PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Measurement”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 73 records · Page 4Linked to original sources
PubMed2002

Upper-extremity volume measurements in women with lymphedema: a comparison of measurements obtained via water displacement with geometrically determined volume.

BACKGROUND AND PURPOSE: Upper-extremity (UE) swelling following breast cancer treatment is a frequent manifestation of lymphedema. In order to document outcomes from lymphedema treatments, reliable, valid, and practical measurements of UE swelling are necessary. The purpose of this study was to compare geometric methods of determining UE volumes with water displacement methods. SUBJECTS: The edematous hand, forearm, and upper arm of 50 women with UE swelling secondary to lymphedema were measured. METHODS: Upper-extremity volumes were determined by water displacement using arm and hand volumeters. Displaced water was weighed to determine volume. Circumferential girth measurements were taken. Width and depth measurements of the hand were taken with a tension-controlled caliper. Geometric volume formulas for a cylinder, frustum, rectangular solid, and trapezoidal solid were used to calculate volumes of the arm and hand at different measurement intervals. RESULTS: Intraclass correlation coefficients [2,1] for interrater and intrarater reliability of all water and geometric measurements of the arm and hand were.91 to.99 and.92 to.99, respectively. Water displacement correlated with geometric measurements in the arm (r=.97-.98) and in the hand (r=.81-.91). The limits of agreement (LOA) indicated that water and geometric measurements of arm volume differed by 479 to 655 mL. Scatterplots of the LOA data indicated in that geometric volumes were either larger or smaller than water volumes. The smallest standard error of measurement for the arm measurements was for the 6-cm frustum method at 115 mL; for the hand measurements, the smallest standard error of measurement was for the frustum method at 16 mL. DISCUSSION AND CONCLUSION: Volume of an edematous UE calculated by geometric formulas correlated strongly with volume determined by water displacement. Although strongly correlated, the measurements obtained by the 2 methods did not agree.

Adult↗
PubMed1989

[Three dimensional shape measurement of teeth (4). On the measurement by the laser displacement meter which is able to move on Z-direction].

A three dimensional shape measurement using a wide area teeth model was constructed using a high precision laser displacement meter, teeth model scanning machine and personal computer. The system employed a Z-directional movement of a laser displacement meter which tracked wide and complicated changes of shape, allowing for the accurate measurement of not only the crown and alveolar crista of the molar, but also maxillary root, the height difference between which extends about 25mm. As for the labialis of the incisors, teeth model was stood on a gonio stage and measured. In the present study, arrange arc and rugged array of incisors were measured. Improvements in the accuracy of measurement were also expected. Higher resolutions were obtained by the measurement at the center of the measurable range of the displacement meter where the laser beam is most focused. Since the lineality of the measured value varies with the sensitivity coefficient, if the coefficient drifted, values measured in the outer measurable ranges yielded large errors than those in the central positions. The present Z-directional movement enables measurement at the center of the measurable range, yielding smaller errors. The data obtained with the present method of Z-directional movement of a laser displacement meter enables not only the precise measurement of the shape and position of teeth for CAD prosthesis design but also provides basic data for simulation of occlusion by adding the relative positions of the maxilla and mandible to computer models.

Computer Graphics↗
PubMed1991

The impact of measurement errors on the diagnostic value of bone mass measurements: theoretical considerations.

It has become clear over the last decade that correlations between measurements of forearm bone mineral content (BMCarm) by single-photon absorptiometry (SPA) and measurements of spinal bone mineral density (BMDspine) by dual-photon absorptiometry (DPA) in healthy subjects and patients with spinal fractures are invariably significant, but not very powerful (i.e. r = 0.5-0.7). Nonetheless, several recent studies have shown that appendicular bone mass measurements discriminate between spinal fracture and non-fracture at least as well as do spinal DPA measurements. Correlations of a given parameter with measured BMDspine are less important than those with true BMDspine. To establish the latter we made the following assumptions: (1) accuracy errors or SPA BMCarm and DPA BMDspine measurements of 2%-4% and 8%-10%, respectively; and (2) a measured biological variation of SD = 14% for both BMCarm and BMDspine, corresponding to that of healthy women at the menopause. On these assumptions, we found that a correlation between true BMCarm and true BMDspine at about r = 0.8-0.9 yields a correlation between measured BMCarm and measured BMDspine at about r = 0.6--corresponding to experimental data in healthy women at the menopause. Furthermore, we found that the correlation between DPA measured BMDspine and true BMDspine is about the same as that between the SPA measured BMCarm and the true BMDspine. Thus, with the assumptions given above, spinal (DPA) and fore-arm (SPA) measurements appears to predict equally the true BMDspine in healthy perimenopausal women.

Bone Density↗
PubMedDate not supplied

Application of item response theory for development of a global functioning measure of dementia with linear measurement properties.

An ideal measure of global functioning for patients with dementia would discriminate at very high and very low levels of functioning and would have linear measurement properties such that a given change in score corresponds to the same amount of change in underlying ability at any part of the ability continuum. Using item response theory methods, linearity of test measurement can be directly assessed and items can be selected to construct a test with desired measurement characteristics. The purpose of this study was to apply item response theory methods to evaluating and developing global functioning scales. Subjects were 1207 patients who had received comprehensive dementia evaluations. Items were selected from two measures of cognitive functioning (Mini Mental State Examination, MMS; Blessed Information Memory Concentration Test, BIMCT) and one measure of independent functioning (Blessed-Roth Dementia Rating Scale, BRDRS). The MMS and BIMCT showed significant non-linearity of measurement, especially at low and high ability levels. A brief composite measure was created by selecting from the three instruments 25 items that fit a uniform distribution of item difficulty across the entire range of ability measured by the three instruments. This composite measure and the BRDRS showed better linearity of measurement than the other two instruments. Results have implications for development of a psychometrically sophisticated, brief measure of global functioning for clinical and research use in dementia.

Activities of Daily Living↗
PubMedDate not supplied

Fundal height measurement. Part 3--The effect of maternal position on fundal height measurements.

The effect of maternal position on fundal height measurements was studied in 192 nonobese women between 21 and 36 weeks of gestation. Four clinicians participated in the study and each clinician obtained measurements on 48 women. Fundal height measurements were obtained in each of four positions: supine; trunk elevation; knee flexion; and trunk elevation with knee flexion. The sequence in which measurements were obtained was assigned randomly. Clinicians were blinded to the results of their measurements. Measurements obtained in the supine position were largest, and measurements obtained in the trunk elevation with knee flexion position were smallest. Repeated measures analysis of variance demonstrated that measurements obtained in the four positions were significantly different (F = 87.71, df = 3,573, P < .001). A posteriori comparisons demonstrated that measurements obtained in each position were significantly different except for measurements obtained in the trunk elevation and knee flexion positions. These findings indicate that clinicians should be consistent when they position patients to obtain fundal height measurements.

Anthropometry↗
PubMed2006

The reliability and reproducibility of foot type measurements using a mirrored foot photo box and digital photography compared to caliper measurements.

UNLABELLED: The height of the medial longitudinal arch (MLA) is thought to be a predisposing factor to various lower extremity injuries. Discrepancy exists as to whether MLA height plays a role in injury prevention. The purpose of this study was to determine the intertester and intratester reliability, and the validity of the mirrored foot photo box (MFPB) and caliper measurements to radiographic measurements. METHODS: Thirty subjects with equal numbers of men and women were recruited. Both feet were tested (n=60) in a 90% weight bearing stance. A set of anatomic landmarks were palpated, marked, and measured using a caliper, MFPB, and radiographs. The protocol was completed by two testers on 2 days approximately 1 week apart. Intertester and intratester reliability were determined using the intraclass correlation coefficient (ICC)(2,k) and the ICC(2,1), respectively. Validity of both measurement techniques to radiographic measurements was determined using the ICC(2,k). RESULTS: The intertester reliability ranged from 0.991 to 0.577, while the intratester reliability ranged from 0.994 to 0.527, with first metatarsal angle being the only variable with poor reliability. Most variables demonstrated acceptable validity between the MFPB and the caliper measurements, and acceptable validity between the MFPB and calipers compared to radiographic measurements. The MFPB took 51.3+/-19.6s per foot while the caliper measurements averaged 227.4+/-68.9s to complete the measurements. DISCUSSION: The MFPB is as reliable as the caliper measurements, and offers better intertester reliability. Both the caliper and MFPB measurements demonstrated acceptable validity to radiographic measurements and testing time was reduced when using the MFPB compared to calipers.

Adolescent↗
PubMed2005

Auditory processing measures: correlation with neuropsychological measures of attention, memory, and behavior.

It has been suggested that measures of auditory processing (AP) are sensitive measures of attention resulting in the high comorbidity of auditory processing disorder (APD) and attention deficit/hyperactivity disorder (ADHD). Others have found that selected AP measures share significant variance with memory tasks. The current study investigated the relation between AP measures and various neuropsychological measures presumed to measure attention and memory in 36 children with a mean age of 7.78 years (SD=1.61) referred to an outpatient facility. Results indicate that AP measures significantly correlated with each other as well as with some measures of attention, memory, and behavior ratings. Results suggest that although AP measures include elements of both attention and memory, these measures also appear to assess processes not tapped by other measures of attention and memory. The correlation of AP measures with parent-and teacher-rated withdrawal, parent-rated somatization, conduct, and depression, as well as teacher-rated attention, anxiety, learning problems, social skills, and leadership suggest that auditory processing problems may manifest in myriad behaviors across settings. Implications for practice and future research are presented.

Attention↗
PubMed1998

A comparison of manual versus computer-assisted radiographic measurement. Intraobserver measurement variability for Cobb angles.

STUDY DESIGN: A comparison between computer-assisted measurement using digitized radiographs, which has the potential to reduce error, and manual measurement using standard radiographs. OBJECTIVE: To assess measurement variability for the Cobb method on digital radiographs and compare it with that of manual measurements on standard radiographs. BACKGROUND DATA: Studies of the Cobb method have demonstrated multiple sources of error leading to significant intraobserver measurement variability. Estimates for the 95% confidence interval for intraobserver variability range from 2.8 degrees to 10 degrees. METHODS: Twenty-four scoliosis radiographs were measured by six examiners. Two measurement sets were done manually ("manual set"), and two measurement sets were done on digitized images using a computer mouse ("computer set"). RESULTS: For the manual set, the 95% confidence interval for intraobserver variability was 3.3 degrees (range, 2.5-4.5 degrees). For the computer set, the value was 2.6 degrees (range, 2.3-3.3 degrees). This difference in 95% confidence intervals between the manual and computer sets was statistically significant (P < 0.001). CONCLUSIONS: The results of this study demonstrate that intraobserver variability for manual and computer Cobb angle measurements yield a 95% confidence interval of approximately 3 degrees, with the computer having a slightly lower variability. The computer technique removes sources of intrinsic error, e.g., the variability introduced by using different manual protractors, the inaccuracy of standard protractors, and the use of wide-diameter radiographic markers. Identical digital images can be shared electronically between centers, without having to duplicate and mail films. Multicenter studies in which different examiners will be measuring Cobb angles may consider using the computer as a measuring device to reduce intrinsic measurement errors.

Arthrography↗
PubMed2003

Toe pressure measurements compared to ankle artery pressure measurements.

The Trans-Atlantic Inter-Society Consensus (TASC)-recommended absolute toe pressure is < 30-50 mm Hg for definition of chronic critical limb ischemia (CLI). Toe pressures can be measured by different techniques. The authors analyzed the clinical use of the Doppler technique and an automatic device with optical sensors and estimated their value in documentation of chronic critical limb ischemia compared to ankle artery pressures. Three different investigations were performed: (1) In 16 healthy subjects the digital artery pressures were measured by using 3 different optical sensors (transmission, reflection, and microcirculation sensor) and compared to the systolic brachial pressure. (2) In 50 patients with and without peripheral arterial occlusive disease the toe pressures at digits 1 and 2 of both feet were determined by Doppler technique (8 MHz) and by optical sensors (cuff width constant 1.5 cm) and were compared to the ankle artery pressure determined by Doppler technique. (3) In 175 patients the toe pressures were measured at 1 toe and the ankle artery pressures were determined. In this group they estimated the clinical use of the toe pressure in regard to the definition of CLI (toe pressure < 50 mm Hg) compared to the ankle pressure < 70 mm Hg. The digital artery pressures measured with the different optical sensors, and the systolic brachial pressures were not significantly different and the correlation coefficients were around 0.7. In 21 of 50 patients the toe pressure at D1 and D2 could not be measured by Doppler technique because with the applied cuff no Doppler signal could be detected at the tip of the toe, but in 24 of these 29 patients the optical measurement was possible. Mean toe pressures at D1 were 108 +/- 45 mm Hg and D2 102 +/- 45 mm Hg, which were statistically not different. The correlation coefficient for the highest ankle artery pressure and the highest toe pressure determined by the Doppler technique was 0.389; for the highest ankle artery pressure and the toe pressure measured by the optical sensors it was 0.369, and for the toe pressures measured by Doppler technique and the optical sensors it was 0.506. Defining systolic ankle artery pressure < or = 50 to 70 mm Hg as the golden standard for CLI, the sensitivity of optical toe pressure measurement for the detection of CLI was 8%, the specificity was 96%, the positive predictive value 12%, and the negative predictive value was 94%. Independent of technique the absolute systolic toe pressures did not correlate with the absolute systolic ankle pressures. The optical measurement was more suitable for toe pressure measurement because it could be used in 90% of all patients. All in all, toe pressure measurements are more useful to exclude CLI than to prove it.

Adult↗
PubMed2005

Patient-focused measures of functional health status and health-related quality of life in pediatric orthopedics: a case study in measurement selection.

The objectives of this report are to review the assessment of patient-focused outcomes in pediatric orthopedic surgery, to describe a framework for identifying appropriate sets of measures, and to illustrate an application of the framework to a challenging orthopedic problem.A detailed framework of study design and measurement factors is described. The factors are important for selecting appropriate instruments to measure health status and health-related quality of life (HRQL) in a particular context. A study to evaluate treatment alternatives for patients with neurofibromatosis type 1 and congenital tibial dysplasia (NF1-CTD) provides a rich illustration of the application of the framework. The application involves great variability in the instrument selection factors. Furthermore, these patients and their supportive caregivers face numerous complex health challenges with long-term implications for HRQL. Detailed summaries of important generic preference-based multi-attribute measurement systems, pediatric health profile instruments, and pediatric orthopedic-specific instruments are presented. Age-appropriate generic and specific measures are identified for study of NF1-CTD patients. Selected measures include the Activities Scale for Children, Gillette Functional Assessment Questionnaire Walking Scale, Health Utilities Index, and Pediatric Inventory of Quality of Life. Reliable and valid measures for application to pediatric orthopedics are available. There are important differences among measures. The selected measures complement each other. The framework in this report provides a guide for selecting appropriate measures. Application of appropriate sets of measures will enhance the ability to describe the morbidity of pediatric orthopedic patients and to assess the effectiveness of alternative clinical interventions. The framework for measurement of health status and HRQL from a patient perspective has relevance to many other areas of orthopedic practice.

Activities of Daily Living↗
PubMed2006

Comparison and problems of measured values of LH, FSH, and PRL among measurement systems.

Several measurement systems are used for LH, FSH, and PRL in Japan, but the comparison of the measured values is difficult in some cases. In this study, we compared the measured values of 3 types of measurement systems widely used in Japan, SPAC-S, ARCHITECT, and Centaur, in females with a normal menstrual cycle and with various ovulatory disorders. Variant LH was discriminated by the criterion, SPAC-S LH/ARCHITECT LH ratio <0.5. Excluding the variant LH, the correlation of the measured LH values among the measurement systems was high, 0.94-0.99, and the value measured by ARCHITECT LH and Centaur LH was slightly higher than that measured by SPAC-S LH. As for FSH, the correlation was also high, 0.94-1.00, and the value measured by ARCHITECT FSH and Centaur FSH was slightly lower than that measured by SPAC-S FSH. The important judgment criterion of polycystic ovary syndrome (PCOS), a high level of LH relative to FSH, has been set to 1.0 or higher LH/FSH using SPAC-S. When the regression line of the LH/FSH ratio among the measurement systems was investigated, it can be said that 1.25 or higher by ARCHITECT and 1.40 or higher by Centaur are appropriate for the judgment criteria of a high level of LH relative to FSH. As for PRL, the correlation was high, 0.96-0.99, but the value showed large differences among the systems. For the diagnosis of hyperprolactinemia, the higher limit of the normal range may be 15 ng/mL for SPAC-S, 30 ng/mL for ARCHITECT, and 24 ng/mL for Centaur.

Adolescent↗
PubMed1997

The string measure of the ERP: what does it measure?

The event-related brain potential (ERP) has been investigated extensively inan effort to understand the neurophysiological bases of intelligence. Measures derived from the ERP have been used as indices of intelligence, particularly the string measure of the complexity of the ERP. However, the string measure has been criticised for being non-specific and for being dependent on ERP amplitude. These criticisms were tested by investigating relationships between ERP string measure, ERP amplitude measures, and the ERP power spectrum. It was found that the string measure was non-specific in that it indexes both low and high frequency event-related activity; the string measure is also dependent on ERP amplitude. The string measure is therefore not a valid measure of the ERP. It was concluded that the string measure should be abandoned; human intelligence cannot map in a simple way onto gross measures of scalp-recorded electrocortical activity.

Adult↗
PubMed1997

Measuring the magnitude of socio-economic inequalities in health: an overview of available measures illustrated with two examples from Europe.

In this paper we review the available summary measures for the magnitude of socio-economic inequalities in health. Measures which have been used differ in a number of important respects, including (1) the measurement of "relative" or "absolute" differences; (2) the measurement of an "effect" of lower socio-economic status, or of the "total impact" of socio-economic inequalities in health upon the health status of the population; (3) simple versus sophisticated measurement techniques. Based on this analysis of summary measures which have previously been applied, eight different classes of summary measures can be distinguished. Because measures of "total impact" can be further subdivided on the basis of their underlying assumptions, we finally arrive at 12 types of summary measure. Each of these has its merits, and choice of a particular type of summary measure will depend partly on technical considerations, partly on one's perspective on socio-economic inequalities in health. In practice, it will often be useful to compare the results of several summary measures. These principles are illustrated with two examples: one on trends in the magnitude of inequalities in mortality by occupational class in Finland, and one on trends in the magnitude of inequalities in self-reported morbidity by level of education in the Netherlands.

Europe↗
PubMed2002

Comparative measurements of total body water in healthy volunteers by online breath deuterium measurement and other near-subject methods.

BACKGROUND: We developed a new near-subject approach, using flowing afterglow-mass spectrometry (FA-MS) and deuterium dilution, which enables the immediate measurement of total body water (TBW) from single exhalations. OBJECTIVES: The objectives were to show the efficacy of the new FA-MS method in measuring TBW in healthy subjects and to compare these measurements with values derived from multifrequency bioelectrical impedance analysis, skinfold-thickness (SFT) measurements, and both recent and historical published regression equations. DESIGN: After baseline measurement of breath deuterium abundance, 24 healthy subjects ingested 0.3 g D(2)O/kg body wt. A second breath sample was taken after 3 h to measure the increase in deuterium, from which TBW was calculated. Bioelectrical impedance analysis was carried out with a multifrequency analyzer, and SFT was measured by a single trained observer. Methods were compared with the use of Pearson's correlation coefficient and Bland-Altman analyses. RESULTS: TBW measures obtained by all methods were highly correlated (r = 0.95-0.98, P < 0.001), especially those between FA-MS, SFT measurement, and recent regression equations. The mean values obtained were within 2% of those published for age-matched control subjects and varied by 1-6% when all methods were compared. Systematic bias was greatest when FA-MS was compared with bioelectrical impedance analysis, which tended to underestimate TBW in smaller, female subjects. No bias related to subject size was observed in a comparison of FA-MS with SFT measurement or with more recent regression equations. CONCLUSIONS: FA-MS is a simple and effective new approach to TBW measurement in healthy subjects. The difficulty of using population-derived equations to estimate TBW in individual subjects is emphasized.

Adult↗
PubMed2004

Detection of masked hypertension by home blood pressure measurement: is the number of measurements an important issue?

BACKGROUND: Office blood pressure (OBP) and home blood pressure (HBP) enable the identification of patients with masked hypertension. Masked hypertension is defined by normal OBP and high HBP and is known as a pejorative cardiovascular risk factor. OBJECTIVE: The objective was to evaluate in the SHEAF study the influence of the number of office or home blood pressure measurements on the classification of patients as masked hypertensives. METHODS: Patients with OBP <140/90 mmHg (mean of six values: three measurements at two separate visits, V1 and V2) and HBP >135/85 mmHg (mean of all valid measurements performed over a 4-day period) were the masked hypertensive reference group. The consistency of the classification was evaluated by using five definitions of HBP values (mean of the 3, 6, 9, 12 and 15 first measurements) and two definitions of OBP values (mean of three measurements at V1 and mean of three measurements at V2). RESULTS: Among the 4939 treated hypertensives included in the SHEAF study, 463 (9.4%) were classified as masked hypertensives (reference group). By decreasing the number of office or home measurements, the prevalence of masked hypertension ranged from 8.9-12.1%. The sensitivity of the classification ranged from 94-69% therefore 6-31% of the masked hypertensives were not detected. The specificity ranged from 98-94% therefore 1-6% of patients were wrongly classified as masked hypertensives. CONCLUSION: A limited number of home and office BP measurements allowed the detection of masked hypertension with a high specificity and a low sensitivity. A sufficient number of measurements (three measurements at two visits for OBP and three measurements in the morning and in the evening over 2 days for HBP) are required to diagnose masked hypertension.

Aged↗