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At least 145 records · Page 8Linked to original sources

Reproducibility of noninvasive tests of peripheral occlusive arterial disease.

We studied the reproducibility of four tests of peripheral occlusive arterial disease in 54 subjects, 32 of whom had this disease. We found that the reproducibility of systolic blood pressures obtained at rest from the thighs, calves, and ankles approximated that of arm systolic and diastolic blood pressures, as did the ankle-to-arm systolic blood pressure ratios. The average of the tenth and ninetieth percentile ranges of the resting systolic blood pressure ankle-to-arm ratios was +/- 0.10. Systolic blood pressures from the fingers were somewhat less reproducible, and those from the toes were even more variable. Systolic blood pressure ankle-to-arm ratios measured after the patient had exercised were less reproducible than resting ratios. The average of the tenth and ninetieth percentile ranges of the 1-, 3-, 5-, and 10-minute ratios after exercise was -0.13 to +0.16. Skin temperatures from the fingers and toes were approximately as reproducible as systolic blood pressures from the arms and legs and as the resting ankle-to-arm blood pressure ratios. Pulse-volume recordings from the thighs, calves, ankles, feet, toes, and fingers were very poorly reproducible. We conclude that information on the reproducibility of these measurements is essential in the evaluation of noninvasive arterial tests that are used to determine the course of peripheral occlusive arterial disease.

Arm↗

Bit-reproducible parallel phylogenetic tree inference.

MOTIVATION: Phylogenetic trees describe the evolutionary history among biological species based on their genomic data. Maximum likelihood (ML) based phylogenetic inference tools search for the tree and evolutionary model that best explain the observed genomic data. Given the independence of likelihood score calculations between different genomic sites, parallel computation is commonly deployed. This is followed by a parallel summation over the per-site scores to obtain the overall likelihood score of the tree. However, basic arithmetic operations on IEEE 754 floating-point numbers, such as addition and multiplication, inherently introduce rounding errors. Consequently, the order by which floating-point operations are executed affects the exact resulting likelihood value since these operations are not associative. Moreover, parallel reduction algorithms in numerical codes re-associate operations as a function of the core count and cluster network topology, inducing different round-off errors. These low-level deviations can cause heuristic searches to diverge and induce high-level result discrepancies (e.g. yield topologically distinct phylogenies). This effect has also been observed in multiple scientific fields beyond phylogenetics. RESULTS: We observe that varying the degree of parallelism results in diverging phylogenetic tree searches (high-level results) for over 31% out of 10&#xa0;179 empirical datasets. More importantly, 8% of these diverging datasets yield trees that are statistically significantly worse than the best-known ML tree for the dataset (AU-test, P&#x2009;<&#x2009;.05). To alleviate this, we develop a variant of the widely used phylogenetic inference tool RAxML-NG, which does yield bit-reproducible results under varying core-counts, with a slowdown of only 0%-12.7% (median 0.8%) on up to 768 cores. For this, we introduce the ReproRed reduction algorithm, which yields bit-identical results under varying core-counts, by maintaining a fixed operation order that is independent of the communication pattern. ReproRed is thus applicable to all associative reduction operations-in contrast to competitors, which are confined to summation. Our ReproRed reduction algorithm only exchanges the theoretical minimum number of messages, overlaps communication with computation, and utilizes fast base-cases for local reductions. ReproRed is able to all-reduce (via a subsequent broadcast) 4.1&#xd7;106 operands across 48-768 cores in 19.7-48.61&#x2009;&#x3bc;s, thereby exhibiting a slowdown of 13%-93% over a non-reproducible all-reduce algorithm. ReproRed outperforms the state-of-the-art reproducible all-reduction algorithm ReproBLAS (offers summation only) beyond 10&#xa0;000 elements per core. In summary, we re-assess non-reproducibility in parallel phylogenetic inference, present the first bit-reproducible parallel phylogenetic inference tool, as well as introduce a general algorithm and open-source code for conducting reproducible associative parallel reduction operations. AVAILABILITY AND IMPLEMENTATION: ReproRed: https://doi.org/10.5281/zenodo.15004918 (LGPL)-Reproducible RAxML-NG version https://doi.org/10.5281/zenodo.15017407 (GPL).

Phylogeny↗

Effect of the introduction of minimum lesion size on interobserver reproducibility using RECIST guidelines in non-small cell lung cancer patients.

We evaluated interobserver reproducibility for the response evaluation criteria in solid tumors (RECIST) guidelines and the influence of minimum lesion size (MLS) on reproducibility. The 110 consecutive patients with non-small cell lung cancer were treated with platinum-based chemotherapy. Five observers measured target lesions according to both the World Health Organization (WHO) criteria and RECIST. The percentage changes for unidimensional measurements (UD; RECIST type) and bidimensional measurements (BD; WHO type) were calculated for each patient. Interobserver reproducibility among five observers, that is 10 pairs, was expressed as the Spearman's correlation coefficient for the percentage changes, the proportion of agreement and the kappa statistics for response categories. The same analysis was carried out using MLS. BD was more reproducible than UD (Spearman rank correlation coefficient, 0.84 vs 0.81; proportion of agreement, 84.4% vs 82.5%; kappa value, 0.69 vs 0.61). When MLS was applied to UD, eligible cases decreased by 6.4% and the number of target lesions by 44.6%, whereas interobserver reproducibility for UD improved (Spearman rank correlation coefficient, 0.81-0.84; proportion of agreement, 82.5-84.2%; kappa value, 0.61-0.65). The introduction of MLS to UD could also improve intercriteria reproducibility between WHO and RECIST. It is important to apply the MLS when using RECIST for the comparable interobserver reproducibility attained with WHO.

Adult↗

BoneMorphing versus freehand localization of anatomical landmarks: consequences for the reproducibility of implant positioning in total knee arthroplasty.

OBJECTIVE: This study analyzed the influence of the acquisition method in image-free computer-assisted total knee arthroplasty (CAS-TKA), and the reproducibility of implant planning using BoneMorphing, a 3D morphometric model obtained by a 3D-to-3D elastic registration of statistical models to sparse point clouds acquired directly on the bone surface with a pointer. MATERIALS AND METHODS: Five surgeons (one expert, four trainees) each performed a CAS-TKA hybrid protocol based on morphometric models and landmarks on a cadaveric knee 10 times. In addition, several additional landmarks were digitized during each acquisition. The reproducibility of the implant positioning and sizing, as determined by an implant planning algorithm with morphometric models, was compared to direct digitization accuracy. RESULTS: Femoral and tibial implant positioning parameters with the hybrid protocol resulted in intra-surgeon standard deviations (SDs) of less than+/-1.4 degrees for rotation and 1.9 mm for translation for all surgeons in all directions except for tibial axial rotation (the only parameter determined by a digitized landmark and not recomputed in the 3D model). The variability in individual landmark digitization varied from 2 to 5 mm SD for certain landmarks, with ranges of 15-25 mm across all surgeons. The comparison study showed an improvement in femoral rotation reproducibility with the morphometric model when using the posterior condylar axis. Tibial implant reproducibility for each method was comparable, with the morphometric model giving better results in well-digitized areas such as the tibial plateau. CONCLUSION: A CAS-TKA protocol based on a deformed statistical model offers reproducible implant positioning. Some landmarks, such as distal condyles, show sufficient reproducibility in the direction of interest, while others, such as the anterior tibial tubercle, can lead to hazardous implant positioning. This should be taken into consideration when designing a CAS-TKA system with bony landmarks. In areas where a sufficient number of points have been digitized with good coverage, such as on the distal and posterior femoral condyles or the tibial plateau areas, the information derived from the 3D model is more accurate and reproducible than that derived from digitization. Good training and a guiding user interface are essential to guarantee coverage quality.

Arthroplasty, Replacement, Knee↗

Reproducibility of normal corneal power measurements with a keratometer, photokeratoscope, and video imaging system.

To determine the reproducibility of currently available instruments for measuring corneal power, two investigators measured comparable locations on 18 normal human corneas using a keratometer (Bausch & Lomb, Rochester, NY), the Corneascope (Kera Corp, Santa Clara, Calif), and the Corneal Modeling System (Computed Anatomy Inc, New York, NY). (For the two keratoscopes, average powers around rings at comparable locations were used.) Comparisons made between instruments at the significance level of .05 indicated that the keratometer was more reproducible than the Corneal Modeling System and the Corneascope, and the Corneal Modeling System was more reproducible than the Corneascope. Of the 31 rings projected on the surface of each cornea by the Corneal Modeling System, rings 2 through 13 were read reasonably reproducibly in that 76% of the measurements on these rings differed by no more than 0.5 diopter. The Corneal Modeling System (software version 1.16) is 83% as reproducible as a keratometer reading at approximately the edge of the 3-mm central zone on normal human corneas and provides information about corneal topography in a more reproducible and visually useful manner than the other two instruments.

Adult↗

Validation and reproducibility of ultrasonography in the detection of synovitis in the knee: a comparison with arthroscopy and clinical examination.

OBJECTIVE: Accurate detection of synovitis is important in both the diagnosis and outcome assessment of arthritis. This study was undertaken to assess the validity and reproducibility of ultrasonography (US) as a means of detecting synovitis in the knee, by comparing US findings with findings of arthroscopy and clinical examination. METHODS: Sixty consecutive patients with knee pain due to various arthritides had a clinical examination and US of their knee performed immediately prior to arthroscopy. All 3 assessments were performed by different clinicians who were blinded to the results obtained with the other modalities. US and clinical examination were compared with arthroscopically detected synovitis as the gold standard. Data from a subset of patients were used for calculating the inter- and intrareader reproducibility of US results, using a standard dichotomous (absence/presence of synovitis) as well as a graded (absence/grade of synovitis) scoring system. RESULTS: With the use of arthroscopy as the gold standard, US had a higher sensitivity (98% versus 85%), specificity (88% versus 25%), accuracy (97% versus 77%), positive predictive value (98% versus 88%), and negative predictive value (88% versus 20%) compared with clinical examination. The Cohen kappa values for inter- and intrareader reproducibility of US for distinguishing between presence and absence of synovitis were 0.71 and 0.85, respectively (P < 0.05 for both). The weighted kappa values for distinguishing grade of synovitis were 0.65 for inter- and 0.74 for intrareader reproducibility. The kappa value for intrareader reproducibility of arthroscopy results was 0.88. CONCLUSION: Ultrasonography is a valid and reproducible technique for detecting synovitis in the knee, and is more accurate than clinical examination. It may be valuable as a tool in studies investigating pain, diagnosis, and treatment response in knee arthritis.

Adolescent↗

Ergonovine maleate test detects anginal patients with poorly reproducible exercise tests.

The aim of the study is to evaluate the reproducibility of exercise testing and to determine whether there is any correlation between the reproducibility of exercise test and response to the ergonovine maleate test. Thirty-eight patients with mixed angina and documented coronary artery disease underwent an ergonovine maleate test and four exercise tests on consecutive days in the same basal conditions. The ergonovine test was positive in 20 patients (Group I) and negative in 18 patients (Group II). There were no significant differences in the clinical and angiographic data of the two groups. All 152 exercise tests were positive. The variability of the response of the repeated tests was assessed by means of an analysis of the following parameters: heart rate, blood pressure, rate-pressure product, watts, and minutes were recorded at the onset of ischemia (ST decreases greater than or equal to 0.1 mV). Range (maximal-minimal obtained value), ratio between range and maximal obtained value, and coefficient of variation (standard deviation/mean of the four parameters) were calculated for each patient. The analysis of these values demonstrated that while the test was reproducible in some patients, a high individual variability was present in others. Moreover, the individual variability results were higher in Group I than in Group II, with a statistically significant difference for all considered parameters. In conclusion, it is possible to have a poorly reproducible exercise test in patients with mixed angina. The correlation between a positive ergonovine test and a poorly reproducible exercise test suggests that abnormal coronary vasomotion may sometimes be present during exercise and may affect the reproducibility of the test.

Adult↗

Reproducibility of the diagnosis of atypical endometrial hyperplasia: a Gynecologic Oncology Group study.

BACKGROUND: Most gynecologists determine therapy based on current International Society of Gynecologic Pathologists (ISGP)/World Health Organization classification of endometrial hyperplasia, the reproducibility of which has been questioned. The Gynecologic Oncology Group (GOG) initiated a protocol to assess the efficacy of hormonal therapy of atypical endometrial hyperplasia (AEH). Primary goals of the first phase (Part A) were to prospectively determine reproducibility of referring institution's pathologist's diagnosis of AEH by a panel of 3 gynecologic pathologists and to determine reproducibility of diagnoses by panel members. METHODS: Three hundred six women were entered on this protocol with a referring institution's pathologist diagnosis of AEH based on biopsy or curettage. Available slides were assessed independently and interpreted by each of a panel of 3 gynecologic pathologists who used International Society of Gynecologic Pathologists (ISGP)/World Health Organization criteria. The majority diagnosis was based on diagnostic concordance by at least 2 of the 3 panelists. RESULTS: The referring institution's pathologist's diagnosis of AEH was supported by the majority of the panel in only 38% of cases. Overall kappa value for the panel diagnosis of AEH was 0.28. The majority diagnosis was adenocarcinoma in 29%, cycling endometrium in 7%, and nonatypical hyperplasia in 18% of cases. Unanimous agreement for any diagnosis was reached among all 3 of the panel in 40% of cases. For the panel, paired kappa values for any diagnosis ranged 0.34-0.43, with an overall kappa value of 0.40. CONCLUSION: Reproducibility of referring institution's pathologists' diagnosis of AEH by a panel of gynecologic pathologists is poor. Both underestimation and overestimation of the severity of the lesion are very common. The level of reproducibility among subspecialist panel members for diagnosis of AEH in these specimens also is poor. Better criteria and better sampling are needed to improve reproducibility of this diagnosis, particularly if it is to be used for clinical decisions.

Adult↗

Some variables affecting reproducibility in capillary electrophoresis.

Several variables that can affect reproducibility of both the peak height and the migration time in capillary electrophoresis (CE) were investigated here. A great part of the imprecision in CE for migration time is related to the interaction of the analyte with the capillary wall. Within a run, acidic compounds with long migration times have a higher relative standard deviation. In general, conditions that decreased the migration time, such as a short capillary length, tended to enhance the reproducibility of the migration time. Sample size also affected the reproducibility of peak height. Too small or too large an injection volume diminished the reproducibility. Sample matrix, such as high levels of proteins or salts in the sample, decreased the reproducibility. Furthermore, improvement in reproducibility can be achieved by using internal standards (especially for migration time), thorough washing of the capillary, or removing the excess proteins by acetonitrile deproteinization. Acetonitrile has an added effect of producing sample stacking. Depending on the migration time and analyte concentration, the peak height and area yielded different reproduciblity results.

Buffers↗

Reproducibility of left ventricular mass measurement using a half-Fourier black-blood single-shot fast spin-echo sequence within a single breath hold: comparison with a conventional multiple breath-hold segmented gradient echo technique in patients.

PURPOSE: To compare the reproducibility of left ventricular (LV) mass measurements using a black-blood half-Fourier single-shot fast spin-echo (SSFSE) and a segmented gradient echo magnetic resonance (MR) pulse sequence. MATERIAL AND METHODS: Breath-hold SSFSE and segmented gradient echo cardiac MR examinations were performed twice in 32 patients and manual detection of the LV endocardium and epicardium was applied by two blinded reviewers. The SSFSE pulse sequence allowed whole-heart coverage in a single breath hold, while multiple breath holds were required using the segmented gradient echo sequence. Spatial presaturation slabs were used with the SSFSE pulse sequence to reduce the field of view (FOV) and thereby achieve higher spatial resolution. RESULTS: Intraclass correlation coefficients were higher with the SSFSE pulse sequence than with the segmented gradient echo pulse sequence: intraobserver reproducibility reached 0.999 vs. 0.991; interobserver reproducibility: 0.997 vs. 0.981; and interstudy reproducibility: 0.998 vs. 0.936. These higher levels of reproducibility were confirmed on Bland and Altman plots. CONCLUSION: LV mass measurements can be assessed more reproducibly with the single breath-hold SSFSE technique than with the standard multiple breath-hold segmented gradient echo method.

Adult↗

Reproducibility of the kinematics and kinetics of the lower extremity during normal stair-climbing.

The purpose of this study was to examine the intrasubject reproducibility of the kinematic and kinetic measures of the lower extremity during normal stair-climbing. Three-dimensional video and force-plate data were collected for three trials per subject during each of three conditions: ascending, descending, and level walking. Three-dimensional angles and moments of the ankle, knee, and hip joints were calculated. The coefficient of multiple correlation was used to determine the intrasubject reproducibility of joint angles and resultant moments. Analysis of variance with repeated measures was conducted to compare the magnitudes of the coefficients between different steps, different joints, and different joint functions. The results showed that (a) generally, the kinematic and kinetic measures of normal subjects climbing stairs were reproducible; (b) the kinetic measures during the transition steps from level walking to ascending and from descending to level walking were significantly less reproducible than those during the other steps; (c) the data from the sagittal plane were more reproducible than those from the other two planes; and (d) the kinetic measures were more reproducible than the kinematic measures, especially for abduction-adduction and internal-external rotation.

Adult↗

Reproducibility of dynamic contrast-enhanced MRI in human muscle and tumours: comparison of quantitative and semi-quantitative analysis.

The purpose of this study was to determine the reproducibility of dynamic contrast-enhanced (DCE)-MRI and compare quantitative kinetic parameters with semi-quantitative methods, and whole region-of-interest (ROI) with pixel analysis. Twenty-one patients with a range of tumour types underwent paired MRI examinations within a week, of which 16 pairs were evaluable. A proton density-weighted image was obtained prior to a dynamic series of 30 T(1)-weighted spoiled gradient echo images every 11.9 s with an intravenous bolus of gadopentetate dimeglumine given after the third baseline data point. Identical ROIs around the whole tumour and in skeletal muscle were drawn by the same observer on each pair of examinations and used for the reproducibility analysis. Semi-quantitative parameters, gradient, enhancement and AUC (area under the curve) were derived from tissue enhancement curves. Quantitative parameters (K(trans), k(ep), v(e)) were obtained by the application of the Tofts' model. Analysis was performed on data averaged across the whole ROI and on the median value from individual pixels within the ROI. No parameter showed a significant change between examinations. For all parameters except K(trans), the variability was not dependent on the parameter value, so the absolute values for the size of changes needed for significance should be used for future reference rather than percentages. The size of change needed for significance in a group of 16 in tumours for K(trans), k(ep) and v(e) was -14 to +16%, -0.20 ml/ml/min (15%) and -1.9[?]ml/ml (6%), respectively (pixel analysis), and -16 to +19%, -0.23 ml/ml/min (16%) and +/- 1.9[?]ml/ml (6%) (whole ROI analysis). For a single tumour, changes greater than -45 to +83%, +/- 0.78 ml/ml/min (60%) and +/- 7.6 ml/ml (24%), respectively, would be significant (pixel analysis). For gradient, enhancement and AUC the size of change needed for significance in tumours was -0.24 (17%), -0.05 (6%) and -0.06 (8%), respectively for a group of 16 (pixel analysis), and +/- 0.96 (68%), +/- 0.20 (25%) and +/- 0.22 (32%) for individuals. In muscle, the size of change needed for significance in a group of 16 for K(trans), k(ep) and v(e) was -30 to +44%, +/- 0.81 ml/ml/min (61%) and +/- 1.7 ml/ml (13%). For gradient, enhancement and AUC it was +/- 0.09 (20%), +/- 0.02 (8%) and +/- 0.03 (12%). v(e), enhancement and AUC are highly reproducible DCE-MRI parameters. K(trans), k(ep) and gradient have greater variability, with larger changes in individuals required to be statistically significant, but are nevertheless sufficiently reproducible to detect changes greater than 14-17% in a cohort of 16 patients. Pixel analyses slightly improve reproducibility estimates and retain information about spatial heterogeneity. Reproducibility studies are recommended when treatment effects are being monitored.

Antineoplastic Agents↗

Reproducibility of computer measurement of maximal isometric strength and electromyography in sedentary middle-aged women.

The objectives of this study were (i) to determine the reproducibility of computer measurements of isometric strength and related electromyography in several muscle groups in sedentary middle-aged women, (ii) to evaluate the effects of different digital signal averaging methods on the reproducibility, (iii) to determine the final test score to be preferred in terms of improved reproducibility of isometric strength measurements, and (iv) to evaluate potential advantages provided by the computer measurement. Fifteen subjects were measured three times within a 2-week period. The measurements consisted of recordings of maximal isometric strength and rate of force production during trunk extension and flexion, leg extension and dominant forearm flexion with simultaneous recordings of surface electromyography, except in the trunk flexors. The following four final test scores were determined for each trial: the maximum of the three scores, the mean of the two highest scores, the median of the three scores and the mean of the three scores. The scores for the strength measurement were generally more reproducible (coefficient of variation, CV, approximately 6% and intraclass correlation coefficient ICCC, approximately 0.90) than those of the other measurements (CV > 10%, ICCC 0.13-0.97). There was no obvious preference for any type of final test score or for the width of the averaging window in the computer analysis. For isometric strength the reproducibility of the computer measurements was comparable to that of the voltmeter assessments. Computer analysis seems to be a versatile method for determining parameters of neuromuscular performance with reasonable reproducibility.

Computers↗

The long-term reproducibility of clinical tests of autonomic cardiovascular function in normal man.

Tests for the integrity of autonomic cardiovascular reflexes have been widely used in the clinic and in space physiology for decades. However, whereas some information on the short-term reproducibility of such tests are available, little is known about their long-term reproducibility. The work in this study was, therefore, directed towards assessing intra- and inter-subject variations in responses (heart rate, mean arterial blood pressure, forearm blood flow and forearm vascular conductance) to cortical arousal, cold face stimulation and lower body negative pressure (at 10, 30 and 50 mmHg) in eleven healthy male subjects (aged between 22 and 45 years). Subjects were studied repeatedly (each month) over a 6-month period. It was found that forearm vascular conductance responses to cold face stimulation were the most reproducible (mean coefficient of variation 10.9%), and with diminishing reproducibility curve responses to lower body negative pressure at 50 mmHg (mean coefficient of variation 12.4%), lower body negative pressure at 30 mmHg (mean coefficient of variation 18.9%), lower body negative pressure at 10 mmHg (mean coefficient of variation 28.0%), and responses to cortical arousal (mean coefficient of variation 39.6%). Generally, subjects who showed the largest responses to cold face stimulation also showed the largest responses to the other tests, and vice versa. It is concluded that there is intra-individual variability in the responsiveness and reproducibility of cardiovascular tests and that the cardiovascular responses to cold face stimulation and lower body negative pressure at 50 mmHg are the most reproducible.

Adult↗

Reproducibility of thermodilution cardiac output determination in critically ill patients: comparison between bolus and continuous method.

OBJECTIVE: A semi-continuous thermodilution method (CCO) was recently developed to measure cardiac output with less risk of bacterial contamination, fluid overload, and user-induced errors than the classical bolus technique (BCO). Previous comparison between these two methods showed negligible bias. However, large limits of agreement suggest that the two methods are not interchangeable. We hypothesized that this poor agreement may be due to differences in reproducibility. METHODS: In 23 critically ill patients, 369 paired measurements of CCO and BCO were compared (range of cardiac outputs: 2.8 to 16 L/min). The reproducibility of BCO and CCO methods was evaluated on a sample of 205 and 209 determinations, respectively. RESULTS: The comparison between the CCO and the BCO methods confirmed previous results: i.e., small bias (-0.39 L/min) and large limits of agreement (-2.06 to +1.28 L/min). Reproducibility showed no bias for either the CCO or the BCO method. Limits of reproducibility agreement between repeated determinations were approximately 50% less for CCO than for BCO method: respectively -0.87 to +0.82 L/min for the CCO method and -1.56 to +1.37 L/min for the BCO method. Consequently, the threshold necessary to ascertain that the difference between two measurements was not due to the internal variability of the method (3 x SEM) was 0.39 for the CCO method and 0.75 L/min for the BCO method. CONCLUSION: Differences in reproducibility may explain the poor agreement between the CCO and BCO methods. The better reproducibility of the CCO method allows the detection of smaller variations in cardiac output and suggests the superiority of this new method.

Cardiac Output↗

Reproducibility of linear tumor measurements using PACS: comparison of caliper method with edge-tracing method.

The aim of this study was to evaluate inter- and intra-observer reproducibility when making electronic caliper linear tumor measurements on picture archiving and communications systems (PACS) and compare them with linear measurements obtained from circumferential tracing of tumor perimeter. Three radiologists measured 64 masses from 30 patients on body CT scans in two separate settings. Long axis and perpendicular short axis were measured using electronic calipers. The edge of each tumor was traced electronically and the long and short axes were calculated by computer software. The reproducibility of a measurement was evaluated by computing and comparing the absolute value of the mean difference between initial and subsequent measurements. The mean differences +/-95% confidence interval (CI) between two measurements of the long by short axis were 3.8+/-2.6x3.1+/-1.8 mm when the caliper method was used and 3.5+/-2.0x3.2+/-1.5 mm when the tumor tracing method was used. There was no statistically significant difference in individual intra-observer reproducibility of tumor axes measurements. Neither long- nor short-axis single-dimension measurements resulted in significantly greater or lesser intra-observer reproducibility. When comparing caliper and tracing measurements, the overall mean difference (3.42+/-1.8 vs 3.38+/-1.4 mm) was not statistically significant. There was close correlation between the individual measurements made by each observer whether these were made by electronic calipers and when these were calculated from electronic tracings (Pearson correlations between 0.79 and 0.949). Current PACS systems allow reproducible linear, long or short axis, tumor measurements. There is no significant difference in reproducibility of measurements whether these are made directly with electronic calipers or calculated from tumor edge tracings.

Humans↗

Reproducibility of a questionnaire for assessment of present and past physical activities.

OBJECTIVE: The aim of this study was to evaluate the reproducibility of a self-administered questionnaire about present and past physical activities at work and during leisure time. METHODS AND DESIGN: The questionnaire, covering the period 1970-1993, comprised 12 questions on physical activities at work, and 12, with similar wording, for such activities in leisure time. There were also four questions on physical training. Two-week reproducibility (test-retest reliability) concerning the period 1970-1993 was analysed in a group of 44 subjects, and 1-year reproducibility, concerning current activities in 1993, was analysed in a second group of 123 subjects in relation to gender, age and low-back health. RESULTS: Test-retest reliability calculated as intraclass correlation coefficients (ri) for physical activities at work (ri 0.41-0.98) exceeded that for leisure time and physical training activities (ri 0.33-0.68). Calculated correlations did not differ markedly between past and present activities. No distinct influence of gender or low back health on 1-year reproducibility was found, in contrast to a slight tendency towards higher reproducibility among subjects of 50 years and older compared with younger subjects. CONCLUSIONS: Reproducibility of this questionnaire about physical activities at work showed no clear tendency to deteriorate regarding activities during the immediately preceding two decades. The questions about physical activities during leisure time have to be revised. Reliable retrospective information about physical activities in leisure time could perhaps not be collected by self-administered questionnaires and other methods, e.g. interview-based questionnaires, may be more suitable.

Adult↗

Classification of thoracic and lumbar spine fractures: problems of reproducibility. A study of 53 patients using CT and MRI.

Reproducibility of fracture classification systems in general has been a matter of controversy. The reproducibility of spinal fracture classifications has not been sufficiently studied. We studied the inter-observer and intra-observer reproducibility of the Magerl (AO) classification using radiograms, CTs and MRIs of 53 patients. We compared this classification with the older and simpler Denis classification. Five observers classified the fractures, first using the radiograms and CTs and, 6 weeks later, with radiograms and MRIs. Three of the observers repeated the readings after 3 months. Three observers also classified the fractures according to Denis. Agreement was measured using Cohen's kappa test. The type (A, B, C) classification of the AO system was fairly reproducible with CTs. With MRI this was only moderate. Group subclassification of the types yielded higher kappa values, corresponding to substantial agreement. The agreement was, in general, better with the Denis classification, but the variance was higher due to the difficulty of finding proper categories for some injury patterns. Although the AO classification allows proper registration of all kinds of injury, the reproducibility, especially at the type level, is problematic. Use of MRI and better definition of the distinctive properties of the three different types may enhance the reproducibility of the scheme.

Diagnosis, Differential↗