PLAIN LANGUAGE SUMMARY

Little evidence of the effectiveness of continuing professional development (CPD)

Continuing professional development (CPD) aims to improve outcomes for the children and young people with whom educational and welfare professionals work. There is no clear evidence that CPD in education improves student academic outcomes.

What is this review about?

CPD is delivered in a variety of settings by different kinds of ‘trainers’ or educators for differing lengths of time and differing intensity. There are many methods of delivery such as coaching sessions, feedback based on observations or videotapes of classroom practice, and feedback and reflection workshops.

This review looked at the effects of CPD approaches for education and welfare practitioners (pre-school teachers, pedagogues, school teachers, social workers, psychologists, police officers) on educational, social, crime and justice outcomes for children and young people; and – as secondary outcomes – any effects on the professional practice of practitioners in these fields. For the purposes of this review, the CPD must involve the development of core professional skills.

What is the aim of this review?

This Campbell systematic review examines the effects of continuing professional development (CPD) approaches for education and welfare practitioners on: educational and social outcomes for children and young people; and outcomes for practitioners. The review summarizes evidence from 51 moderate-quality studies, including 48 randomized controlled trials and three quasi-experiments.

What studies are included?

This review includes studies that evaluate the effects of CPD on children’s or young people’s and professionals’ outcomes. Fifty-one studies were identified, all related to education. No eligible studies were identified for social welfare or crime and justice.

The 51 education studies were grouped into three sub-topic areas: 12 studies (reporting 10 trials) considered CPD in social and emotional development interventions (in daycare, kindergarten, pre-school and school settings); 38 studies (reporting 33 trials) dealt with CPD in language and literacy development interventions; one study looked at CPD in stress reduction. Most (48) studies used experimental designs with random assignment.

Only 26 of the 51 studies were included in the meta-analyses. The reduction was caused by studies reporting on the same trial (five studies), insufficient reporting of outcomes to calculate an effect size (four studies) and studies being rated to have too high risk of bias. In total 16 studies were assessed not to be of sufficient methodological quality to be included in the meta-analyses.

The studies spanned the period 1999 to 2018. Thirty-three trials were undertaken in the USA, two in the UK, and one in each of the following countries: Denmark, Ireland, the Netherlands, New Zealand, Portugal, Australia, Chile and Germany.

What are the main findings of this review?

Social and emotional development interventions (nine studies)
A very small body of evidence for social and emotional development interventions (in daycare, kindergarten, pre-school and school settings) finds no effect of CPD on student academic outcomes (four studies). Results from only two individual studies could be combined in a single meta-analysis of other student outcomes (i.e. non-academic) and teacher outcomes, precluding any conclusions concerning effectiveness or ineffectiveness of this type of CPD on these outcomes.

Language and literacy development interventions (17 studies)
A moderate body of evidence for language and literacy development interventions finds no effect for CPD on student academic outcomes (13 studies). The results from only three individual studies could be combined in a single meta-analysis of teacher outcomes, thus precluding any conclusions concerning effectiveness or ineffectiveness of this type of CPD on teacher outcomes.

Stress reduction (one study)
It is not possible to draw conclusions from the one study placed in the sub-topic of stress reduction.

What do the findings of the review mean?

There is insufficient evidence for conclusions to be drawn, with the exception of language and literacy development interventions. For this type of CPD, there seems to be no effect on student academic outcomes.

The dominance of the USA as the main country in which the types of CPD interventions covered by this review have been evaluated clearly limits the generalizability of the findings. Moreover, the limited number of studies means that it was not possible to conduct an analysis of specific CPD-approaches across cultures, professions/service-deliverer types, organizations and service-receiver types.

Agencies should consider conducting a large randomized controlled trial (or a series of large RCTs) evaluating the effectiveness of a CPD intervention in countries outside the USA.

How up-to-date is this review?

The review authors searched for studies up to December 2018.

PLAIN LANGUAGE SUMMARY

Limited evidence on the effectiveness of psychosocial interventions to promote well-being among children exposed to intimate partner violence

Children’s exposure to intimate partner violence (IPV) is a significant public health and social justice concern with potentially severe and long-lasting effects. The extent to which psychosocial interventions promote well-being among children exposed to IPV, and under what circumstances, such as the modality and setting, is unclear.

What is this review about?

Exposure to IPV in childhood can have both short- and long-term negative impacts to health and well-being that persist across generations. There is therefore an increased interest in the development of intervention strategies to promote well-being following exposure. Over the last two decades, theory-driven psychosocial programmes serving children exposed to violence have been developed and established in a range of venues (e.g., school-based mental health clinics, outpatient psychotherapy settings). This review provides a synthesis of the state of this literature and implications for research and practice.

Specifically, the effectiveness of psychosocial interventions in improving total problems, externalising distress, internalising distress, interpersonal/social problems, and cognitive functioning are assessed. Variation in effects by intervention modality (e.g., individual, family-based) and setting of the intervention (e.g., home, outpatient clinic) are also examined.

What is the aim of this review?

This Campbell systematic review examines the effects of psychosocial interventions to promote well-being among children exposed to intimate partner violence. The review summarizes evidence from eight methodologically rigorous randomized controlled trials.

What studies are included?

This review includes eight randomised controlled trials (RCTs), with a total of 924 participants.

The majority of studies were conducted in the USA, with one study each carried out in the Netherlands and India. The age range of target children varied, although all fell within the age range of 0 to 18 years.

Three of the studies recruited general populations of parents and/or children who had been exposed to IPV, without stated inclusion criteria around parent or child symptomatology or functioning.

Four studies had more explicit inclusion requirements such as children with IPV-related post-traumatic stress disorder (PTSD) symptoms and fathers with alcohol dependence. Studies varied widely regarding the nature of IPV experienced by parents and witnessed or heard by children.

What are the main findings of this review?

Studies examined following outcomes: total problems, externalising distress, internalising distress, interpersonal/social problems, and cognitive functioning. However, differences in the specific measures used, interventions employed, and comparison groups limit the ability to synthesize findings.

Evidence from two studies suggests there is preliminary evidence that in-home intensive services (parent training and provision of emotional support to the parent) decreases child externalising behaviour among children who have been exposed to IPV and have clinical levels of behaviour problems. However, support for this evidence was only found immediately post-treatment and at an eight-month follow-up, but not at a four-month follow-up.

Intervention targeting the non-offending parent (mother) had the largest effect, followed by those that targeted the family together and, finally, the single study that targeted parent and child, separately.

Interventions conducted in the home had a larger effect compared to those conducted in an outpatient setting. However, these findings should be interpreted with great caution due to the heterogeneity in study characteristics such as the nature of the comparators.

Overall, it is largely unclear the extent to which psychosocial interventions promote well-being among children exposed to IPV, and under what circumstances.

What do the findings of the review mean?

The findings from this systematic review indicate that it is largely unclear the extent to which psychosocial interventions promote well-being among children exposed to IPV, and under what circumstances.

More rigorous evaluation of psychosocial interventions needs to be conducted using common outcomes across studies in order to draw conclusions. We suggest that in addition to increased rigour in evaluation design (such as efforts to minimise selection bias), researchers assess the nature of child exposure and multiple subtypes of IPV; this will help elucidate whether interventions are more or less effective depending on the IPV exposure context.

How up-to-date is this review?

The review authors searched for studies up to April 2018.

PLAIN LANGUAGE SUMMARY

Payment for environmental services (PES) remains high-risk strategy for climate change mitigation until rigorous impact evaluations can determine its effects

Programmes that provide economic incentives to reduce the negative environmental impact of land use are a popular means to reduce deforestation and degradation and mitigate climate change. In some cases they also aim to improve socio-economic outcomes. The effects of Payment for environmental services (PES) programmes on these outcomes, however, remain unclear due to the low quality of available evidence.

What is this review about?

Greenhouse gas is released by unsustainable practices in the land use sector. PES programmes seek to create positive environmental outcomes by providing an economic incentive to the owners and managers of environmental services in low- and middle-income countries to change their behaviour.

This review uses existing evidence to assess whether PES programmes have positive effects on environmental and socio-economic outcomes. It also assesses how these effects vary across different contexts and implementation strategies.

What is the aim of this review?

This Campbell systematic review examines the effects of Payment for Environmental Services (PES) programmes on environmental and socio-economic outcomes in low- and middle-income countries. The review summarises findings from 44 quantitative and 60 qualitative studies from 12 countries.

What studies are included?

Studies were included that evaluated a PES programme in low- and middle-income countries and targeted populations living in or near forests, agricultural land, wetlands, grasslands and mangroves.

Forty-four impact evaluations and 60 qualitative studies were included. They covered 18 programmes from 12 countries in Latin America and the Caribbean, East Asia and Pacific, South Asia and sub-Saharan Africa.

Ten of the 18 programmes had as their objectives the improvement of both environmental and socio-economic outcomes.

What are the main findings of this review?

PES may produce reduced deforestation, improved forest cover and increased household income. These findings are, however, based on low and very low quality evidence from a small number of countries, and should be treated with caution.

Qualitative data indicates that the effects will vary, depending on where and to whom projects are targeted, the quality of implementation, presence of governance structures, contextual factors, and attitudes towards environmental protection and towards PES itself.

What do the findings of the review mean?

Until higher quality research is conducted, the large-scale implementation of PES programmes should be considered a high-risk strategy for mitigating climate change.

Based on the current evidence, strong conclusions about the impact of PES cannot be made, however effective targeting and including strong governance structures may improve project results.

To address the evidence gap, funders and implementing agencies should collaborate to develop rigorous methods for impact evaluation. They should also invest in the collection and analysis of qualitative data that examines diverse research participants and follows change over longer periods.

How up-to-date is this review?

The review authors searched for studies in August and September 2017.

PLAIN LANGUAGE SUMMARY

Single-track year-round education modestly improves average math and reading achievement of K-12 students

Single-track year-round education (YRE) is linked to higher average achievement in both math and reading, though not overall student proficiency rates. Achievement gains are similar in magnitude to the degree of summer learning loss documented in other studies.

What is this review about?

Over the long summer break, students forget some of what they learned during the school year. This “summer learning loss” is especially large for low-income students. One policy aimed at decreasing summer learning loss is year-round education (YRE): re-distributing the usual number of school days so that students have more short breaks during the school year, and a much shorter summer vacation.

A specific design used to achieve this goal is single-track YRE, which involves placing all students at a given school on the same year-round calendar.

This review considers evidence on the effect of single-track YRE on academic achievement – test scores and proficiency rates – of K-12 students in math and reading from studies published between 2001 and 2016.

What is the aim of this review?

This Campbell systematic review synthesizes the findings from 30 studies that compared the performance of students at schools using single-track year-round calendars to the performance of students at schools using a traditional calendar.

What studies are included?

This review includes studies that compare achievement in single-track YRE schools to achievement in traditional-calendar schools. Of a total of 39 studies on the topic, nine reported outcomes in a way that could not be combined with the 30 that this review focuses on. The studies were from 2001-2016 and were all of K-12 schooling in the USA, but varied in school characteristics (state, size, percent minority, percent low-income).

None of the studies used an experimental design (random assignment); studies were about evenly split between (a) comparing one school to another that is very similar, (b) comparing one school to a nearby school, and (c) comparing students at a school before versus after a switch to a year-round calendar.

What are the findings of this review?

Is academic achievement higher at YRE schools?

Average student achievement was higher in both reading and math at single-track YRE schools, but proficiency rates were no higher in either subject. Compared to a prior meta-analysis of summer learning loss, which found that students typically forget the equivalent of one month’s learning over the summer, this review found the gain from YRE to be slightly more than this in reading and slightly less in math.

Do some students benefit more from YRE?

For the most part, no. Low-income and minority students do not see greater benefit from YRE than average students in either reading or math. Elementary and middle school students show about the same gain in reading. However, we find that middle school students’ achievement in math increases more than elementary school students’ from the year-round calendar.

Do some year-round calendars help students more than others?

Tentatively, yes: the schools that shortened summers to the fewest weeks had the largest effect on student achievement in both math and reading.

What do the findings of the review mean?

Single-track YRE appears to have a benefit to student achievement that is similar in magnitude to the learning loss students experience over the traditional 10-week summer break.

YRE does not appear to be more helpful for low-income or minority students than for the average student, but might have a larger effect for middle school students than elementary school students in math.

Schools that shortened summer to the fewest weeks of vacation showed the greatest gain in student achievement. This seems to indicate that most schools can expect an improved student achievement gain from a year-round calendar, equivalent to one month of learning, with a larger improvement from shortening the summer break to 4-6 weeks than from shortening the summer break to 7-8 weeks.

How up-to-date is this review?

The review authors searched for studies up to 2016, with electronic searches conducted in July and August 2017.

PLAIN LANGUAGE SUMMARY

Mass deworming during pregnancy reduces anaemia but has no effect on other maternal or pregnancy outcomes

Pregnant women are at particular risk from soil transmitted helminthiasis (STH) – a group of diseases caused by infection with four intestinal parasites and schistosomiasis. Individual-level data analysis with data from three studies shows that mass deworming during pregnancy reduces anaemia but has no effect on any other maternal or pregnancy outcomes.

What is this review about?

Soil transmitted helminthiasis (STH) are a group of diseases caused by infection with four intestinal parasites (two types of hookworm, roundworm, and whip worm) which contributed to a total of 4.98 million years lived with disability (YLDs) in 2010. Anaemia is one of the most common side effects of infection with STH or schistosomes, due to blood loss in the intestine or urinary tract. Women in low- and middle-income countries (LMICs) are especially prone since they may be pregnant or lactating for as much as half of their reproductive lives, with over 50% of the pregnant women having iron-deficiency anaemia.

This review explores whether the effect of mass deworming during pregnancy varies with individual characteristics (nutritional status, anaemia), intensity of infection (as assessed by egg count), infection status (including species of worm), socioeconomic status, sanitation environment and co-interventions. The analysis uses individual patient data (IPD), which means that the original individual-level data are obtained for the included studies and combined into a single data set.

What is the aim of this review?

This Campbell systematic review explores whether the effect of mass deworming during pregnancy varies with individual characteristics, intensity of infection, infection status, socioeconomic status, sanitation environment and co-interventions.

What studies are included?

Included studies have to be individually randomised controlled trials: cluster randomised controlled trials and quasi randomised studies providing preventive or therapeutic deworming drugs for STH and schistosomiasis during pregnancy.

From a total of 16 studies on mass deworming during pregnancy, we identified seven trials with 8,515 participants which were eligible for individual data analysis. Of these seven trials, we received data from three trials so that data was captured for 5,957 participants.

What are the main findings of this review?

Mass deworming during pregnancy reduces maternal anaemia by nearly one quarter (23%).

There is no effect of mass deworming during pregnancy on any other outcomes including Trichiura infection, hookworm infection, low birth weight, and pre-term birth.

The size of the effect is not affected by Trichiura intensity at baseline, maternal anemia at baseline and maternal BMI at baseline. However these findings should be interpreted with caution due to small sample sizes. Other potential moderating characteristics could not be assessed because of lack of data.

The quality of evidence for our findings is rated as moderate. Further research on maternal baseline worm intensities and birth outcomes could change our findings.

What do the findings of the review mean?

The analyses suggest that mass deworming during pregnancy is associated with reducing anaemia, with no effect on any other maternal or pregnancy outcomes.

The analyses were limited by the availability of data for the impact by sub-groups and effect modification. Thus, there is a need to assess mass deworming for STH and schistosomiasis during pregnancy in large-scale programmatic settings, along with an attempt to measure various individual and environmental factors that could potentially affect its impact.

There is also a need to support and promote open data for future individual level data analysis.

How up-to-date is this review?

The review authors searched for studies up to March 2018.

PLAIN LANGUAGE SUMMARY

Focused deterrence is associated with moderate reductions in crime

A relatively small number of groups and persons are responsible for a disproportionate share of crime. Focused deterrence strategies attempt to reduce offending behaviour for specific types of crime. These strategies are associated with moderate overall reductions in crime.

Crime is not displaced to other areas, rather it is more likely that there is a diffusion of crime control benefits to adjacent areas and similar people and groups.

What is this review about?

Focused deterrence strategies combine law enforcement, community mobilisation, and social services in an attempt to reduce offending behaviour for specific crime types. A key feature of this crime control strategy is that the consequences of continued criminal offending and available social services are directly communicated to targeted subjects.

This review examines the relationship between focused deterrence policing and crime, and gives consideration to the different types of focused deterrence strategies and programme evaluation designs.

What is the aim of this review?

This Campbell systematic review examines the effects of focused deterrence policing on crime. The review summarises and analyses results from 24 quasi-experimental evaluations of focused deterrence interventions, including 12 programmes targeting criminally active gangs or groups, nine programmes targeting open-air drug markets, and three programmes targeting high-risk individual offenders. All but one of the studies are from the USA.

What studies are included?

A total of 24 studies of focused deterrence policing interventions were identified. All studies were published from 2001 to 2015. Twenty-three studies were conducted in the USA and one in Scotland. None of the identified studies used a randomised controlled trial design.

What are the main findings of this review?

Is focused deterrence an effective approach to reducing criminal offending among problem persons and groups?

Yes. The available evidence suggests an overall reduction in crime when focused deterrence strategies are used. The largest reductions are generated by focused deterrence programmes that target criminally active gangs or groups, followed by interventions that target chronic individual offenders and drug market interventions.

Do some programmes work better than others?

Yes. Gang/group intervention programmes have the largest effect, followed by the high-risk individuals programmes, with the smallest effect from drug market intervention (DMI) programmes. DMI programmes are most likely to suffer implementation problems, which reduce effectiveness.

Does crime get displaced to other areas?

No. No studies found significant crime displacement effects into surrounding areas. There is some evidence of the diffusion of crime control benefits.

What do the findings of the review mean?

Findings from this review support the growing use of focused deterrence as a proactive crime reduction strategy. Practitioners and policymakers should continue to implement focused deterrence programmes to address serious crime problems.

The number of studies included in the updated review is more than double the number of studies included in the previous iteration of the review. However, despite the increase in eligible studies, no evaluations utilised a randomised controlled trial design. The growth of focused deterrence warrants more methodologically rigorous programme evaluations and further exploration into the specific components of the strategy, to improve our understanding into how the programme reduces crime.

How up-to-date is this review?

The review authors searched for studies up to October 2015.

PLAIN LANGUAGE SUMMARY

Policing disorder through community and problem-solving policing is associated with reductions in crime, but aggressive, order maintenance approaches are not

Disorderly conditions are seen as a precursor to more serious crime, fear of crime, and neighbourhood decline. Policing disorder is associated with reductions in crime, but only when community and problem-solving tactics are used. Aggressive, order maintenance based approaches are not effective.

What is the aim of this review?

This Campbell systematic review examines the effects of disorder policing interventions on crime. The review summarises evidence from 28 high-quality studies (representing 30 independent tests), including nine randomised controlled trials. Most the studies come from the USA.

What is this review about?

Policing social and physical disorderly conditions is rooted in the broken windows approach: disorder is a precursor to more serious crime, fear of crime, and neighborhood decline. Addressing disorder has become a central fixture of policing, especially in the USA. Yet, evaluations of the effectiveness of disorder policing strategies in controlling crime yield conflicting results.

Policing disorderly conditions can be divided into two main strategies: (1) Order maintenance or zero tolerance policing, where police attempt to impose order through strict enforcement; and (2) Community policing and problem-solving policing, where police attempt to produce order and reduce crime through cooperation with community members and by addressing specific recurring problems.

This review examined the effects of disorder policing strategies compared to traditional law enforcement actions (e.g., regular levels of patrol) on the rates of crime, including property crime, violent crime, and disorder/drug crime. This review also examined whether policing disorder actions at specific locations result in crime displacement (i.e., crime moving around the corner) or diffusion of crime control benefits (i.e., crime reduction in surrounding areas).

What studies are included?

A total of 28 disorder policing studies (representing 30 independent tests) met the criteria to be included in this review. The studies spanned the period from 1985 to 2012, and were mostly carried out in the USA. All of the studies used high-quality designs to evaluate the impact of the intervention; nine were randomised controlled trials. Twelve tests were completed in large cities (more than 500,000 residents), nine tests were completed in medium-sized cities (200,000 to 500,000 residents), and the other nine tests were completed in smaller cities. All of the tests were carried out in specific geographical settings, including small places (e.g., crime hot spots and problem buildings), smaller police-defined areas (e.g., patrol beats), neighbourhoods and selected stretches of highways, and larger police-defined areas (e.g., precincts and divisions).

What are the main findings of this review?

Do policing interventions focused on disorderly conditions reduce crime?

Yes, in addition to an overall reduction in crime, there is a reduction in property crime, violent crime, and disorder/drug crime when disorder policing interventions are implemented.

Do policing interventions focused on disorder result in crime being displaced or crime control benefits being diffused to surrounding areas?

Disorder policing interventions are associated with diffusion of crime control benefits in areas surrounding targeted locations. This conclusion is based on 15 tests that measured displacement or diffusion effects.

Of the two main strategies used in policing disorder, is one more effective than the other?

Yes, policing disorder through community and problem-solving is associated with reductions in crime. Aggressive, order maintenance approaches are not effective.

What do the findings of the review mean?

The types of strategies used by police departments to address disorderly conditions seem to matter in controlling crime, and this holds important implications for police-community relations, justice, and crime prevention. Further research is needed to understand the key programmatic elements that maximise the capacity of these strategies

How up-to-date is this review?

This review includes studies completed before 2013.