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PubMed1979

The reproducibility of pantographic tracings on medicated and nonmedicated subjects.

Tracings were made on three patients using a modified pantographic device. The tracings were made on glass flags with wax, etched, and superimposed. The effects of body position and modification were investigated. From this research project the following can be concluded: 1. A precise method has been developed which permits superimposition of pantographic tracings for analysis. 2. There is a significant difference in reproducibility between medicated and nonmedicated subjects. 3. The percentage coincidence of border tracings increases significantly when the patient is pantographed while under the influence of medication (Valium). 4. The angulation of the body does not appear to be significant for reproducing border tracings. 5. There appears to be no significant difference in the reproducibility of the border tracings relative to time (1, 1 1/2, 2, and 2 1/2 hours) after medication. 6. The lateral side shift of the jaw cannot always be reproduced accurately. 7. The neuromusculature appears to be the overriding factor governing border movements.

Adolescent↗

PubMed1986

Reproducibility of occlusal marking techniques.

Our study was designed to (1) test clinically the reproducibility of the NPT by comparing two consecutive occlusal records and records made at 1-month intervals (2) test the reproducibility of a color-marking technique under the same conditions, and (3) compare the location of occlusal contacts as registered by these two techniques. Results showed that neither technique is highly reproducible. However, the NPT is more reproducible than the CMT. The advantages and disadvantages of the NPT and the CMT were described. It was suggested that more research should be conducted to improve the accuracy of occlusal record techniques.

Dental Articulators↗

PubMed1985

Stress testing predischarge and six weeks after myocardial infarction to compare submaximal and maximal exercise predischarge and to assess the reproducibility of induced abnormalities.

Submaximal and maximal treadmill exercise tests were performed predischarge in 64 patients after acute myocardial infarction to assess the relative yield of residual ischaemic abnormalities. The reproducibility of individual abnormalities resulting from maximal stress tests performed predischarge and 6 weeks after infarction was also assessed in 55 of these patients. Compared with predischarge submaximal exercise testing, a maximal exercise test identified a significantly greater number of patients with residual myocardial ischaemia (26 vs. 15, P less than 0.05) and this was associated with a significantly longer average maximal exercise duration (P less than 0.001), and a higher rate-pressure product (P less than 0.001). Among the 55 patients who had maximal stress tests both predischarge and 6 weeks after infarction, there was a significant lack of reproducibility in the occurrence of exercise induced angina (P less than 0.01) and an abnormal blood pressure response (P less than 0.02). In contrast, exercise induced ST segment depression and elevation and ventricular arrhythmias were relatively reproducible. More patients had an ischaemic test result (ST depression or angina) at the later test compared to the predischarge test (33 vs. 25 patients) but this increase was not statistically significant. There were, however, significant increases at the later test in mean maximal exercise duration (P less than 0.001). mean maximal heart rate (P less than 0.001) and heart rate-systolic blood pressure double product (P less than 0.001). The majority of patients who had a cardiac event in the period between the two tests had a predischarge test abnormality. We conclude that a significantly greater number of patients with residual reversible myocardial ischaemia after infarction will be identified by symptom limited exercise testing compared with a submaximal predischarge test. Because ST depression and elevation appear reproducible, patients who develop these abnormalities during a predischarge test do not, for prognostic reasons, need retesting 6 weeks after infarction. Exercise induced angina pectoris and an abnormal blood pressure response, however, are highly variable and in these patients a repeat test may be useful.

Adult↗

PubMed1985

Reproducibility of metabolical parameters during successive coronary sinus pacing in patients known to have coronary artery disease.

We have studied the reproducibility of myocardial extraction ratios of lactate, glucose and free fatty acids in patients with stable angina during atrial pacing. Two pacing periods, separated by an interval of 45 min, were imposed. The individual data were highly reproducible for lactate. Mean values for glucose and for free fatty acids were closely similar in the two successive tests, but the individual response was not so highly reproducible. We recommend the demonstration of the reproducibility of events during pacing in studies in which the effects of the therapeutic interventions are being assessed. This is especially so when observations are made in a small number of patients.

Angina Pectoris↗

PubMed1990

Reproducibility of carcinogenic potencies estimated in different rodent species. Methylene chloride: a useful example.

The aim of this study was to investigate the reproducibility of carcinogenic potencies estimated by multistage model (and its linearized form) fitting to dose-response relationships referring to different rodent species and strains, different sexes, target organs and severity of prognosis. Methylene chloride represented a useful example since there were 11 single dose-response relationships available for the same administration route (inhalation) and for the above-mentioned variables. The multistage mathematical model and the 'linearized multistage' model (EPA's conservative procedure), which are the mainly adopted models for regulatory purposes, were used for the dose-response fitting of single trends and other different cumulative trends. The reproducibility of response frequencies at equal exposure doses was also analyzed. The mathematical function best describing each trend showed the constant presence of a linear component (for low doses) and, in the majority of cases, a quadratic second order component. Carcinogenic potencies were fairly consistent for the various parameters. A good interspecies reproducibility of carcinogenic potencies was observed. A high intraspecies reproducibility was also observed, even though obtained from different sexes, as well as varying degrees of severity of prognosis and, in the case of rats, different strains. The fluctuation of the estimated carcinogenic potencies was lower in mice than in rats.

Animals↗

PubMed2004

Cardiorespiratory requirements and reproducibility of the six-minute walk test in elderly patients with coronary artery disease.

OBJECTIVES: To measure the cardiorespiratory requirements of the six-minute walk test (6MWT), to compare this demand with the symptom-limited exercise test (SLET) at ventilatory threshold and at maximal level in elderly patients with coronary artery disease (CAD), and to assess the reproducibility of the 6MWT in cardiorespiratory exchanges in those patients. DESIGN: Comparative and reproducibility sample. SETTING: Cardiac rehabilitation service. PARTICIPANTS: Twenty-five people with CAD. INTERVENTIONS: Subjects performed an SLET and a 6MWT. To test 6MWT reproducibility, 9 patients performed 2 repeated 6MWTs. MAIN OUTCOME MEASURES: The 6MWT cardiorespiratory values, measured with a portable gas analyzer, were compared with the SLET data and with the data from the 2 repeated 6MWTs. RESULTS: The 6MWT peak oxygen uptake (VO2peak, 14.27+/-2.94 mL.min(-1).kg(-1)) and heart rate (94+/-14 beats/min) did not differ from the SLET values at ventilatory threshold (VO2, 13.4+/-2.65 mL.min(-1).kg(-1); heart rate, 91+/-17 beats/min), whereas the 6MWT ventilation (VEpeak, 36.72+/-10.03 L/min) was higher than the SLET at ventilatory threshold (Ve, 31.54+/-8.93 L/min, P<.03). Maximal 6MWT cardiorespiratory data were lower than the SLET maximal values. Cardiorespiratory values did not differ between the 2 repeated 6MWT (VO2peak, 15.33+/-3.52 mL.min(-1).kg(-1) vs 15.11+/-2.65 mL.min(-1).kg(-1); VEpeak, 39.07+/-12.33 L/min vs 39.07+/-12.13 L/min; heart rate, 95+/-21 beats/min vs 89+/-15 beats/min). CONCLUSIONS: The 6MWT cardiorespiratory requirement values did not differ from SLET values at ventilatory threshold except for ventilation, and 6MWT values are reproducible in elderly patients with CAD.

Age Factors↗

PubMed2004

Reproducibility of internal atrial defibrillation threshold in paroxysmal and persistent atrial fibrillation.

BACKGROUND: Several pharmacological or technical factors may affect atrial defibrillation threshold (ADFT) for internal cardioversion (ICV) in the treatment of atrial fibrillation (AF). METHODS: We evaluated the reproducibility of ADFT in lone paroxysmal (electrically induced AF, 10 pts, 51+/-4 years) or persistent AF (15 pts, 64+/-7 years). The AF pattern (F-F interval) was characterised before each ICV attempt. A first step-up synchronised ICV test (ICV1, biphasic shock waveform 6 ms/6 ms) with increasing energy levels from 0.2 to 20 J was performed by a dual-lead defibrillation system (right atrium-coronary sinus configuration) connected to an external cardioverter defibrillator. After 30 min of stable sinus rhythm, a new sustained AF was induced (>20 min duration) and ICV protocol was repeated (ICV2). The AF cycle length was recorded for 30 s from the lateral wall of right atrium in basal condition and before each cardioversion attempt. RESULTS: The mean values of AF cycle length before a successful shock were similar in both AF populations (paroxysmal AF: pre-ICV1 175+/-21 ms vs pre-ICV2 181+/-20 ms (p=NS); persistent AF pre-ICV1 194+/-25 ms vs pre-ICV2 202+/-15 ms (p=NS)). No significant differences were observed between the two successful ICV tests concerning intensity, energy and impedance levels. The value of ADFT energy was reproducible in paroxysmal AF population (SD differences 1.2, coefficient of variability 9.6%). In persistent AF group only the impedance was reproducible (SD differences 2.6 Omega, coefficient of variability 4.5%), but not the energy requirements (SD differences 9.6, coefficient of variability 44.3%). CONCLUSIONS: ADFT is reproducible in paroxysmal AF patients, while a high coefficient of variability is present in persistent AF, possibly related to different patterns of re-entrant circuits in the reinduced AF. This observation is important in order to evaluate factors influencing ICV-ADFT correctly in AF patients.

Aged↗

PubMed2005

Reproducibility of energy parameters in the pole vault.

The purpose of this study was to analyze the reproducibility of kinematic, dynamometric and derived mechanical energy parameters in the pole vault as a main precondition for the practical applicability of the concept of energy exchange in the pole vault. A total of 46 vaults of six experienced vaulters were analyzed. On the basis of 3D kinematic data of the athlete and the pole and ground reaction forces measured at the end of the pole in the planting box the reproducibility of parameters that describe the energy transfer into the pole and the energy exchange between the athlete and the pole during the vault was proofed. Intraclass correlation, mean root mean square and the coefficient of variance were determined, additionally the Wilcoxon Test was applied. Parameters of the athlete's 3D total mechanical energy, e.g. initial energy and final energy, and the pole energy (maximum pole energy, energy of the pole due to compressive force and bending moment) were highly reproducible. The distribution of the energy transferred into the pole due to compressive force and bending moment, the same as the energy gain of the vaulter-pole system during the vault, which indicates the strategy of interacting with the pole, were also reproducible. With this the concept of energy exchange in the pole vault can be used to analyze the impact of training interventions, changes in movement pattern respectively, on the vaulters performance during different phases of the vault. The analysis of one trial of an athlete should be sufficient to identify changes in the athlete's interaction with the elastic pole.

Biomechanical Phenomena↗

PubMed2004

Brazilian version of airways questionnaire 20: a reproducibility study and correlations in patients with COPD.

This study describes the correlations and reproducibility of AQ20, a simple health status questionnaire with 20 questions, which was designed to be useful especially in time sparing situations. A formal language validation process was done, in order to validate the AQ20 before studying its reproducibility. Thirty stable COPD patients answered the final version twice within 15 days. To test the reproducibility of AQ20, the interclass correlation coefficient and Bland-Altman display were used. Results were correlated with FEV1, SpO2, BMI, Mahler BDI, and the Saint George Respiratory Questionnaire (SGRQ). Twenty-five patients (83.3%) were male, with a mean age of 68.6 years. The mean predicted FEV1 (%) was 56.8%. The interclass correlation ratio for the total score was alpha=0.90 for the intraobserver variability and alpha=0.93 for the interobserver variability. The correlation with total SGRQ score was 0.76, with P<0.001. The mean application time for AQ20 was 4 min and 6 s, and the score calculation time, was 8 s. It can be concluded that AQ20 is reproducible, with an excellent correlation with SGRQ total score, and also having the advantage of taking just a few minutes to be applied and to have its score calculated.

Aged↗

PubMed1986

Measurement of trunk flexibility in normal subjects: reproducibility of three clinical methods.

Although measurements of trunk flexibility are an important part of a clinical examination, subjective methods are usually used to assess spinal mobility. We studied three easily performed objective techniques for determining trunk flexibility (the common "fingertip-to-floor" test, the modified Schober and Moll tests, and the Loebl inclinometer method) and their interexaminer and intraexaminer reproducibility. On 3 different days, each of 25 normal subjects was tested by the same investigator. In 25 other subjects, the studies were performed by a different examiner (one of three) on each of 3 days. We recorded the following mean coefficients of variation for interexaminer and intraexaminer reproducibility of results, respectively: fingertip-to-floor, 83% and 76.4%; flexion (Schober), 6.3% and 6.6%; right lateral flexion (Moll), 11.9% and 8.9%; left lateral flexion (Moll), 10.2% and 9.5%; extension (Moll), 9.5% and 7.3%; lumbar flexion (Loebl), 9.6% and 13.4%; and lumbar extension (Loebl), 65.4% and 50.7%. Although the reproducibility of the "fingertip-to-floor" test and the Loebl extension test was poor, all other tests studied had good reproducibility. The consistency of results with repeated testing should be considered in the application of various trunk flexibility tests to clinical and research data.

Adolescent↗

PubMed1988

The uterine artery blood flow velocity waveform: reproducibility and results in normal pregnancy.

Uterine artery blood flow velocity waveforms (FVW) were recorded longitudinally in normal pregnancies (n = 41) at 4-week intervals from a gestational age of 18 weeks onwards. Furthermore, reproducibility of the uterine artery FVWs and the relation with maternal heart rate (MHR) was studied. The uterine artery FVW showed a low resistance flow pattern already from 18 weeks onwards, with high diastolic flow velocity relative to systolic flow velocity. Mean values (+/- S.D.) for the Pulsatility-Index (PI) before and after 32 weeks of normal pregnancy were 0.73 (+/- 0.17) and 0.67 (+/- 0.15) respectively; for the A/B ratio these values were 1.98 (+/- 0.30) and 1.85 (+/- 0.25) respectively. Intra- and interobserver reproducibility could be established for uterine artery FVW analysis. A varying time-period between the FVWs (0-4 min), repositioning of the flow probe and different observers did not cause any systematic effect on the PI, although variation increased in case of a longer time-period between the FVWs. Overall variation of the PI in the reproducibility experiments appeared to be caused more by inter- than intrapatient variance. Inter- and intrapatient variance were in the same range for the results of the longitudinal study. A statistically significant, inverse relationship between uterine artery PI and MHR could be established in a majority of cases. The mean regression coefficient for all patients of the reproducibility study was -0.0061; PI decreases with 0.0061 when maternal heart rate increases 1 beats/min.

Arteries↗

PubMed1999

Reproducing a cancer patient's pain on physical examination: bedside provocative maneuvers.

While various aspects of the physical examination in pain patients have been validated, the value of screening maneuvers that reproduce a cancer patient's pain on physical examination has been less well defined. The purpose of this prospective case series is to better characterize the role of bedside provocative maneuvers as part of the comprehensive evaluation of cancer pain patients. Fifty consecutive patients referred to an ambulatory cancer pain clinic were evaluated; they described a total of 89 discrete pains. All or much of the pain that brought each patient to medical attention was reproduced by a provocative maneuver in 47 (94%) patients; 79 of 89 (89%) pains were elicited at the bedside. Pains that were not reproducible with any provocative maneuver included paroxysmal spells of pain, neuropathic pain, and steady headache. On the basis of the history, physical examination, and both positive and negative provocative maneuvers, all pains were characterizable as somatic, visceral, neuropathic, or mixed, and a pathophysiological basis for the pain was inferred in 85 of 89 (95%) pains. On the basis of this preliminary report, we conclude that provocative bedside maneuvers are usually able to reproduce a cancer patient's pain. They help to better characterize the pain and identify the pain sensitive structure, and should be a routine part of the comprehensive assessment of cancer pain patients. Further research is needed to validate the diagnostic role of standardized pain-provoking maneuvers in a variety of clinical situations.

Humans↗

PubMed1992

The reproducibility of colour-coded duplex scanning in measuring arterial wall dimensions.

Intimal hyperplasia continues to be a major problem following vascular surgery but experimental evidence suggests that it can be reduced pharmacologically. For clinical studies an accurate, reproducible and non-invasive image of the intima and lumen is required. We have assessed the value of the Acuson 128 Colour Duplex for such studies. Ten patients had their common femoral arteries scanned at a fixed point by two experienced observers on two separate occasions. External vessel diameter, luminal diameter and internal diameter (i.e. the diameter within the internal elastic lamina) were measured in both longitudinal and cross-sectional views. Cross-sectional area and degree of stenosis were all measured and all parameters expressed as limits of agreement. The mean external diameter of the common femoral arteries was 10.5 +/- 1.6 mm. Measurements in the longitudinal view were highly reproducible with limits of agreement ranging from -0.67 - +0.25 mm (internal diameter) to -1.49 - +1.31 mm (luminal diameter). In order to detect a meaningful change in longitudinal external diameter a real difference of 0.86 mm is required representing a change of less than 10%. Cross-sectional diameter measurements were similarly reproducible (-0.73 - +0.47 mm to -1.97 - +1.79 mm). However, cross-sectional area measurements had a wide variation so that the error in degree of stenosis was -25.4 - +30.2%. Thus, duplex ultrasound reproducibly images the layers of the arterial wall. Prospective studies of intimal hyperplasia are feasible but must be based on longitudinal and cross-sectional diameters rather than cross-sectional areas.

Aged↗

PubMed2000

Electrochemical pretreatment of polycrystalline gold electrodes to produce a reproducible surface roughness for self-assembly: a study in phosphate buffer pH 7.4

It has been emphasized in several studies that the state of the surface, including the surface roughness, is very important for the reproducible formation of high-quality self-assembled monolayers on gold. The pulsed-potential pretreatment procedure described in this paper can, in a reproducible way, reduce the surface roughness of mechanically polished polycrystalline gold electrodes by a factor 2. The developed procedure, in which the gold is alternately oxidized and reduced, has been optimized for use in a flow system (100 mM phosphate buffer pH 7.4). The influence of the pretreatment procedure on the surface roughness of the electrodes has been studied by in-situ oxygen adsorption measurements using cyclic voltammetry. The most effective pulse regime in producing a gold surface with a reproducible and relatively low surface roughness is a triple-potential pulse waveform, with potentials of +1.6, 0.0, and -0.8 Vvs SCE and pulse widths of 100 ms for each potential. Prolonged pulsing for 2000-5000 s with the gold working electrode in a flow-through cell showed an electropolishing effect, i.e., a decrease of the roughness in time. Flow conditions are very important: the roughness decreased faster at higher flow rates, while an increase was observed without flow. A process of reconstruction and dissolution of gold during application of the potential pulses under flow conditions is assumed to account for the observed phenomena. A self-assembled monolayer of thioctic acid with reproducible characteristics, determined with impedance measurements, could be formed on a pretreated gold surface.

Journal Article↗

PubMed1986

A collaborative study to investigate the retention reproducibility of barbiturates in HPLC with a view to establishing retention databases for drug identification.

A collaborative study among 10 laboratories has been undertaken to investigate the interlaboratory reproducibility of retention measurements in a high performance liquid chromatographic (HPLC) system for separating barbiturates. The system involved an ODS-Hypersil column with an eluent of methanol:phosphate buffer (40:60, v/v) at pH 8.5; all laboratories used the same batch of packing material. The conventional methods of recording retention properties (retention times and capacity factors) gave poor interlaboratory reproducibility. Better results were obtained by expressing the retentions relative to a standard barbiturate (quinalbarbitone); relative adjusted retention times proved to be more effective than straightforward relative retention times. Retention indices based on the alkylarylketone scale were not as reproducible as the methods based on a single closely related compound. The best reproducibility was obtained using corrected capacity factors based on the retention of four barbiturates in a standard mixture. The results of the study are discussed with a view to selecting the best methods of recording retention in HPLC when considering the establishment of databases for drug identification.

Barbiturates↗

PubMed1987

Reproducibility of reports of frequency of food use in the Tecumseh Diet Methodology Study.

Frequency reports in 1967-1969 for 83 foods were compared to frequency reports for the same foods asked retrospectively in 1982-1983 about use in 1967-1969 for 1,184 respondents aged 45-64 in the Tecumseh Community Health Study cohort. Food frequency reports of the current (1982-1983) diet were also compared to baseline reports to indicate diet stability and to retrospective reports to indicate the influence of current diet on retrospective reporting. Comparisons were also made for 13 food groups and vitamin A and C indices. Short-term reproducibility of seven foods, measured by two reports 1-3 weeks apart in 1967-1969, was compared to long-term reproducibility for the same foods. Short-term reproducibility was consistently greater than long-term. Reproducibility was associated positively with stability of use. For the two nutrient indices and nine of the ten food groups examined, mean intake estimated from the retrospective report differed significantly from mean intake from the baseline report. Agreement between retrospective and current reports exceeded agreement between retrospective and baseline reports, indicating that retrospective reports were greatly influenced by current behavior; yet, the retrospective reports were better indicators of baseline consumption than were the current reports. While misclassification from use of the retrospective report to measure baseline consumption was large, risk differences may still be detected with usual sample sizes.

Ascorbic Acid↗

PubMed1981

Reproducing movement in the lower extremity using kinesthetic cues of distance and location.

The purpose of this study was to determine if kinesthetic cues of distance or location serve as references in motor memory for reproducing movement in the lower extremity. Thirty normal subjects randomly reproduced criterion movements of 30, 60, and 90 degrees of knee flexion. Starting positions of the criterion and reproduction movements were varied. Reproducing distance required that subjects move the same amplitude as the criterion movement, while reproducing location involved moving to the end position of the criterion movement. Results showed that reproductions based on location were significantly (p less than .05) more accurate than those based on distance cues. Reproductions of 30 and 60 degrees were found to be significantly (p less than .05) less variable than 90-degree reproduction movements. The results were explained according to the theories that have been proposed for retention of kinesthetic distance and location cues in motor memory.

Adult↗

PubMed1997

Ability to reproduce head position after whiplash injury.

STUDY DESIGN: A two-group design with repeated measures. OBJECTIVES: To determine if there is loss of the ability to reproduce target position of the cervical spine individuals who have sustained a whiplash injury. SUMMARY OF BACKGROUND DATA: The ability to sense position is a prerequisite for functional movement. Injury may have a deleterious effect on this ability, resulting in inaccurate positioning of the head and neck with respect to the body coordinates and to the environment. METHODS: Eleven subjects with history of whiplash injury (age, 42 +/- 8.7 years) and 11 age-matched asymptomatic subjects (age, 43 +/- 3.1 years) participated in the study. Effects of whiplash injury on the ability to replicate a target position of the head were assessed. Maximum rotation of the neck and ability to reproduce the target angle were measured using a standard cervical range-of-motion device. Subjects' perception of "neutral" position was also assessed. RESULTS: Analysis of variance indicated the whiplash subjects were less accurate in reproducing the target angle than were control subjects. These whiplash subjects tended to overshoot the target. In addition, the subjects in the whiplash group were often inaccurate in their assessment of neutral position. CONCLUSIONS: Subjects who have experienced a whiplash injury demonstrate a deficit in their ability to reproduce a target position of the neck. These data are consistent with the hypothesis that these subjects possess an inaccurate perception of head position secondary to their injury. This study has implications for the rehabilitation of individuals with whiplash injury.

Adult↗