Suchergebnisse

When properly implemented, Randomized Controlled Trials (RCT) achieve a high degree of internal validity. Yet, if an RCT is to inform policy, it is critical to establish external validity. This paper systematically reviews all RCTs conducted in developing countries and published in leading economic journals between 2009 and 2014 with respect to how they deal with external validity. Following Duflo, Glennerster, and Kremer (2008), the hazards to external validity we scrutinize are Hawthorne effects, general equilibrium effects, specific sample problems, and special care in treatment provision. Based on a set of objective indicators, we find that the majority of published RCTs does not discuss these hazards and many do not provide the necessary information to assess potential problems. The paper calls for including external validity dimensions in a more systematic reporting on the results of RCTs. This may create incentives to avoid overgeneralizing findings and help policy makers to interpret results appropriately. ; Bei sorgfältiger Implementierung weisen randomisierte kontrollierte Studien ein hohes Maß an interner Validität auf. Sollen die Ergebnisse eines RCT jedoch Politik informieren, ist es entscheidend externe Validität zu etablieren. Dieses Papier untersucht systematisch alle RCTs, die in Entwicklungsländern durchgeführt und in führenden ökonomischen Fachzeitschriften zwischen 2009 und 2014 publiziert wurden, auf ihren Umgang mit externer Validität. In Anlehnung an Duflo, Glennerster und Kremer (2008) untersuchen wir folgenden Gefahren für externe Validität: Hawthorne Effekte, generelle Gleichgewichtseffekte, Probleme spezifischer Stichproben und der Randomisierung geschuldeten Besonderheiten im Treatment. Unter Zuhilfenahme objektiver Indikatoren stellen wir fest, dass ein Großteil der publizierten Papiere nicht die Probleme externer Validität diskutiert und viele nicht die notwendigen Informationen zur Abschätzung dieser durch den Leser bereitstellen. Wir plädieren deshalb für ein Berichtswesen bei der Publikation von RCTs, das den verschiedenen Dimensionen externer Validität Rechnung trägt. Dadurch könnten Anreize entstehen, die zu starke Verallgemeinerung verhindern und Politikern helfen, Ergebnisse angemessen zu interpretieren.

Objective: This study assessed the effectiveness of Seeking Safety on depression and post-traumatic stress disorder (PTSD) with incarcerated women. Method: A randomized controlled trial ( N = 40) was used to analyze Seeking Safety's effectiveness compared to a treatment-as-usual control group. Analyses of covariance were used to assess differences at posttest ( n = 33) and 4-month follow-up ( n = 29) while repeated measures analysis of variance was used to assess the influence of the intervention on changes over time ( n = 29). The researchers also analyzed individual participants' scores from pretest to 4-month follow-up ( n = 29). Results: Both groups decreased their scores on the Center for Epidemiology Studies–Depression Scale and the PTSD Checklist, although improvement was greater for treatment group participants except for depression at 4-month follow-up. Conclusion: Results support the continued use of Seeking Safety as a helpful corrections-based intervention for women, but more research with larger sample sizes is needed to consider it an effective intervention.

Randomized controlled trials (RCTs) are rarely used to evaluate social and behavioral interventions designed for releasing prisoners. Objective: We use a pilot RCT of a social support intervention (Support Matters) as a case example to discuss obstacles and strategies for conducting RCT intervention evaluations that span prison and community contexts. Method: First, we summarize existing studies with current and former prisoner samples that highlight RCT methodological techniques. Then, we introduce the trial of Support Matters and discuss obstacles and efforts to overcome those obstacles. Results and Conclusions: We focus on factors related to sampling frame, participant eligibility, sample size, engagement, and attrition. We conclude with general recommendations related to project delays, compromised research sites, and retention. This article provides guidance based on lessons learned from an RCT of a social support intervention with releasing prisoners and their loved ones. Barriers discussed and recommendations presented here will help interventionists develop and implement RCTs in prison to community contexts.

This article brings a historical perspective to explain the recent dissemination of randomized controlled trials (RCTs) as the new "gold standard" method to assess international development projects. Although the buzz around RCT evaluations dates from the 2000s, we show that what we are witnessing now is a second wave of RCTs, while a first wave began in the 1960s and ended by the early 1980s. Drawing on content analysis of 123 RCTs, participant observation, and secondary sources, we compare the two waves in terms of the participants in the network of expertise required to carry out field experiments and the characteristics of the projects evaluated. The comparison demonstrates that researchers in the second wave were better positioned to navigate the political difficulties caused by randomization. We explain the differences in the expertise network and in the type of projects as the result of concurrent transformations in the fields of development aid and the economics profession. We draw on Andrew Abbott's concept of "hinges," as well as on Bourdieu's concept of "homology" between fields, to argue that the similar positions and parallel struggles conducted by two groups of actors in the two fields served as the basis for a cross-field alliance, in which RCTs could function as a "hinge" linking together the two fields.

Purpose. To evaluate the effectiveness of a cognitive behavioral treatment (CBT) addressing cessation-related weight concerns delivered via a tobacco quitline that does not address weight concerns. Design. Randomized controlled trial, blinded 6-month follow-up. Setting. The Oklahoma Tobacco Helpline (OKHL). Subjects. All 7998 smokers who called the OKHL were screened; 4240 were eligible; 2000 were randomized to the standard quitline (STD) or the brief version of the CBT weight concerns program (WCP). Intervention. Telephone counseling to help people quit smoking and address concerns about cessation-related weight gain. Measures. Demographics, weight, tobacco status, weight concerns, self-efficacy in quitting, and quitting without weight gain. Analysis. Descriptive statistics and logistic regression. Results. Of those randomized, 1002 participants completed the 6-month survey (response rates = 53.2% for STD, 47% for WCP). Compared with STD, WCP led to reduced weight concerns (p < .01) and less weight gain among quitters (1.8 vs. −3.4 pounds; p = .01). Although not significant, participants in the WCP were more likely to report 30-day abstinence (33.3% vs. 36.8%, p = .24; intent to treat = 17.7 vs. 17.3). Conclusion. The WCP was successfully delivered via a quitline and resulted in improved attitudes about weight and decreased cessation-related weight gain without harming quit rates. Promotion of a quitline focused on addressing weight in conjunction with quitline treatment for smoking cessation may improve cessation and weight outcomes. Study limitations include use of self-report and survey response.

Dealing with physical and social disorder to prevent serious crime has become a central strategy for policing. This study evaluates the effects of policing disorder, within a problem‐oriented policing framework, at crime and disorder hot spots in Lowell, Massachusetts. Thirty‐four hot spots were matched into 17 pairs, and one member of each pair was allocated to treatment conditions in a randomized block field experiment. The officers engaged "shallow" problem solving and implemented a strategy that more closely resembled a general policing disorder strategy rather than carefully designed problem‐oriented policing responses. Nevertheless, the impact evaluation revealed significant reductions in crime and disorder calls for service, and systematic observations of social and physical disorder at the treatment places relative to the control places uncovered no evidence of significant crime displacement. A mediation analysis of the isolated and exhaustive causal mechanisms that comprised the strategy revealed that the strongest crime‐prevention gains were generated by situational prevention strategies rather than by misdemeanor arrests or social service strategies.

This article elaborates on the centrality of interventions for social work practice and the importance of understanding the effects of interventions for a more efficient, harmless, transparent, and ethical social work practice. Low-bias research designs and meta-analyses are important means of generating the best possible evidence on what works in social work practice. An evidence-based practice model is promising in terms of translating and implementing scientific evidence that is uncertain, volatile, and incomplete and might be difficult to access.

OBJECTIVE: A randomized controlled trial was conducted to determine whether 7 days of intravenous eflornithine (100 mg/kg every 6 h) was as effective as the standard 14-day regimen in the treatment of late-stage Trypanosoma brucei gambiense trypanosomiasis. METHODS: A total of 321 patients (274 new cases, 47 relapsing cases) were randomized at four participating centres in Congo, Côte d'Ivoire, the Democratic Republic of the Congo, and Uganda to one of these treatment regimens and followed up for 2 years. RESULTS: Six patients died during treatment, one of whom was on the 7-day regimen, whereas the other five had been on the 14-day regimen (P = 0.2). The response to eflornithine differed markedly between Uganda and other countries. Among new cases in Uganda, the 2-year probability of cure was 73% on the 14-day course compared with 62% on the 7-day regimen (hazard ratio (HR) for treatment failure, 7-day versus 14-day regimen: 1.45, 95% CI: 0.7, 3.1, P = 0.3). Among new cases in Côte d'Ivoire, Congo, and the Democratic Republic of the Congo combined, the 2-year probability of cure was 97% on the 14-day course compared with 86.5% on the 7-day regimen (HR for treatment failure, 7-day vs 14-day: 6.72, 95% confidence interval (CI): 1.5, 31.0, P = 0.003). Among relapsing cases in all four countries, the 2-year probability of cure was 94% with 7 days and 100% with 14 days of treatment. Factors associated with a higher risk of treatment failure were: a positive lymph node aspirate (HR 4.1; 95% CI: 1.8-9.4), a cerebrospinal fluid (CSF) white cell count > or = 100/mm3 (HR 3.5; 95% CI: 1.1-10.9), being treated in Uganda (HR 2.9; 95% CI: 1.4-5.9), and CSF trypanosomes (HR 1.9; 95% CI: 0.9-4.1). Being stuporous on admission was associated with a lower risk of treatment failure (HR 0.18; 95% CI: 0.02-1.4) as was increasing age (HR 0.977; 95% CI: 0.95-1.0, for each additional year of age). DISCUSSION: The 7-day course of eflornithine is an effective treatment of relapsing cases of Gambian trypanosomiasis. For new cases, a ...

Consultation of scientific evidence by policy actors has been the foci of attention of knowledge utilization scholars for decades. The present study questioned the extent to which randomized controlled trials (RCTs)-generally seen as the gold standard of scientific research-are known and consulted by policy analysts in ministerial settings. Using cross-sectional data collected in 17 ministries in Quebec (Canada), our study showed that fairly high levels of policy analysts report never having heard of RCTs, thus possibly hindering effective communication of scientific results to relevant policy makers. Statistical analyses reveal the importance of cognitive factors in explaining both phenomena. Adapted from the source document.