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At least 73 records · Page 4Linked to original sources
PubMed2005

How reproducible is cutaneous electrogastrography? An in-depth evidence-based study.

AIM: To check on reproducibility of parameters of the cutaneous electrogastrogram registered at a close or a distant time span. METHODS: Twenty-two volunteers recruited by an advertisement (11 females and 11 males, median age 25 years, range: 18-35) underwent three surface electrogastrography examinations of which two were taken on consecutive days and the third one was accomplished at least 2 weeks before or after the two other sessions. The examination involved a 30-min fasted recording, followed by a 90-min postprandial registration after intake of a 394-kcal mixed solid-liquid test meal. RESULTS: Parameters of the electrogastrogram pertaining to the frequency of the gastric slow waves exhibited good to moderate reproducibility, whereas fair reproducibility characterized parameters expected to describe the power of gastric slow waves. With the exception of the difference fed minus fasted power (DeltaDP), in no instance was the medium term reproducibility any worse than the short term one. Categorical data analysis revealed that the relative time share of normogastria postprandially exhibited a better reproducibility than in the fasted period. The Cohen's kappa-value of 0.459 for the DeltaDP for the medium term reproducibility placed this parameter within the range of moderate agreement between repeat examinations. Of the two two-parameter combinations considered, the alliance of the fasted and fed normogastria performed worse than any of those parameters considered alone, whereas a combination of the DeltaDP with the fed-state normogastria revealed a kappa-value amounting to 0.510 for the medium term reproducibility. CONCLUSIONS: The feasibility of some electrogastrographic parameters to convey clinically useful information may be hampered by their fair reproducibility. Recoding of parameters of the cutaneous electrogastrogram from primary continuous to secondary categorical may help achieve a better agreement between repeat examinations.

Adolescent↗
PubMed2000

Short-, mid-, and long-term reproducibility of the atrial signal-averaged electrocardiogram in healthy subjects: comparison with the conventional ventricular signal-averaged electrocardiogram.

Although atrial signal-averaged electrocardiogram (SAECG) has been proposed for noninvasive identification of patients with atrial tachyarrhythmias, the substantial variability of the measurement limits the clinical value. The aim of the study was to assess the short- to long-term reproducibility of atrial SAECG and to compare it to that of the conventional ventricular SAECG in 51 healthy volunteers (30 men; age 32 +/- 8 years). In each subject, SAECG recordings were obtained using MAC-VU electrocardiograph and HiRES and PHiRES software (Marquette Medical Systems) and repeated after 5 minutes, 1 day, 1 week, and 1 month. Automatically detected onset and offset of the filtered QRS complex and P wave were subsequently corrected by two independent observers, and the averaged values were used for the analysis. Conventional ventricular SAECG parameters: filtered QRS duration (QRStot), low amplitude signal duration, and root mean square voltage (RMS) of the terminal 40 ms of QRS, and 5 atrial parameters: filtered P wave duration (Ptot), RMS of the terminal 40, 30, 20 ms, and of the entire P wave were obtained. Relative errors of different pairs of measures were used to assess the intrasubject reproducibility. QRStot and Ptot were the most reproducible parameters. The relative errors after 5 minutes, 1 day, 1 week, and 1 month were 0.8% to 2.4% for QRStot, and 1.3% to 4.2% for Ptot. For RMS voltages, the relative errors exceeded 15% in short-term and 20% in long-term recordings. Although Ptot was statistically less reproducible than QRStot, the reproducibility of the former was good and comparable to that of the QRStot. The reproducibility of the voltage parameters was significantly poorer than that of the duration parameters. The study showed a satisfactory short- and long-term reproducibility of Ptot in the atrial SAECG in healthy subjects. However, low reproducibility of the voltage parameters should be considered in clinical applications.

Adolescent↗
PubMed2005

Coronary calcium measurements: effect of CT scanner type and calcium measure on rescan reproducibility--MESA study.

PURPOSE: To evaluate the effect of scanner type and calcium measure on the reproducibility of calcium measurements. MATERIALS AND METHODS: This investigation was approved by the institutional review boards of each study site and by the Institutional Review Board of the Los Angeles Biomedical Research Institute. Informed consent for scanning and participation was obtained from all participants. The study was Health Insurance Portability and Accountability Act compliant. The Multi-Ethnic Study of Atherosclerosis (MESA) is a multicenter observational study of 6814 participants undergoing demographic, risk factor, and subclinical disease evaluations. Coronary artery calcium was measured by using duplicate CT scans. Three study centers used electron-beam computed tomography (CT), and three used multi-detector row CT. Coronary artery calcium was detected in 3355 participants. Three calcium measurement methods-Agatston score, calcium volume, and interpolated volume score-were evaluated. Mean absolute differences between calcium measures on scans 1 and 2, excluding cases for which both scans had a measure of zero, was modeled by using linear regression to compare reproducibility between scanner types. A repeated measures analysis of variance test was used to compare reproducibility across calcium measures, with mean percentage absolute difference as the outcome measure. Rescan reproducibility in relation to misregistrations, noise, and motion artifacts was also examined. Variables were log transformed to create a more normal distribution. RESULTS: Concordance for presence of calcium between duplicate scans was high and similar for both electron-beam and multi-detector row CT (96%, kappa = 0.92). Mean absolute difference between calcium scores for the two scans was 15.8 for electron-beam and 16.9 for multi-detector row CT scanners (P = .06). Mean relative differences were 20.1 for Agatston score, 18.3 for calcium volume, and 18.3 for interpolated volume score (P < .01). Reproducibility was lower for scans with versus those without image misregistrations or motion artifacts (P < .01 for both). CONCLUSION: Electron-beam and multi-detector row CT scanners have equivalent reproducibility for measuring coronary artery calcium. Calcium volumes and interpolated volume scores are slightly more reproducible than Agatston scores. Reproducibility is lower for scans with misregistrations or motion artifacts.

Calcinosis↗
PubMed2004

Reproducibility of nerve fiber thickness, macular thickness, and optic nerve head measurements using StratusOCT.

PURPOSE: The measurement reproducibility of the third generation of commercial optical coherence tomography, OCT-3 (StratusOCT, software ver. A2, Carl Zeiss Meditec Inc., Dublin, CA) was investigated. The nerve fiber layer (NFL) thickness, macula thickness map, and optic nerve head (ONH) parameters in normal eyes were studied. METHODS: Ten normal subjects were imaged six times (three before and three after dilation) per day, and the series was repeated on three different days. The order of the scans before pupil dilation was randomized in each of the 3 days of scanning. After pupil dilation, the scans were also randomized in each of the 3 days of scanning. Each series was performed separately for standard-density (128 A-scans per macular and ONH image and 256 A-scans per NFL image) and high-density (512 A-scans per image for all three scan types) scanning. RESULTS: The mean macular thickness was 235 +/- 9.8 micro m. A-scan density (or image acquisition speed) had a statistically significant effect (P < 0.05) on the reproducibility of the mean macular thickness, macular volume, and a few sectors of the macular map. No significant dilation effect was found for any of the macular parameters. The best intraclass correlation coefficient (ICC; 94%) for macular scans was found for dilated high-density scanning, with an intervisit SD of 2.4 micro m and an intravisit SD of 2.2 micro m. The mean NFL thickness for standard scanning was 98 +/- 9 micro m. NFL reproducibility showed mixed results and had interactions between scan density and dilation for some parameters. For most of the NFL parameters, reproducibility was better with dilated standard-density scanning. The mean NFL thickness ICC for dilated standard scanning was 79%, with an intervisit SD of 2.5 micro m and an intravisit SD of 1.6 micro m. For the ONH analysis, the reproducibility was better for dilated standard-density scanning for almost all the parameters, except for disc area, horizontal integrated rim volume, and vertical integrated rim area, which were better before dilation. The best reproducibility was found for cup-to-disc ratio (ICC = 97%, with intervisit SD of 0.04 micro m and intravisit SD of 0.02 micro m). CONCLUSIONS: StratusOCT demonstrated reproducible measurements of NFL thickness, macular thickness, and optic nerve head parameters. The best reproducibility was found for dilated standard scanning for NFL and ONH parameters and for dilated high-density scanning for macular parameters.

Adult↗
PubMedDate not supplied

Intra- and interobserver reproducibility of the shoulder laxity examination.

The present study evaluates the inter- and intraobserver reproducibility of clinical examination of glenohumeral laxity in the unanesthetized shoulder. Forty-three asymptomatic Division I collegiate athletes underwent bilateral shoulder laxity examination initially and again after 3 months. Translation of the humeral head on the glenoid fossa in the anterior, posterior, and inferior directions was graded by four physicians who were blinded to their own previous grading and that of the other examiners. Overall intraobserver reproducibility of examination was 46%. When grades 0 and 1 were equalized, overall intraobserver reproducibility improved to 74%. For both the equalized and non-equalized reproducibility values reported by all examiners, the kappa values for intraobserver correlation were less than 0.5, which suggests that correlations were not better than those achieved by chance alone. Overall interobserver reproducibility was 47%. When grades 0 and 1 were equalized, interobserver reproducibility improved to 78%. Kappa values were greater than 0.5 only in equalized posterior and inferior laxity. The data demonstrate that the laxity examination of the unanesthetized shoulder is not easily reproducible in either intra- or interobserver comparison. Equalization of grade 0 and grade 1 laxity improves both intra- and interobserver reproducibility. We recommend caution when determining diagnosis and treatment based on this examination.

Adult↗
PubMed2002

The disc damage likelihood scale: reproducibility of a new method of estimating the amount of optic nerve damage caused by glaucoma.

PURPOSE: The major objective of this study was to test the reproducibility of a new method of estimating the amount of optic disc damage in patients with glaucoma. METHODS: The Disc Damage Likelihood Scale (DDLS) is based on the appearance of the neuroretinal rim of the optic disc corrected for disc diameter. The eight stages, extending from no damage to far advanced damage, are based on the width of the neuroretinal rim or the circumferential extent of absence of neuroretinal rim. Reproducibility was measured by two masked observers staging 48 optic nerve stereoscopic photographs by two different methods, the cup/disc ratio (c/d) and the DDLS. Also, reproducibility was assessed by three observers examining 34 eyes of 24 patients. RESULTS: With regard to the photographs, the intraobserver and interobserver reproducibility was better using the DDLS than the c/d ratio (98% versus 85% for intraobserver of reproducibility, and 85% versus 74% for interobserver reproducibility). The DDLS correlated better with the Humphrey Visual Field than did any Heidelberg Retina Tomograph parameter. CONCLUSION: In a clinical setting, the DDLS is as reproducible as, or more reproducible than, the c/d ratio system of estimating the amount of disc damage in patients with glaucoma.

Diagnostic Techniques, Ophthalmological↗
PubMed1989

[Assessment of reproducibility of transcranial Doppler velocimetry].

In recent years, transcranial Doppler velocimetry has been widely used as a noninvasive method for measurement of blood flow velocity in basal cerebral arteries. As for the reproducibility of this method, however, there have been only few reports so far. In the present study, we attempted to evaluate the reproducibility of this method by changing the examiners and the timing of the examination. Fifteen healthy volunteers were investigated by using a pulsed wave Doppler ultrasound device with a 2 MHz transducer. Both peak and mean spatial frequencies calculated from the frequency spectrum of the Doppler signals from the middle cerebral artery (MCA) and the basilar artery (BA) were used as blood flow parameters for assessing the reproducibility. The arterial blood pressure and the end-tidal carbon dioxide partial pressure (PECO2) were also monitored during the ultrasonic examinations. The intra- and inter-observer reproducibilities were evaluated by obtaining the coefficient of variation (CV) of the differences and/or analyzing the correlation between the values from the two measurements by the same examiner and by two separate examiners, respectively. The intraobserver reproducibility in separate days was also evaluated. Both in the mean arterial blood pressure and in PECO2, no significant changes were observed between the two measurements in each subjects. In the present examination, the CV and r values ranged from 6.7 to 19.5% and from 0.69 to 0.95, respectively, showing good reproducibility of the transcranial Doppler method for measurement of blood flow velocity, though some differences were observed as follows. The intraobserver reproducibility was better than the interobserver reproducibility.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

Qualitative and quantitative histopathology in transitional cell carcinomas of the urinary bladder. An international investigation of intra- and interobserver reproducibility.

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. This may confound comparisons of treatment results. Using objective, unbiased stereologic techniques and ordinary histomorphometry, such problems may be solved. EXPERIMENTAL DESIGN: A study of 110 patients with papillary or solid transitional cell carcinomas of the urinary bladder in stage Ta through T4 was carried out, addressing reproducibility of both qualitative and quantitative grading methods. Grading of malignancy was performed by one observer in Japan (using the World Health Organization scheme), and by two observers in Denmark (using the Bergkvist system). A "translation" between the systems, grade for grade, and kappa statistics were used in evaluating the reproducibility. Unbiased estimates of nuclear mean volume, nuclear mean profile area, nuclear volume fraction, nuclear profile density index, and mitotic profile density index were obtained twice in 55 of the studied cases by one observer in Japan and one in Denmark, using a random, systematic sampling scheme. RESULTS: The results were compared by bivariate correlation analyses and Kendall's tau. The international interobserver reproducibility of qualitative gradings was rather poor (kappa = 0.51), especially for grade 2 tumors (kappa = 0.28). Likewise, the interobserver agreement on the Bergkvist scheme was poor (kappa = 0.43). On the other hand was the interobserver agreement on invasion high (kappa = 0.75). The intraobserver reproducibility of the quantitative histopathologic variables was excellent in both Japan and Denmark for estimates of nuclear mean volume (r = 0.93), for nuclear mean profile area (0.78 < r < 0.83), and for nuclear profile density index (0.85 < r < 0.89), whereas the reproducibility for nuclear volume fraction was somewhat poorer (0.68 < r < 0.64). The slopes of the correlation lines were not significantly different from unity. Estimates of mitotic profile density index also showed acceptable intraobserver reproducibility (Kendall's tau > 0.53). CONCLUSIONS: The international, interobserver reproducibility of the quantitative estimators yielded similar results for all histopathologic variables investigated, except for nuclear volume fraction (r = 0.54). This can probably be related to the manual design of the sampling scheme and may be solved by introducing a motorized object stage in the systematic selection of fields of vision for quantitative measurements. However, the nuclear mean size estimators are unaffected by such sampling variability. The results obtained in this study stress the need for objective, quantitative histopathologic techniques substituting qualitative, subjective methods in prognosis-related grading of malignancy.

Adult↗
PubMed1997

Reproducibility of p53 and Ki-67 immunoquantitation in Barrett's esophagus.

OBJECTIVE: To test the reproducibility and time effectiveness of two immunoquantitation and sampling methods in Barrett's esophagus (BE) mucosa. STUDY DESIGN: Measurements were performed using image cytometry (CAS 200/486) with "at convenience" sampling and stereology (QPRODIT 5.2) with both at convenience and systematic random sampling. RESULTS: Quantitation of p53 immunohistochemistry (IHC) by CAS was very reproducible by the same observer (r = .99), but its interobserver reproducibility was lower, and the measurement was time consuming (r = .81, 35 minutes). Moreover, CAS also detected a "signal" in the absence of any visually observable brown stain, giving false positive results. Both intraobserver and interobserver reproducibility by QPRODIT 5.2 were good. With QPRODIT, using systematic random sampling, the measurements were more reproducible by different observers and faster (r = .96, 10 minutes) than with QPRODIT with at convenience sampling (r = .91, 20 minutes). Therefore, for assessment of the Ki-67 labelling index (LI) and area percentage (area%) of Ki-67-positive nuclei, we used only QPRODIT with systematic random sampling. While intraobserver reproducibility of both Ki-67 LI and area% was good (r = .96, r = .99), interobserver reproducibility of Ki-67 LI was poorer than area% (r = .72 vs. r = .97). The assessment of Ki-67 LI was time consuming, whereas the measurement of the area% of Ki-67-positive nuclei was very time effective (45 vs. 7 minutes). A strong correlation was found between Ki-67 LI and area% of Ki-67-positive nuclei (r = .92). CONCLUSION: Therefore, we conclude that quantitation of p53 and Ki-67 IHC in BE mucosa can be very reproducible and highly time effective by means of stereology with systematic random sampling.

Barrett Esophagus↗
PubMed1998

Reproducibility of the laser flare meter and laser cell counter in assessing anterior chamber inflammation following cataract surgery.

BACKGROUND AND OBJECTIVES: To determine the interobserver and intraobserver reproducibility of the laser flare meter and laser cell counter in assessing anterior chamber inflammation following cataract surgery. PATIENTS AND METHODS: Thirty-nine eyes with varied degrees of inflammation and 9 normal eyes were included in the study. Anterior chamber flare and cells were evaluated with the slit lamp and graded on a scale of 0 to 4+. The flare and cells were then measured three times each using the flare meter and cell counter by two different, experienced observers. The intraobserver reproducibilities were computed to evaluate repeatability of the instruments operated by the same observer. The first measurement taken by each observer was used to assess reproducibility between the two observers. RESULTS: The intraobserver reproducibility for overall flare was 0.995 for both observers. The intraobserver reproducibility for overall cells was 0.996 for observer 1 and 0.991 for observer 2. The overall interobserver reproducibility was 0.994 for flare and 0.988 for cells. The correlation between measurements and slit-lamp ratings was 0.78 for flare and 0.56 for cells. CONCLUSIONS: The intraobserver and interobserver reproducibilities were excellent, with good correlation to slit-lamp measurements. Reproducible results can be obtained using the laser flare meter and the laser cell counter. It is not known whether these results are applicable to other inflammatory processes with higher grades of flare and cells and with different protein and cell types.

Anterior Chamber↗
PubMed1996

Intratester and intertester reproducibility of the lumbar motion monitor as a measure of range, velocity and acceleration of the thoracolumbar spine.

OBJECTIVE: The purpose of this study was to examine the intra- and intertester reproducibility of the Lumbar Motion Monitor (LMM) as a measure of thoracolumbar range of motion (RoM), velocity and acceleration. DESIGN: The study was a clinical trial using asymptomatic subjects. BACKGROUND: The LMM is a promising device from a clinical and research perspective, though the reproducibility of it's measurements has yet to be fully determined on subjects under free motion conditions. METHODS: For intratester reproducibility, 15 subjects were required to move as far and as fast as they could in 8 s through flexion, side flexion, and rotation. They were tested on three occasions with 48 h separating tests. For intertester reproducibility, 10 subjects were tested by two examiners, and were required to move as far and as fast as they could in 8 s. RESULTS: Intratester reproducibility coefficients ranged between 0.82 and 0.87 for RoM, 0.61 and 0.87 for velocity, and 0.46 and 0.72 for acceleration. Rotation had the poorest reproducibility in each instance. Intertester reproducibility ranged between 0.93 and 0.98. CONCLUSIONS: The reproducibility of the LMM is suitably high for RoM and velocity for the device to be used for evaluation in a clinical and research setting.

Journal Article↗
PubMed1984

Diurnal variation and reproducibility of predischarge submaximal exercise testing after myocardial infarction.

Diurnal variation and reproducibility of abnormalities occurring during predischarge postinfarction treadmill exercise testing were investigated in 41 patients. Each patient was exercised using a limited Naughton protocol before 0800 and after 1800 h on two consecutive days. No complications arose. Individual ischaemic abnormalities were poorly reproducible in any patient. No abnormality and no patient showed significant diurnal variation. When the presence of any one of three ischaemic abnormalities (ST segment depression or elevation and angina) was analysed the reproducibility of an ischaemic result in the two morning and the two evening tests was 72% and 95% respectively with no significant difference between the two. The reproducibility of an ischaemic result in all four tests was 66%. The reproducibility of the test for either the presence or absence of an ischaemic result was 71%. No training effect could be shown either for the group as a whole or for any individual patient. There were no appreciable differences in either the heart rates or systolic blood pressures during exercise among those patients with non-reproducible ischaemic test results. Thus it is concluded that an assessment of any one of three ischaemic abnormalities improves the reproducibility of the result of submaximal exercise testing after infarction. Mechanisms other than increased myocardial oxygen consumption related to increased heart rate and systolic blood pressure at submaximal exercise tolerance are needed to explain non-reproducible ischaemic test results.

Adult↗
PubMed2025

Reproducibility of genetic risk factors identified for long COVID using combinatorial analysis across US and UK patient cohorts with diverse ancestries.

BACKGROUND: Long COVID is a major public health burden causing a diverse array of debilitating symptoms in tens of millions of patients globally. In spite of this overwhelming disease prevalence, staggering cost, severe impact on patients' lives and intense global research efforts, study of the disease has proved challenging due to its complexity. Genome-wide association studies (GWAS) have identified only four loci potentially associated with the disease, although these results did not statistically replicate between studies. A previous combinatorial analysis study identified a total of 73 genes that were highly associated with two long COVID cohorts in the predominantly (>&#x2009;91%) white European ancestry Sano GOLD population, and we sought to reproduce these findings in the independent and ancestrally more diverse All of Us (AoU) population. METHODS: We assessed the reproducibility of the 5343 long COVID disease signatures from the original study in the AoU population. Because the very small population sizes provide very limited power to replicate findings, we initially tested whether we observed a statistically significant enrichment of the Sano GOLD disease signatures that are also positively correlated with long COVID in the AoU cohort after controlling for population substructure. RESULTS: For the Sano GOLD disease signatures that have a case frequency greater than 5% in AoU, we consistently observed a significant enrichment (77-83%, p&#x2009;<&#x2009;0.01) of signatures that are also positively associated with long COVID in the AoU cohort. These encompassed 92% of the genes identified in the original study. At least five of the disease signatures found in Sano GOLD were also shown to be individually significantly associated with increased long COVID prevalence in the AoU population. Rates of signature reproducibility are strongest among self-identified white patients, but we also observe significant enrichment of reproducing disease associations in self-identified black/African-American and Hispanic/Latino cohorts. Signatures associated with 11 out of the 13 drug repurposing candidates identified in the original Sano GOLD study were reproduced in this study. CONCLUSION: These results demonstrate the reproducibility of long COVID disease signal found by combinatorial analysis, broadly validating the results of the original analysis. They provide compelling evidence for a much broader array of genetic associations with long COVID than previously identified through traditional GWAS studies. This strongly supports the hypothesis that genetic factors play a critical role in determining an individual's susceptibility to long COVID following recovery from acute SARS-CoV-2 infection. It also lends weight to the drug repurposing candidates identified in the original analysis. Together these results may help to stimulate much needed new precision medicine approaches to more effectively diagnose and treat the disease. This is also the first reproduction of long COVID genetic associations across multiple populations with substantially different ancestry distributions. Given the high reproducibility rate across diverse populations, these findings may have broader clinical application and promote better health equity. We hope that this will provide confidence to explore some of these mechanisms and drug targets and help advance research into novel ways to diagnose the disease and accelerate the discovery and selection of better therapeutic options, both in the form of newly discovered drugs and/or the immediate prioritization of coordinated investigations into the efficacy of repurposed drug candidates.

Humans↗
PubMed2006

Increase of peak intraocular pressure during sleep in reproduced diurnal changes by posture.

OBJECTIVE: To characterize diurnal intraocular pressure (IOP) changes in primary open-angle glaucoma by reproducing IOPs based on patient posture. METHODS: In 148 patients with untreated primary open-angle glaucoma who had IOPs recorded during clinic hours that were less than 21 mm Hg (average, 14.8 +/- 3.2 mm Hg), we measured IOP by noncontact tonometry every 2 hours from 6 am to midnight and every 3 hours from midnight to 6 am with patients sitting and supine. The IOP was reproduced by designating the sitting IOP as measurements taken when the patient was awake and the supine IOP as measurements taken when the patient was asleep for each individual. The reproduced diurnal IOP was composed of 12 measurements that included 2 to 4 IOP levels measured with the patients supine and the rest while they were sitting. RESULTS: The peak of sitting diurnal IOP (mean +/- SD) for 148 patients was 16.0 +/- 2.7 mm Hg, which was significantly lower than the peak of supine IOP (18.9 +/- 3.9 mm Hg) or the reproduced IOP (17.5 +/- 3.6 mm Hg) (P<.001 for both comparisons). The average reproduced IOP at each measurement time peaked at 3 am during sleep; with sitting diurnal IOP or supine diurnal IOP, the peak IOPs were at noon. Twenty-nine patients (20%) with an IOP less than 21 mm Hg during clinic hours had a reproduced IOP of 21 mm Hg or greater while asleep, compared with only 5 patients (3%) when the patients were sitting only. CONCLUSIONS: In patients with primary open-angle glaucoma and IOPs less than 21 mm Hg during clinic hours, 20% of patients had a reproduced IOP of 21 mm Hg or greater, compared with only 3% who had an IOP of 21 mm Hg or greater while sitting. Intraocular pressures peaked in most patients during sleep.

Adolescent↗
PubMed2000

Reproducibility of home spirometry in children with newly diagnosed asthma.

We evaluated the reproducibility of home spirometry in 110 children aged 5-10 years with newly diagnosed asthma according to the criteria proposed by the American Thoracic Society (level of reproducibility < or = 5%). Flow-volume spirometry was performed in the clinic. Spirometric values were then monitored twice daily at home for 24 days (mean), using a novel device, the Vitalograph(R) Data Storage Spirometer (Vitalograph, Ltd., Buckingham, UK). During this period, the mean (SD) compliance in performing the spirometric tests was 94% (7). In the whole study population, the mean (SD) percentage of reproducible spirometric measurements was 77% (17), although there was wide individual variation (range, 21-100%). In the 5-6-year age group (n = 51), the mean (SD) percentage of reproducible spirometric values was 72.8% (18.6), in the 7-8-year group (n = 38) 77.1% (13.8), and in the 9-10-year group (n = 21) 84. 5% (13.7) analysis of variance, P = 0.02). We conclude that most of the children aged 5-10 years could perform reproducible spirometric tests during home monitoring, although there was wide individual variation. Younger children were less likely to perform reproducible tests than older children. However, a considerable proportion of the measurements (23%) did not meet the criteria of acceptable reproducibility. In order to improve the quality of home monitoring, nonreproducible measurements should be excluded from the calculations.

Anti-Asthmatic Agents↗
PubMed1996

Reproducibility of head-up tilt test in patients with syncope.

As the head-up tilt test (HUT) is employed to verify the efficacy of undertaking a treatment, we prospectively evaluated the reproducibility of positive and negative results, as well as that of the response type in 64 consecutive patients (mean age 34.6 +/- 22.9 years) with syncope of unknown cause. Two HUTs (60 min, 75 degrees), separated by an interval of 9.77 +/- 8.21 days, were performed on each patient. Positive responses were reproduced in the second HUT in 54.5% of the patients. A greater reproducibility (84.3%) was observed for negative responses. Of the 31 patients with a negative first test, 5 had a positive response during the second HUT. Using a multivariate analysis, no clinical variable correlated with the reproducibility of positive or negative results. Likewise, neither arterial pressure nor heart rate observed during the test were correlated with reproducibility. Of 18 patients who reproduced positive responses, 12 (66.6%) did so with the same response modality. In three patients with documented monomorphic sustained ventricular tachycardia, which was hemodynamically well tolerated, and in one patient with temporal spike wave activity in the electroencephalogram, HUT was also positive. It was concluded that the low reproducibility of HUT limits its usefulness as a tool for evaluating treatment efficacy. The variability of the type of response suggests a common mechanism leading to cardioinhibitory and vasodepressor reactions. A positive result in only the second study shows the rationale of performing two tests when the first one is negative.

Adolescent↗
PubMedDate not supplied

Measurement of regional aortic compliance by MR imaging: a study of reproducibility.

The reproducibility of MR imaging for the measurement of aortic compliance was studied in 47 healthy volunteers. Long and short term reproducibility and intraobserver variability were tested. The method was modified to improve image quality and short term reproducibility and intraobserver variability retested. For comparison, spin echo imaging was compared with cine gradient echo imaging. Initial long term reproducibility showed a mean difference (+/-SE) of 3% (+/- 7%) with 95% confidence interval (CI) for limits of agreement of +/- 69%. Short term reproducibility (7% +/- 6%, 95% CI +/- 46%) and intraobserver variability (1% +/- 2%, 95% CI +/- 31%) were better. After modification of the technique and optimization of image quality, both short term reproducibility and intraobserver variability improved (0% +/- 3%, 95% CI +/- 17% and 5% +/- 2%, 95% CI +/- 16% respectively). Aortic compliance can be measured using spin echo MR imaging with good reproducibility provided care is taken to obtain good quality images with high spatial resolution.

Adult↗
PubMed2004

Quantitative 1H-MRS of healthy human cortex, hippocampus, and thalamus: metabolite concentrations, quantification precision, and reproducibility.

PURPOSE: To evaluate metabolite concentrations in cortical gray matter, hippocampus, and thalamus of healthy adults, and to investigate precision and reproducibility of quantitative proton magnetic resonance spectroscopy (1H-MRS) in these gray matter regions. MATERIALS AND METHODS: Quantitative single-voxel short echo-time spectra were obtained from healthy human cortex, hippocampus, and thalamus. Subjects were examined twice. Metabolite concentrations, quantification precision, and reproducibility were determined. RESULTS: There were no significant differences between test and retest measurements. Regional differences were observed with respect to metabolite concentrations, quantification precision, and reproducibility. Quantification precision and reproducibility of N-acetylaspartate and N-acetyl aspartylglutamate (tNAA), creatine and phosphocreatine (tCr), choline-containing compounds (Cho), and myo-inositol (myo-Ins), were better than those of glutamate (Glu) and glutamine (Gln). Generally, precision and reproducibility were better in cortex than in hippocampus or thalamus. The quantification precision was shown to correlate both with reproducibility and spectral linewidth. CONCLUSION: The reliability of quantitative MRS depends on the metabolite concerned, its concentration, and on the brain area studied. Moreover, the quantification precision of a metabolite in a single spectrum appears to be a reliable measure for its reproducibility in a longitudinal study.

Adult↗