The robust result in meta-analysis of aid effectiveness : a response to Mekasha and Tarp

In this response to Mekasha and Tarp (2013) we show that contrary to what they state, their study validates our basic analysis. They confirm that the literature finds that aid is of little economic importance in generating growth. The results also show that the literature systematically selects control variables for their effect on aid effectiveness. We argue that their choice of the random effects model is not appropriate for the problem at hand, and that the way they use multiple meta-regression analysis contradicts the robust results reached at the basic analysis.

Effectiveness of interventions to promote physical activity among socioeconomically disadvantaged women : a systematic review and meta-analysis

Physical activity is important for preventing weight gain and obesity, but women experiencing socioeconomic disadvantage are at high risk of inactivity. This study aimed to determine the effectiveness of interventions to increase physical activity among women experiencing disadvantage, and the intervention factors (i.e. physical activity measure, delivery mode, delivery channel, setting, duration, use of theory, behavioural techniques, participant age, risk of bias) associated with effectiveness. We conducted a meta-analysis of controlled trials using random-effects models and meta-regression. Seven databases were searched for trials among healthy women (18–64 years), which included a physical activity intervention, any control group, and statistical analyses of a physical activity outcome at baseline and post-intervention. Nineteen studies were included (n = 6,339). Because of substantial statistical heterogeneity (χ2 = 53.61, df = 18, P < 0.0001, I2 = 66%), an overall pooled effect is not reported. In subgroup analyses, between-group differences were evident for delivery mode, which modestly reduced heterogeneity (to 54%). Studies with a group delivery component had a standardized mean difference of 0.38 greater than either individual or community-based delivery. Programs with a group delivery mode significantly increase physical activity among women experiencing disadvantage, and group delivery should be considered an essential element of physical activity promotion programs targeting this population group.

The impact of statins on psychological wellbeing : a systematic review and meta-analysis

Background : Cholesterol-lowering medications such as statins have anti-inflammatory and antioxidant properties, which may be beneficial for treating depression and improving mood. However, evidence regarding their effects remains inconsistent, with some studies reporting links to mood disturbances. We aimed to conduct a meta-analysis to determine the impact of statins on psychological wellbeing of individuals with or without hypercholesterolemia.

Methods : Articles were identified using medical, health, psychiatric and social science databases, evaluated for quality, and data were synthesized and analyzed in RevMan-5 software using a random effects model.

Results : The 7 randomized controlled trials included in the analysis represented 2,105 participants. A test for overall effect demonstrated no statistically significant differences in psychological wellbeing between participants receiving statins or a placebo (standardized mean difference (SMD) = -0.08, 95% CI -0.29 to 0.12; P = 0.42). Sensitivity analyses were conducted to separately analyze depression (n = 5) and mood (n = 2) outcomes; statins were associated with statistically significant improvements in mood scores (SMD = -0.43, 95% CI -0.61 to -0.24).

Conclusions : Our findings refute evidence of negative effects of statins on psychological outcomes, providing some support for mood-related benefits. Future studies could examine the effects of statins in depressed populations.

Physical activity for cancer survivors : a meta-analysis of randomised controlled trials

Objective To systematically evaluate the effects of physical activity in adult patients after completion of main treatment related to cancer. Design Meta-analysis of randomised controlled trials with data extraction and quality assessment performed independently by two researchers. Data sources Pubmed, CINAHL, and Google Scholar from the earliest possible year to September 2011. References from meta-analyses and reviews. Study selection Randomised controlled trials that assessed the effects of physical activity in adults who had completed their main cancer treatment, except hormonal treatment. Results There were 34 randomised controlled trials, of which 22 (65%) focused on patients with breast cancer, and 48 outcomes in our meta-analysis. Twenty two studies assessed aerobic exercise, and four also included resistance or strength training. The median duration of physical activity was 13 weeks (range 3-60 weeks). Most control groups were considered sedentary or were assigned no exercise. Based on studies on patients with breast cancer, physical activity was associated with improvements in insulin-like growth factor-I, bench press, leg press, fatigue, depression, and quality of life. When we combined studies on different types of cancer, we found significant improvements in body mass index (BMI), body weight, peak oxygen consumption, peak power output, distance walked in six minutes, right handgrip strength, and quality of life. Sources of study heterogeneity included age, study quality, study size, and type and duration of physical activity. Publication bias did not alter our conclusions. Conclusions Physical activity has positive effects on physiology, body composition, physical functions, psychological outcomes, and quality of life in patients after treatment for breast cancer. When patients with cancer other than breast cancer were also included, physical activity was associated with reduced BMI and body weight, increased peak oxygen consumption and peak power output, and improved quality of life.

Constraints to park visitation: a meta-analysis of North American studies

The constraints that curb visitation to parks have received considerable research attention and remain an important issue. Constraints to outdoor leisure in parks include structural barriers, such as cost of entry, interpersonal barriers, for example, lack of a partner to visit with, or intrapersonal barriers, including lack of interest. Using a meta-analysis approach, this article integrates the findings of 22 North American studies with 541 estimates, conducted over a 30-year period, to determine the key constraints to park visitation based on various socio-demographic factors. The findings highlight the varying roles that constraints play in limiting the visitation of people according to race, age, gender, education and income. Gaps in the literature are identified, with implications for encouraging visitation for more constrained groups discussed. An agenda for future research is presented.

Economic evaluation of adult rehabilitation: a systematic review and meta-analysis of randomized controlled trials in a variety of settings

Objectives:
To report if there is a difference in costs from a societal perspective between adults receiving rehabilitation in an inpatient rehabilitation setting versus an alternative setting. If there are cost differences, to report whether opting for the least expensive program setting adversely affects patient outcomes.

Data Sources:
Electronic databases from the earliest possible date until May 2011. All languages were included.

Study Selection
Multiple reviewers identified randomized controlled trials with a full economic evaluation that compared adult inpatient rehabilitation with an alternative. There were 29 included trials with 6746 participants.

Data Extraction
Multiple observers extracted data independently. Trial appraisal included a risk of bias assessment and a checklist to report the strength of the economic evaluation.

Data Synthesis:
Results were synthesized using standardized mean differences (SMDs) and meta-analyses for the primary outcome of cost. The Grading of Recommendations Assessment, Development, and Evaluation was applied to assess for risk of bias across studies for meta-analyses. There was high-quality evidence that cost was significantly reduced for rehabilitation in the home versus inpatient rehabilitation in a meta-analysis of 732 patients poststroke (pooled SMD [δ]=−.28; 95% confidence interval [CI], −.47 to −.09), without compromise to patient outcomes. Results of individual trials in other patient groups (orthopedic, rheumatoid arthritis, and geriatric) receiving rehabilitation in the home or community were generally consistent with the meta-analysis. There was moderate quality evidence that cost was significantly reduced for inpatient rehabilitation (stroke unit) versus general acute care in a meta-analysis of 463 patients poststroke (δ=.31; 95% CI, .15–.48), with improvement to patient outcomes. These results were not replicated in 2 individual trials with a geriatric and a mixed cohort, where costs did not differ between general acute care and inpatient rehabilitation. Three of the 4 individual trials, inclusive of a stroke or orthopedic population, reported less cost for an intensive inpatient rehabilitation program compared with usual inpatient rehabilitation. Sensitivity analysis included a health service perspective and varied inflation rates with no change to the significant findings of the meta-analyses.

Conclusions:
Based on this systematic review and meta-analyses, a single rehabilitation service may not provide health economic benefits for all patient groups and situations. For some patients, inpatient rehabilitation may be the most cost-effective method of providing rehabilitation; yet, for other patients, rehabilitation in the home or community may be the most cost-effective model of care. To achieve cost-effective outcomes, the ideal combination of rehabilitation services and patient inclusion criteria, as well as further data for nonstroke populations, warrants further research.

Interventions designed to limit gestational weight gain: a systematic review of theory and meta-analysis of intervention components

Limiting gestational weight gain (GWG) to recommended levels is important to optimize health outcomes for mother and baby. Surprisingly, a recent review revealed that theory-based interventions to limit GWG were less effective than interventions that did not report a theory-base; however, strict criteria were used to identify theory-informed studies. We extended this review and others by systematically evaluating the theories of behaviour change informing GWG interventions using a generalized health psychology perspective, and meta-analysing behaviour change techniques reported in the interventions. Interventions designed to limit GWG were searched for using health, nursing and psychology databases. Papers reporting an underpinning theory were identified and the CALO-RE taxonomy was used to determine individual behaviour change techniques. Nineteen studies were identified for inclusion. Eight studies were informed by a behaviour change theory; six reported favourable effects on GWG. Overall, studies based on theory were as effective as non–theory-based studies at limiting GWG. Furthermore, the provision of information, motivational interviewing, behavioural self-monitoring and providing rewards contingent on successful behaviour appear to be key strategies when intervening in GWG. Combining these behaviour change techniques with dietary interventions may be most effective. Future research should focus on determining the exact combination of behaviour change techniques, or which underpinning theories, are most useful for limiting GWG.

An efficient meta-heuristic algorithm for grid computing

A grid computing system consists of a group of programs and resources that are spread across machines in the grid. A grid system has a dynamic environment and decentralized distributed resources, so it is important to provide efficient scheduling for applications. Task scheduling is an NP-hard problem and deterministic algorithms are inadequate and heuristic algorithms such as particle swarm optimization (PSO) are needed to solve the problem. PSO is a simple parallel algorithm that can be applied in different ways to resolve optimization problems. PSO searches the problem space globally and needs to be combined with other methods to search locally as well. In this paper, we propose a hybrid-scheduling algorithm to solve the independent task- scheduling problem in grid computing. We have combined PSO with the gravitational emulation local search (GELS) algorithm to form a new method, PSO–GELS. Our experimental results demonstrate the effectiveness of PSO–GELS compared to other algorithms.

Meta-analysis of movements in Atlantic leatherback turtles during the nesting season : conservation implications

Despite decades of conservation efforts on the nesting beaches, the critical status of leatherback turtles shows that their survival predominantly depends on our ability to reduce at-sea mortality. Although areas where leatherbacks meet fisheries have been identified during the long distance movements between 2 consecutive nesting seasons, hot-spots of lethal interactions are still poorly defined within the nesting season, when individuals concentrate close to land. Here we report movements of satellite-tracked gravid leatherback turtles during the nesting season in Western Central Africa, South America and the Caribbean Sea, which account for about 70% of the world population. We show that during and at the end of the nesting season, leatherback turtles have the propensity to remain over the continental shelf, yet sometimes perform extended movements and may even nest in neighbouring countries. Leatherbacks exploit coastal commercial fishing grounds and face substantial accidental capture by regional coastal fisheries (e.g. at least 10% in French Guiana). This emphasises the need for regional conservation strategies to be developed at the ocean scale—both at sea and on land—to ensure the survival of the last leatherback turtles.