A new method of isometric dynamometry for the craniocervical flexor muscles

Background and Purpose. A new method of dynamometry has been developed to measure the performance of the craniocervical (CC) flexor muscles by recording the torque that these muscles exert on the cranium around the CC junction. This report describes the method, the specifications of the instrument, and the preliminary reliability data. Subjects and Methods. For the reliability study, 20 subjects (12 subjects with a history of neck pain, 8 subjects without a history of neck pain) performed, on 2 occasions, maximal voluntary isometric contraction (MVIC) tests of CC flexion in 3 positions within the range of CC flexion and submaximal sustained tests (20% and 50% of MVIC) in the middle range of CC flexion (craniocervical neutral position). Reliability coefficients were calculated to establish the test-retest reliability of the measurements. Results. The method demonstrated good reliability over 2 sessions in the measurement of MVIC (intraclass correlation coefficient [ICC] =.79-.93, SEM=0.6-1.4 N-m) and in the measurement of steadiness (standard deviation of torque amplitude) of a sustained contraction at 20% of NMC (ICC=.74-.80, SEM=0.01 N-m), but not at 50% of MVIC (ICC=.07-.76, SEM=0.04-0.13 N-m). Discussion and Conclusion. The new dynamometry method appears to have potential clinical application in the measurement of craniocervical flexor muscle performance.

Behaviour state analysis in Rett syndrome: Continuous data reliability measurement

Awareness of optimal behaviour states of children with profound intellectual disability has been reported in the literature as a potentially useful tool for planning intervention within this population. Some arguments have been raised, however, which question the reliability and validity of previously published work on behaviour state analysis. This article sheds light on the debate by presenting two stages of a study of behaviour state analysis for eight girls with Rett syndrome. The results support Mudford, Hogg, and Roberts' (1997, 1999) concerns with the pooling of participant data. The results of Stage 2 also suggest, however, that most categories of behaviour state can be reliably distinguished once definitions of behaviours for each state are clearly defined.

The Northern HIPASS catalogue - data presentation, completeness and reliability measures

The Northern HIPASS catalogue (NHICAT) is the northern extension of the HIPASS catalogue, HICAT. This extension adds the sky area between the declination (Dec.) range of +2 degrees < delta < +25 degrees 30' to HICAT's Dec. range of -90 degrees < delta < +2 degrees. HIPASS is a blind H I survey using the Parkes Radio Telescope covering 71 per cent of the sky (including this northern extension) and a heliocentric velocity range of - 1280 to 12 700 km s(-1). The entire Virgo Cluster region has been observed in the Northern HIPASS. The galaxy catalogue, NHICAT, contains 1002 sources with nu(hel) > 300 km s(-1). Sources with -300 < nu(hel) < 300 km s(-1) were excluded to avoid contamination by Galactic emission. In total, the entire HIPASS survey has found 5317 galaxies identified purely by their HI content. The full galaxy catalogue is publicly available at http://hipass.aus-vo.org.

Reliability measures for local nodes assessment in classification trees

Most of the modem developments with classification trees are aimed at improving their predictive capacity. This article considers a curiously neglected aspect of classification trees, namely the reliability of predictions that come from a given classification tree. In the sense that a node of a tree represents a point in the predictor space in the limit, the aim of this article is the development of localized assessment of the reliability of prediction rules. A classification tree may be used either to provide a probability forecast, where for each node the membership probabilities for each class constitutes the prediction, or a true classification where each new observation is predictively assigned to a unique class. Correspondingly, two types of reliability measure will be derived-namely, prediction reliability and classification reliability. We use bootstrapping methods as the main tool to construct these measures. We also provide a suite of graphical displays by which they may be easily appreciated. In addition to providing some estimate of the reliability of specific forecasts of each type, these measures can also be used to guide future data collection to improve the effectiveness of the tree model. The motivating example we give has a binary response, namely the presence or absence of a species of Eucalypt, Eucalyptus cloeziana, at a given sampling location in response to a suite of environmental covariates, (although the methods are not restricted to binary response data).

Random error in willingness to pay measurement: A multiple indicators, latent variable approach to the reliability of contingent values

The reliability of measurement refers to unsystematic error in observed responses. Investigations of the prevalence of random error in stated estimates of willingness to pay (WTP) are important to an understanding of why tests of validity in CV can fail. However, published reliability studies have tended to adopt empirical methods that have practical and conceptual limitations when applied to WTP responses. This contention is supported in a review of contingent valuation reliability studies that demonstrate important limitations of existing approaches to WTP reliability. It is argued that empirical assessments of the reliability of contingent values may be better dealt with by using multiple indicators to measure the latent WTP distribution. This latent variable approach is demonstrated with data obtained from a WTP study for stormwater pollution abatement. Attitude variables were employed as a way of assessing the reliability of open-ended WTP (with benchmarked payment cards) for stormwater pollution abatement. The results indicated that participants' decisions to pay were reliably measured, but not the magnitude of the WTP bids. This finding highlights the need to better discern what is actually being measured in VVTP studies, (C) 2003 Elsevier B.V. All rights reserved.

Single-subject research designs and data analyses for assessing elite athletes' conditioning

Research in conditioning (all the processes of preparation for competition) has used group research designs, where multiple athletes are observed at one or more points in time. However, empirical reports of large inter-individual differences in response to conditioning regimens suggest that applied conditioning research would greatly benefit from single-subject research designs. Single-subject research designs allow us to find out the extent to which a specific conditioning regimen works for a specific athlete, as opposed to the average athlete, who is the focal point of group research designs. The aim of the following review is to outline the strategies and procedures of single-subject research as they pertain to.. the assessment of conditioning for individual athletes. The four main experimental designs in single-subject research are: the AB design, reversal (withdrawal) designs and their extensions, multiple baseline designs and alternating treatment designs. Visual and statistical analyses commonly used to analyse single-subject data, and advantages and limitations are discussed. Modelling of multivariate single-subject data using techniques such as dynamic factor analysis and structural equation modelling may identify individualised models of conditioning leading to better prediction of performance. Despite problems associated with data analyses in single-subject research (e.g. serial dependency), sports scientists should use single-subject research designs in applied conditioning research to understand how well an intervention (e.g. a training method) works and to predict performance for a particular athlete.

The HIPASS catalogue - II. Completeness reliability and parameter accuracy

The H I Parkes All Sky Survey (HIPASS) is a blind extragalactic H I 21-cm emission-line survey covering the whole southern sky from declination -90degrees to +25degrees. The HIPASS catalogue (HICAT), containing 4315 H I-selected galaxies from the region south of declination +2degrees, is presented in Meyer et al. (Paper I). This paper describes in detail the completeness and reliability of HICAT, which are calculated from the recovery rate of synthetic sources and follow-up observations, respectively. HICAT is found to be 99 per cent complete at a peak flux of 84 mJy and an integrated flux of 9.4 Jy km. s(-1). The overall reliability is 95 per cent, but rises to 99 per cent for sources with peak fluxes >58 mJy or integrated flux >8.2 Jy km s(-1). Expressions are derived for the uncertainties on the most important HICAT parameters: peak flux, integrated flux, velocity width and recessional velocity. The errors on HICAT parameters are dominated by the noise in the HIPASS data, rather than by the parametrization procedure.

Testing the reliability of a new ultrasonic cardiac output monitor, the USCOM, by using aortic flowprobes in anesthetized dogs

We have used an animal model to test the reliability of a new portable continuous-wave Doppler ultrasonic cardiac output monitor, the USCOM. In six anesthetized dogs, cardiac output was measured with a high-precision transit time ultrasonic flowprobe placed on the ascending aorta. The dogs' cardiac output was increased with a dopamine infusion (0-15 mug (.) kg(-1) (.) min(-1)). Simultaneous flowprobe and USCOM cardiac output measurements were made. Up to 64 pairs of readings were collected from each dog. Data were compared by using the Bland and Altman plot method and Lin's concordance correlation coefficient. A total of 319 sets of paired readings were collected. The mean (+/-SD) cardiac output was 2.62 +/- 1.04 L/min, and readings ranged from 0.79 to 5.73 L/min. The mean bias between the 2 sets of readings was -0.01 L/min, with limits of agreement (95% confidence intervals) of -0.34 to 0.31 L/min. This represents a 13% error. In five of six dogs, there was a high degree of concordance, or agreement, between the 2 methods, with coefficients >0.9. The USCOM provided reliable measurements of cardiac output over a wide range of values. Clinical trials are needed to validate the device in humans.

The reliability and validity of the Therapeutic activity index

Purpose To assess the psychometric properties of the Simplified Therapeutic Intervention Scoring System (TISS 28) scale. Materials and Methods A prospective observational design was used. Patients were recruited from a medical-surgical intensive care unit (ICU) and 4 rehabilitation wards of 2 university-affiliated hospitals in Hong Kong. Results Data necessary for the calculation of the TISS 28, the Therapeutic Intervention Scoring System (TISS 76), and severity of illness scoring system (Simplified Acute Physiology Score [SAPS II]) were recorded for each patient during the first 24 hours after his/her admission to an ICU. A significant positive correlation was found between the TISS 76 and the TISS 28 scores as well as the TISS 28 and the SAPS II scores. There was a significant difference between the TISS 28 scores among ICU patients and patients in rehabilitation wards. A significant correlation was found between the TISS 28 scores of the first and second set of TISS 28 scores. Conclusions Although the findings supported the validity and reliability of the TISS 28, there were limitations of the TISS 28 in measuring nursing workload in ICUs. Hence, continued amendment and validation of the TISS 28 on larger samples in different ICUs would be required so as to provide clinical nurses with a valid and reliable assessment of nursing workload.

Reliability and validity of arm volume measurements for assessment of lymphedema

Background and Purpose. Arm lymphedema following breast cancer In this study, we assessed the surgery is a continuing problem. reliability and validity of circumferential measurements and water displacement for measuring upper-limb volume. Subjects. Participants included subjects who had had breast cancer surgery, including axillary dissection-19 with and 22 without a diagnosis of arm lymphedema-and 25 control subjects. Methods. Two raters measured each subject by using circumferential tape measurements at specified distances from the fingertips and in relation to anatornic landmarks and by using water displacement. Interrater reliability was calculated by analysis of variance and multilevel modeling. Volumes from circumferential measurements were compared with those from water displacement by use of means and correlation coefficients, respectively. The standard error of measurement, minimum detectable change (MDC), and limits of agreement (LOA) for volumes also were calculated. Results. Arm volumes obtained with these methods had high reliability. Compared with volumes from water displacement, volumes from circumferential measurements had high validity, although these volumes were slightly larger. Expected differences between subjects with and without clinical lymphedema following breast cancer were found. The MDC of volumes or the error associated with a single measure for data based oil anatomic landmarks was lower than that based oil distance from fingertips. The mean LOA with water displacement were lower for data based on anatomic landmarks than for data based on distance from fingertips. Discussion and Conclusion. Volumes calculated from anatomic landmarks are reliable, valid, and more accurate than those obtained from circumferential measurements based on distance from fingertips.

Reliability of a measure of prediagnosis physical activity for cancer survivors

Purpose: This study was conducted to examine the test-retest reliability of a measure of prediagnosis physical activity participation administered to colorecial cancer survivors recruited from a population-based state cancer registry. Methods: A total of 112 participants completed two telephone interviews. I month apart, reporting usual weekly physical activity in the year before their cancer diagnosis. Intraclass correlation coefficients (ICC) and standard en-or of measurement (SEM) were used to describe the test-retest reliability of the measure across the sample: the Bland-Altman approach was used to describe reliability at the individual level. The test-retest reliability for categorized total physical activity (active, insufficiently active, sedentary) was assessed using the kappa statistic. Results: When the complete sample was considered, the ICC ranged from 0.40 (95% Cl: 0.24, 0.55) for vigorous gardening to 0.77 (95% Cl: 0.68, 0.84) for moderate physical activity. The SEM, however, were large. indicating high measurement error. The Bland-Altman plots indicated that the reproducibility of data decreases as the aniount of physical activity reported each week increases The kappa coefficient for the categorized data was 0.62 (95% Cl: 0.48, 0.76). Conclusion: Overall. the results indicated low levels of repeatability for this measure of historical physical activity. Categorizing participants as active, insufficiently active, or sedentary provides a higher level of test-retest reliability.

The diagnostic interview for psychoses (DIP): development, reliability and applications

Background. We describe the development, reliability and applications of the Diagnostic Interview for Psychoses (DIP), a comprehensive interview schedule for psychotic disorders. Method. The DIP is intended for use by interviewers with a clinical background and was designed to occupy the middle ground between fully structured, lay-administered schedules, and semi-structured., psychiatrist-administered interviews. It encompasses four main domains: (a) demographic data; (b) social functioning and disability; (c) a diagnostic module comprising symptoms, signs and past history ratings; and (d) patterns of service utilization Lind patient-perceived need for services. It generates diagnoses according to several sets of criteria using the OPCRIT computerized diagnostic algorithm and can be administered either on-screen or in a hard-copy format. Results. The DIP proved easy to use and was well accepted in the field. For the diagnostic module, inter-rater reliability was assessed on 20 cases rated by 24 clinicians: good reliability was demonstrated for both ICD-10 and DSM-III-R diagnoses. Seven cases were interviewed 2-11 weeks apart to determine test-retest reliability, with pairwise agreement of 0.8-1.0 for most items. Diagnostic validity was assessed in 10 cases, interviewed with the DIP and using the SCAN as 'gold standard': in nine cases clinical diagnoses were in agreement. Conclusions. The DIP is suitable for use in large-scale epidemiological studies of psychotic disorders. as well as in smaller Studies where time is at a premium. While the diagnostic module stands on its own, the full DIP schedule, covering demography, social functioning and service utilization makes it a versatile multi-purpose tool.