Are randomised controlled trials positivist? Reviewing the social science and philosophy literature to assess positivist tendencies of trials of social interventions in public health and health services

Background: We have previously proposed that trials of social interventions can be done within a ‘realist’ research paradigm. Critics have countered that such trials are irredeemably positivist and asked us to explain our philosophical position. Methods: We set out to explore what is meant by positivism and whether trials adhere to its tenets (of necessity or in practice) via a narrative literature review of social science and philosophical discussions of positivism, and of the trials literature and three case studies of trials. Results: The philosophical literature described positivism as asserting: 1) the epistemic primacy of sensory information; 2) the requirement that theoretical terms equate with empirical terms; 3) the aim of developing universal laws; and 4) the unity of method between natural and social sciences. Regarding 1), it seems that rather than embodying the epistemic primacy of sensory data, RCTs of social interventions in health embrace an anti-positivist approach aiming to test hypotheses derived deductively from prior theory. Considering 2), while some RCTs of social interventions appear to limit theorization to concepts with empirical analogues, others examine interventions underpinned by theories engaging with mechanisms and contextual contingencies not all of which can be measured. Regarding 3), while some trialists and reviewers in the health field do limit their role to estimating statistical trends as a mechanistic form of generalization, this is not an inevitable feature of RCT-based research. Trials of social interventions can instead aim to generalize at the level of theory which specifies how mechanisms are contingent on context. In terms of 4), while RCTs are used to examine biomedical as well as social interventions in health, RCTs of social interventions are often distinctive in using qualitative analyses of data on participant accounts to examine questions of meaning and agency not pursued in the natural sciences. Conclusion: We conclude that the most appropriate paradigm for RCTs of social interventions is realism not positivism

Psychosocial mediators of change in physical activity in the Welsh national exercise referral scheme: secondary analysis of a randomised controlled trial

Objective: While an increasing number of randomised controlled trials report impacts of exercise referral schemes (ERS) on physical activity, few have investigated the mechanisms through which increases in physical activity are produced. This study examines whether a National Exercise Referral Scheme (NERS) in Wales is associated with improvements in autonomous motivation, self-efficacy and social support, and whether change in physical activity is mediated by change in these psychosocial processes.<p></p> Methods: A pragmatic randomised controlled trial of NERS across 12 LHBs in Wales. Questionnaires measured demographic data and physical activity at baseline. Participants (N = 2160) with depression, anxiety or CHD risk factors were referred by health professionals and randomly assigned to control or intervention. At six months psychological process measures were collected by questionnaire. At 12 months physical activity was assessed by 7 Day PAR telephone interview. Regressions tested intervention effects on psychosocial variables, physical activity before and after adjusting for mediators and socio demographic patterning.<p></p> Results: Significant intervention effects were found for autonomous motivation and social support for exercise at 6 months. No intervention effect was observed for self-efficacy. The data are consistent with a hypothesis of partial mediation of the intervention effect by autonomous motivation. Analysis of moderators showed significant improvements in relative autonomy in all subgroups. The greatest improvements in autonomous motivation were observed among patients who were least active at baseline.<p></p> Discussion: The present study offered key insights into psychosocial processes of change in an exercise referral scheme, with effects on physical activity mediated by autonomous motivation. Findings support the use of self-determination theory as a framework for ERS. Further research is required to explain socio-demographic patterning in responses to ERS, with changes in motivation occurring among all sub-groups of participants, though not always leading to higher adherence or behavioural change. This highlights the importance of socio-ecological approaches to developing and evaluating behaviour change interventions, which consider factors beyond the individual, including conditions in which improved motivation does or does not produce behavioural change

Exploratory studies to inform full-scale evaluations of complex public health interventions: the need for guidance

No abstract available

Marking machinima : a case study in assessing student use of a Web 2.0 technology

The model of learning best suited to the future may be one which sees learning as the process of managing the different kinds of participation an individual might have in complex social systems. Learning capability and engagement is thus dependent on the relationship between an individual identity and social systems. We report on the incorporation of machinima, a Web 2.0 technology, as part of an interdisciplinary and collaborative project where the focus is not on the mastery of the tools or the acquisition of predetermined knowledge, but on the development of learning engagement. We provide the case study of a pilot project involving students across two Arts disciplines collaborating via the game, World of Warcraft, to produce an animated adaptation of one of Geoffrey Chaucer\u27s Canterbury Tales. Their contributions were differently assessed according to the pre-existing requirements of their home disciplines. We argue that the assessment in such projects, in conjunction with innovations and experimentation with Web 2.0 technologies, should shift from an emphasis on product to process. We believe that this has a sound pedagogical and theoretical foundation, and also fits better with the increasingly digitalised, unfixed and interdisciplinary world that students will face on graduation. <br /

Gender, relationship breakdown, and suicide risk: a review of research in western countries

An association between divorce and suicide risk has been noted in numerous studies, but the gender profile of this risk has not been clearly established. This article reviews the evidence on gender differentials in suicide risk following the breakdown of an intimate relationship (including divorce and separation). Nineteen published articles that included individuallevel data were identified. Twelve reported a greater risk of suicide in men following relationship breakdown, two indicated a greater risk in women, and a further five showed no clear gender differential. Although there are possible indications of increased risk for men, no definitive conclusion about gender differential can be drawn. Furthermore, research is required that directly compares men with women for suicide risk following relationship breakdown

A four year longitudinal sero-epidemiology study of Neospora caninum in adult cattle from 114 cattle herds in south west England : associations with age, herd and dam-offspring pairs

Background: Neosporosis caused by the protozoan parasite Neospora caninum, is an economically important cause of abortion, stillbirth, low milk yield, reduced weight gain and premature culling in cattle. Consequently, a seroepidemiological study of N. caninum antibodies was conducted in England with 29,782 samples of blood taken from 15,736 cattle from 114 herds visited on three occasions at yearly intervals. Herds were categorised into lower (< 10%) and higher (≥ 10%) median herd seroprevalence. Hierarchical models were run to investigate associations between the sample to positive (S/P) ratio and herd and cattle factors. Results: Ninety-four percent of herds had at least one seropositive cow; 12.9% of adult cattle had at least one seropositive test. Approximately 90% of herds were seropositive at all visits; 9 herds (8%) changed serological status between visits. The median N. caninum seroprevalence in positive herds was 10% (range 0.4% to 58.8%). There was a positive association between the serostatus of offspring and dams that were ever seropositive. In the hierarchical model of low seroprevalence herds there was no significant association between S/P ratio and cattle age. There was a significantly lower S/P ratio in cattle in herds that were totally restocked after the foot-and-mouth epidemic of 2001 compared with those from continuously stocked herds and cattle purchased into these herds had a higher S/P ratio than homebred cattle. In the model of high seroprevalence herds the S/P ratio increased with cattle age, but was not associated with restocking or cattle origin. Conclusion: There were no strong temporal changes in herd seroprevalence of N. caninum but 90% of herds had some seropositive cattle over this time period. Vertical transmission from seropositive dams appeared to occur in all herds. In herds with a high seroprevalence the increasing S/P ratio in 2–4 year old cattle is suggestive of exposure to N. caninum: horizontal transmission between adult cattle, infection from a local source or recrudescence and abortions. Between-herd movements of infected cattle enhance the spread of N. caninum, particularly into low seroprevalence herds. Some restocked herds had little exposure to N. caninum, while in others infection had spread in the time since restocking

Impacts of the Primary School Free Breakfast Initiative on socio-economic inequalities in breakfast consumption among 9–11-year-old schoolchildren in Wales

Objectives - Universal interventions may widen or narrow inequalities if disproportionately effective among higher or lower socio-economic groups. The present paper examines impacts of the Primary School Free Breakfast Initiative in Wales on inequalities in children's dietary behaviours and cognitive functioning.&lt;p&gt;&lt;/p&gt; Design Cluster - randomised controlled trial. Responses were linked to free school meal (FSM) entitlement via the Secure Anonymised Information Linkage databank. Impacts on inequalities were evaluated using weighted school-level regression models with interaction terms for intervention × whole-school percentage FSM entitlement and intervention × aggregated individual FSM entitlement. Individual-level regression models included interaction terms for intervention × individual FSM entitlement.&lt;p&gt;&lt;/p&gt; Setting - Fifty-five intervention and fifty-six wait-list control primary schools.&lt;p&gt;&lt;/p&gt; Subjects - Approximately 4500 children completed measures of dietary behaviours and cognitive tests at baseline and 12-month follow-up.&lt;p&gt;&lt;/p&gt; Results School-level models indicated that children in intervention schools ate a greater number of healthy items for breakfast than children in control schools (b = 0·25; 95 % CI 0·07, 0·44), with larger increases observed in more deprived schools (interaction term b = 1·76; 95 % CI 0·36, 3·16). An interaction between intervention and household-level deprivation was not significant. Despite no main effects on breakfast skipping, a significant interaction was observed, indicating declines in breakfast skipping in more deprived schools (interaction term b = −0·07; 95 % CI −0·15, −0·00) and households (OR = 0·67; 95 % CI 0·46, 0·98). No significant influence on inequality was observed for the remaining outcomes.&lt;p&gt;&lt;/p&gt; Conclusions - Universal breakfast provision may reduce socio-economic inequalities in consumption of healthy breakfast items and breakfast skipping. There was no evidence of intervention-generated inequalities in any outcomes

Fluorescence in situ hybridization on vibratome sections of plant tissues

9 pages; 1 figure; 1 tableThis protocol describes the application of fluorescence in situ hybridization (FISH) to three-dimensionally (3D) preserved tissue sections derived from intact plant structures such as roots or florets. The method is based on the combination of vibratome sectioning with confocal microscopy. The protocol provides an excellent tool to investigate chromosome organization in plant nuclei in all cell types and has been used on tissues of both monocot and dicot plant species. The visualization of 3D well-preserved tissues means that cell types can be confidently identified. For example, meiocytes can be clearly identified at all stages of meiosis and can be imaged in the context of their surrounding maternal tissue. FISH can be used to localize centromeres, telomeres, repetitive regions as well as unique regions, and total genomic DNAs can be used as probes to visualize chromosomes or chromosome segments. The method can be adapted to RNA FISH and can be combined with immunofluorescence labeling. Once the desired plant material is sectioned, which depends on the number of samples, the protocol that we present here can be carried out within 3 d.Biotechnology and Biological Sciences Research Council of the UK.Peer reviewe

Mediating urban politics

Despite the turn to relational vocabularies in urban theory, most work on urban politics acknowledging the importance of media has tended to reproduce a centred image of ‘the media’ and a functionalist account of mediation. This essay suggests, by contrast, that media might be understood more phenomenologically, as those technologies embedded in the dispersed practices of urban life, and as assemblages of integrative practices (i.e. ‘the media’), both of which identify and subject to action a range of issues that are problematized as ‘urban’. Such a focus on media-in-practices is an important shift in perspective for research hoping to bring together the shared political concerns of urban and media studies, and to take advantage of the converging spatial imaginations and reconfigured understandings of mediation emerging across both fields