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At least 649 records · Page 36Linked to original sources
PubMed2001

The accuracy of bone mineral density at distal radius on non-forearm osteoporosis identification.

The accuracy of BMD at distal radius was evaluated in terms of sensitivity, specificity, false negative, false positive, predictive value of a positive (osteoporosis) and a negative (normal) test for non-forearm osteoporosis. 278 women (150 osteoporotic and 128 normal) were measured for both distal radius bone mineral density (BMD) using Panasonic (DXA-70) dual energy X-ray absorptiometry (DEXA) and non-forearm BMD using Hologic (QDR-4500) DEXA on the same day. The results showed that mean age, menopause age, height and weight in the osteoporotic group were not different from the healthy group (p=0.168, 0.091, 0.274 and 0.097, respectively). Mean BMD of both distal radius and lumbar spine in the normal women was significantly higher than that in the osteoporotic group (p<0.001, = 0.002, <0.001, respectively). While mean BMD of the hip, femoral neck and Ward's triangle in both groups was not different (p = 0.330, 0.874, 0.847, respectively). The sensitivity of BMD of the right radius was very high (90.00-95.45%) and specificity was moderately high (53.85-73.68%). While false negative (4.55-10.00%) was less than false positive (26.32-46.15%). The accuracy of right radius BMD when compared with spine, hip, femoral neck and Ward's triangle was 82.35, 66.66, 80.00 and 86.49 per cent, respectively. The sensitivity (85.00-96.67%), specificity (57.69-81.58%), false negative (3.33-15.00%) and false positive (18.42-42.31%) of left radius BMD had the same trend as right radius BMD. Accuracy of the left radius when compared with non-forearm BMD was 88.24, 66.67, 75.71 and 86,49 per cent, respectively. The predictive value of right radius osteoporosis was 73.68, 47.37, 77.78 and 89.66 per cent for detecting osteoporosis at spine, hip, femoral neck and Ward's triangle, respectively. The predictive value of normal right radius BMD was 93.33, 92.86, 87.50 and 75.00 per cent, respectively for normal non-forearm BMD. Moreover, the predictive value of left radius osteoporosis for identifying spinal, hip, femoral neck and Ward's triangle osteoporosis was (80.56, 47.22, 77.55 and 91.07%, respectively) and the predictive value of normal left radius BMD for identifying normal BMD at non-forearm sites (96.88, 90.00, 71.43 and 72.22%, respectively) was revealed. It indicated that forearm DEXA provides adequate accuracy for in vivo determination of spinal, femoral neck and Ward's triangle osteoporosis. However, there was inadequate accuracy and very low predictive ability for identifying hip osteoporosis.

Absorptiometry, Photon↗
PubMed2002

Theoretical considerations on the health checkup accuracy of combination testing.

OBJECTIVES: To find basic theoretical evidence for an optimum combination of multi-phasic health checkup testing obtained by considering how the health checkup accuracy changes with the number of tests (n) and kinds of combination methods (A, B, C, D and E). METHODS: To find how the health checkup accuracy changes with the number of tests and type of combination method, generalized formulas as functions of the number of tests, are obtained to calculate the over-all health checkup accuracy which is defined by sensitivity (alpha), specificity (beta) and odds-ratio (gamma), based on the two-by-two table. Five kinds of combination methods were considered: A) Sequential tests. B) Sequential tests after changing the order in A. C) Simultaneous tests using the Believe-the-Negative Rule. D) Simultaneous tests using the Believe-the-Positive Rule. E) Simultaneous tests using the Believe-all-Positive-all-Negative Rule. RESULTS: It was proved that combination methods A, B and C are "equivalent" for health checkup accuracy. Therefore, the five methods could be summarized into three patterns. For A, B and C: beta and gamma increased but a decreased with increasing n. For D: alpha increased but beta and gamma decreased with n. For E: alpha, beta and gamma increased with n. CONCLUSION: Health checkup accuracy of combination testing is the best in case of E, although problems exist concerning how to judge the borderline subjects.

Humans↗
PubMedDate not supplied

New die design for dimensional accuracy assessment of crown castings.

PURPOSE: The aim of this study was to introduce a newly designed die for ceramometal restoration, and to compare the dimensional accuracy with the traditional complete-crown design. Two methods of dimensional accuracy assessment, vertical axial discrepancy and transverse diametral percentage, were compared. MATERIALS AND METHODS: Patterns were prepared from two different die designs--complete crown and ceramometal. Two investments available for titanium crown casting were used, Titavest CB and T-invest C & B. Titanium castings were made from each investment with a high-pressure casting machine. Vertical axial discrepancy of casting was determined by measuring the discrepancy for each set of wax patterns and their castings on the same die under a traveling microscope. Dimensional accuracy was expressed as vertical axial discrepancy and by transforming the vertical axial discrepancy into transverse diametral percentage. RESULTS: Both dies produced undersized castings with T-invest C & B and oversized castings with Titavest CB. Dimensional accuracy assessment of the two different types of crown casting design showed no significant difference in vertical axial discrepancy. CONCLUSION: Compared to the traditional transverse diametral percentage calculation, the vertical axial discrepancy assessment is independent of the die's dimensions. The two types of investment materials studied resulted in castings with different dimensional accuracies.

Crowns↗
PubMed2001

The accuracy of myocardial perfusion SPECT imaging in the evaluation of coronary artery disease in women and men.

BACKGROUND: The purpose of this study is to compare sensitivity, specificity and accuracy of myocardial perfusion SPECT for the detection of coronary artery disease (CAD) in women and men. MATERIAL AND METHODS: 588 patients (455 males and 133 females, 273 after a previous myocardial infarction) underwent stress myocardial perfusion SPECT. The accuracy of myocardial perfusion SPECT was proved by coronary angiography (stenosis > 50% was considered as a CAD). RESULTS: The sensitivity of SPECT was slightly higher, but statistically not significant, in men than in women (94% versus 91%, p > 0.05). The specificity was higher in women than in men (93% versus 82%), but this difference was not statistically significant either (p > 0.05). The accuracy of SPECT was the same for both sexes (92%). In angiographically verified group of patients the selection bias was obvious--patients with CAD dominated (74%) and the fraction of patients with CAD in men's group (83%) was significantly higher than in women's group (50%), p < 0.05. CONCLUSIONS: No significant difference was revealed in the accuracy of myocardial perfusion SPECT in men and women. Our results are in accordance with the prevailing opinion in literature that discovered differences in sensitivity, specificity and diagnostic accuracy are usually not statistically significant or that they can be explained by the selection bias of patients in angiographically verified groups (significantly higher fraction of patients with CAD in men's group).

Journal Article↗
PubMed2003

A clinical evaluation of the agar alginate combined impression: dimensional accuracy of dies by new master crown technique.

PURPOSE: To evaluate the dimensional accuracy of several impression methods including agar alginate combined impression in vivo; the marginal accuracy of stone dies was determined using a new electroformed master crown technique. MATERIALS AND METHODS: Cast cores with knife-edge and chamfer margins and electroformed master crowns were fabricated for 3 patients. Five impressions were taken of each preparation, using agar alginate combined impression and silicone impression materials. Dies were made after impression. The marginal fit of the master crown on each die was analyzed by four-way analysis of variance (ANOVA) and Tukey HSD test (p<0.05). RESULTS: The marginal fit of the master crown on the dies with chamfer margin was better than those with knife-edge margin for agar alginate combined impression. The shape of the margin did not affect the accuracy when silicone impression material was used. CONCLUSIONS: The results suggest that the agar alginate impression method is clinically acceptable for the chamfer margin, but shape of the margin may affect the dimensional accuracy of dies. The shape of the margin does not affect the accuracy of dies when silicone impression was used. Furthermore, the master crown made by electroforming technique could be useful for clinical evaluation of impression methods.

Agar↗
PubMed2004

Accuracy of criteria for predicting recurrence and metastasis in stage II and III gastric cancer patients with lymph node metastasis.

This study assessed the prediction of gastric cancer recurrence based on detection of occult neoplastic cells (ONCs) in lymph nodes, and by using criteria that were developed to identify patients with a high risk of recurrence/metastasis. The subjects were 60 patients of stage II or III gastric cancer with lymph node metastasis. Prediction of recurrence based on the detection of ONCs showed a sensitivity of 33.3% (2/6), specificity of 70.0% (7/10), and accuracy of 51.7% in stage II patients, while the sensitivity was 73.5% (25/34), specificity was 100.0% (10/10), and accuracy was 86.8% in stage III patients. Prediction of recurrence based on the presence of at least 2 high-risk criteria had a sensitivity of 33.3% (2/6), specificity of 100.0% (10/10), and accuracy of 66.7% in stage II patients, while the sensitivity was 82.4% (28/34), specificity was 80.0% (8/10), and accuracy was 81.2% in stage III patients. These results suggest that prediction of recurrence/metastasis soon after surgery using ONCs plus the high-risk criteria can increase the specificity in stage II cancer, and can achieve a sensitivity of 80% or more with a high specificity and accuracy in stage III cancer.

Humans↗
PubMed2004

Effects of noise, image resolution, and ROI definition on the accuracy of standard uptake values: a simulation study.

UNLABELLED: Semiquantitative standard uptake values (SUVs) are used for tumor diagnosis and response monitoring. However, the accuracy of the SUV and the accuracy of relative change during treatment are not well documented. Therefore, an experimental and simulation study was performed to determine the effects of noise, image resolution, and region-of-interest (ROI) definition on the accuracy of SUVs. METHODS: Experiments and simulations are based on thorax phantoms with tumors of 10-, 15-, 20-, and 30-mm diameter and background ratios (TBRs) of 2, 4, and 8. For the simulation study, sinograms were generated by forward projection of the phantoms. For each phantom, 50 sinograms were generated at 3 noise levels. All sinograms were reconstructed using ordered-subset expectation maximization (OSEM) with 2 iterations and 16 subsets, with or without a 6-mm gaussian filter. For each tumor, the maximum pixel value and the average of a 50%, a 70%, and an adaptive isocontour threshold ROI were derived as well as with an ROI of 15 x 15 mm. The accuracy of SUVs was assessed using the average of 50 ROI values. Treatment response was simulated by varying the tumor size or the TBR. RESULTS: For all situations, a strong correlation was found between maximum and isocontour-based ROI values resulting in similar dependencies on image resolution and noise of all studied SUV measures. A strong variation with tumor size of > or =50% was found for all SUV values. For nonsmoothed data with high noise levels this variation was primarily due to noise, whereas for smoothed data with low noise levels partial-volume effects were most important. In general, SUVs showed under- and overestimations of > or =50% and depended on all parameters studied. However, SUV ratios, used for response monitoring, were only slightly dependent of ROI definition but were still affected by noise and resolution. CONCLUSION: The poor accuracy of the SUV under various conditions may hamper its use for diagnosis, especially in multicenter trials. SUV ratios used to measure response to treatment, however, are less dependent on noise, image resolution, and ROI definition. Therefore, the SUV might be more suitable for response-monitoring purposes.

Computer Simulation↗
PubMed2004

[Accuracy analysis of vegetation mapping for Meili Snow Mountain area, northwest Yunnan, China].

The Meili Snow Mountain (28 degrees 20'-28 degrees 33'N, 98 degrees 30'-8 degrees 52'E) is a very famous mountain in Northwest Yunnan of China by its rich and well protected biodiversity and Tibetan cultural diversity. By applying 3S (RS-Remote Sensing, GIS-Geography Information System, GPS-Global Position System) technology, the 1:50000 vegetation map of Meili Snow Mountain area (total about 332 km2) was drawn out. The vegetation in this area was classified into 18 vegetation types except for stone, glacier and river system. The vegetation map was rectified by applying the GPS points got from the fields. The numbers of GPS points were calculated by the formula of numbers of samples in statistics. 313 GPS points were used to rectify the vegetation map. The numbers were fit for the formula of numbers of samples in Statistics. The accuracy and verify of vegetation types distribution in the map was analyzed by building a Probability Error Matrix (PEM) and through the variance analysis. The results indicated that the overall accuracy (OA) of the vegetation map was 84.7%. The accuracy of vegetation map finished by 3S technology was lied on the area of the region and the grade of vegetation class first, but the grade of vegetation class classified by remote sensing technology disaccord with the traditional vegetation class system. The other factos deciding the accuracy of vegetation were the distinguish ability of Remote Sensing image, the accuracy of distinguish, and the numbers of the samples, including vegetation class experts knowledge.

Abies↗
PubMed2005

Diagnostic accuracy of MRCP in choledocholithiasis.

PURPOSE: To evaluate the accuracy of MRCP in diagnosing choledocholithiasis considering Endoscopic Retrograde Cholangiopancreatography (ERCP) as the gold standard. To compare the results achieved during the first two years of use (1999-2000) of Magnetic Resonance Cholangiopancreatography (MRCP) in patients with suspected choledocholithiasis with those achieved during the following two years (2001-2002) in order to establish the repeatability and objectivity of MRCP results. MATERIALS AND METHODS: One hundred and seventy consecutive patients underwent MRCP followed by ERCP within 72 h. In 22/170 (13%) patients ERCP was unsuccessful for different reasons. MRCP was performed using a 1.5 T magnet with both multi-slice HASTE sequences and thick-slice projection technique. Choledocholithiasis was diagnosed in the presence of signal void images in the dependent portion of the duct surrounded by hyperintense bile and detected at least in two projections. The MRCP results, read independently from the ERCP results, were compared in two different and subsequent periods. RESULTS: ERCP confirmed choledocholithiasis in 87 patients. In these cases the results of MRCP were the following: 78 true positives, 53 true negatives, 7 false positives, and 9 false negatives. The sensitivity, specificity and accuracy were 90%, 88% and 89% respectively. After the exclusion of stones with diameters smaller than 6 mm, the sensitivity, specificity and accuracy were 100%, 99% and 99%, respectively. MRCP accuracy was related to the size of the stones. There was no significant statistical difference between the results obtained in the first two-year period and those obtained in the second period. CONCLUSIONS: MRCP is sufficiently accurate to replace ERCP in patients with suspected choledocholithiasis. The results are related to the size of stones. The use of well-defined radiological signs allows good diagnostic accuracy independent of the learning curve.

Adult↗
PubMed2005

Evaluation of the diagnostic accuracy of the endoscopic ultrasonography results in the patients examined in a period of three years.

INTRODUCTION: Endoscopic ultrasonography (EUS) is a well-established method of evaluating patients with gastrointestinal diseases, especially malignancies. EUS is like other similar endoscopy techniques, based on high frequency ultrasonography. This high level technology allows examination of tissue to almost microscopic level, not only in digestive system but its surrounding structures. OBJECTIVE: The aim of this study was to determine the contribution of endoscopic experience, based on the number of endosopic ultrasonography examination performed in the three years period, to obtain 80% diagnostic accuracy with staging of the disease in order to achieve a 30-60% change rate in treatment decisions which is accepted standard. RESULTS: First group with 210 patients was examined in the first year of work; 325 examined in the second year of work and 295 in the third year. DIAGNOSTIC: Accuracy in the first year of work, were 45% (p<0.001 for the choledocholithiasis; p=0.197 for the pancreatic cancer; p=0.195 for LN detection in the gastric cancer). In the second year of work diagnostic accuracy were 78%/p=0.550 for the choledocholithiasis; p=0.228 for the pancreatic cancer; p=0.503 for LN detection in the gastric cancer/. Diagnostic accuracy in the third year of work were 81%/p<0.001 for the choledocholithiasis; p=0.018 for the pancreatic carcinoma; p=0.042 LN detection in the gastric cancer/. CONCLUSION: Application of Endoscopic ultrasonography in diagnostics, based on number of EUS examination performed, after three years of work, achieved 80% diagnostic accuracy, compared to standard imaging methods and results of surgery in staging of the disease. EUS results made a change in treatment decisions in 30-60% of patients which is world standard and completely justify use of endoscopic ultrasonography in clinical practice.

Adult↗
PubMed2006

[Diagnostic accuracy].

Clinical decision making while making a diagnosis is based on pre-test probability evaluation, a decision whether further tests are needed, and post-test probability evaluation based on test results. The add value of the test is the increase in probability, which depends on its diagnostic accuracy. Some measures of diagnostic accuracy are sensitivity, specificity, positive predictive value, negative predictive value, likelihood ratio, area under the curve, Youden index, and diagnostic odds ratio. ROC curve is the most efficient way of graphic description of the relationship between sensitivity and specificity. Diagnostic accuracy of a test is evaluated in a cross-sectional study on a group of individuals subjected simultaneously to the index test and the gold standard. All parameters of diagnostic accuracy are very sensitive to the study design, therefore it is of utmost importance to perform and write a study to adhere to the proposed STARD standards. This lecture gives an insight into the basics of biostatistical terminology from the field of diagnostic accuracy.

Biometry↗
PubMed2006

Accuracy of sixteen-slice CT scanners in detected coronary artery disease.

BACKGROUND: The coronary artery disease, now, the incidence is increasing in both developed and developing countries. The investigation is evoluted and non-invasive multislice CT scanners have been used more frequently, although the gold standard is still the coronary angiography. OBJECTIVE: To investigate the accuracy in detected coronary artery disease by using 16-slice CT scanners compared to the conventional coronary angiography. MATERIAL AND METHOD: Fifty-five patients were 43 males, 12 females, median aged 62 years (43-82 years), and average heart rates 67 beats/minute (46-147 beats/minute) had the ECG-gated CT angiography followed by coronary angiography in 3 months. The ECG-gated CT angiography was performed by using 16-slice MSCT detector (0.42-s rotation time, 16 x 0. 75-mm detector collimation). RESULTS: All patients were classified into two major groups; one was significant coronary artery stenosis which was designed by stenosis at least 50% and the other was non-significant stenosis which was designed by normal or stenosis less than 50%. The site having blooming artifact due to calcification that causes complete obliteration of the lumen or having significant motional artifacts was ruled out. There were 285 evaluable sites in 19 patients with high heart rates, more than 70 beats/minute. The sensitivity, specificity, and accuracy in significant stenosis were 72.9%, 99.6%, and 94.0% respectively. In 36 patients with a lower heart rate, there were 563 evaluable sites, the sensitivity was 86.5%, specificity was 98.5%, and accuracy was 96.6%. The overall showed 81.1% of sensitivity, 98.9% of specificity, and 95.8% of accuracy. CONCLUSION: The accuracy of the 16-slice CT angiography for patients suspected of having coronary artery disease was high. However, blooming artifacts from the calcium, respiratory artifacts, and small size of the distal and branching artery still caused limited luminal assessment. These problems have challenged the new coming generation of MDCT.

Adult↗
PubMed2006

The accuracy of WinSmash delta-V estimates: the influence of vehicle type, stiffness, and impact mode.

The objective of this paper is to investigate the accuracy of WinSmash delta-V estimates as a function of crash mode, vehicle body type, and vehicle stiffness. The accuracy of WinSmash delta-V estimates was evaluated for 121 NASS/CDS 2000-2003 cases for which direct measurements of delta-V had been retrieved from an Event Data Recorder on the case vehicle. WinSmash was found to underestimate delta-V by 23% on average. WinSmash was found to be most accurate in crashes involving full frontal engagement of the vehicle structure. When using categorical stiffness coefficients, the accuracy of delta-V estimates was found to be a strong function of vehicle type. WinSmash underestimated delta-V for pickup trucks by only 3%, but underestimated delta-V for front-wheel drive cars by 31%. The use of vehicle-specific stiffness coefficients improved the accuracy of the longitudinal delta-V estimate. The single most important factor in improving WinSmash accuracy was the inclusion of restitution. After adjusting for restitution, WinSmash underestimated delta-V in frontal crashes by only 1% on average.

Acceleration↗
PubMedDate not supplied

Accuracy of blood glucose self monitoring in elderly insulin treated diabetic patients.

We investigated the accuracy of blood glucose self monitoring in 131 patients (mean +/- SD age 65 +/- 7 years, duration of diabetes 11 +/- 6 years) who participated in a 5-day inpatient group treatment and teaching programme especially designed for elderly insulin-treated patients. Patients' estimations and laboratory blood glucose measurements were compared on day 1 (after theoretical and practical introduction into blood glucose self monitoring) and on day 4 of the programme. Patients were trained in the visual reading of Haemoglukotest 20-800R; blood glucose meters were recommended only exceptionally. Error grid analysis showed a high accuracy of visually assessed blood glucose values, both on day 1 (94% of measurements in zone A, 5% in zone B) and on day 4 (95% in zone A, 4% in zone B). Patients with no prior experience in blood glucose self monitoring (n = 67) showed a significant improvement (p less than 0.02) in accuracy from day 1 to day 4. Values determined by blood glucose meters were less accurate, although this trend did not reach statistical significance. A second group of 94 consecutive patients was reexamined 5 years after participation in the treatment and teaching programme. 55 patients were still alive and 42 could be evaluated. Accuracy of blood glucose estimations was assessed in all 26 patients practising blood glucose self monitoring (age 69 +/- 5 years, diabetes duration 18 +/- 8 years), either at their homes (n = 23) or at our diabetes outpatient clinic (n = 3). Error grid analysis showed a high accuracy by visual reading (n = 21, 95% zone A, 5% zone B).(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1991

[Diagnostic accuracy of breast sonography. Comparison among three different techniques].

Mechanical arc scanning is widely used for breast sonography in Japan. The authors have used three different kinds of devices over the past seven years. The diagnostic accuracy was compared among three groups of patients with pathologically confirmed breast masses. In group A, 309 cases (77 carcinomas) were evaluated with a 10 MHz contact compound scanner, and the sensitivity, specificity and accuracy rates were 77.9%, 97.8% and 92.9%, respectively. In group B, 306 cases (56 carcinomas) were evaluated with a 5 or 7.5 MHz mechanical arc scanner, and the sensitivity, specificity and accuracy rates were 89.3%, 84.8% and 85.6%, respectively. In group C, 296 cases (71 carcinomas) were evaluated with a 7.5 MHz real time scanner, and the sensitivity, specificity and accuracy rates were 95.8%, 92.4% and 93.2%, respectively. In cases with T1 breast cancer, the methods had sensitivities of 60.0%, 85.7% and 94.5%, respectively. The sensitivity of the real-time scanner was not significantly different from that of the mechanical arc scanner. In conclusion, the hand-held real-time scanner with high-frequency transducer is a simple, useful device with high diagnostic accuracy for breast examination and can be used as a substitute for the mechanical arc scanner.

Breast↗
PubMed1991

Accuracy of maternal dietary recall for preschool children.

We assessed the effects of socioeconomic status and amount of time mother and child were together during the day on the accuracy of the mother's 24-hour recall report of her 3- or 4-year-old child's dietary intake. Accuracy of the mother's report was compared for nutrients and foods with dietary intake recorded by an observer. Neither socioeconomic status nor amount of time mother and child were together were related to any of the nutrient indicators of accuracy. Although socioeconomic status and amount of time mother and child were together were not related to the indicators of food accuracy, only 64.8% agreement was obtained between mothers and observers on foods consumed. Mothers were more likely to underreport (17.7%) than overreport (10.4%) foods. The low mean difference scores for nutrient indicators supported the use of the 24-hour recall method when collecting group data. The substantial disagreement on foods, however, suggests that previous studies assessing agreement on nutrients have overestimated the accuracy of the 24-hour recall method.

Chi-Square Distribution↗
PubMed1990

1990 Volvo Award in clinical sciences. The consistency and accuracy of roentgenograms for measuring sagittal translation in the lumbar vertebral motion segment. An experimental model.

An experimental model of the L4-L5 lumbar motion segment was developed that allowed precise manipulation of sagittal translation, rotation of L5 relative to L4, tilt of L4 on L5, and control of roentgenogram quality (image clarity) by placing a water bath between the tube and the vertebral body. A series of experiments were designed to systematically assess the consistency and accuracy of sagittal translation measurements from roentgenograms of varying quality, using different measurement protocols and various rater combinations on models with varying degrees of concomitant motions (rotations and tilts). Study 1 assessed the effects of roentgenogram quality, raters, and seven measurement methods on the consistency and accuracy of evaluating translations in the sagittal plane. Results indicated very high reliabilities across roentgenogram quality, raters, and measurement. As expected, high-quality roentgenograms were more accurately evaluated than lower-quality roentgenograms. However, closer inspection of the consequences of errors in measured translations indicated surprisingly high false-positive and false-negative rates, with significant differences observed between measurement methods. Study 2 assessed the effects of concomitant motions and measurement methods on the consistency and accuracy of evaluations. Within-rater consistency and accuracy indices were remarkably high and similar across measurement methods and degrees of concomitant motions. However, important differences in the false-positive and false-negative rates were again observed. Method 2, described by Morgan and King, demonstrated the overall best performance and the least interference due to concomitant motions. Study 3 assessed the effects of raters and measurement methods on the consistency of measuring translation in clinical roentgenograms, where concomitant motion factors may be present, but not explicitly considered. Results indicated substantially lower within- and between-rater consistency estimates relative to consistencies obtained from the model, although these magnitudes were similar to those reported by others evaluating clinical roentgenograms. The implications of lower consistency estimates relative to increased false-positive and false-negative rates must be more closely examined. These studies present evidence suggesting that high consistency and accuracy indices do not ensure acceptable false-positive and false-negative rates and, thus, provide empirical evidence supporting the view that using roentgenograms as a basis for diagnosing instability often can lead to errors in classification. This is less so when observed translations are relatively large (+/- 5+ mm) on roentgenograms that are relatively clear, with little obliquity, and when concomitant motions are minimal.(ABSTRACT TRUNCATED AT 400 WORDS)

Awards and Prizes↗
PubMed1986

[Analysis of the accuracy of the Holter system ICR 6201-G3].

UNLABELLED: The accuracy of the Holter System ICR 6201-G3 was investigated by evaluation of 32 Holter recordings taken randomly from the hospital's ECG laboratory. All events were classified into true positive, false positive and false negative diagnoses. Sensitivity (S) and predictive accuracy (PA) were calculated. RESULTS: QRS complexes: S 99.9%, PA 99.9%; supraventricular premature beats: S 98.3%, PA 81.1%; single ventricular premature beats: S 96.8%, PA 97.4%; ventricular couplets: S 96.4%, PA 95.6%; ventricular salvos: S 98.6%, PA 90.8%; pauses: S 100%, PA 91.7%. It is concluded that despite a relatively good overall accuracy of automatic arrhythmia detection, on account of the lower accuracy in the evaluation of all clinically important arrhythmias and of the markedly worse accuracy in some instances, a fully automatic use of the system cannot be recommended. Repetitive ventricular arrhythmias and asystolies must be controlled by hand.

Arrhythmias, Cardiac↗