Biomedical subjects

Chris Roberts

Publications and source records attributed to Chris Roberts.

At least 19 recordsLinked to original sources

PubMed2006

Trends in vigorous physical activity and TV watching of adolescents from 1986 to 2002 in seven European Countries.

BACKGROUND: The aim is to study trends in physical activity and TV viewing in seven European countries in the period 1985-2002. METHODS: The data are collected through questionnaires in the survey 'Health Behaviour in School-aged Children. A WHO Cross-national study', using nationally representative samples of 11-, 13-, and 15-year-olds. Between 1985/86 and 2001/02, a standard set of items was used to measure vigorous physical activity and TV watching in the study. Austria, Finland, Hungary, Norway, Scotland, Sweden, and Wales used these measures in all surveys. RESULTS: Between 1985/86 and 2001/02, there was a slight increase in Finland in the proportions reporting vigorous physical activity 4 or more times a week, whereas as pattern of stability was observed for the other countries. Across all surveys and countries boys were more likely to report regular vigorous physical activity than girls. No clear pattern emerges when examining trends over time in TV watching. Boys reported spending more time watching TV than girls in all countries. The correlation between the two behaviours at the 1986 and 1998 measurement points was non-significant. CONCLUSION: The finding that boys were more likely to report regular vigorous physical activity and TV watching confirms results of previous studies. The present study of seven European countries generally indicates stability or a small increase in physical activity of boys and girls aged 11-15 from the mid-1980s to the early 2000s.

Adolescent↗

PubMed2006

Telephone administered cognitive behaviour therapy for treatment of obsessive compulsive disorder: randomised controlled non-inferiority trial.

OBJECTIVES: To compare the effectiveness of cognitive behaviour therapy delivered by telephone with the same therapy given face to face in the treatment of obsessive compulsive disorder. DESIGN: Randomised controlled non-inferiority trial. SETTING: Two psychology outpatient departments in the United Kingdom. PARTICIPANTS: 72 patients with obsessive compulsive disorder. INTERVENTION: 10 weekly sessions of exposure therapy and response prevention delivered by telephone or face to face. MAIN OUTCOME MEASURES: Yale Brown obsessive compulsive disorder scale, Beck depression inventory, and client satisfaction questionnaire. RESULTS: Difference in the Yale Brown obsessive compulsive disorder checklist score between the two treatments at six months was -0.55 (95% confidence interval -4.26 to 3.15). Patient satisfaction was high for both forms of treatment. CONCLUSION: The clinical outcome of cognitive behaviour therapy delivered by telephone was equivalent to treatment delivered face to face and similar levels of satisfaction were reported. TRIAL REGISTRATION: Current Controlled Trials ISRCTN500103984 [controlled-trials.com].

Adolescent↗

PubMed2006

Television viewing behaviour and associations with food habits in different countries.

OBJECTIVE: Several environmental factors influence adolescents' food habits and television (TV) viewing is thought to be one of these factors. The purpose of the present study was to describe sociodemographic differences in TV viewing and to examine associations of TV viewing with the consumption of sweets, soft drinks, fruit and vegetables in different countries. METHODS: Data were collected from 162,305 young people completing the 2001/02 Health Behaviour in School-Aged Children survey, a World Health Organization cross-national study on health and health behaviours among 11-, 13- and 15-year-old school pupils. Analyses of variance were used to examine sociodemographic differences in TV viewing and logistic regression analyses to examine associations between TV viewing and food habits. RESULTS: Large differences were found between countries in reported daily TV viewing time, from an average of 2.0 h in Switzerland to 3.7 h in Ukraine. The results indicate that those most likely to watch TV are boys, 13-year-olds and pupils of lower socio-economic status. Those who watched more TV were more likely to consume sweets and soft drinks on a daily basis and less likely to consume fruit and vegetables daily, although the latter associations were not so apparent among Central and Eastern European countries. CONCLUSIONS: Given the high TV viewing rates among adolescents and the association with less healthy food options, many young people are at increased risk of overweight or obesity. Interventions to modify TV viewing behaviour are needed. The findings underscore the importance of tackling socio-economic differences.

Adolescent↗

PubMed2006

Discovering professionalism through guided reflection.

Doctors need to identify and understand the professional behaviours of both themselves and others. In order for students to think critically about these issues we encouraged them to use the tenets of the General Medical Council's Duties of a Doctor as a framework in which to reflect on the actions of healthcare professionals at work. Although the critical incident technique is a well-known process for encouraging reflection, little is known about its usefulness for assessment purposes in this setting. We aimed to discover the validity, feasibility and educational impact of the critical incident as an assessment method for first year students undertaking guided reflection in the context of their first exposure to multi-professional health and social care experiences. First year medical students submitted two critical incidents they had observed during multi-professional health and social care attachments and an evaluation of their experiences. Students engaged in the reflective cycle on the professional behaviours of others providing evidence of a varied range of situations. With adequate preparation, junior students are able to reflect on social and healthcare experiences using the Duties of a Doctor as a framework. Critical incidents are a valid and feasible method for assessing students' reflections on professionalism, with good educational impact.

Attitude of Health Personnel↗

PubMed2006

Assuring the quality of high-stakes undergraduate assessments of clinical competence.

In the UK, and in many Commonwealth countries, a university degree is accepted by registration bodies as an indication of competence to practice as a PRHO or intern. Concerns have been raised that the quality of university examinations may not always be sufficient for such high-stakes decision-making. Assessments of clinical competence are subject to many potential sources of error. The search for standardization, and high validity and reliability, demands the identification and reduction of measurement errors and biases due to poor test design or variation in test items, judges, patients or examination procedures. Generalizability and other research studies have identified where the likely sources of error might arise and have been taken into account in the development of published guidelines on international best practice, which institutions should strive to follow. The purpose of this paper is to describe the development of the integrated final-year assessment of clinical competence at the University of Sheffield. The aim was to introduce a range of strategies to ensure the examination met the best practice guidelines. These included blueprinting the assessment to achieve a high degree of content validity; lengthening the examination by adding a written component to the OSCE component to ensure an adequate level of reliability; providing training and feedback for examiners and simulated patients; paying attention to item development; and providing statistical information to assist the examination committee in standard setting and decision-making. This evidence-based approach should be readily achievable by all medical schools.

Clinical Competence↗

PubMed2006

Identification of potential pharmacological and toxicological targets differentiating structural analogs by a combination of transcriptional profiling and promoter analysis in LS-180 and Caco-2 adenocarcinoma cell lines.

Detecting and understanding the potential for off-target pharmacological effects is critical in the optimization of lead compounds in drug discovery programs. Compound-mediated activation of the pregnane X receptor (PXR; NR1I2), a key regulator for drug metabolism genes, is often monitored to avoid potential drug-drug interactions. Two structural analogs, MRL-1 and MRL-2, were determined to be equivalent PXR activators in trans-activation assays. To differentiate these two PXR activators, their transcriptional effects were examined in PXR-sufficient (LS180) and PXR-deficient (Caco-2) adenocarcinoma cell lines. Both compounds regulated drug-management genes (e.g. CYP3A4, CYP2B6, UGT1A1 and ABCB1) in LS180 cells, but not in PXR-deficient Caco-2 cells. The potency of MRL-1 and MRL-2 on PXR activation was again equivalent as revealed by a set of 113 genes that were regulated by four prototypical PXR agonists (rifampicin, ritonavir, troglitazone and dexamethasone) in the LS180 cells. The specificity of the PXR signature genes was supported by the enrichment of putative PXR binding sites uncovered by sequence-based promoter analyses. Interestingly, an additional off-target activity of MRL-2 was suggested where sterol response element binding protein binding sites were found enriched in a subset of PXR signature genes. These genes, involved in cholesterol and fatty acid synthesis, were significantly regulated by ritonavir, chlorpromazine and MRL-2, which were linked to the manifestation of phospholipidosis. The present study demonstrates the utility of our approach in the differentiation and selection of lead compounds for drug development.

Benzopyrans↗

PubMed2006

The reliability and validity of a matrix to assess the completed reflective personal development plans of general practitioners.

INTRODUCTION: We wished to determine whether assessors could make reliable and valid judgements about the quality of completed reflective personal development plans (PDPs) for the purpose of accrediting UK general practitioners (GPs) for a postgraduate education allowance using a marking matrix, and secondly, to plan a feasible model of PDP assessment in the context of forthcoming GP appraisal/revalidation that would overcome the main sources of error identified from this study. METHODS: Within generalisability theory, a variance components analysis on PDP scores estimated reliability and the effect on them of varying, for example, the number of assessors. We investigated the construct validity of the matrix through its internal consistency and detection of differences in the quality of PDPs. RESULTS: For a single PDP and one assessor, 37.6% of the variance in scores was due to true differences in the quality of the PDP. Between 5 and 7 PDP assessors are needed to achieve summative reliability of greater than 0.8. While increasing the number of judges is important, reliability could also be improved by addressing assessor subjectivity. Construct validity was demonstrated, as the matrix distinguished between good, satisfactory and poor PDPs, and it had good internal consistency. CONCLUSION: PDP assessment has reasonable summative characteristics for the purpose of assessing GPs' reflective continuing professional development. If doctors could include their PDPs within their revalidation folders as evidence of their reflections on pursuing better clinical performance, we have described a reliable, valid and feasible method of external assessment.

Accreditation↗

PubMed2006

Group cognitive-behavioural therapy for schizophrenia. Randomised controlled trial.

BACKGROUND: The efficacy of cognitive-behavioural therapy for schizophrenia is established, but there is less evidence for a group format. AIMS: To evaluate the effectiveness of group cognitive-behavioural therapy for schizophrenia. METHOD: In all, 113 people with persistent positive symptoms of schizophrenia were assigned to receive group cognitive-behavioural therapy or treatment as usual. The primary outcome was positive symptom improvement on the Positive and Negative Syndrome Scales. Secondary outcome measures included symptoms, functioning, relapses, hopelessness and self-esteem. RESULTS: There were no significant differences between the cognitive-behavioural therapy and treatment as usual on measures of symptoms or functioning or relapse, but group cognitive-behavioural therapy treatment resulted in reductions in feelings of hopelessness and in low self-esteem. CONCLUSIONS: Although group cognitive-behavioural therapy may not be the optimum treatment method for reducing hallucinations and delusions, it may have important benefits, including feeling less negative about oneself and less hopeless for the future.

Adult↗

PubMed2006

Is self-care a cost-effective use of resources? Evidence from a randomized trial in inflammatory bowel disease.

OBJECTIVES: To determine if a whole-system approach to self-management in inflammatory bowel disease (IBD), using a guidebook developed with patients and physicians trained in patient-centred care, leads to cost-effective use of health system resources. METHODS: Cost-effectiveness analysis over a one-year time horizon comparing the whole systems self-management approach to treatment with usual treatment. Nineteen hospitals in the northwest England were randomized to the intervention or to be controls; 651 patients (285 at intervention sites and 366 at control sites) with established IBD were included. The economic evaluation related differential health service costs, from a UK NHS perspective, to differences in quality-adjusted life years (QALYs) based on patients' responses to the EQ-5D. RESULTS: The intervention was associated with a mean reduction in costs of 148 pounds sterling per patient and a small mean reduction in QALYs of 0.00022 per patient compared with the control group. This resulted in an incremental cost per QALY gained of 676,417 pounds sterling for treatment as usual and a probability of around 63% that the whole-system approach to self-management is cost-effective, assuming a willingness to pay up to 30,000 pounds sterling for an additional QALY. CONCLUSIONS: Although there is uncertainty associated with these estimates, more widespread use of this method in chronic disease management seems likely to reduce health care costs without evidence of adverse effect on patient outcomes.

Cost-Benefit Analysis↗

PubMed2006

Predicting persistent disabling low back pain in general practice: a prospective cohort study.

BACKGROUND: Patients may adopt active and/or passive coping strategies in response to pain. However, it is not known whether these strategies may also precede the onset of chronic symptoms and, if so, whether they are independent predictors of prognosis. AIM: To examine, in patients with low back pain in general practice, the prognostic value of active and passive coping styles, in the context of baseline levels of pain, disability and pain duration. DESIGN OF STUDY: Prospective cohort study. SETTING: Nine general practices in north west England. METHOD: Patients consulting their GP with a new episode of low back pain were recruited to the study. Information on coping styles, pain severity, disability, duration, and a brief history of other chronic pain symptoms was recorded using a self-completion postal questionnaire. Participants were then sent a follow-up questionnaire, 3 months after their initial consultation, to assess the occurrence of low back pain. The primary outcome was persistent disabling low back pain, that is, low back pain at 3-month follow-up self-rated as >or=20 mm on a 100 mm visual analogue scale, and >or=5 on the Roland and Morris Disability Questionnaire. RESULTS: A total of 974 patients took part in the baseline survey, of whom 922 (95%) completed a follow-up questionnaire; 363 individuals (39%) reported persistent disabling pain at follow-up. Persons who reported high levels of passive coping experienced a threefold increase in the risk of persistent disabling low back pain (relative risk [RR] = 3.0; 95% confidence interval [CI] = 2.3 to 4.0). In contrast, active coping was associated with neither an increase nor a decrease in the risk of a poor prognosis. After adjusting for baseline pain severity, disability, and other measures of pain and pain history, persons who reported a high passive coping score were still at 50% increased risk of a poor outcome (RR = 1.5; 95% CI = 1.1 to 2.0). CONCLUSION: Patients who report passive coping strategies experience a significant increase in the risk of persistent symptoms. Further, this risk persists after controlling for initial pain severity and disability. The identification of this low back pain subgroup may help target future treatments to those at greatest risk of a poor outcome.

Adaptation, Psychological↗

PubMed2005

Attitudes toward antipsychotic medication: the impact of clinical variables and relationships with health professionals.

CONTEXT: Nonadherence to antipsychotic medication is a major cause of psychotic relapse and is strongly influenced by attitudes toward treatment. Although patient variables such as insight and symptoms that contribute toward attitudes have been identified, the contributions of relationship and service factors have not been adequately studied. OBJECTIVE: To determine relations between clinical and service variables and attitudes toward medication in people with a diagnosis of schizophrenia and schizoaffective disorder. DESIGN: Consecutively admitted patients were approached to take part; 23 refused. Measures included symptoms, insight, drug adverse effects, self-reported adherence, attitudes toward treatment, perceived relationship with the prescriber, ward atmosphere, and admission experience. Data were analyzed by a proportional odds model and structural equation modeling to test predicted paths between experience of admission, relationship variables, attitudes toward treatment, and self-reported adherence to medication. SETTING: Twenty-eight inpatient wards at 8 hospitals in North Wales and the Northwest of England. Sites included hospitals with inner-city and rural catchment areas. Patients Two hundred twenty-eight patients meeting DSM-IV criteria for schizophrenia or schizoaffective disorder, assessed during acute admission. MAIN OUTCOME MEASURES: Attitudes toward treatment and self-reported adherence to medication. RESULTS: The data fit a model in which attitudes toward treatment were predicted by insight, relationship with staff (especially the physician-prescriber), and the patient's admission experience (maximum likelihood chi(2)(49) = 89.3, P<.001). A poor relationship with the prescriber, experience of coercion during admission, and low insight predicted a negative attitude toward treatment. CONCLUSIONS: The quality of relationships with clinicians during acute admission appears to be an important determinant of patients' attitudes toward treatment and adherence to medication. Enhancing such relationships may yield important clinical benefits.

Adolescent↗

PubMed2005

Validity of self-reported height and weight and predictors of bias in adolescents.

PURPOSE: The purpose of this study was to assess the validity of self-reported height and weight, the accuracy of screening for overweight and obesity using these data, and the predictors of bias in self-reported height and weight in adolescents. METHOD: The Health Behavior in School-Aged Children (HBSC) survey was used to assess self-reported and measured height and weight in a community sample of 418 students in year 11 from 21 secondary schools in Wales. Participants also provided self-report data on dieting and body perception. RESULTS: Self-reported and measured height and weight were highly correlated but a bias of underreporting of body weight by an average of .52 kg contributed to underestimation of the prevalence of overweight and obesity. Based on self-report data, 13.9% of the sample was identified as overweight and 2.8% was identified as obese, but measured data showed rates of 18.7% and 4.4%, respectively. Overweight and obese participants showed greater bias and variability in self-reported weight than normal/underweight participants. Body mass index (BMI) and body dissatisfaction predicted bias in self-reported weight. CONCLUSION: Self-report bias had significant consequences for the accuracy of a screen for overweight and obesity. Actual and perceived body size each contribute to underreporting body weight. Self-reports will remain an important health surveillance tool but should not be relied on exclusively to detect weight problems. Accuracy checks of self-report data may improve surveys of weight problems in young people.

Adolescent↗

PubMed2005

The clinical effectiveness of guided self-help versus waiting-list control in the management of anxiety and depression: a randomized controlled trial.

BACKGROUND: There are significant barriers to accessing effective psychological therapy in primary care resulting from a lack of suitably trained therapists to meet current demand. More efficient service delivery using minimal interventions (such as bibliotherapy) provided by paraprofessional therapists may be one method of overcoming these problems, and is the subject of attention in the UK and elsewhere. A randomized trial was conducted to test the clinical effectiveness of this model. Assistant psychologists delivered a guided self-help intervention to patients with anxiety and depression who were currently waiting for psychological therapy. METHOD: A total of 114 patients were randomized either to guided self-help or a waiting-list control group. All patients were followed up 3 months later, prior to starting conventional psychological therapy. Measures included self-reported adherence to the intervention, anxiety and depressive symptoms, social functioning and patient satisfaction. RESULTS: Adherence to the guided self-help intervention was acceptable and patients reported satisfaction with the intervention. However, there were no statistically significant differences between groups in anxiety and depression symptoms at 3 months. CONCLUSIONS: The results demonstrate that this model of guided self-help did not provide additional benefit to patients on a waiting list for psychological therapy. The results are considered in the context of possible internal and external validity threats, and compared with previous trials of minimal interventions. The implications of the results for the design of future minimal interventions are considered.

Adult↗

PubMed2005

The introduction of large class problem-based learning into an undergraduate medical curriculum: an evaluation.

When considering implementing integrated curriculum models, such as problem-based learning (PBL), concerns may be expressed about the need for increased staff resources required to deliver tutor-led small group PBL. Less staff intensive ways of supporting PBL need to be explored. We compared the outcomes of a PBL module conducted in a large class format within a lecture theatre with a module having the same defined learning outcomes delivered in small group PBL format, both supported by e-learning resources. The pre-existing 27 small groups within the whole class (n = 246) of first year students undertaking a cardiovascular basic science module at Sheffield undergraduate medical school, UK, were randomized to 22 groups undertaking the large class Integrated Learning Activity (ILA) and 5 groups to traditional small group facilitated PBL sessions. Outcome measures were: a pre-post knowledge based test, a student educational effectiveness questionnaire, and assessment of student group work and presentations. There seemed to be no significant differences in learning outcomes between the methods although it is recognized that students would prefer the small group teaching format. Within institutions where resources to support small group PBL are limited, the large group ILA format supported with e-learning techniques may be a useful alternative approach.

Education, Medical, Undergraduate↗

PubMed2005

Income inequality and alcohol use: a multilevel analysis of drinking and drunkenness in adolescents in 34 countries.

BACKGROUND: Economic inequality has been hypothesized to be a health determinant, independent of poverty and household income. The goal of this study was to explore the contextual influences of income inequality on alcohol use and frequency of drunkenness in adolescents. METHODS: The Health Behaviour in School-aged Children study surveyed 162 305 adolescents (ages 11, 13 and 15 years) in 34 countries, providing self-report data on family affluence, alcohol consumption and episodes of drunkenness. Country-level data on income inequality and overall wealth were retrieved from the United Nations Development Program. RESULTS: Multilevel logistic regression revealed that 11- and 13-year-olds in countries of high income inequality consumed more alcohol than their counterparts in countries of low income inequality (after adjustment for sex, family affluence and country wealth). No such effect on alcohol consumption was found in 15-year-olds. Eleven-year-olds in countries of high income inequality reported more episodes of drunkenness than their counterparts in countries of low income inequality. No such effect of income inequality on drunkenness was found in 13- or 15-year-olds. CONCLUSIONS: Income inequality may have a contextual influence on the use of alcohol among younger adolescents. Findings suggest that economic policies that affect the distribution of wealth within societies may indirectly influence the use of alcohol during early and mid-adolescence.

Adolescent↗

PubMed2005

Assessing the reliability of ordered categorical scales using kappa-type statistics.

Methods for the analysis of reliability of ordered categorical scales are discussed, focussing on the limitation of the single summary-weighted kappa coefficients. A symmetric matrix of kappa-type coefficients is suggested as an alternative. The method is proposed as being suitable for ordinal scale where there is no underlying continuum. Their application is illustrated using two data sets from reliability studies. If, instead, distances between categories can be specified, a weighted mean of the matrix terms can be used as a summary measure. This is equal to a weighted kappa coefficient with squared weights, provided distances between adjacent categories are equal. When a study design corresponds to a one-way random effects model, estimates of precision of kappa-type coefficient, including the coefficients described here, can be obtained using the delta-method, bootstrap resampling by subjects or jack-knifing by subjects. In the case of interobserver reliability studies, where there may be systematic differences between observers, the investigator may wish to generalise to a population of observers and subjects. In this case, jack-knifing by observer and subject is suggested. Empirical comparisons are made between standard error estimates based on the delta-method, on jack-knifing by subjects and a two-way jack-knife by subjects and observers. The results suggest that standard errors based on the delta-method or jack-knifing by subject alone may be overly precise.

Biomedical Research↗

PubMed2005

Design and analysis of clinical trials with clustering effects due to treatment.

Where patients receive therapy as a group, there are good theoretical reasons to believe that variation in the outcome will be smaller for patients treated in the same group than for patients treated in different groups. Similarly, where different therapists treat different groups of patients, outcome for patients treated by the same therapist may differ less than outcome for patients treated by different therapists. Clinical trials evaluating such therapies need to consider this potential lack of independence. As with cluster-randomized trials, this has implications for the precision of treatment effects estimates and statistical power. There are nevertheless differences between clustering due to the organization of treatment and that due to randomization. In cluster-randomized trials the distribution of cluster sizes in each treatment arm should be similar as a consequence of randomization unless there is differential loss to follow-up. With clustering due to therapy group or therapist, cluster size may differ systematically between treatment arms, due to size of therapy groups or differing health professional caseload. Intra-cluster correlation may also differ between treatment arms. The implications of differential cluster size and intracluster correlation for design and analysis will be illustrated by data from two trials, the first comparing nurse practitioner care with general practitioner care, and the second comparing a group therapy with individual treatment as usual. The special case where a group therapy or therapist is compared with an unclustered treatment is examined in detail using a simulation study. The implications of differential clustering effects for sample size and power are addressed. It is argued that the design and analysis of this type of trial should take account of possible heterogeneity in cluster size and intracluster correlation.

Cluster Analysis↗

PubMed2004

Does primary care referral to an exercise programme increase physical activity one year later? A randomized controlled trial.

OBJECTIVE: To assess the effectiveness of a primary care referral scheme on increasing physical activity at 1 year from referral. Design Two-group randomized controlled trial recruiting primary care referrals to a borough-based exercise scheme. Setting A local authority borough in the north-west of England. Participants 545 patients defined as sedentary by a primary care practitioner. Intervention Referral to a local-authority exercise referral scheme and written information compared with written information only. Main outcome measures Meeting physical activity target at 12 months following referral, with a secondary outcome measured at 6 months from referral. RESULTS: At 12 months, a non-significant increase of 5 per cent was observed in the intervention compared with control group, for participation in at least 90 minutes of moderate/vigorous activity per week (25.8 versus 20.4 per cent, OR 1.45, 0.84 to 2.50, p = 0.18). At 6 months, a 10 per cent treatment effect was observed which was significant (22.6 versus 13.6 per cent, OR 1.67, 1.08 to 2.60, p = 0.05). The intervention increased satisfaction with information but this did not influence adherence with physical activity. CONCLUSION: Community-based physical activity referral schemes have some impact on reducing sedentary behaviour in the short-term, but which is unlikely to be sustained and lead to benefits in terms of health.

Adolescent↗