Disease relevance of Observer Variation

• In the Kuopio Ischaemic Heart Disease Risk Factor Study, we have assessed the reliability of B-mode ultrasound through studying intraobserver and interobserver variability [1].
• IOIBD report no 1: Observer variation in calculating indices of severity and activity in Crohn's disease. International Organisation for the Study of Inflammatory Bowel Disease [2].
• We determined: (a) the intraobserver and interobserver variability of the BSI; (b) the comparison between a change in BSI and prostate-specific antigen (PSA); (c) the regional distribution of bony metastases in early stage D prostate cancer (<3% skeletal involvement); and (d) the rate of growth of bony metastases from prostate cancer [3].
• CONCLUSION: MR staging of rectal cancer with an endorectal coil and gadolinium enhancement is inaccurate for early tumours (stage T1 or T2) and is associated with a considerable degree of interobserver variation for individual scan sequences [4].
• BACKGROUND: Histopathologic, prognosis-related grading of malignancy by means of morphologic examination in transitional cell carcinomas of the urinary bladder (TCC) may be subject to observer variation, resulting in a reduced level of reproducibility [5].

Psychiatry related information on Observer Variation

• These findings were, however, not reflected in the patient self-assessment of function and quality of life, raising question about the possibility of observer bias in recording LENT SOMA scores [6].

High impact information on Observer Variation

• The ATge demonstrated good day-to-day reproducibility (r = 0.91, p less than 0.001, SEE = 1.74 ml/kg/min) and low interobserver variability and was associated with comparable increases in arterial lactate in the two groups above the resting value, 0.9 +/- 0.4 mM/l in patients and 0.8 +/- 0.5 mM/l in normal subjects [7].
• We conclude that interobserver variability is high in interpreting biopsy specimens from patients with dilated cardiomyopathy and that quantitative and standardized methods are needed to increase diagnostic consistency [8].
• CONCLUSIONS: Oral contrast bowel US is comparable with BE in defining anatomic location and extension of CD and superior to conventional US in detecting luminal complications, as well as reducing interobserver variability between sonographers [9].
• As a potential alternative for assessment of HER2, we explored quantitative real-time reverse transcription-PCR (RT-PCR), a fast and inexpensive method yielding quantitative results insensitive to interobserver variability and amenable to standardized scoring [10].
• The limitations of the study are discussed, including the limited power, the declines in latex protein concentrations, and the possibility of information (observer) bias [11].

Biological context of Observer Variation

• This study was designed to assess intra- and interobserver variability and diagnostic accuracy of nuclear medicine physicians in their evaluation of baseline and captopril renograms [12].
• Using a protocol designed to eliminate observer bias, we studied the relationship of duration of diabetes, age, blood glucose control, and the presence of retinopathy to motor nerve conduction velocity in patients with juvenile-onset diabetes of short duration [13].

Anatomical context of Observer Variation

• Inter- and intraobserver variability measurements of high frequency echocardiographic measurements demonstrated excellent reproducibility (r = 0.95, interobserver variability for wall thickness; r = 0.97, interobserver variability for luminal diameter; n = 10 postmortem human coronary arteries) [14].
• To investigate interobserver variation in assessment of encapsulated follicular lesions, eight pathologists (four American and four Japanese) reviewed the same hematoxylin and eosin-stained slide of each of 21 cases of thyroid lesions showing encapsulation and follicular growth pattern [15].
• OBJECTIVE: The purpose of this study was to evaluate diagnostic accuracy and interobserver variability of time-resolved three-dimensional gadolinium-enhanced MR angiography in the detection of renal artery stenosis in comparison with intraarterial digital subtraction angiography as the standard of reference [16].
• The angiographic criteria used by most do not permit unequivocal separation of normal mitral valve systolic bulging from pathologic MVP, and the interobserver and intraobserver variability of interpretation is high [17].

Associations of Observer Variation with chemical compounds

• Paired t test analyses were also performed to determine significant differences between sagittal, transverse, and coronal measurements, as well as to determine preliminary intraobserver and interobserver variability of measurements in a subset of cases [18].
• CONCLUSION: Evaluation of cross-sectional images reconstructed from high-spatial-resolution three-dimensional gadolinium-enhanced MR renal angiographic data increases the accuracy of the technique and decreases interobserver variability [19].
• The purpose of this investigation was to determine the level of interobserver variability among a large group of Belgian nuclear medicine physicians who evaluated a randomly selected series of DMSA planar scintigraphic examinations performed on children and adults [20].
• Intraobserver variability was not different between exercise and dipyridamole studies for lesions of similar size [21].
• Interobserver variability in the interpretation of myocardial images with Tc-99m-labeled diphosphonate and pyrophosphate [22].

Gene context of Observer Variation

• Using strict methods to avoid observer bias, Ki-67 antigen was found in a high proportion of nuclei in the suprabasal layers together with HPV antigens, in the absence of PCNA staining [23].
• Expression of p16 was restricted to CIN 2/CIN 3, CIN 1 associated with high-risk human papillomavirus, or cervical cancer. p16 immunostaining allowed precise identification of even small CIN or cervical cancer lesions in biopsy sections and helped to reduce interobserver variation in the histopathologic interpretation of cervical biopsy specimens [24].
• By means of MIB1 expression we could recognize differences in proliferation among serous ovarian tumors, overcoming interobserver variability [25].
• Interobserver variability showed moderate multirater kappa values concerning the ER (Reiner score: kappa=0.57) and PR scores (Reiner score: kappa=0.53) [26].
• Especially with newly developed markers, such as MUM-1, the development of standardized techniques for staining and interpretation is critical to reduce inter-observer variability [27].

Analytical, diagnostic and therapeutic context of Observer Variation

• Evaluation of severity scoring systems in ICUs--translation, conversion and definition ambiguities as a source of inter-observer variability in Apache II, SAPS and OSF [28].
• The interobserver variability was lower with tetrofosmin scintigraphy because generally higher kappa values were noted, especially in the lateral wall [29].
• These data indicate that GRES reduces both the intra- and the inter-observer variability in assessing the area of MS lesions on PDWI and may prove useful in multicentre studies [30].
• Quantification of central benzodiazepine receptor binding potential in the brain with 123I-iomazenil SPECT: technical and interobserver variability [31].
• OBJECTIVES: To investigate whether intravenous injection of Infoson facilitates the assessment of left ventricular wall motion and definition of endocardial border and thereby reduces inter- and intra-observer variability during dobutamine stress echocardiography [32].

References