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Results for “Reproducibility”

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At least 1,063 records · Page 59Linked to original sources

PubMed2000

The reproducibility of multi-joint isokinetic and isometric assessments in a healthy and patient population.

DESIGN: Test re-test reliability design. OBJECTIVE: To determine a reproducible protocol for lower limb simultaneous multi-joint assessments on a healthy group of subjects and a patient group with patellofemoral pain syndrome. BACKGROUND: Although single joint assessment with isokinetic dynamometers has been utilised for many years in knee rehabilitation, simultaneous multi-joint assessment has not attracted comparable attention. METHODS: Twenty healthy volunteers mean age 30.6 years and 16 patients with patellofemoral pain syndrome mean age 29.6 years performed isometric maximum voluntary contractions and concentric isokinetic contractions of the lower limb. Data were collected on three separate days for resultant extension/flexion peak torque, average power and total work which were analysed using intraclass correlation coefficients with a 95% level of confidence. RESULTS: In healthy subjects, intraclass correlation coefficients estimates were > or =0.75 for isokinetic peak torque and >0.83 for average power and total work. The intraclass correlation coefficients estimate for isometric peak torque extension was 0.82. In the patient group, intraclass correlation coefficients estimates were >0.82 for isokinetic peak torque and > or =0.75 for average power and total work. The intraclass correlation coefficients estimate for isometric peak torque extension was 0.89. Discarding the first session's data for both groups improved the intraclass correlation coefficients estimates for virtually all assessments. CONCLUSIONS: This study has demonstrated high reproducibility of lower limb multi-joint testing for peak torque, average power, and total work on healthy subjects and then has employed the protocol to demonstrate similarly high reliability on a patient group. It has also highlighted the need for a practice session before the data can be said to be reliable. RELEVANCE: Reliability studies often use healthy subject groups, which although useful, have limited relevance to patient populations. This study has not only gained comprehensive reproducibility data on multi-joint assessment in healthy subjects, it has also shown that multi-joint testing can be used safely and reliably in patients with patellofemoral pain syndrome. Clinicians may now be able to measure objectively lower limb function in this patient group both pre and post treatment.

Adult↗

PubMed1997

Three-dimensional ultrasound assessment of fetal liver volume in normal pregnancy: a comparison of reproducibility with two-dimensional ultrasound and a search for a volume constant.

The purposes of this study are to compare the reproducibility of two-dimensional ultrasound (2DUS) and three-dimensional ultrasound (3DUS) in the assessment of fetal liver volume (LV), and to test whether the fetal LV assessed by the traditional method with 2DUS is equal to that with 3DUS in normal pregnancy. If significantly different, we then try to calculate a new constant of fetal LV for the traditional equation from the LV values obtained with 3DUS. In total, 30 normal singleton fetuses with gestational ages ranging from 20 to 30 weeks were included for the reproducibility test and 55 cases ranging from 20 to 31 weeks gestation were enrolled for finding a new volume constant of LV. The results showed that 3DUS is superior to 2DUS in the reproducibility test of fetal LV assessment. Moreover, the LV assessed with the traditional 2DUS method (identified as LV_42) was significantly smaller than that measured with 3DUS (P < 0.001). If the traditional 2DUS equation is to be used, the multiplying factor in the equation for the calculation of LV should be modified to 0.55 (SE = 0.017, N = 55). With the new volume constant, the new derived LV with 2DUS (identified as LV 55) was not different from that with 3DUS (identified as LV_3D). In conclusion, we recommend that 3DUS, instead of 2DUS, should be used for reaching an accurate assessment of fetal LV. Otherwise, applying our new volume constant may be of help in detecting abnormal fetal liver growth when only 2DUS is available.

Female↗

PubMed2003

Three-dimensional evaluation of intra- and interfraction immobilization of lung and chest wall using active breathing control: a reproducibility study with breast cancer patients.

PURPOSE: A CT-based three-dimensional (3D) method was used to analyze the intra- and interfraction reproducibility of lung immobilization during moderate deep inspiration breath hold (mDIBH), defined as 75% of the maximal inspiration using an active breathing control (ABC) apparatus. METHODS AND MATERIALS: The ABC apparatus was used to immobilize the breathing motion with a computer-controlled valve. Immobilization of the lungs in breast cancer patients was used as a model to evaluate the reproducibility of mDIBH using the ABC apparatus. CT scans were acquired twice at mDIBH in the same session for 30 breast cancer patients. Twenty-three of them were immobilized with an alpha-cradle, of which 14 had a repeat scan at mDIBH 1-4 weeks later. Twelve of those patients received intensity-modulated radiotherapy to the left breast at mDIBH to displace the heart from the beam. The remaining patients were treated at free breathing, with either intensity-modulated irradiation to the whole breast or conformal partial breast irradiation. To remove the component of setup error, mDIBH scans were registered with respect to the vertebrae. The lungs and carina were auto-contoured to form 3D surfaces for each data set. The closest distance-to-agreement (DTA) for each point between the 3D surfaces of the corresponding CT scans was displayed on a 3D surface map. For analysis, each lung was divided along its inferior to superior extent into six regions, from the basal 10%, the next four consecutive 20% sections in height, to the last apical 10%. Likewise, the carina was divided into regions of the trachea and bifurcation. The mean and standard deviation (SD) of the DTA for each of these regions was computed. RESULTS: With the patient positioned in an alpha-cradle, the mean +/- SD intrafraction DTA was 1.5 +/- 1.4 mm for the left lung and 1.0 +/- 1.4 mm for the right lung. The corresponding values without the use of an alpha-cradle were significantly greater, with 1.9 +/- 2.1 mm and 2.2 +/- 2.2 mm for the left and right lung, respectively (p <0.005 for the SD of the left lung and p <0.0003 for the SD of the right lung). The interfraction DTA for the left and right lungs was 1.4 +/- 1.7 mm and 1.4 +/- 1.6 mm, respectively. The regional analysis demonstrated better immobilization for the upper two-thirds of the chest wall compared with that for the lung base. The DTA values obtained for the tracheal bifurcation were 0.9 +/- 0.8 mm for intrafraction and 1.4 +/- 1.0 mm for interfraction. CONCLUSION: The ABC device can be used to reduce respiratory motion at mDIBH in breast cancer patients or those patients who can perform the maneuver. This device demonstrated excellent intra- and interfraction reproducibility of chest wall and carina immobilization, especially when combined with alpha-cradle immobilization. Internal margins for suspended breathing can be extrapolated from these data for various anatomic regions within the lung and chest wall.

Breast Neoplasms↗

PubMed1997

Validity and reproducibility of self-reported age at menopause in women participating in the DOM-project.

OBJECTIVES: To study validity and reproducibility of self reported age at menopause. METHODS: Subjects were 1003 and 4892 Dutch women respectively aged 58-73, who participated in a population-based breast cancer screening project. The median time since menopause was 7 years for the validity study. The time span between the two questionnaires in the reproducibility study was 7-9 years. RESULTS: Of the women with a natural menopause, 70% recalled their age at menopause correctly to within one year. For women with a surgical menopause this percentage was 80%. The validity decreased with increasing number of years since menopause. Reproducibility to within one year was 71% for women with a natural menopause and 79% for women with a surgical menopause; 95% of the women were consistent in reporting whether they had had a natural or a surgical menopause. CONCLUSIONS: As a consequence of this misclassification, the effect of age at menopause may be underestimated in studies relating self reported age at menopause to disease occurrence or mortality.

Age Factors↗

PubMed1998

Reproducibility of phalanx osteosonography and relation with forearm peripheral quantitative computed tomography: single finger versus average measurement on the last four fingers.

The aim of this study was to evaluate the in vivo short-term reproducibility of amplitude-dependent speed of sound (AD-SOS) measured at the proximal phalanx, using an Igea DBM Sonic 1200 device, as well as its relationship with bone mineral density of the ultradistal radius, assessed using peripheral quantitative computed tomography (pQCT). In particular, the authors wished to evaluate whether average measurements on the last four fingers, as recommended by the manufacturer, yielded or not more information than measurements on one single finger. For the precision study, the authors carried out phalanx osteosonography ten times once every other day in ten healthy young women. To compare with pQCT of the radius, 37 women referred for screening of osteoporosis (mean age 60 years) were studied. AD-SOS was reported for each finger separately, as well as an average; pQCT (XCT 960 Stratec) yielded trabecular (BMDt); cortical (BMDc); and total (BMDtot) bone mineral densities, as well as the cortical area (Ac). The reproducibility of AD-SOS was significantly higher for the middle finger (mean coefficient of variation (CV) 1.1%) and the index than for the ring and small (mean CV 2.7%) finger. The middle finger consistently showed the best correlations with pQCT variables; the relationships involving BMDc (r = 0.54), BMDtot (r = 0.62) and Ac (r = 0.61) were stronger than that with BMDt (r = 0.34). The authors conclude that phalanx AD-SOS is moderately correlated with BMD of the ultradistal radius--at least when it includes the cortical component--and that reporting AD-SOS for the middle finger--instead of an average value--improves the reproducibility and possibly the relevance of phalanx osteosonography.

Adult↗

PubMedDate not supplied

Reproducibility of color Doppler flow quantification of aortic regurgitation.

The preferred method for quantification of aortic regurgitation severity with color Doppler echocardiography is the assessment of the ratio of jet diameter to left ventricular outflow tract diameter and jet area to left ventricular outflow tract area. However, the reproducibility of these measurements is not known and may limit its clinical application. This study was performed to identify sources of variability and reproducibility of the echocardiographic data. We examined 62 color Doppler echocardiographic examinations of patients showing isolated aortic regurgitation after human tissue valve implantation. The mean differences with standard deviations between paired measurements were calculated. The interobserver, intraobserver, and interframe variability showed a close agreement for the jet diameter and left ventricular outflow tract diameter measurements. The agreement for jet area and left ventricular outflow tract area measurements showed a small bias, but a large variance. The reproducibility of jet-left ventricular outflow tract diameter is better than the jet-left ventricular outflow tract area measurement and is more accurate to assess the severity of aortic regurgitation from color Doppler images.

Adult↗

PubMed2003

Reproducibility and relative validity of the short questionnaire to assess health-enhancing physical activity.

BACKGROUND/OBJECTIVES: The purpose of this study is to determine reproducibility and relative validity of the Short QUestionnaire to ASsess Health-enhancing physical activity (SQUASH). METHODS: Participants (36 men and 14 women, aged 27-58) were asked to complete the SQUASH twice with an inbetween period of approximately 5 weeks. In addition, participants wore the Computer Science and Applications (CSA) Activity Monitor for a 2-week period following the first questionnaire. RESULTS: The Spearman correlation for overall reproducibility of the SQUASH was 0.58 (95%-CI 0.36-0.74). Correlations for the reproducibility of the separate questions varied between 0.44 and 0.96. Spearman's correlation coefficient between CSA readings and the total activity score was 0.45 (95%-CI 0.17-0.66). CONCLUSIONS: In conclusion, the SQUASH is a fairly reliable and reasonably valid questionnaire and may be used to order subjects according to their level of physical activity in an adult population. Because the SQUASH is a short and simple questionnaire, it may proof to be a very useful tool for the evaluation of health enhancing physical activity in large populations.

Adolescent↗

PubMed2002

Reproducibility of home, ambulatory, and clinic blood pressure: implications for the design of trials for the assessment of antihypertensive drug efficacy.

BACKGROUND: The aims of this study were to compare the reproducibility of blood pressure (BP) measured in the clinic (CBP), at home (HBP), and by ambulatory monitoring (ABP), and to assess its implications on the accuracy of antihypertensive drug trials. METHODS: A total of 133 untreated subjects with elevated CBP were assessed with repeated measurements of CBP (five visits within 3 months), HBP (6 workdays within 2 weeks), and ABP (twice, 2 weeks apart). The reproducibility of CBP (one visit), HBP (2 days), and ABP (24 h) was quantified using the SD of differences (SDD) between repeated measurements. The number of subjects required in a comparative trial of two drugs was calculated for each measurement method. RESULTS: We found that HBP provided the lowest SDD values (6.9/4.7 mm Hg, systolic/diastolic, compared with 8.3/5.6 for ABP and 11.0/6.6 for CBP). For a parallel trial aiming to detect a difference in the effect of two drugs of 10 mm Hg systolic BP, 51 subjects would be required when using CBP compared with 29 using ABP and 20 using HBP (73, 53 and 37 subjects, respectively, for the detection of a 5 mm Hg difference in diastolic BP). CONCLUSIONS: The study shows that HBP seems to have superior reproducibility compared with both CBP and ABP. In addition, HBP can improve the accuracy of antihypertensive drug trials, thereby reducing the sample size required.

Adult↗

PubMed2000

Rapid and reproducible deactivation of rhodopsin requires multiple phosphorylation sites.

Efficient single-photon detection by retinal rod photoreceptors requires timely and reproducible deactivation of rhodopsin. Like other G protein-coupled receptors, rhodopsin contains multiple sites for phosphorylation at its COOH-terminal domain. Transgenic and electrophysiological methods were used to functionally dissect the role of the multiple phosphorylation sites during deactivation of rhodopsin in intact mouse rods. Mutant rhodopsins bearing zero, one (S338), or two (S334/S338) phosphorylation sites generated single-photon responses with greatly prolonged, exponentially distributed durations. Responses from rods expressing mutant rhodopsins bearing more than two phosphorylation sites declined along smooth, reproducible time courses; the rate of recovery increased with increasing numbers of phosphorylation sites. We conclude that multiple phosphorylation of rhodopsin is necessary for rapid and reproducible deactivation.

Animals↗

PubMed2000

The validity and reproducibility of clinical assessment of nutritional status in the elderly.

Malnutrition is an important predictor of morbidity and mortality. In the non-elderly, a subjective global assessment (SGA) has been developed. It has a high inter-rater agreement, correlates with other measures of nutritional status, and predicts subsequent morbidity. The purpose of this study was to determine the validity and reproducibility of the SGA in a group of patients older than 70 y of age. Consecutive patients from four geriatric/rehabilitation units were considered for the study. Each patient underwent independent nutritional assessments by a geriatrician and senior medical resident. At the completion of the assessment, skinfold caliper measurements were obtained and the patient reclassified according to the results, which were then compared with objective measures of nutritional status. Six-month follow-up was obtained on all patients. The agreement between the two clinicians was 0.48 +/- 0.17 (unweighted kappa), which represents moderate agreement and is less than the reported agreement in nonelderly subjects. Skin calipers improved the agreement between clinicians but did not improve the correlation with other nutritional markers or prediction of morbidity and mortality. There was a correlation between a patient's severely malnourished state and mortality. In addition, patients with a body mass index (BMI) of <75% or >150% age/sex standardized norms had an increased mortality. The SGA is a reproducible and valid tool for determining nutritional status in the elderly. The reproducibility is less than in the nonelderly, which may relate to changes in body composition or ability to obtain an accurate nutritional history.

Aged↗

PubMed2001

Reproducibility of in vivo brain measures of 5-HT2A receptors with PET and.

The test/retest reproducibility of brain measures of 5-HT2A receptors with positron emission tomography (PET) and [18F]deuteroaltanserin was examined in a group of eight healthy human subjects. PET measures of 5-HT2A receptors were obtained under an equilibrium paradigm, with a 40-min PET acquisition starting approximately at 300 min (308+/-11 min) after bolus plus constant infusion of the radiotracer. Three brain outcome measures were obtained at equilibrium, V(3) (ratio of specific brain uptake to free parent plasma concentration of radiotracer), V(3)' (ratio of specific brain uptake to total parent plasma concentration) and RT (ratio of specific to non-displaceable brain uptakes). V(3)' and RT had high test/retest reproducibility, as measured by mean intra-subject% change for cortical brain areas of 14.1 and 11.0%, respectively. They also had high reliability, as measured by mean intra-class correlation coefficients (ICC) for cortical brain areas of 0.86 and 0.88, respectively. V(3) had low test/retest reproducibility, due to high variability in the measures of free parent tracer in plasma. This study supports the feasibility of equilibrium imaging of 5-HT2A receptors with PET and [18F]deuteroaltanserin. The equilibrium imaging method with [18F]deuteroaltanserin allows a single acquisition and blood measurement to provide an image whose pixel values equal a receptor volume of distribution. Since the single image pixel values are proportional to receptor densities, the images can be used in pixel-by-pixel statistical methods, such as SPM, to assess the distribution and density of 5-HT2A receptors in neuropsychiatric disorders.

Adult↗

PubMed1997

Reproducibility of normal facial motor nerve conduction studies and their relevance in the electrophysiological assessment of peripheral facial paralysis.

To determine the intra-examiner intertrial reproducibility of normal facial motor nerve conduction studies (FNCS) and their relevance in electrophysiological assessments of peripheral facial paralysis, 52 patients with acute unilateral Bell's palsy were examined on two separate occasions 1 months apart. Three electroneurographic methods were assessed. On the unaffected side of the face, FNCS are reliable when performed by a single examiner over time. Nevertheless, compound muscle action potential (CMAP) baseline-to-peak and peak-to-peak amplitude showed a rather high intertrial variability. Reproducibility of the assessed surface electrode recording procedures was similar. Regarding the affected side, in patients with mild axonotmesis of the facial nerve variations of electroneurographic parameters 1 months apart fell within the range of normal intertrial variability. In patients with severe or moderate axonotmesis, the distal latency and the M wave amplitude variations showed significant intertrial variations. Reproducibility of FNCS appears to be similar to that found in limb motor nerves. Normal variability curtails the sensitivity of FNCS in detecting mild facial nerve axonotmesis, although this technique remains useful in severe cases.

Action Potentials↗

PubMed1997

Reproducibility of the HERITAGE Family Study intervention protocol: drift over time.

PURPOSE: The primary goal of the HERITAGE Family Study was to document the role of the genotype in the response to aerobic exercise training. Toward this end, nuclear families were enrolled in a 20-week exercise training program, with a large variety of tests performed before and after the training. Since study drift has the potential to adversely affect the results, reproducibility and potential bias over six consecutive 4-month periods were examined for selected test. METHODS: Intraclass correlations (ICC), technical errors (TE), coefficients of variation within subject (CV), and means were calculated with use of the pretraining test results for each of the six time periods. To check for homogeneity, hypothesis tests were performed on the intraclass correlations and means. If homogeneity was not found across all six periods, further tests were performed to assess differences between pairs of time periods. RESULTS: There was little evidence for real drifts in reproducibility, with most tests having ICCs of 0.8 or better. Only a few tests showed any change over time, and in no case was there evidence of a systematic drift in mean values. CONCLUSIONS: Overall, the reproducibility of the HERITAGE Family Study tests and assays considered in this paper was found to be very good, with no evidence of any systematic drift over time.

Adolescent↗

PubMed2003

From diffusion tractography to quantitative white matter tract measures: a reproducibility study.

The aim of this study is to propose methods for assessing the reproducibility of diffusion tractography algorithms in future clinical studies and to show their application to the tractography algorithm developed in our unit, fast marching tractography (FMT). FMT estimates anatomical connectivity between brain regions using the information provided by diffusion tensor imaging. Three major white-matter pathways were investigated in 11 normal subjects--anterior callosal fibers, optic radiations, and pyramidal tracts. FMT was used to generate maps of connectivity metric, and regions of voxels with highest connectivity metric to an anatomically defined starting point were identified for each tract under investigation. The reproducibilities of tract-"normalized" volume (NV) and fractional anisotropy (FA) measurements were assessed over such regions. The values of tract volumes are consistent with the postmortem data. Coefficients of variation (CVs) for FA and NV ranged from 1.7 to 7.1% and from 2.2 to 18.6%, respectively. CVs were lowest in the anterior callosal fibers (range: 1.7- 7.8%), followed by the optic radiations (range: 1.2-18.6%) and pyramidal tracts (range: 2.6-15.5%), suggesting that fiber organization plays a role in determining the level of FMT reproducibility. In conclusion, these findings underline the importance of assessing the reliability of diffusion tractography before investigating white matter pathology.

Adult↗

PubMedDate not supplied

Myocardial infarction in the C57BL/6J mouse: a quantifiable and highly reproducible experimental model.

INTRODUCTION: The laboratory mouse is a powerful tool in cardiovascular research. In this report, we describe a method for a reproducible mouse myocardial infarction model that would allow subsequent comparative and quantitative studies on molecular and pathophysiological variables. METHODS: (A) The distribution of the major coronary arteries including the septal artery in the left ventricle of the C57BL/6J mice (n=20) was mapped by perfusion of latex dye or fluorescent beads through the aorta. (B) The territory of myocardial infarction after the ligation of the most proximal aspect of the left anterior descending (LAD) coronary artery was quantified. (C) The consistency in the histological changes parallel to the infarction at different time points was analyzed. RESULTS: (A) The coronary artery tree of the mouse is different from human and, particularly, in regard to the blood supply of the septum. (B) Contrary to previous belief, the septal coronary artery in the mouse is variable in origin. (C) A constant ligation of the LAD immediately below the left auricular level ensures a statistically significant reproducible infarct size. (D) The ischemic changes can be monitored at a histological level in a way similar to what is described in the human. CONCLUSION: We illustrate a method for maximal reproducibility of experimental acute myocardial infarction in the mouse model, due to a consistent loss of perfusion in the lower half of the left ventricle. This will allow the study of molecular and physiological variables in a controlled and quantifiable experimental model environment.

Animals↗

PubMedDate not supplied

Interpretive reproducibility of stress Tc-99m sestamibi tomographic myocardial perfusion imaging.

BACKGROUND: Observer variability has been shown with interpretation of planar thallium-201 images. The interpretive reproducibility of technetium-99m sestamibi tomographic imaging is unknown. This study evaluated the interpretive reproducibility of interpretable Tc-99m sestamibi tomographic images among nuclear cardiologists with a wide range of training and experience. METHODS: Three experienced readers (EX) and 3 less-experienced readers (LEX) interpreted 138 exercise and rest Tc-99m sestamibi tomographic images (101 were abnormal in patients with coronary artery disease [CAD], 37 were normal in patients with <5% likelihood of CAD) twice in random sequence without clinical data. Images of good to excellent quality were randomly selected from a database at 2 nuclear cardiology laboratories. Intraobserver and interobserver agreement for global, left anterior descending (LAD) territory, non-LAD first (normal/abnormal) and second (normal/fixed/reversible) order, and defect extent (normal/single-vessel CAD/multi-vessel CAD) were assessed with percent agreement and Cohen's kappa (kappa) statistic. RESULTS: With regard to intraobserver agreement, first and second order ranged from 87% to 94% and 80% to 90% for global, 82% to 96% and 78% to 95% for LAD, and 88% to 91% and 80% to 90% for non-LAD, respectively. Defect extent ranged from 75% to 90%. There were no differences between EX and LEX for global and non-LAD first and second order, LAD first order, and defect extent. LAD second order was 93% for EX compared with 88% (P = .015) for LEX. With regard to interobserver agreement, first and second order ranged from 73% to 89% and 64% to 85% for global, 73% to 93% and 69% to 91% for LAD, and 76% to 88% and 68% to 84% for non-LAD, respectively. Defect extent ranged from 61% to 82%. Global first and second order ranged from 85% to 87% and 78% to 82% for EX compared with 73% to 84% and 64% to 79% for LEX. LAD first and second order ranged from 89% to 91% and 88% to 89% for EX compared with 73% to 91% and 69% to 70% for LEX. Non-LAD first and second order ranged from 82% to 86% and 76% to 77% for EX compared with 76% to 86% and 68% to 81% for LEX. Defect extent ranged from 69% to 75% for EX compared with 59% to 77% for LEX. CONCLUSIONS: There is moderate to excellent interpretive reproducibility with stress Tc-99m sestamibi SPECT imaging among nuclear cardiologists with a wide range of training and experience.

Coronary Circulation↗

PubMed2000

Felodipine improves left ventricular emptying in patients with chronic heart failure: V-HeFT III echocardiographic substudy of multicenter reproducibility and detecting functional change.

BACKGROUND: The echocardiographic substudy of the Vasodilator-Heart Failure Trial III (V-HeFT III) aimed to determine if felodipine treatment in patients with heart failure who were taking an angiotensin-converting enzyme inhibitor had a favorable effect on left ventricular (LV) structure and function. Earlier V-HeFT trials showed that hydralazine-isosorbide dinitrate improved ejection fraction (EF) and survival, whereas enalapril achieved greater survival with smaller increases in EF. Would the combination of a potent vasodilator and enalapril produce greater improvements in function and survival? METHODS AND RESULTS: Doppler-echocardiographic data were collected from 260 males with heart failure who were randomized to felodipine or a placebo. Mean intrasubject differences between baseline, at 3 months, and at 12 months were compared. Intersite and intrareader reproducibilities were measured from duplicate recordings and readings. At 3 months, no changes in ultrasound variables from baseline occurred in either group. At 12 months, felodipine patients achieved greater increases in EF, shortening of LV end-systolic length, and increases in stroke volume index. Reproducibility coefficients of variation were 7.4% (EF), 6.0% (end-diastolic length), and 13.0% (stroke volume index). CONCLUSIONS: The echocardiographic substudy showed that felodipine, added to heart failure therapy, increased EF, shortened end-systolic length, and increased stroke volume index. The changes were small and confirmed that reproducibility from multiple laboratories can be coordinated into a useful research tool.

Calcium Channel Blockers↗

PubMed2004

Reproducibility of response to nasal lysine-aspirin challenge in patients with aspirin-induced asthma.

BACKGROUND: Peak nasal inspiratory flow (PNIF) and acoustic rhinometry objectively measure the effects of nasal provocation testing. Although the latter is conventionally used in nasal lysine-aspirin challenge, use of the former in aspirin-induced asthma (AIA) has never been evaluated. OBJECTIVE: To evaluate the reproducibility of PNIF and acoustic rhinometry following nasal lysine-aspirin challenge in AIA. METHODS: Fourteen patients with a clear-cut history of AIA underwent nasal lysine-aspirin challenge at 2 separate visits 1 week apart. Both PNIF and minimum cross-sectional area (MCA) were measured using acoustic rhinometry for 120 minutes following standard nasal lysine-aspirin challenge (25 mg). RESULTS: Prechallenge values were not significantly different at visit 1 vs visit 2 for mean [SEM] PNIF (128 [13] vs 127 [9] L/min) and MCA (6.89 [0.51] vs 6.94 [0.57] cm2). The mean (SEM) maximum percent PNIF change from baseline for visit 1 and visit 2 was -42 (5) and -42 (6), respectively, and the mean (SEM) average percent PNIF change from baseline was -25 (4) and -25 (6), respectively. The mean (SEM) maximum percent MCA change from baseline for visit 1 and visit 2 was -49 (4) and -48 (3), respectively, and the mean (SEM) average percent MCA change from baseline was -25 (8) and -24 (4), respectively. Coefficients of variation for maximum and average responses were 2.3% and 6.5%, respectively, for PNIF and 7.4% and 16.1% for MCA. CONCLUSIONS: Measurement of PNIF following nasal lysine-aspirin challenge is a simple and reproducible alternative to acoustic rhinometry, with maximum response being a more reproducible outcome measure than average response.

Adrenal Cortex Hormones↗