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PubMed2000

Reproducibility and instrument validity of a new ultrasonography-based system for measuring cervical spine kinematics.

OBJECTIVE: To report instrument validity of CMS 70P, a new ultrasonography-based system for spatial kinematic analysis of the spine and its application in studying the reproducibility of cervical motion findings in healthy subjects. BACKGROUND: Reproducibility of cervical motion has been investigated using various instruments and consisting in most cases of short test-retest time intervals of between minutes to days. METHODS: Performance of the instrument was validated against a digital inclinometer, at ranges of motion compatible with actual cervical motion. To study reproducibility, 25 healthy individuals, 22 women and 3 men aged 26-48 were tested twice within an average time interval of 3.3 weeks. Performed in the seated position and at a self-determined pace, cervical motion was defined in terms of head motion relative to a sternal (reference) system, in all six primary motions: flexion, extension, right rotation, left rotation, right lateral flexion and left lateral flexion. RESULTS: The system exhibited excellent agreement with the digital inclinometer, establishing its instrument validity for testing cervical motion. No significant differences were indicated between the test and retest for both the net maximal displacements and average velocities. The correlation coefficients for the single plane motions (e.g. flexion+extension) were higher than those derived for the primary motions, and ranged between 0.78 (sagittal plane) and 0.88 (frontal plane). The magnitude of the standard error of the measurement reflected the same trend with the lowest value recorded for the frontal plane. The self-selected velocity at which these motions were performed was similar in the frontal and saggital planes but was significantly higher for the transverse plane (rotations). CONCLUSIONS: This study indicates that spanned over time intervals that are measured in weeks, cervical motion findings derived from the CMS 70P are well reproducible. Findings also imply the need for a more stringent control of subject positioning and stabilization. RELEVANCE: Reduction of range of motion and average is typically observed in various pathologies of the cervical spine and is regarded, together with pain, as a major impairment. Therefore, valid assessment of cervical motion which is essential for follow-up and treatment outcome strongly depends on reproducibility of the findings. This study indicates that acceptable reproducibility is maintained over periods of time which are clinically meaningful using the system described herewith.

Adult↗
PubMed2002

Measures of low back function: a review of reproducibility studies.

OBJECTIVE: The objective of the present study was to make a systematic literature review with preset quality criteria concerning reproducibility of the tests of the low back regarding strength, endurance and range of motion. DESIGN: Literature in Medline and local databases was reviewed for articles concerning the reproducibility of strength, endurance, and range of motion measurements. BACKGROUND: Measures of low back function are widely used, and are important for both clinical and research purposes in relation to low back problems. A review of the reproducibility of these tests has not previously been made. METHODS: After extensive discussion among all the authors, general evaluation parameters were defined for the quality assessment. Every study was graded from 0 to 2 for each parameter. Parameters evaluated were: number of subjects, subject description, method description, test/retest interval, description of results, and statistics. RESULTS: The literature search revealed a total of 79 studies. Most studies suffered from methodological weaknesses and only eleven studies received ten or more quality points (maximum 14). The results from the highest graded studies are highlighted. CONCLUSIONS: It may be concluded that there is a considerable lack of information about the reproducibility of functional measures for the low back, and therefore a recommendation for consensus is difficult. However, most tests performed in the sagittal plane are reliable for use on groups. RELEVANCE: Measures of low back function are thought to be of great importance for clinicians, and low back researchers in general. A review of reproducibility will be helpful both as a survey of tests, and to provide information on the usefulness in relation to the level of reproducibility.

Biomechanical Phenomena↗
PubMed2002

Reproducibility of pain measurement and pain perception.

The reproducibility of both the conscious experience of pain and the reproducibility of psychophysical assessments of pain remain critical, yet poorly characterized factors in pain research and treatment. To assess the reproducibility of both the pain experience and two methods of pain assessment, 15 subjects evaluated experimental heat pain during four weekly sessions. In each session, both brief (5s) and prolonged (90s) heat stimuli were utilized to determine effects of stimulus duration on reproducibility. Multiple presentations of the brief heat stimuli in each session were used to evaluate effects of response averaging. Both visual analog scales (VAS) and randomized verbal descriptor scales (VDS) were employed to better distinguish variations in the pain experience from variations in pain scale usage. Subjects also rated the intensity of visual stimuli in order to provide an independent assessment of the session-to-session variation in the use of both types of scales. Within-subjects analyses revealed that ratings of visual stimuli exhibited significantly less session-to-session variation than ratings of heat pain. Thus, pain perceptions were more variable than perceptions of visual stimuli after controlling for session-to-session variations in scale usage. Comparisons between scales indicated that intensity ratings acquired with the VAS had significantly smaller session-to-session variation than those acquired with the VDS, although VDS ratings were spread across a larger range of the scale. For both scales, analyses of the effects of stimulus averaging and stimulus duration revealed that averaging multiple assessments of the same stimulus substantially reduces session-to-session variation and that multiple assessments of brief stimuli produce responses which are more reproducible than a single presentation of a prolonged stimulus. However, the VAS was significantly more sensitive to small differences in perceived pain intensity and pain unpleasantness, and did not exhibit some of the order effects present with the VDS. Taken together, these results indicate that the reproducibility of psychophysical ratings of pain can be maximized: (1) by averaging responses to multiple, brief stimuli; (2) by providing subjects with a training period distinct from the study period; and (3) by ensuring that interpretation of scale parameters remains constant over time. Thus, although the experiences of both experimental and clinical pain are highly variable, pain assessment procedures can be structured to minimize session-to-session variability.

Adult↗
PubMed1998

Within-subject reproducibility of visual activation patterns with functional magnetic resonance imaging using multislice echo planar imaging.

Within-subject reproducibility of visual brain activation using multislice echo planar functional magnetic resonance imaging (fMRI) was tested. Ten healthy subjects underwent fMRI with visual stimulation on three occasions: two studies in one scanning session (without repositioning); and a third study 1 h to 2 weeks later. Following a three-dimensional matching procedure, activation was measured and compared between sessions on a voxel-by-voxel basis. Data were filtered to full-width-at-half-maximum of 4.0 x 4.0 x 5.0 mm and a conservative Bonferroni-corrected significance threshold was applied to correlation maps. For reproducibility, change in centre of mass of the activated volume, a ratio of the number of pixels and a ratio of the number of overlapping pixels was calculated. Further, reproducibility was tested varying significance thresholds and at different filter widths. Average changes in centre of mass of the activated volume were 2.63 and 3.96 mm between Studies 1 and 2 and 1 and 3, respectively. The reproducibility of the number of activated voxels was 90% and 88% (Studies 1 and 2 and 1 and 3). The ratio of overlapping pixels was 74% between Studies 1 and 2 and 64% between Studies 1 and 3. Varying the significance threshold showed that at a certain range, the overlap reached a maximum, and increasing the filter widths increased reproducibility. It is concluded that fMRI with visual stimulation can be used to measure brain activity with reasonably good reproducibility on a routine clinical system equipped with echo planar imaging. Difficulties remain in separating the contribution of motion, repositioning errors, and true physiological changes.

Adolescent↗
PubMed1999

Fifteen-year reproducibility of natural head posture: A longitudinal study.

Natural head posture continues to be widely used as the logical reference position for the evaluation of craniofacial morphology. The basic underlying premise is that the long-term clinical reproducibility (variability) of natural head posture is significantly less than the variability of conventional reference planes with respect to the vertical. This study reports the 15-year longitudinal reproducibility of natural head posture. Twenty Chinese adults in Hong Kong, who had initial natural head posture radiographs at age 12 years, were followed up and had repeated cephalograms after 15 years. The method error (reproducibility) after 15 years was 2.2 degrees, which compared favorably with the 5-year reproducibility (method error = 3.0 degrees ) and the 5 to 10 minutes reproducibility (method error = 1.9 degrees ). The individual variability of natural head posture reproducibility increased slightly over time. After 15 years the variance of natural head posture (4.8 degrees [= 2.2(2)]) remains significantly less than the variance of intracranial reference planes to the vertical (25 degrees to 36 degrees ). Cephalometric analyses based on natural head posture therefore remain valid over time.

Adult↗
PubMed1999

Reproducibility of pulsed wave tissue Doppler echocardiography.

Four hundred and eighty paired recordings obtained from 16 patients (55 +/- 10 yrs; 10 men, 6 women) were analyzed to determine the reproducibility of both acquiring and measuring myocardial velocities recorded by tissue Doppler echocardiography. To assess intraobserver variability, 1 observer recorded and measured the data twice, from the same patients, and to assess interobserver variability, patients were examined by 2 independent observers. For the left ventricle, intraobserver reproducibility was higher when assessing long-axis velocities (+/- 10% to 16%) than short-axis velocities (+/- 14% to 24%). For the right ventricle, intraobserver reproducibility was high for the tricuspid annulus (+/- 9% to 15%), but unsatisfactory for the right ventricular anterior wall (+/- 21% to 25%). The highest interobserver reproducibilities were obtained for systolic and diastolic velocities of the lateral mitral annulus (+/- 9% to 17%) and systolic velocity of the tricuspid annulus (+/-13%). Interobserver reproducibility of the ratio of early-to-late peak diastolic velocities was very low for all investigated sites (+/- 20% to 52%). With the use of current techniques and software, reproducibility of acquiring and measuring tissue Doppler echocardiography is suboptimal for both systolic and diastolic myocardial velocities.

Echocardiography, Doppler↗
PubMed1999

Reproducibility of surface EMG variables and peak torque during three sets of ten dynamic contractions.

The interpretation of the electromyogram (EMG) of dynamic contractions might be difficult because the movement per se introduces additional factors that could affect its characteristics. There is a lack of studies concerning the reproducibility of surface EMG registrations during dynamic contractions. The aim was to investigate the during-the-day reproducibility (using intra-class correlation; ICC) of the peak torque (PT) and the EMG variables (without removing the electrodes) of dynamic contractions. Ten healthy subjects performed three sets of 10 dynamic maximum right-knee extensions with a one-hour interval in between, using an isokinetic dynamometer and the PT was determined. EMG signals were recorded from the right vastus lateralis, rectus femoris and vastus medialis muscles using surface electrodes and the mean frequency of the power spectrum (MNF [Hz]) and the signal amplitude (RMS [microV]), were computed. The ability to relax in-between the maximum extensions was calculated as a ratio of the RMS during the passive flexion phase and the RMS during the active extension phase of each contraction cycle: the signal amplitude ratio (SAR). Both PT (ICC = 0.99) and RMS (ICC = 0.83-0.98) had good reproducibility. The reproducibility of MNF was good for all muscles when the mean of contraction nos.: 1-10 was used. Vastus lateralis had the highest ICC among the three muscles. The reproducibility of SAR was generally poor (ICC < 0.60). The present study showed good reproducibility for common EMG variables (MNF and RMS) obtained during maximum isokinetic contractions.

Adult↗
PubMed2003

Short- and long-term reproducibility of capsaicin cough challenge testing.

The tussive agent capsaicin has achieved common usage in clinical research because it induces cough in a safe, dose-dependent, and reproducible manner. However, the reproducibility of capsaicin challenge testing has been demonstrated only in the short term (study intervals of 20 min to 14 days). In the present study, evaluation of data from several hundred cough challenges performed in the author's laboratory yielded two groups of 40 subjects. In the short-term reproducibility group, subjects underwent cough challenge at an interval of 14 days. Subjects in the long-term reproducibility group were challenged at intervals of at least 6 months (mean 16.7+/-2.4 months, range 6-62 months). All subjects were healthy adult volunteers who underwent identical cough challenge testing, which involved inhalation of incremental, doubling concentrations (microM) of capsaicin until the concentrations inducing two or more (C(2)) and five or more coughs (C(5)) were reached. Results were evaluated in terms of the percentage of subjects whose repeat studies yielded C(2) and C(5) values within one and two doubling concentrations of the initial values. Overall, reproducibility was quite good, with 90-100% of challenges yielding C(2) and C(5) values within two doubling concentrations. Short-term reproducibility of C(5) was superior to that of C(2), suggesting that C(5) is the preferred end point for trials involving serial cough challenges performed within a 14-day period.

Administration, Inhalation↗
PubMed1997

Reproducibility of techniques using Archimedes' principle in measuring cancellous bone volume.

Researchers have been interested in developing techniques to accurately and reproducibly measure the volume fraction of cancellous bone. Historically bone researchers have used Archimedes' principle with water to measure the volume fraction of cancellous bone. Preliminary results in our lab suggested that the calibrated water technique did not provide reproducible results. Because of this difficulty, it was decided to compare the conventional water method to a water with surfactant and a helium method using a micropycnometer. The water/surfactant and the helium methods were attempts to improve the fluid penetration into the small voids present in the cancellous bone structure. In order to compare the reproducibility of the new methods with the conventional water method, 16 cancellous bone specimens were obtained from femoral condyles of human and greyhound dog femora. The volume fraction measurements on each specimen were repeated three times with all three techniques. The results showed that the helium displacement method was more than an order of magnitudes more reproducible than the two other water methods (p < 0.05). Statistical analysis also showed that the conventional water method produced the lowest reproducibility (p < 0.05). The data from this study indicate that the helium displacement technique is a very useful, rapid and reproducible tool for quantitatively characterizing anisotropic porous tissue structures such as cancellous bone.

Animals↗
PubMed2003

Reproducibility and repeatability: errors of three groups of physiotherapists in locating spinal levels by palpation.

Location of spinal levels by palpation is an essential part of physiotherapy assessment and treatment of spinal musculoskeletal conditions. This study aimed to (i) investigate the reproducibility and repeatability of three groups of physiotherapists in locating three randomly selected spinal levels by palpation, (ii) explore whether these groups were palpating similar points at each level, and (iii) investigate whether there were differences in palpation across the spinal levels tested. Reproducibility was estimated using a convenience sample of 30 physiotherapists: 13 undergraduate students, 10 clinicians, and seven manual therapists (MTs). Repeatability was investigated using six physiotherapists (two students, two clinicians and two MTs). Each therapist palpated the spinous processes (C5, T6, L5) once for reproducibility, and 10 times for repeatability, on each asymptomatic model. The skin overlying the spinal levels was marked with an invisible pen. Using an ultra-violet light, marks were transcribed onto transparent plastic strips for analysis, and the distances were measured with an electronic caliper. Repeated measures analyses of variance (ANOVA) indicated poor reproducibility across therapists at all spinal levels (F=18.43, P=0.001), but good repeatability within therapists (F=2.09, P=0.161). Students produced different mean locations of their palpatory marks from the other two groups in two spinal levels. Clinicians and MTs were more reproducible than students, and located similar levels. Palpation of L5 spinous process presented the most difficulty, for all groups. Further research is needed to compare different methods of palpation and explore whether reproducibility can be improved.

Adult↗
PubMed1998

Reproducibility of bipolar endocavitary electrogram measurements at sites of radiofrequency energy delivery in patients with the Wolff-Parkinson-White syndrome.

BACKGROUND: Radiofrequency ablation of atrioventricular accessory pathway is widely used to cure patients with the Wolff-Parkinson-White syndrome. The site of successful ablation is determined using electrophysiological parameters, endocavitary bipolar electrogram measurements being the most commonly used. Interobserver reproducibility of these measurements may limit the reliability of ablation criteria based upon bipolar measurements only but, to our knowledge, this reproducibility has not been evaluated so far. Such was the aim of this study. METHODS: Three independent observers reviewed the bipolar electrograms recorded at sites were radiofrequency energy was delivered (successfully or not) in 28 consecutive patients with the Wolff-Parkinson-White syndrome. In each tracing, 4 intervals were measured: (1) A0V0 (onset of the atrial electrogram to onset of the ventricular electrogram), (2) AaVa (activation time of the atrial electrogram to activation time of the ventricular electrogram), (3) V0-QRS (onset of the ventricular electrogram to onset of delta wave on the surface ECG) and (4) Va-QRS (activation time of the ventricular electrogram to onset of delta wave on the surface ECG). RESULTS: The interobserver reproducibility was low since only 50% of A0V0 intervals were measured with an interobserver difference lower than 10 ms and up to 43% of Va-QRS intervals were measured with an interobserver difference greater than 30 ms. The reproducibility of interval measurement was graded from the highest to the lowest as follows: A0V0, AaVa, V0-QRS and Va-QRS (Chi-square statistic, chi 2 = 71.72, p < 0.0001). Kappa values were lower than 0.40, indicating a poor interobserver reproducibility. CONCLUSIONS: Our study suggests that interobserver reproducibility of only bipolar electrograms interval measurements at sites of radiofrequency ablation of atrioventricular accessory pathway is poor, which limits the reliability of bipolar criteria to predict a successful ablation site.

Adult↗
PubMed2001

Smallest real difference, a link between reproducibility and responsiveness.

The aim of this study is to show the relationship between test-retest reproducibility and responsiveness and to introduce the smallest real difference (SRD) approach, using the sickness impact profile (SIP) in chronic stroke patients as an example. Forty chronic stroke patients were interviewed twice by the same examiner, with a 1-week interval. All patients were interviewed during the qualification period preceding a randomized clinical trial. Test-retest reproducibility has been quantified by the intraclass correlation coefficient (ICC). the standard error of measurement (SEM) and the related smallest real difference (SRD). Responsiveness was defined as the ratio of the clinically relevant change to the SD of the within-stable-subject test-retest differences. The ICC for the total SIP was 0.92, whereas the ICCs for the specified SIP categories varied from 0.63 for the category 'recreation and pastime' to 0.88 for the category 'work'. However, both the SEM and the SRD far more capture the essence of the reproducibility of a measurement instrument. For instance, a total SIP score of an individual patient of 28.3% (which is taken as an example, being the mean score in the study population) should decrease by at least 9.26% or approximately 13 items, before any improvement beyond reproducibility noise can be detected. The responsiveness to change of a health status measurement instrument is closely related to its test-retest reproducibility. This relationship becomes more evident when the SEM and the SRD are used to quantify reproducibility, than when ICC or other correlation coefficients are used.

Adult↗
PubMed1997

Intraimage reproducibility of measurements in the macular area using a computerized system.

An accurate analysis of the morphological changes which take place during pathological processes of the posterior pole is important for a correct diagnosis and therapeutic approach. The purpose of the study was to determine the intraobserver and interobserver reproducibility of the Image-net system 100 (Topcon, Japan) to take measurements on the retina. The program 'Linear/Areal Measurement functions' of Image-net system 100 which is an image digitalization technique, was tested. Twelve patients were consecutively selected from the patients of the Retina Center of the Department of Ophthalmology, University of Genoa. Three images of each eye were taken from each subject and only the best image was used in this study. The intraobserver and interobserver reproducibility of both the distance between two pre-set points (linear measurement), and the perimeter and area of preselected retinal zones were calculated. The repeatability (or intraobserver reproducibility) of the linear sizes was measured by the coefficient of variation and ranged from 0.32% to 7.38%, while the interobserver reproducibility ranged from 0.46% to 5.22%. The repeatability and reproducibility of the perimeters ranged from 0.72% to 9.63% and from 0.6% to 5.7%, respectively, while the repeatability and reproducibility of the areas ranged from 0.72% to 9.63% and from 0.6% to 5.7%, respectively. Although the results were quite good, the quality of the image of the fundus and the number of observers influenced the coefficient of variation; furthermore, the anatomy of the areas to be measured and the computer 'mouse' could increase the value of the coefficient of variation.

Angiography, Digital Subtraction↗
PubMed2002

Reproducibility of in vitro contracture test results in patients tested for malignant hyperthermia susceptibility.

BACKGROUND: The in vitro contracture test (IVCT) is the golden standard to diagnose malignant hyperthermia susceptibility (MHS). A high reproducibility is important for a high validity of a test. METHODS: We have therefore analyzed IVCT in 838 patients, investigated in two laboratories. Each halothane and caffeine test was performed in two muscle strips. The test results were analyzed with respect to reproducibility of abnormal outcomes within pairs of tested muscle strips and size of contractures, thresholds and quality criteria. The patients were tested according to the European Malignant Hyperthermia Group protocol (EMHG). To fulfill quality criteria in the EMHG protocol the twitch height should be 10 mN (1 g) or more. For the caffeine test a minimum contracture of 50 mN (5 g) or more at 32 mmol l-1 caffeine could be used as an alternative quality criterion. RESULTS: There was better reproducibility with larger contractures. The correlation between size of contractures and fraction of muscle strips with abnormal contractures was 0.77 or larger. Contractures < 5 mN (0.5 g) were reproducible in less than half of the tests. There was no difference in reproducibility or size of contractures between tests fulfillling all quality criteria and those not fulfillling these criteria. CONCLUSIONS: IVCT responses close to cut off limits, i.e. <5 mN (0.5 g) in the EMHG protocol, are less reproducible and must scientifically be considered as less reliable. The clinical cut off limits must remain unchanged for reasons of clinical safety. The outcome of quality measurements does not influence the test results.

Adult↗
PubMed2001

Relevance and reproducibility of patch-test reactions to corticosteroids.

We present our patch test findings with dermatocorticosteroids during the period 1995-1999. We retrospectively studied the % of doubtful and positive reactions to each allergen in our corticosteroid series and assessed the relevance of these reactions. To assess reproducibility, we retested 15 patients with doubtful or positive reactions in 1999. The % of + or ++ reactions on D2-D3 and D7 ranged from 0.0% to 0.9% for most of the compounds tested. Hydrocortisone acetate 1% alc.abs./DMSO 50/50 showed a much higher % of positive reactions. Most of these reactions were not relevant and therefore probably due to the irritant nature of the vehicle. An overall reproducibility of 47.2% was obtained. 100.0% of the non-reproducible patch test reactions were not relevant. Definite relevance was much higher in the reproducible + or ++ reactions than in the reproducible doubtful reactions: 100.0% and 18.2%, respectively. We conclude that the mean % of + and ++ reactions to the corticosteroid series on D2-D3 is 0.5%, with an overall reproducibility of 47.2%. Tixocortol pivalate and budesonide proved to be important markers for dermatocorticosteroid allergy.

Administration, Topical↗
PubMed1999

Reproducibility of ambulatory blood pressure monitoring in daily practice.

The reproducibility of ambulatory blood pressure monitoring (ABPM) was investigated in 45 untreated hypertensive patients in an out-patient clinic. Subjects with symptoms or diseases which could probably give rise to an increase in blood pressure (BP) variability were excluded. Patients underwent office BP (OBP) measurements and ABPM measurements with the Oxford Medilog device twice. The data were edited following previous set standards. Reproducibility of ABPM was good for the group: 24 h ABPM difference 0/2 mm Hg, standard deviation of the difference (SDD) 12/6 mm Hg for systolic BP and diastolic BP respectively. For OBP the difference between the two visits was 5/2 mm Hg with a SDD of 15/8 mm Hg. Intra-individual reproducibility was poor; almost half of the patients had a systolic difference of more than 10 mm Hg between both ABPM recordings. Reproduciblity of the day-night difference with a BP fall of at least 10% (dipper status) was moderate. About 60% of the subjects were dippers at one of the ABPM recordings but only 42% had a reproducible dip. Possible factors playing a role in the disappointing reproducibility of the ABPM recordings are the difference in daily activities between both recording days, decreased accuracy at higher BP, quality of sleep and the probable lower accuracy of the device during real ambulant conditions. In daily practice ABPM has no better reproducibility than OBP measurements, despite the larger number of measurements.

Adult↗
PubMed1998

How reproducible is bilateral forearm plethysmography?

AIMS: In studies using strain-gauge forearm plethysmography to measure changes in forearm blood flow (FBF) during intra-arterial infusions of vasoactive substances, measurements are often made in both arms simultaneously and the change in ratio of the infused and control arms used to express responses. However, the reproducibility of bilateral plethysmography in this setting has not been addressed in published studies. The unilateral technique remains in use, and forearm vascular resistance (FVR), an alternative method of expressing responses, is used by some investigators. We have assessed: (a) the intra-subject variability of bilateral FBF measurements (FBF ratios) at rest, after unilateral forearm exercise, and during intra-arterial infusions of vasoconstrictor substances; (b) whether bilateral plethysmography is more reproducible than unilateral plethysmography; and (c) the reproducibility of FVR (unilateral and bilateral). METHODS: Study 1 Nine healthy subjects attended 3 study days, 1 week apart. FBF was measured at rest and after 2 min of standardized unilateral forearm exercise; between-day intra-subject variability was expressed as coefficients of variation (CV) calculated using two-way analysis of variance (ANOVA). Study 2 Five healthy subjects attended 2 study days when FBF was measured during incremental infusions of noradrenaline (15, 30, 150, 300 pmol min[-1]) and angiotensin II (1, 5, 10, 50 pmol min[-1]); for each individual subject at each dose intra-subject variability was assessed using the difference between responses (percentage change from baseline) on days 1 and 2. RESULTS: Study 1 At rest, intra-subject variability (CV) of baseline FBF ratios was 19% compared with 31% (left) and 39% (right) for unilateral FBF measurements. After ipsilateral exercise, unilateral FBF measurements were more reproducible (32 vs 17%) than FBF ratios; by 20 min after exercise, the previous pattern had been re-established (19 vs 27%). Intra-subject variability (CV) of baseline FVR ratio and post-exercise FVR was 14%. Study 2 Inter-quartile ranges of the differences between responses on days 1 and 2 (FBF ratios vs FBF) were: angiotensin II 14 vs 18%; noradrenaline 16 vs 27%. CONCLUSIONS: FBF ratios are more reproducible than unilateral FBF measurements at rest (CV 19% vs 39%) and for measuring responses to intra-arterial infusions of vasoconstrictor substances. FVR may have a small reproducibility advantage. Non-experimental stimuli can cause significant and misleading changes in measured responses if unilateral measurements are used; it is therefore recommended that responses to intra-arterial infusions should be measured using bilateral forearm plethysmography with the results expressed as FBF ratios.

Angiotensin II↗
PubMed2003

Reproducibility of a four-point clinical severity score for glabellar frown lines.

BACKGROUND: Focal injections of botulinum toxin A are used successfully for the treatment of hyperkinetic facial wrinkles. Efficacy can be measured by several methods. However, so far none has been investigated for its reproducibility. Objectives To investigate the reproducibility of a clinical 0-3 score for glabellar frown lines. METHODS: In the first part of the study, a standardized photographic documentation of glabellar frown lines was produced. Based on the results of this phase, a consensus atlas of glabellar frown lines was developed and participants were trained using this atlas. In the main study, 50 standardized photographs were shown on two consecutive days to 28 dermatologists. The reproducibility of the score was investigated by conventional kappa statistics. RESULTS: In the main study, we found an unweighted kappa according to Fleiss of 0.62 for interobserver reproducibility. Intraobserver reproducibility showed an unweighted kappa according to Cohen of between 0.57 and 0.91 for each observer, and a weighted kappa according to Cicchetti and Allison of between 0.68 and 0.94. CONCLUSIONS: The clinical 0-3 score for glabellar frown lines shows a good inter- and intraobserver reproducibility.

Female↗