standard of portal branch wall thickness (PBWT) for height was established using 150 healthy subjects. Intra and inter-observer variation in image pattern identification and PBWT measurements were assessed in 94 and 35 subjects, respectively, with differing stages of periportal thickening fibrosis. WHO's diagnostic criteria were evaluated in 2,451 community members (1,277 males, 1,174 females; mean age 18.8 years) with an overall Schistosoma mansoni prevalence estimate of 65.9%. RESULTS: There were no significant inter/intra-observer variations in image pattern identification and PBWT measurements. Based on Ethiopian PBWT-for-height standard, 128/2,451 (5.2%) had insipient, 46/2,451 (1.9%) had possible/probable and 112/2451 (4.6%) had definite/advanced periportal thickening/fibrosis. Comparable figures were obtained using the Senegalese PBWT-for-height standard and there was good agreement between Ethiopian and Senegalese healthy control-based diagnostic criteria in classifying the 286 subjects into stages of periportal thickening/fibrosis (kappa = 0.87, P < 0.001). CONCLUSIONS: With further improvement, the WHO's ultrasonographic diagnostic criteria can be used in health institutions and community surveys. Image pattern based assessment is simple and more reproducible than PBWT based assessment of periportal thickening/fibrosis. The latter is, however, more useful in clarifying the status of an individual with doubtful image pattern, and in monitoring post-treatment outcome of periportal thickening/fibrosis. Considering the comparability of PBWT-for-height standards, setting one international standard of PBWT-for-height is more practical than developing local standards for each endemic area.

Adolescent↗

PubMed1997

Interpretation of uroflowmetry curves by urologists.

PURPOSE: Uroflowmetry has become a routine investigation in patients with symptoms of the lower urinary tract. Little is known about the variation in the use of uroflowmetry and in the interpretation of its outcomes. We investigated the diagnostic value of uroflowmetry as a freestanding test, and examined the interobserver and intra-observer variation in the interpretation of uroflowmetry curves. MATERIALS AND METHODS: A representative panel of 58 urologists was questioned about the relevance of visual inspection and flow parameters for interpretation. In addition, they individually assessed 25 randomly selected uroflowmetry curves (from patients with no abnormalities and those with various lower urinary tract symptoms) regarding normal findings and the most likely diagnosis. To investigate intra-observer agreement 4 of these curves were studied twice. RESULTS: Voided volume (81%), visual inspection (77%) and maximum flow rate (77%) were most frequently mentioned as relevant for interpretation. Large differences existed between panel opinions and actual case information. For 43% of the normal cases the panel members considered the curves as abnormal. Of the abnormal cases 6% of the curves were regarded as normal. The urologists predicted correctly the actual diagnosis in 36% of all cases. Interobserver agreement was moderate for normalcy (kappa 0.46, standard error 0.087) and poor for the most likely diagnosis (kappa 0.30, standard error 0.043). Intra-observer agreement was also not satisfactory. On average, for the 4 cases studied twice 29% of the panel members chose another option for normalcy, while 41% mentioned another diagnosis the second time. CONCLUSIONS: These results necessitate reconsideration of the diagnostic use of uroflowmetry in daily urological practice.

Humans↗

PubMed1994

Inter-observer variability in ultrasonic evaluation of abdominal aortic aneurysms.

This study was undertaken to assess the consistency in 16 independent observations of the diameters of abdominal aortic aneurysms by diagnostic ultrasound. Confidence intervals were developed for the anterior-posterior dimension and the transverse dimension. Clinical treatment decisions should be made with appreciation that measurements of diameter increases greater than 0.21 cm in the anterior-posterior dimension and 0.31 cm in the transverse dimension are significant and are not a result of inter-observer variation.

Aortic Aneurysm, Abdominal↗

PubMed1994

Prescribing endodontic retreatment: towards a theory of dentist behaviour.

The large variations observed in dentists' management of periapical lesions in endodontically treated teeth suggest that disease concepts used in clinical practice should be investigated. In the present study it was hypothesized that dentists regard various periapical conditions as different stages on a health continuum. Variations could then be regarded as the result of the individuals selection of differing cut-off points for prescribing retreatment. The hypothesized decision-making model was tested using dental students in Amsterdam (Holland), Gothenburg (Sweden) and Pavia (Italy). The students were shown six simulated cases among which the quality of root filling seal and presence of post and crown were systematically varied. For each case, management of five periapical conditions was assessed. Five options were offered: no therapy, wait-and-see, nonsurgical retreatment, surgical retreatment, and extraction. For each examiner and case a 'retreatment preference score (RPS)' was established. The investigation showed large interindividual variations in RPS. A statistically significant higher mean RPS was seen among students in Pavia compared with students in Amsterdam and Gothenburg. Among all observers and cases it was found that if retreatment was proposed for a certain size of lesion, retreatment was subsequently selected for all larger lesions. The experiment gave evidence in support of the proposed hypothesis. The data also suggest that the choice of retreatment criterion is affected by values, costs of retreatment and technical quality of the original treatment.

Adult↗

PubMed1979

Variations of technique in the face-lift operation.

Observed variations in face-life technique prompted an analysis of these techniques to determine whether experience correlated with certain aspects of the surgery. A questionnaire was returned by 565 of 1,750 plastic surgeons, quantifying varying techniques in over 121,000 face lifts. The respondents were placed into three groups according to the number of rhytidectomies performed, and correlations were determined.

Face↗

PubMed2000

The subjective assessment of echogenic fetal bowel.

OBJECTIVES: To assess the subjective interpretation of the echogenicity of fetal bowel compared to bone from antenatal ultrasound images taken during examinations conducted between 17 and 22 weeks of gestation. METHODS: Eighty-seven women attending for their antenatal scan were selected in a random prospective manner over a 9-month period. Images of the fetal bowel were taken and evaluated by 10 sonographers, one consultant obstetrician and one consultant radiologist. Images from a further 13 fetuses, in which the subjective assessment of echogenic bowel was made, were also included. All ultrasound images were acquired on a dedicated ultrasound scanner, with a standard transducer, thermal paper printer and single operator using standardized equipment settings and reproducible image sections. Questionnaires with 100 sets of images of fetal bowel were distributed to the participants. Performance was assessed by means of percentage agreement and levels of chance corrected agreement (Kappa). RESULTS: The subjective assessment of fetal bowel echogenicity is very variable. Intra- and inter-observer variation discrepancies in the assessment of bowel echogenicity compared to bone were demonstrated between the sonographers. Good agreement was identified between the consultants with good to almost perfect intra-observer agreement. Overall, only moderate agreement was observed between the sonographers and the consultants. CONCLUSIONS: The lack of agreement demonstrated between sonographers when evaluating the echogenicity of fetal bowel should be addressed if this ultrasound marker is to be incorporated into routine fetal screening programs.

Adult↗

PubMed1997

Evaluation of X-ray beam angulation for successful twin canal identification in mandibular incisors.

This study was undertaken to determine the most effective horizontal beam angulation for the diagnosis of twin canals in mandibular incisors. Two hundred extracted mandibular incisor teeth, in groups of four, were aligned in the form of a lower dental arch and radiographed using a beam alignment device at 10 degrees intervals between 0 degree and 50 degrees from both right and left sides. Five observers with varying degrees of experience were asked to assess the number of canals in each of the four teeth from these radiographs. A further radiograph of each individual tooth was taken at 90 degrees through the mesio-distal plane to identify the number of twin canals present. A random sample of 10% of the radiographs were viewed for a second time 3 months later to assess intra-observer variation. The 20 degrees right and 30 degrees left horizontal beam angulations showed significantly more accurate diagnosis of twin canals than the ortho-radial view (0 degree) by all five observers. Analysis of the inter-observer results suggests that the experienced viewers were no better but more consistent at identifying twin canals in mandibular incisors.

Dental Pulp Cavity↗

PubMed1997

Interobserver variations in clinical signs for diagnosis of pleuritis.

A study was conducted on 150 patients admitted in a teaching hospital to find out reliable clinical signs for diagnosing pleuritis. Cases were selected based on suspicion of pleural involvement by history and examination. Final diagnosis was made by correlations with radiographic and ultrasonographic reports. Reliability of the signs was determined on the basis of high concordance of independently observed variations between two medical consultants. Inflammatory involvement of pleura was seen in 69.3% cases and 30.7% were due to oedema disorders. Concordance between observers was high for crepitations (95.5%) and pleural rub (93.8%) followed by vocal resonance (87.6%), dull percussion note (76.9%) and mediastinal shift (76.9%).

Adult↗

PubMed2003

Intergenerational trend of some dermatoglyphic traits in Vaidyas of West Bengal, India.

In order to investigate the intergenerational change of dermatoglyphics, fingerprints of 400 individuals were collected from an endogamous caste Vaidyas of Barasat, West Bengal. Results were compared with the data of an earlier sample of Banerjee collected in 35 years before on the same community of the same area. As it is generally known that dermatoglyphics is selectively neutral, thus if no other evolutionary forces play a role, we cannot expect any change of dermatoglyphic characters after several years. In the present study, non-significant change in the frequency of pattern and more or less same PII have been observed in both sexes. But significant quantitative differences were found between the two samples. These differences may not be due to the change of intra-uterine environment, rather due to the inter-observer error of these two studies and the small sample size of the earlier study. Because though same methods were used in both studies, inter-observer variation is much possible in ridge counting than pattern type determination.

Adult↗

PubMed1990

Regional cerebral blood flow velocity patterns in newborn infants.

Using range-gated pulsed Doppler sonography, cerebral blood flow velocity (CBFV) waveforms from the anterior cerebral artery (ACA), middle cerebral artery (MCA) and circle of Willis artery (CW) were examined in a total of 34 newborn infants. We compared the pulsatility index (PI) from the three cerebral arteries sampled in 10 term and 10 preterm (29 +/- 2 weeks) newborn infants without a history of perinatal asphyxia or intracranial pathology. The Pl in the ACA ranged from 0.60 to 1.03. There were no significant differences in Pl between the three vessels by paired comparisons. The Pl of the MCA differed from that of the ACA by 0.00 +/- 0.05. The variation coefficient (CV) was 7%. For CW with ACA, the difference was 0.00 +/- 0.04 and CV was 6%. Both intra- and interexaminer variation in Pl measurements were studied in another 14 infants. The variation coefficients were 5-8% for all three cerebral arteries. We showed that CBFV waveform patterns were similar in regional cerebral arteries, with Pl being a consistent CBFV index. In normal cerebral circulation, the intervessel Pl differences were within observer variations. Deviation from this may suggest abnormal regional cerebral haemodynamics.

Blood Flow Velocity↗

PubMed2006

Use of reconstructed computed tomography for the assessment of joint spaces in the canine elbow.

OBJECTIVES: To assess the accuracy of reconstructed computed tomography for imaging canine elbow joint spaces. METHODS: Computed tomography scans of eight cadaveric elbows were obtained and reconstructed computed tomography images were formatted in the dorsal and sagittal planes. Humeroradial and humeroulnar joint space measurements were obtained from these images. Intra-observer and inter-observer variations in joint space measurements were assessed, as was the effect of specimen positioning (inter-image variation). After freezing, four elbows were sectioned in the dorsal plane and four in the sagittal plane. In addition to visual comparison of the frozen sections with reconstructed computed tomography images, joint space measurements were obtained from frozen sections and compared with those from reconstructed computed tomography images. Variation was assessed using statistical calculations and graphical techniques. RESULTS: Both inter-image and intra-observer analyses revealed good agreement and low variation between data sets. Inter-observer correlation was only moderate, though variation was low. Visually, the reconstructed computed tomography images accurately reflected the frozen section anatomy. Agreement between frozen section and reconstructed computed tomography joint space measurements was good, with minimal variation. CLINICAL SIGNIFICANCE: These results indicate that reconstructed computed tomography is capable of accurately imaging elbow joint spaces and precise joint space measurements can be obtained. Reconstructed computed tomography may be useful for determining joint space measurements and detecting elbow incongruencies in dogs with elbow dysplasia.

Animals↗

PubMedDate not supplied

Ductal carcinoma in situ. Part I: Definition and diagnosis.

The frequency of diagnosis of ductal carcinoma in situ (DCIS) has increased in Australia, largely because of the national screening programme. Ductal carcinoma in situ presents a dilemma because of problems with its diagnosis and variations in reporting pathological and radiological findings, making it difficult to define optimal treatment and communicate information in a way that helps the patient understand the problems and make decisions. There is considerable inter-observer variation, particularly in differentiating low-grade DCIS from ductal hyperplasia, with or without atypia, but pathologists who participate in regular pathological review sessions vary less in their opinions. Mammography remains the main investigative tool for DCIS and the American College of Radiology has recommended standardized reports. A team approach is required for the removal and diagnosis of possible DCIS. Although the team may be best co-located in the one facility, this is not practical in many community hospital settings which lack on-site radiology and pathology services. The decision about how much breast tissue to remove will need to be made for each patient and depends on the size of the microcalcification and how suspicious the mammogram is for DCIS. We recommend the use of synoptic reports for DCIS, and we document the minimum factors that should be reported by pathologists. The evaluation and management of DCIS by a multidisciplinary team will allow the patient access to information required to make often difficult treatment decisions. In this paper, we review the literature about the natural history, pathology, cytology and radiology of DCIS and document the 20 critical steps required for the diagnosis of impalpable, mammographic microcalcifications suspected to be DCIS.

Biopsy↗

PubMedDate not supplied

The correlation between microscopical examination and erythrocyte band 3 (AE1) gene deletion in South-east Asian ovalocytosis.

South-east Asian ovalocytosis status was determined by microscopical examination of peripheral blood samples collected from 137 individuals in Papua New Guinea. The examination was performed separately by 2 microscopists, one of whom was very experienced in examining peripheral blood films for the diagnosis of south-east Asian ovalycytosis and the other was recently trained. The samples were also analysed by polymerase chain reaction (PCR) to determine ovalocytosis status by demonstrating a 27 base pair deletion in erythrocyte band 3 protein of the affected individuals. The microscopists were unaware of each other's results and of those obtained by PCR. Generally, there was very good agreement between the results obtained by both microscopists and the PCR. Although there was considerable inter-observer variation in the final ovalocyte count between the 2 microscopists, this did not affect their ability to discriminate between ovalocytic and normocytic individuals. Taking the PCR results as the standard, for the first, more experienced observer, the most efficient ovalocyte count cut-off point was around 50%. At this ovalocyte count the sensitivity and specificity of microscopical examination were 93.6% and 92.2%, and the positive and negative predictive values 86.3% and 96.5%, respectively. The second microscopist generally underscored the ovalocyte counts and his most efficient cut-off point was 20%, with sensitivity and specificity of 85.1% and 93.3% and positive and negative predictive values of 87.0% and 92.3%, respectively.

Anion Exchange Protein 1, Erythrocyte↗