Robert Trevethan - Academia.edu (original) (raw)

Papers by Robert Trevethan

The Foot, Sep 1, 2018

To be effective in screening, prognostic, and monitoring contexts, the toe-brachial index (TBI) s... more To be effective in screening, prognostic, and monitoring contexts, the toe-brachial index (TBI) should not be susceptible to large sporadic fluctuations from one time to another. In order to identify whether those fluctuations exist in people who have suboptimal TBIs, the temporal stability of their TBIs was examined in detail across 6 months. Methods: TBI readings from SysToe and Omron automated devices were taken from 21 participants at baseline and at 2-and 6-month timepoints subsequently. The primary inclusion criterion was that participants had at least one of three baseline TBIs on either foot ≤0.65 if a standard 25-mm wide occlusion cuff was used, or ≤0.85 if a 15-mm occlusion cuff was used. Results: After excluding five participants because of their extremely high TBI fluctuations, TBI stability within the remaining 16 participants was examined. Ipsilateral TBIs changed by ≥0.10 on at least one foot for 11 participants across the initial 2-month timespan (maximum difference 0.26) and for same number of participants across the full 6-month timespan (maximum difference 0.36), with the composition of the 11-person groups differing slightly for the two timespans. Contralateral differences were ≥0.10 for five participants across the 2month timespan (maximum difference 0.26) and for nine participants across the 6-month timespan (maximum difference 0.42), again with some group overlap. The foot with the higher TBI at baseline remained so across the 6 months. Conclusions: For many people with suboptimal TBIs there might be inherent ipsilateral and contralateral inconsistency among TBI readings. This threatens the effectiveness of TBIs for screening, prognostic, and monitoring purposes. In order to maximize the prospects of the TBI as a valuable metric, adherence to standard protocols should be observed and other prospects for the TBI to assess vascular supply to the foot more effectively should be considered.

Frontiers of Education in China, Jun 1, 2020

This study comprises the second stage of a research program in which sense of efficacy for teachi... more This study comprises the second stage of a research program in which sense of efficacy for teaching (SET) was investigated in Chinese mainland preservice and inservice teachers (PSTs and ISTs, respectively). Scores on SET were calculated and described, and SET comparisons were made between and within PSTs and ISTs. Relative to PSTs, ISTs had higher SET; within both the PSTs and IST samples there were no gender differences; but among ISTs there were some associations of SET with years of teaching, teacher roles, and whether the schools were categorized as advanced or standard. Tentative comparisons are drawn concerning SET in Chinese and Western contexts, and recommendations are made concerning effective measurement of teacher sense of efficacy in China and elsewhere.

Modern health science, Jun 13, 2019

This article is concerned with the sensitivity, specificity, predictive values, and other metrics... more This article is concerned with the sensitivity, specificity, predictive values, and other metrics associated with screening tests. It has direct origins in two previous articles. In this third article, the author of the first article writes about topics and issues that were addressed only minimally in his previous article and expands on topics raised by authors of the second article. In particular, attention is turned to wording and terminology that can be idiosyncratic and confusing with regard to screening versus diagnosis as well as to issues associated with reference ("gold") standards and screening tests, and to the importance of cutpoints and prevalence in relation to metrics associated with screening tests. The primary aims are to help readers attain clarity about topics that they might have felt unsure about; gain reassurance about conceptual difficulties in the field that, once recognized for what they are, can become less problematic because it is possible to be confident about not being confident; and, where appropriate, adopt a skeptical attitude about screening tests and their associated metrics. Examples are drawn from the use of ankle-brachial and toe-brachial indices for identifying peripheral artery disease, although wider applicability is intended.

Frontiers of Education in China, Dec 1, 2019

In this study, issues concerning the design of scales for measuring teacher sense of efficacy (TS... more In this study, issues concerning the design of scales for measuring teacher sense of efficacy (TSE) are first identified with particular attention to the Teacher Sense of Efficacy Scale (TSES). Psychometric issues concerning analysis and reporting of TSE data are subsequently identified. Recommendations are offered about all identified issues, and these recommendations are taken into account when obtaining and analyzing TSE data from Chinese mainland preservice and inservice teachers. Exploratory factor analyses yielded a single factor for both samples as well as for four subgroups within the inservice teacher sample. Results also provided insights about scale design as well as the TSES being limited for capturing the breadth of TSE. Suggestions are made for improvements in the assessment of TSE.

Scandinavian Journal of Clinical & Laboratory Investigation, Dec 17, 2017

Abstract Although the ankle-brachial index (ABI) has been used as an indicator of peripheral arte... more Abstract Although the ankle-brachial index (ABI) has been used as an indicator of peripheral artery disease and vascular supply to the foot for over 50 years, it is now associated with reservations and qualifying empirical evidence to the extent that the provocative step of abandoning it totally might be advisable. In this article, the results of three publications concerning the ABI are initially described in some depth and the results from eight additional publications are then summarized more briefly. Cumulatively, the research indicates that ABIs that seem to be normal, as well as those in the subnormal range, are often inflated by medial arterial calcification and can therefore produce a high proportion of false-negative screening test results for arterial disease as well as a misleadingly high impression of vascular sufficiency to the lower extremity. The toe-brachial index is suggested as being likely to overcome the problems associated with the ABI, and other alternatives to the ABI and TBI are acknowledged.

American Journal of Men's Health, Apr 21, 2010

This study reports on a survey of 166 gay men in Sydney, Australia, that explores the links betwe... more This study reports on a survey of 166 gay men in Sydney, Australia, that explores the links between internalized shame, internalized homophobia, and attachment style. These variables were linked to the age of coming out, family and peer acceptance of their sexuality, relationship status, and previous marriage. Findings suggest a strong relationship between shame, internalized homophobia, and anxious and avoidant attachment style. Shame was predicted by internalized homophobia and anxious and avoidant attachment style. A significant proportion of gay men reported that they were not easily accepted when they first came out. There was a significant relationship between coming out and internalized homophobia but not with shame and attachment style. Furthermore, men who had never come out to family and friends reported higher levels of internalized homophobia but not higher levels of shame and attachment style. Of particular significance was the connection between previous marriage and higher levels of shame and internalized homophobia. Finally, gay men who were not currently in a relationship reported higher levels of shame anxious and avoidant attachment style. These findings are related to therapeutic work with gay men who have previously been married and those who are concerned with their current single status.

Frontiers in Public Health, Nov 20, 2017

Within the context of screening tests, it is important to avoid misconceptions about sensitivity,... more Within the context of screening tests, it is important to avoid misconceptions about sensitivity, specificity, and predictive values. In this article, therefore, foundations are first established concerning these metrics along with the first of several aspects of pliability that should be recognized in relation to those metrics. Clarification is then provided about the definitions of sensitivity, specificity, and predictive values and why researchers and clinicians can misunderstand and misrepresent them. Arguments are made that sensitivity and specificity should usually be applied only in the context of describing a screening test's attributes relative to a reference standard; that predictive values are more appropriate and informative in actual screening contexts, but that sensitivity and specificity can be used for screening decisions about individual people if they are extremely high; that predictive values need not always be high and might be used to advantage by adjusting the sensitivity and specificity of screening tests; that, in screening contexts, researchers should provide information about all four metrics and how they were derived; and that, where necessary, consumers of health research should have the skills to interpret those metrics effectively for maximum benefit to clients and the healthcare system.

Personality and Individual Differences, 1987

ABSTRACT Investigated the personality correlates of authoritarian attitudes (Ray, 1979) and anti-... more ABSTRACT Investigated the personality correlates of authoritarian attitudes (Ray, 1979) and anti-submissive behaviour (Rigby, 1986), among an Australian college sample (N = 198). Authoritarianism (in the attitudinal sense) was found not to correlate with the major dimensions of the EPQ for the whole sample although female authoritarians scored high on the N subscale (r = 0.40; P < 0.01). By contrast, anti-submissive behaviour was found to be associated with extraversion for females and tough-mindedness for males. Further factor analysis revealed the P subscale of the EPQ not to load on a factor identified as ‘authoritarianism’. This does not support the research of Kline and Cooper (1984).

Current Diabetes Reviews, Jan 18, 2019

Background & Aims: Toe Systolic Blood Pressures (TSPs) and Toe-Brachial Indices (TBIs) ha... more Background & Aims: Toe Systolic Blood Pressures (TSPs) and Toe-Brachial Indices (TBIs) have been identified as useful adjuncts in the identification of pedal ischemia, peripheral artery occlusive diseases, and risk for either nonhealing of lower extremity wounds or for amputation. Valid measurement of TSPs and TBIs is therefore essential. However, it could be jeopardized by rater, instrument, and intratestee inconsistency. These three sources of inconsistency were examined in this research. Methods: Five publications addressing TSP and TBI consistency were identified and their results were analyzed using intraclass correlation coefficients. Results: Moderate variability in TSPs was found across all studies; greater variability was evidenced in brachial systolic pressure, particularly for people who had diabetes; and TBI values also exhibited considerable variability, but little difference between people who did and did not have diabetes. Conclusion: These findings provide qualified evidence of consistency regarding measurement of TSPs but challenge TBI as a valid and useful indicator in screening, prognostic, and monitoring contexts, particularly for people who have diabetes. However, there is a prospect that TBI assessment could be improved by adherence to standardized protocols and by obtaining multiple measurements from toes and arms on a single occasion as well as on different occasions.

Frontiers in Public Health, Jan 14, 2020

Frontiers in Public Health, Aug 7, 2017

When people's knowledge and awareness are the subject of public health research, the meanings app... more When people's knowledge and awareness are the subject of public health research, the meanings applied to the words knowledge and awareness are often unclear. Although frequently used interchangeably without that being problematic, these words sometimes appear to have different intended meanings but those meanings are not made explicit or, despite the meanings having been made explicit, they are not adhered to. It is necessary to overcome obscurities when knowledge and awareness are intended to represent different domains. This occurs when they are compared with each other; it also occurs when knowledge and awareness are assessed separately in relation to such variables as health behavior; physical, psychological, or socioeconomic statuses; gender; age; and ethnic backgrounds. For those particular research ventures, recommendations are made that knowledge be used to refer to information that is, to a greater or lesser extent, detailed and factual, and that awareness be associated with information that is personally relevant. Some suggestions are made, and issues are raised, about how the psychometric foundations for each of those two domains might be established prior to use in empirical research. Adopting the recommendations and suggestions made in this article provides opportunities for greater conceptual and empirical clarity and success.

The Foot, Dec 1, 2010

Two foot health inventories, the Foot Function Index and the Foot Health Status Questionnaire, ar... more Two foot health inventories, the Foot Function Index and the Foot Health Status Questionnaire, are evaluated in terms of the developmental procedures used to create them. Both instruments have a number of deficiencies with regard to the initial stages of their development and with their purported reliability and validity. These deficiencies indicate that these instruments may have limited value and that in both clinical and research situations they may not produce sufficiently accurate or informative results. Given that these instruments are typical of many self-referent instruments used in health contexts, clinicians and researchers should carefully evaluate the credentials of such instruments before using them. This article demonstrates how such evaluations might be conducted.

Health Services and Outcomes Research Methodology, Aug 23, 2016

Intraclass correlation coefficients (ICCs) are frequently employed in health science research, of... more Intraclass correlation coefficients (ICCs) are frequently employed in health science research, often to assess intrarater and interrater reliability. In many cases, insufficient details are provided about these ICCs and there seem to be misunderstandings about their selection and how they should be interpreted. This paper is intended primarily to provide a clear, accessible description of ICCs, including how they should be selected, interpreted, and reported. Emphasis is given to areas where researchers seem to encounter the greatest conceptual difficulties and to exhibit the greatest misconceptions. Two extended examples are used to support the points being made. Major additional aims of this paper are to raise the awareness of authors, reviewers, and editors concerning the importance of using appropriate ICCs, and to encourage them to ensure that complete and accurate information about ICCs is reported in journal articles. Failure to do so perpetuates a risk that incorrect decisions might be made about matters that are of crucial importance for people's health.

Scandinavian Journal of Clinical & Laboratory Investigation, May 11, 2019

Journal of the Australian Library and Information Association, Jan 2, 2017

Abstract Although commendable in many respects, some university library websites categorise acade... more Abstract Although commendable in many respects, some university library websites categorise academic referencing styles and systems in ways that are unhelpful and inaccurate. In this article, the four major styles of referencing (Harvard, Oxford, Vancouver and Modern Language Association) are described in sufficient detail to demonstrate that they should be clearly differentiated from each other. Where appropriate, systems that fall within these styles are also described to illustrate that they should be grouped according to the style within which they belong but should also be clearly demarcated. As a result of this, recommendations are made that university library websites provide clearer and more coherent, complete and accurate information about referencing.

BioMed Research International, Jul 14, 2021

The Physical Activity Questionnaire for Adolescents (PAQ-A) has been used in a variety of forms a... more The Physical Activity Questionnaire for Adolescents (PAQ-A) has been used in a variety of forms and in a range of countries. This study involves a detailed examination of the PAQ-A to determine its applicability and effectiveness in an Ethiopian setting. We administered the scale to 110 Ethiopian adolescents on two occasions, 5 weeks apart. Data were inspected for features typical of the participants and analyzed to identify interitem correlations, the scale's factor structure, and a range of descriptive statistics concerning composite scores. Most of the scale's items were satisfactorily interrelated according to lenient criteria, and most items loaded on a single factor in exploratory factor analyses. However, a number of the scale's properties were deficient according to stringent or conventionally accepted psychometric criteria. Close inspection of participants' responses highlighted problems in the way the scale is worded, interpreted by participants, and scored. Although the scale does not capture PA as an homogeneous construct, we argue that this is not a problem and neither is its poor test-retest reliability. We make recommendations concerning presentation and scoring of the PAQ-A that are likely to enhance its validity beyond Ethiopia, and we provide a modified version of the scale.