495 research outputs found

    Strengthening nonrandomized studies of health communication strategies for HIV prevention.

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    BACKGROUND: There is growing interest in impact evaluations of health communication (HC) interventions for HIV prevention. Although cluster randomized trials may be optimal in terms of internal validity, they are often unfeasible for political, practical, or ethical reasons. However, a common alternative, the observational study of individuals who do and do not self-report HC intervention exposure, is prone to bias by confounding. Cluster-level quasi-experimental study designs offer promising alternatives to these extremes. METHODS: We identified common rollout strategies for HC initiatives. We mapped these scenarios against established quasi-experimental evaluation designs. We identified key issues for implementers and evaluators if these designs are to be more frequently adopted in HC intervention evaluations with high internal validity. RESULTS: Stronger evaluations will document the planned intervention components in advance of delivery and will implement interventions in clusters according to a predefined systematic allocation plan. We identify 4 types of allocation plan and their associated designs. Where some places get the HC intervention, whereas others do not, a nonrandomized controlled study may be feasible. Where HC is introduced everywhere at a defined point in time, an interrupted time series may be appropriate. Where the HC intervention is introduced in phases, a nonrandomized phased implementation or stepped-wedge design may be used. Finally, where there is variation in strength of implementation of HC, a nonrandomized, dose-response study can be planned. DISCUSSION: Our framework will assist teams planning such evaluations by identifying critical decisions for the implementers and for the evaluators of HC interventions

    Public target interventions to reduce the inappropriate use of medicines or medical procedures: a systematic review.

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    BACKGROUND: An epidemic of health disorders can be triggered by a collective manifestation of inappropriate behaviors, usually systematically fueled by non-medical factors at the individual and/or societal levels. This study aimed to (1) landscape and assess the evidence on interventions that reduce inappropriate demand of medical resources (medicines or procedures) by triggering behavioral change among healthcare consumers, (2) map out intervention components that have been tried and tested, and (3) identify the "active ingredients" of behavior change interventions that were proven to be effective in containing epidemics of inappropriate use of medical resources. METHODS: For this systematic review, we searched MEDLINE, EMBASE, the Cochrane Library, and PsychINFO from the databases' inceptions to May 2019, without language restrictions, for behavioral intervention studies. Interventions had to be empirically evaluated with a control group that demonstrated whether the effects of the campaign extended beyond trends occurring in the absence of the intervention. Outcomes of interest were reductions in inappropriate or non-essential use of medicines and/or medical procedures for clinical conditions that do not require them. Two reviewers independently screened titles, abstracts, and full text for inclusion and extracted data on study characteristics (e.g., study design), intervention development, implementation strategies, and effect size. Data extraction sheets were based on the checklist from the Cochrane Handbook for Systematic Reviews. RESULTS: Forty-three studies were included. The behavior change technique taxonomy v1 (BCTTv1), which contains 93 behavioral change techniques (BCTs), was used to characterize components of the interventions reported in the included studies. Of the 93 BCTs, 15 (16%) were identified within the descriptions of the selected studies targeting healthcare consumers. Interventions consisting of education messages, recommended behavior alternatives, and a supporting environment that incentivizes or encourages the adoption of a new behavior were more likely to be successful. CONCLUSIONS: There is a continued tendency in research reporting that mainly stresses the effectiveness of interventions rather than the process of identifying and developing key components and the parameters within which they operate. Reporting "negative results" is likely as critical as reporting "active ingredients" and positive findings for implementation science. This review calls for a standardized approach to report intervention studies. TRIAL REGISTRATION: PROSPERO registration number CRD42019139537

    How important is randomisation in a stepped wedge trial?

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    In cluster randomised trials, randomisation increases internal study validity. If enough clusters are randomised, an unadjusted analysis should be unbiased. If a smaller number of clusters are included, stratified or matched randomisation can increase comparability between trial arms. In addition, an adjusted analysis may be required; nevertheless, randomisation removes the possibility for systematically biased allocation and increases transparency. In stepped wedge trials, clusters are randomised to receive an intervention at different start times ('steps'), and all clusters eventually receive it. In a recent study protocol for a 'modified stepped wedge trial', the investigators considered randomisation of the clusters (hospital wards), but decided against it for ethical and logistical reasons, and under the assumption that it would not add much to the rigour of the evaluation. We show that the benefits of randomisation for cluster randomised trials also apply to stepped wedge trials. The biggest additional issue for stepped wedge trials in relation to parallel cluster randomised trials is the need to control for secular trends in the outcome. Analysis of stepped wedge trials can in theory be based on 'horizontal' or 'vertical' comparisons. Horizontal comparisons are based on measurements taken before and after the intervention is introduced in each cluster, and are unbiased if there are no secular trends. Vertical comparisons are based on outcome measurements from clusters that have switched to the intervention condition and those from clusters that have yet to switch, and are unbiased under randomisation since at any time point, which clusters are in intervention and control conditions will have been determined at random. Secular outcome trends are a possibility in many settings. Many stepped wedge trials are analysed with a mixed model, including a random effect for cluster and fixed effects for time period to account for secular trends, thereby combining both vertical and horizontal comparisons of intervention and control clusters. The importance of randomisation in a stepped wedge trial is that the effects of time can be estimated from the data, and bias from secular trends that would otherwise arise can be controlled for, provided the trends are correctly specified in the model

    Re-analysis of health and educational impacts of a school-based deworming programme in western Kenya: a pure replication.

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    BACKGROUND: Helminth (worm) infections cause morbidity among poor communities worldwide. An influential study conducted in Kenya in 1998-99 reported that a school-based drug-and-educational intervention had benefits regarding worm infections and school attendance. Effects were seen among children treated with deworming drugs, untreated children in intervention schools and children in nearby non-intervention schools. Combining these effects, the intervention was reported to increase school attendance by 7.5% in treated children. Effects on other outcomes (worm infections, anaemia, nutritional status and examination performance) were also investigated. METHODS: In this pure replication, we used data provided by the original authors to re-analyse the study according to their methods. We compared these results against those presented in the original paper. RESULTS: Although most results were reproduced as originally reported, we identified discrepancies of several types between the original findings and re-analysis. For worm infections, re-analysis showed reductions similar to those originally reported. For anaemia prevalence, in contrast to the original findings, re-analysis found no evidence of benefit. For nutritional status, both original findings and re-analysis described modest evidence for a small improvement. For school attendance, re-analysis showed benefits similar to those originally found in intervention schools for both children who did and those who did not receive deworming drugs. However, after correction of coding errors, there was little evidence of an indirect effect on school attendance among children in schools close to intervention schools. Combining these effects gave a total increase in attendance of 3.9% among treated children, which was no longer statistically significant. As in the original results, re-analysis found no effect of the intervention on examination performance. CONCLUSIONS: Re-applying analytical approaches originally used, but correcting various errors, we found little evidence for some previously-reported indirect effects of a deworming intervention. Effects on worm infections, nutritional status, examination performance and school attendance on children in intervention schools were largely unchanged

    Is the sexual behaviour of young people in sub-Saharan Africa influenced by their peers? A systematic review.

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    Adolescents in sub-Saharan Africa are highly vulnerable to HIV, other sexually transmitted infections (STIs) and unintended pregnancies. Evidence for the effectiveness of individual behaviour change interventions in reducing incidence of HIV and other biological outcomes is limited, and the need to address the social conditions in which young people become sexually active is clear. Adolescents' peers are a key aspect of this social environment and could have important influences on sexual behaviour. There has not yet been a systematic review on the topic in sub-Saharan Africa. We searched 4 databases to find studies set in sub-Saharan Africa that included an adjusted analysis of the association between at least one peer exposure and a sexual behaviour outcome among a sample where at least 50% of the study participants were aged between 13 and 20 years. We classified peer exposures using a framework to distinguish different mechanisms by which influence might occur. We found 30 studies and retained 11 that met quality criteria. There were 3 cohort studies, 1 time to event and 7 cross-sectional. The 11 studies investigated 37 different peer exposure-outcome associations. No studies used a biological outcome and all asked about peers in general rather than about specific relationships. Studies were heterogeneous in their use of theoretical frameworks and means of operationalizing peer influence concepts. All studies found evidence for an association between peers and sexual behaviour for at least one peer exposure/outcome/sub-group association. Of all 37 outcome/exposure/sub-group associations tested, there was evidence for 19 (51%). There were no clear patterns by type of peer exposure, outcome or adolescent sub-group. There is a lack conclusive evidence about the role of peers in adolescent sexual behaviour in Sub-Saharan. We argue that longitudinal designs, use of biological outcomes and approaches from social network analysis are priorities for future studies

    Re-analysis of health and educational impacts of a school-based deworming programme in western Kenya: a statistical replication of a cluster quasi-randomized stepped-wedge trial.

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    INTRODUCTION: Helminth (worm) infections cause morbidity among poor communities worldwide. An influential study conducted in Kenya in 1998-99 reported that a school-based drug-and-educational intervention had benefits for worm infections and school attendance. METHODS: In this statistical replication, we re-analysed data from this cluster quasi-randomized stepped-wedge trial, specifying two co-primary outcomes: school attendance and examination performance. We estimated intention-to-treat effects using year-stratified cluster-summary analysis and observation-level random-effects regression, and combined both years with a random-effects model accounting for year. The participants were not blinded to allocation status, and other interventions were concurrently conducted in a sub-set of schools. A protocol guiding outcome data collection was not available. RESULTS: Quasi-randomization resulted in three similar groups of 25 schools. There was a substantial amount of missing data. In year-stratified cluster-summary analysis, there was no clear evidence for improvement in either school attendance or examination performance. In year-stratified regression models, there was some evidence of improvement in school attendance [adjusted odds ratios (aOR): year 1: 1.48, 95% confidence interval (CI) 0.88-2.52, P = 0.147; year 2: 1.23, 95% CI 1.01-1.51, P = 0.044], but not examination performance (adjusted differences: year 1: -0.135, 95% CI -0.323-0.054, P = 0.161; year 2: -0.017, 95% CI -0.201-0.166, P = 0.854). When both years were combined, there was strong evidence of an effect on attendance (aOR 1.82, 95% CI 1.74-1.91, P < 0.001), but not examination performance (adjusted difference -0.121, 95% CI -0.293-0.052, P = 0.169). CONCLUSIONS: The evidence supporting an improvement in school attendance differed by analysis method. This, and various other important limitations of the data, caution against over-interpretation of the results. We find that the study provides some evidence, but with high risk of bias, that a school-based drug-treatment and health-education intervention improved school attendance and no evidence of effect on examination performance

    Living with COVID-19 and preparing for future pandemics: revisiting lessons from the HIV pandemic

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    In April, 2020, just months into the COVID-19 pandemic, an international group of public health researchers published three lessons learned from the HIV pandemic for the response to COVID-19, which were to: anticipate health inequalities, create an enabling environment to support behavioural change, and engage a multidisciplinary effort. We revisit these lessons in light of more than 2 years’ experience with the COVID-19 pandemic. With specific examples, we detail how inequalities have played out within and between countries, highlight factors that support or impede the creation of enabling environments, and note ongoing issues with the scarcity of integrated science and health system approaches. We argue that to better apply lessons learned as the COVID-19 pandemic matures and other infectious disease outbreaks emerge, it will be imperative to create dialogue among polarised perspectives, identify shared priorities, and draw on multidisciplinary evidence

    Teachers' classroom feedback: still trying to get it right

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    This article examines feedback traditionally given by teachers in schools. Such feedback tends to focus on children's acquisition and retrieval of externally prescribed knowledge which is then assessed against mandated tests. It suggests that, from a sociocultural learning perspective, feedback directed towards such objectives may limit children's social development. In this article, I draw on observation and interview data gathered from a group of 27 9- to 10-year olds in a UK primary school. These data illustrate the children's perceived need to conform to, rather than negotiate, the teacher's feedback comments. They highlight the children's sense that the teacher's feedback relates to school learning but not to their own interests. The article also includes alternative examples of feedback which draw on children's own inquiries and which relate to the social contexts within which, and for whom, they act. It concludes by suggesting that instead of looking for the right answer to the question of what makes teachers' feedback effective in our current classrooms, a more productive question might be how a negotiation can be opened up among teachers and learners themselves, about how teachers' feedback could support children's learning most appropriately

    Will it work here? A realist approach to local decisions about implementing interventions evaluated as effective elsewhere.

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    There is increasing interest in what evidence is needed to inform decisions about transporting interventions evaluated as effective to new settings. There has been less attention to how local decision-makers decide whether to implement such interventions immediately or subject to further evaluation. Using the example of school-based social and emotional learning, we consider this drawing on realist methods. We suggest decisions need to assess existing evaluations not merely in terms of whether the intervention was effective but also: how the intervention was implemented and what contextual factors affected this (drawing on process evaluation); and for whom the intervention was effective and through what mechanisms (drawing on mediation, moderation and qualitative comparative analyses from primary studies and/or systematic reviews). We contribute new insights to local needs assessments, suggesting that these should assess: the potential, capability, contribution and capacity present in the new setting for implementation; and whether similar 'aetiological mechanisms' underlie adverse outcomes locally as in previous evaluations. We recommend that where there is uncertainty concerning whether an intervention can feasibly be implemented this indicates the need for piloting of implementation. Where there is uncertainty concerning whether implementation of the intervention will trigger intended mechanisms, this suggests the need for a new effectiveness trial. Where there is uncertainty concerning whether intervention mechanisms, even if triggered, will generate the intended outcomes, this suggests that decision-makers may need to look to other types of intervention as being needed for their setting instead
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