Reliability of moderate-intensity and vigorous physical activity stage of change measures for young adults

Background. The purpose of this study was to examine the reliability of stage of change (SOC) measures for moderate-intensity and vigorous physical activity in two separate samples of young adults. Staging measures have focused on vigorous exercise, but current public health guidelines emphasize moderate-intensity activity. Method. For college students in the USA (n = 105) and in Australia (n = 123), SOC was assessed separately on two occasions for moderate-intensity activity and for vigorous activity. Test-retest repeatability was determined, using Cohen's kappa coefficient. Results. In both samples, the reliability scores for the moderate-intensity physical activity staging measure were lower than the scores for the vigorous exercise staging measure. Weighted kappa values for the moderate-intensity staging measure were in the fair to good range for both studies (0.50 and 0.45); for the vigorous staging measure kappa values were excellent and fair to good (0.76 and 0.72). Conclusions. There is a need to standardize and improve methods for staging moderate-intensity activity, given that such measures are used in public health interventions targeting HEPA (health-enhancing physical activity). (C) 2003 American Health Foundation and Elsevier Science (USA). All rights reserved.

The diagnostic reliability of Internet-based observational kinematic gait analysis

We investigated the accuracy and reliability of observational kinematic gait assessments performed via a low-bandwidth Internet link (118 kbit/s) and a higher-speed Internet link (128 kbit/s). Twenty-four subjects were randomized to either bandwidth group. Gait was assessed with the Gait Assessment Rating Scale (GARS) in the traditional manner, which is from video-recordings, and with repeated measurements via the online method. Online assessment was found to provide as accurate a measure of gait performance as the traditional assessment (limits of agreement

The List of Social Situation Problems: Reliability and validity in an adolescent Spanish-speaking sample

The aim of this study was to analyze the psychometric properties of the Spanish translation of the List of Social Situation Problems (LSSP; S. H. Spence, 1980). The questionnaire was administered to a sample of 388 adolescents between the ages of 12 and 18. Exploratory factor analysis identified four factors: Social Anxiety, Adult Oppositional, Assertiveness, and Making Friends, which accounted for 26.64% of the variance. Internal consistency of the total scale was high (alpha = .86). Correlations between the LSSP and two self-report measures of social anxiety, the Questionnaire about Interpersonal Difficulties for Adolescents (r = .45) and the Social Phobia and Anxiety Inventory (r = .48), were statistically significant. A significant difference was found between LSSP total scores for adolescents with and without social anxiety (d = 1.14), supporting the construct validity of the scale.

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).

Telephone counselling for adolescent suicide prevention: Changes in suicidality and mental state from beginning to end of a counselling session

Telephone counselling is an accessible and confidential means by which distressed young people can seek help. Telephone counselling services were funded under Australia's National Youth Suicide Prevention Strategy between 1997 and 2000. In this study, the effectiveness of telephone counselling for young people seeking help in the context of suicidal ideation or intent was evaluated in an investigation of calls made by suicidal young people to a telephone counselling service. Independent raters measured callers' suicidality and mental state at the beginning and, end of 100 taped counselling sessions. Changes in suicidality and mental state were measured using a reliable rating scale developed for the study. Significant decreases in suicidality and significant improvement in mental state were found to occur during the course of counselling sessions, suggesting positive immediate impact.-Limitations of the study with respect to longer-term outcomes and the relevance of the results for suicide prevention are discussed. Notwithstanding the study limitations, the results lend support for continuing development of hotline services.

Optimal reliability improvement for used items sold with warranty

The market for used products is becoming more competitive and dealers of used products use warranty to promote sales as well as to provide assurnace to customers. Offering warranty results in additional costs associated with warranty servicing. This cost can be reduced through actions such as overhaul and upgrade that improves the reliability of the item. This is worthwhile only if the cost of improvement is less than the reduction in the warranty servicing cost. This paper deals with two models to decide on the reliability improvement strategies for used items sold with FRW policy.

Reliability of the Knee Examination in Osteoarthritis: Effect of Standardization

Objective. To assess the reliability of physical examination of the osteoarthritic (OA) knee by rheumatologists, and to evaluate the benefits of standardization. Methods. Forty-two physical signs and techniques were evaluated using a 6 X 6 Latin square design. Patients with mild to severe knee OA, based on physical and radiographic signs, were examined in random order prior to and following standardization of techniques. For those signs with dichotomous scales, agreement among the rheumatologists was calculated as the prevalence-adjusted bias-adjusted kappa (PABAK), while for the signs with continuous and ordinal scales, a reliability coefficient (R-c) was calculated using analysis of variance. A PABAK of >0.60 and an Re of >0.80 were considered to indicate adequate reliability. Results. Adequate poststandardization reliability was achieved for 30 of 42 physical signs/techniques (71%). The most highly reliable signs identified by physical examination of the OA knee included alignment by goniometer (R-c = 0.99), bony swelling (R-c = 0.97), general passive crepitus (R-c = 0.96), gait by inspection (PABAK = 0.78), effusion bulge sign (R-c = 0.97), quadriceps atrophy (R. = 0.97), medial tibiofemoral tenderness (R-c = 0.94), lateral tibiofemoral tenderness (R-c = 0.85), patellofemoral tenderness by grind test (R-c = 0.94), and flexion contracture (R-c = 0.95). The standardization process resulted in substantial improvements in reliability for evaluation of a number of physical signs, although for some signs, minimal or no effect of standardization was noted. After standardization, warmth (PABAK = 0.14), medial instability at 30degrees flexion (PABAK = 0.02), and lateral instability at 30degrees flexion (PABAK = 0.34) were the only 3 signs that were highly unreliable. Conclusion. With the exception of physical examinations for instability, a comprehensive knee examination can be performed with adequate reliability. Standardization further improves the reliability for some physical signs and techniques. The application of these findings to future OA studies will contribute to improved outcome assessments in OA.

Mediated approaches for influencing physical activity: Update of the evidence on mass media, print, telephone and website delivery of interventions

The aim of this paper is to review evidence published since 1997 on the effectiveness of mass media, print, telephone and website-delivered physical activity (PA) interventions. For mass media, there is consistent evidence for impacts on recall of campaign tag lines and message content and modest evidence of short-term impacts on behaviour in some population subgroups. Print-based delivery of programs can have a modest impact on behaviour; research is needed on supplementary strategies to support print programs. Although there is a strong case for the potential of telephone and Internet delivered interventions, there is as yet little evidence that they can be effective. All of these 'mediated' approaches to PA program delivery are likely to be important elements of future public health interventions. The body of evidence for their effectiveness in changing behaviour is currently modest, however, and it is clear that these approaches have not yet been fully developed and evaluated. Combinations of different media and mutually supportive, integrated strategies are likely to be more effective and need to be developed and evaluated systematically, building on the current research evidence base.

Trial of print and telephone delivered interventions to influence walking

Background. Both self-help print materials and telephone-assisted counseling have generally proved useful strategies to increase physical activity. This study examined their effectiveness in an intervention aimed specifically at promoting walking for specific purposes. Methods. Participants (n = 399) were randomly allocated to one of two 3-week intervention programs. The Print program comprised multiple mailing of brochures that emphasized walking within the local community environments. The Print plus Telephone program received the same brochures plus three telephone calls. Data collected via mailed self-completed surveys were analyzed by exploring outcomes related to walking for specific purposes. Results. There were no significant differences between the two programs in any of the walking measures. Both groups significantly increased time reported walking for exercise per week [Print: t(1,277) = -3.50, P < 0.001; Print plus telephone: t(1,106) = -2.44, P < 0.016]. Significantly, more participants in the Print plus Telephone group reported receiving and reading the materials (chi(2) = 20.11, P < 0.0001). Conclusions. The intervention programs were more successful at increasing walking for exercise than for any other purpose. The addition of brief telephone support was successful in focusing participants' attention on the print materials, but did not result in any additional increase in walking. (C) 2004 The Institute For Cancer Prevention and Elsevier Inc. All rights reserved.

Test-retest reliability of four physical activity measures used in population surveys

Accurate monitoring of prevalence and trends in population levels of physical activity (PA) is a fundamental public health need. Test-retest reliability (repeatability) was assessed in population samples for four self-report PA measures: the Active Australia survey (AA, N=356), the short International Physical Activity Questionnaire (IPAQ, N=104), the physical activity items in the Behavioral Risk Factor Surveillance System (BRFSS, N=127) and in the Australian National Health Survey (NHS, N=122). Percent agreement and Kappa statistics were used to assess reliability of classification of activity status as 'active', 'insufficiently active' or 'sedentary'. Intraclass correlations (ICCs) were used to assess agreement on minutes of activity reported for each item of each survey and for total minutes. Percent agreement scores for activity status were very good on all four instruments, ranging from 60% for the NHS to 79% for the IPAQ. Corresponding Kappa statistics ranged from 0.40 (NHS) to 0.52 (AA). For individual items, ICCs were highest for walking (0.45 to 0.78) and vigorous activity (0.22 to 0.64) and lowest for the moderate questions (0.16 to 0.44). All four measures provide acceptable levels of test-retest reliability for assessing both activity status and sedentariness, and moderate reliability for assessing total minutes of activity.

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.

Papillary urothelial neoplasm of low malignant potential: reliability of diagnosis and outcome

OBJECTIVE To determine the ability of pathologists to reproducibly diagnose a newly defined lesion, i.e. the papillary urothelial neoplasm of low malignant potential (PUNLMP) using the published criteria, defined by the 1998 World Health Organisation/International Society of Urological Pathology (WHO/ISUP) classification system; in addition, debate remains about the clinical behaviour of these lesions, thus the rates of recurrence and progression of PUNLMP lesions were assessed and compared with low-grade papillary urothelial carcinomas (LG-PUC) and high-grade (HG-PUC) over a 10-year follow-up. PATIENTS AND METHODS Forty-nine cases of superficial bladder cancer (G1-3 pTa) representing an initial diagnosis of transitional cell carcinoma made in 1990 were identified and re-graded using the 1998 WHO/ISUP classification by two pathologists. Inter-observer agreement was assessed using Cohen weighted kappa statistics. After reclassification the clinical follow-up was reviewed retrospectively, and episodes of recurrence and progression recorded. RESULTS The inter-observer agreement was moderate, regardless of whether one (kappa 0.45) or two (kappa 0.60) pathologists were used to grade these lesions. Re-classification identified 12 PUNLMP, 28 LG-PUC and nine HG-PUC. PUNLMP lesions recurred in 25% (3/12) of cases; no progression was documented. Recurrence rates were 75% (21/28) and 67% (6/9) for LG- and HG-PUC, respectively, and progression rates were 4% (1/28) and 22% (2/9). CONCLUSION The 1998 WHO/ISUP classification of urothelial neoplasms can be reproducibly applied by pathologists, with a moderate level of agreement. There is evidence that PUNLMP lesions have a more indolent clinical behaviour than urothelial carcinomas. However, the risk of recurrence and progression remains, and clinical monitoring of these patients is important.