Standardized mean differences in individually-randomized and cluster-randomized trials, with applications to meta-analysis

Home-Based Compared with Hospital-Based Rehabilitation Program for Patients Undergoing Total Knee Arthroplasty for Osteoarthritis: A Systematic Review and Meta-analysis of Randomized Controlled Trials

OBJECTIVE

The aim of this study was to compare the effects of home-based with those of hospital-based rehabilitation on patients undergoing total knee arthroplasty (TKA).

DESIGN

PubMed, Web of Science, EMBASE, and Cochrane Library were systematically searched for randomized controlled trials; the studies were assessed with the modified Jadad scale. Ten trials involving 1240 patients were eligible for meta-analysis.

RESULTS

The results revealed that home-based rehabilitation is not inferior to hospital-based rehabilitation according to the total Western Ontario and McMaster Universities Osteoarthritis index score, physical function, stiffness, walk test, and Oxford Knee Score at 12 or 52 weeks after TKA (P > 0.05). Neither pain nor knee flexion range of motion differed between the groups in the first 12 weeks. Unexpectedly, the pain score in the hospital-based group was better than that in the home-based group (P < 0.05), whereas the knee flexion range of motion in the home-based group was superior to that in the hospital-based group (P < 0.05) at 52 weeks. The meta-analysis revealed that the 2 rehabilitation programs have similar costs (P > 0.05).

CONCLUSION

Home-based rehabilitation after primary TKA was comparable to hospital-based rehabilitation and thus is a significant alternative for patients.

Effects of the Informed Health Choices podcast on the ability of parents of primary school children in Uganda to assess claims about treatment effects: a randomised controlled trial

BACKGROUND

As part of the Informed Health Choices project, we developed a podcast called The Health Choices Programme to help improve the ability of people to assess claims about the benefits and harms of treatments. We aimed to evaluate the effects of the podcast on the ability of parents of primary school children in Uganda to assess claims about the effects of treatments.

METHODS

We did this randomised controlled trial in central Uganda. We recruited parents of children aged 10-12 years who were in their fifth year of school at 35 schools that were participating in a linked trial of the Informed Health Choices primary school resources. The parents were randomly allocated (1:1), via a web-based random number generator with block sizes of four and six, to listen to either the Informed Health Choices podcast (intervention group) or typical public service announcements about health issues (control group). Randomisation was stratified by parents' highest level of formal education attained (primary school, secondary school, or tertiary education) and the allocation of their children's school in the trial of the primary school resources (intervention vs control). The primary outcome, measured after listening to the entire podcast, was the mean score and the proportion of parents with passing scores on a test with two multiple choice questions for each of nine key concepts essential to assessing claims about treatments (18 questions in total). We did intention-to-treat analyses. This trial is registered with the Pan African Clinical Trial Registry, number PACTR201606001676150.

FINDINGS

We recruited parents between July 21, 2016, and Oct 7, 2016. We randomly assigned 675 parents to the podcast group (n=334) or the public service announcement group (n=341); 561 (83%) participants completed follow-up. The mean score for parents in the podcast group was 67·8% (SD 19·6) compared with 52·4% (17·6) in the control group (adjusted mean difference 15·5%, 95% CI 12·5-18·6; p<0·0001). In the podcast group, 203 (71%) of 288 parents had a predetermined passing score (≥11 of 18 correct answers) compared with 103 (38%) of 273 parents in the control group (adjusted difference 34%, 95% CI 26-41; p<0·0001). No adverse events were reported.

INTERPRETATION

Listening to the Informed Health Choices podcast led to a large improvement in the ability of parents to assess claims about the effects of treatments. Future studies should assess the long-term effects of use of the podcast, the effects on actual health choices and outcomes, and how transferable our findings are to other countries.

FUNDING

Research Council of Norway.

Effects of the Informed Health Choices primary school intervention on the ability of children in Uganda to assess the reliability of claims about treatment effects: a cluster-randomised controlled trial

BACKGROUND

Claims about what improves or harms our health are ubiquitous. People need to be able to assess the reliability of these claims. We aimed to evaluate an intervention designed to teach primary school children to assess claims about the effects of treatments (ie, any action intended to maintain or improve health).

METHODS

In this cluster-randomised controlled trial, we included primary schools in the central region of Uganda that taught year-5 children (aged 10-12 years). We excluded international schools, special needs schools for children with auditory and visual impairments, schools that had participated in user-testing and piloting of the resources, infant and nursery schools, adult education schools, and schools that were difficult for us to access in terms of travel time. We randomly allocated a representative sample of eligible schools to either an intervention or control group. Intervention schools received the Informed Health Choices primary school resources (textbooks, exercise books, and a teachers' guide). Teachers attended a 2 day introductory workshop and gave nine 80 min lessons during one school term. The lessons addressed 12 concepts essential to assessing claims about treatment effects and making informed health choices. We did not intervene in the control schools. The primary outcome, measured at the end of the school term, was the mean score on a test with two multiple-choice questions for each of the 12 concepts and the proportion of children with passing scores on the same test. This trial is registered with the Pan African Clinical Trial Registry, number PACTR201606001679337.

FINDINGS

Between April 11, 2016, and June 8, 2016, 2960 schools were assessed for eligibility; 2029 were eligible, and a random sample of 170 were invited to recruitment meetings. After recruitment meetings, 120 eligible schools consented and were randomly assigned to either the intervention group (n=60, 76 teachers and 6383 children) or control group (n=60, 67 teachers and 4430 children). The mean score in the multiple-choice test for the intervention schools was 62·4% (SD 18·8) compared with 43·1% (15·2) for the control schools (adjusted mean difference 20·0%, 95% CI 17·3-22·7; p<0·00001). In the intervention schools, 3967 (69%) of 5753 children achieved a predetermined passing score (≥13 of 24 correct answers) compared with 1186 (27%) of 4430 children in the control schools (adjusted difference 50%, 95% CI 44-55). The intervention was effective for children with different levels of reading skills, but was more effective for children with better reading skills.

INTERPRETATION

The use of the Informed Health Choices primary school learning resources, after an introductory workshop for the teachers, led to a large improvement in the ability of children to assess claims about the effects of treatments. The results show that it is possible to teach primary school children to think critically in schools with large student to teacher ratios and few resources. Future studies should address how to scale up use of the resources, long-term effects, including effects on actual health choices, transferability to other countries, and how to build on this programme with additional primary and secondary school learning resources.

FUNDING

Research Council of Norway.

Antiretroviral Treatment in HIV-1-Positive Mothers: Neurological Implications in Virus-Free Children

Since the worldwide introduction of antiretroviral therapy (ART) in human immunodeficiency virus type 1, HIV-1-positive mothers, together with HIV-1 testing prior to pregnancy, caesarian birth and breastfeeding cessation with replacement feeding, a reduction of HIV-1 mother-to-child transmission (MTCT) has been observed in the last few years. As such, an increasing number of children are being exposed in utero to ART. Several questions have arisen concerning the neurological effects of ART exposure in utero, considering the potential effect of antiretroviral drugs on the central nervous system, a structure which is in continuous development in the fetus and characterized by great plasticity. This review aims at discussing the possible neurological impairment of children exposed to ART in utero, focusing attention on the drugs commonly used for HIV-1 MTCT prevention, clinical reports of ART neurotoxicity in children born to HIV-1-positive mothers, and neurologic effects of protease inhibitors (PIs), especially ritonavir-“boosted” lopinavir (LPV/r) in cell and animal central nervous system models evaluating the potential neurotoxic effect of ART. Finally, we present the findings of a meta-analysis to assess the effects on the neurodevelopment of children exposed to ART in utero.

Mindfulness Training for Health Profession Students-The Effect of Mindfulness Training on Psychological Well-Being, Learning and Clinical Performance of Health Professional Students: A Systematic Review of Randomized and Non-randomized Controlled Trials

BACKGROUND

High levels of stress have been identified in medical students and increasingly in other health profession student population groups. As stress can affect psychological well-being and interfere with learning and clinical performance, there is a clear argument for universities to include health professional student well-being as an outcome in core curriculum. Mindfulness training is a potential construct to manage stress and enhance academic success.

OBJECTIVES

The aims of this systematic review were to assess the effectiveness of mindfulness training in medical and other health professional student population groups and to compare the effectiveness of the different mindfulness-based programs.

DATA SOURCES

A literature search was completed using The Cochrane library, Medline, Cinahl, Embase, Psychinfo, and ERIC (proquest) electronic databases from inception to June 2016. Randomized and non-randomized controlled trials were included. Of the potential 5355 articles, 19 met the inclusion criteria.

STUDY SELECTION PARTICIPANTS AND INTERVENTIONS

Studies focused on medical (n = 10), nursing (n = 4), social work (n = 1), psychology (n = 1), and medical plus other health (n = 3) students. Interventions were based on mindfulness.

DATA EXTRACTION

The 19 studies included 1815 participants. Meta-analysis was performed evaluating the effect of mindfulness training on mindfulness, anxiety, depression, stress, mood, self-efficacy, and empathy. The effect of mindfulness on academic performance was discussed.

DATA SYNTHESIS AND CONCLUSIONS

Mindfulness-based interventions decrease stress, anxiety, and depression and improve mindfulness, mood, self-efficacy, and empathy in health profession students. Due to the range of presentation options, mindfulness training can be relatively easily adapted and integrated into health professional training programs.

A meta-analysis of lasalocid effects on rumen measures, beef and dairy performance, and carcass traits in cattle

The effects of lasalocid on rumen measures, beef and dairy performance, and carcass traits were evaluated using meta-analysis. Meta-regression was used to investigate sources of heterogeneity. Ten studies (20 comparisons) were used in the meta-analysis on rumen measures. Lasalocid increased total VFA and ammonia concentrations by 6.46 and 1.44 m, respectively. Lasalocid increased propionate and decreased acetate and butyrate molar percentage (M%) by 4.62, 3.18, and 0.83%, respectively. Valerate M% and pH were not affected. Meta-regression found butyrate M% linearly increased with duration of lasalocid supplementation (DUR; = 0.017). When >200 mg/d was fed, propionate and valerate M% were higher and acetate M% was lower ( = 0.042, = 0.017, and = 0.005, respectively). Beef performance was assessed using 31 studies (67 comparisons). Lasalocid increased ADG by 40 g/d, improved feed-to-gain ratio (F:G) by 410 g/kg, and improved feed efficiency (FE; combined measure of G:F and the inverse of F:G). Lasalocid did not affect DMI, but heterogeneity in DMI was influenced by DUR ( = 0.004) and the linear effect of entry BW ( = 0.011). The combination of ≤100 vs. >100 d DUR and entry BW ≤275 vs. >275 kg showed that cattle ≤275 kg at entry fed lasalocid for >100 d had the lowest DMI. Heterogeneity of ADG was influenced by the linear effect of entry BW ( = 0.028) but not DUR. Combining entry BW ≤275 vs. >275 kg and DUR showed that cattle entering at >275 kg fed ≤100 d had the highest ADG. The FE ( = 0.025) and F:G ( = 0.015) linearly improved with dose, and entry BW >275 kg improved F:G ( = 0.038). Fourteen studies (25 comparisons) were used to assess carcass traits. Lasalocid increased HCW by 4.73 kg but not dressing percentage, mean fat cover, or marbling score. Heterogeneity of carcass traits was low and not affected by DUR or dose. Seven studies (11 comparisons) were used to assess dairy performance but the study power was relatively low and the evidence base is limited. Lasalocid decreased DMI in total mixed ration-fed cows by 0.89 kg/d but had no effect on milk yield, milk components, or component yields. Dose linearly decreased DMI ( = 0.049). The DUR did not affect heterogeneity of dairy measures. This work showed that lasalocid improved ADG, HCW, FE, and F:G for beef production. These findings may reflect improved energy efficiency from increased propionate M% and decreased acetate and butyrate M%. Large dairy studies are required for further evaluation of effects of lasalocid on dairy performance.

Interventions to achieve ongoing exercise adherence for adults with chronic health conditions who have completed a supervised exercise program: systematic review and meta-analysis

OBJECTIVE

To determine which exercise adherence interventions are most effective for achieving ongoing exercise adherence in adults with chronic health conditions who had already completed a supervised short-term program.

METHOD

Search of MEDLINE (Ovid Medline 1946 to April 8^th, 2016), EMBASE (1980 to April 8^th, 2016), CINAHL (1982-April 8^th 2016) and the Cochrane Central Register of Controlled Trials was conducted. The chronic health conditions search terms as per the Chronic Disease and Participation in Work AIHW Report, 2008. Included were randomised (or quasi-randomised) trials and observational studies evaluating interventions that aimed to improve exercise adherence in adults with chronic health conditions that had completed a supervised exercise program. Random-effects meta-analyses and random-effects logistic meta-regression were used to examine relationships between exercise adherence strategy and adherence.

RESULTS

Eleven studies were included with a total of 1231 participants with Chronic Obstructive Pulmonary Disease, Diabetes, Cardiovascular disease or Osteoarthritis. Methods used for maintaining adherence were categorized post hoc as: centre based programs; home exercise programs with telephone follow-up; home exercise programs with no follow-up; and weaning programs that transitioned patients to an independent, off-site exercise program. There was no difference in the proportion of participants who were fully adherent to an exercise program 12 months between the centre-based follow-up (pooled proportion fully adherent=0.34) and telephone follow-up (pooled proportion fully adherent=0.30, difference p-value=0.75).

CONCLUSION

Interventions such as centre-based exercise programs or home exercise programs (with or without telephone follow-up) do not differentially impact exercise adherence for people who have completed a short-term supervised program.

Epidemiology of Mental Health Attendances at Emergency Departments: Systematic Review and Meta-Analysis

Background

The characteristics of Emergency Department (ED) attendances due to mental or behavioural health disorders need to be described to enable appropriate development of services. We aimed to describe the epidemiology of mental health-related ED attendances within health care systems free at the point of access, including clinical reason for presentation, previous service use, and patient sociodemographic characteristics.

Method

Systematic review and meta-analysis of observational studies describing ED attendances by patients with common mental health conditions.

Findings

18 studies from seven countries met eligibility criteria. Patients attending due to mental or behavioural health disorders accounted for 4% of ED attendances; a third were due to self-harm or suicidal ideation. 58.1% of attendees had a history of psychiatric illness and up to 58% were admitted. The majority of studies were single site and of low quality so results must be interpreted cautiously.

Conclusions

Prevalence studies of mental health-related ED attendances are required to enable the development of services to meet specific needs.

A systematic review and meta-analysis of the n-3 polyunsaturated fatty acids effects on inflammatory markers in colorectal cancer

BACKGROUND

Cancer and inflammation are closely related and an exacerbated inflammatory process can lead to tumor progression and a worse prognosis for the patient with cancer. Scientific literature has shown evidence that n-3 polyunsaturated fatty acids (PUFA) have anti-inflammatory action, and for this reason could be useful as an adjuvant in the treatment of some cancers.

OBJECTIVE

A systematic review and meta-analysis of the literature was conducted until September, 2014, to evaluate the effects of n-3 PUFA on inflammatory mediators in colorectal cancer (CRC) patients.

PATIENTS AND METHODS

Clinical trials were systematically searched in three electronic databases and screening reference lists. Random meta-analysis model was used to calculate the overall and stratified effect sizes.

RESULTS

Nine trials, representing 475 patients with CRC, evaluated effects of n-3 PUFA on cytokines (n = 6) and/or acute phase proteins (n = 5) levels. n-3 PUFA reduce the levels of IL-6 (SMD -2.34; 95% CI -4.37, -0.31; p = 0.024) and increase albumin (SMD 0.31; 95% CI 0.06, 0.56; p = 0.014) in overall analyses. In stratified analyses, reduction in IL-6 levels occurs in surgical patients that received 0.2 g/kg of fish oil parenterally at postoperative period (SMD -0.65; 95% CI -1.06, -0.24; p = 0.002), while, increase in albumin concentration occurs in surgical patients that received ≥ 2.5 g/d of EPA + DHA orally at preoperative period (SMD 0.34; 95% CI 0.02, 0.66; p = 0.038). In patients undergoing chemotherapy, the supplementation of 0.6 g/d of EPA + DHA during 9 week reduces CRP levels (SMD -0.95; 95% CI -1.73, -0.17; p = 0.017), and CRP/albumin ratio (SMD -0.95; 95% CI -1.73, -0.18; p = 0.016).

CONCLUSIONS

The results suggest benefits on some inflammatory mediators with the use of n-3 PUFA on CRC patients, but these benefits are specific to certain supplementation protocols involving duration, dose and route of administration, and also, the concomitant anti-cancer treatment adopted.

A meta-analysis of zilpaterol and ractopamine effects on feedlot performance, carcass traits and shear strength of meat in cattle

This study is a meta-analysis of the effects of the beta-agonists zilpaterol hydrochloride (ZH) and ractopamine hydrochloride (RAC) on feedlot performance, carcase characteristics of cattle and Warner Bratzler shear force (WBSF) of muscles. It was conducted to evaluate the effect of the use of these agents on beef production and meat quality and to provide data that would be useful in considerations on the effect of these agents on meat quality in Meat Standards Australia evaluations. We conducted a comprehensive literature search and study assessment using PubMed, Google Scholar, ScienceDirect, Scirus, and CAB and identification of other studies from reference lists in papers and searches. Searches were based on the key words: zilpaterol, zilmax, ractopamine, optaflexx, cattle and beef. Studies from theses obtained were included. Data were extracted from more than 50 comparisons for both agents and analysed using meta-analysis and meta-regression. Both agents markedly increased weight gain, hot carcase weight and longissimus muscle area and increased the efficiency of gain:feed. These effects were particularly large for ZH, however, fat thickness was decreased by ZH, but not RAC. Zilpaterol also markedly increased WBSF by 1.2 standard deviations and more than 0.8 kg, while RAC increased WBSF by 0.43 standard deviations and 0.2 kg. There is evidence in the ZH studies, in particular, of profound re-partitioning of nutrients from fat to protein depots. This work has provided critically needed information on the effects of ZH and RAC on production, efficiency and meat quality.

Meta-analysis of absolute mean differences from randomised trials with treatment-related clustering associated with care providers

Nesting of patients within care providers in trials of physical and talking therapies creates an additional level within the design. The statistical implications of this are analogous to those of cluster randomised trials, except that the clustering effect may interact with treatment and can be restricted to one or more of the arms. The statistical model that is recommended at the trial level includes a random effect for the care provider but allows the provider and patient level variances to differ across arms. Evidence suggests that, while potentially important, such within-trial clustering effects have rarely been taken into account in trials and do not appear to have been considered in meta-analyses of these trials. This paper describes summary measures and individual-patient-data methods for meta-analysing absolute mean differences from randomised trials with two-level nested clustering effects, contrasting fixed and random effects meta-analysis models. It extends methods for incorporating trials with unequal variances and homogeneous clustering to allow for between-arm and between-trial heterogeneity in intra-class correlation coefficient estimates. The work is motivated by a meta-analysis of trials of counselling in primary care, where the control is no counselling and the outcome is the Beck Depression Inventory. Assuming equal counsellor intra-class correlation coefficients across trials, the recommended random-effects heteroscedastic model gave a pooled absolute mean difference of -2.53 (95% CI -5.33 to 0.27) using summary measures and -2.51 (95% CI -5.35 to 0.33) with the individual-patient-data. Pooled estimates were consistently below a minimally important clinical difference of four to five points on the Beck Depression Inventory.

A systematic review and meta-analysis of the prebiotics and synbiotics effects on glycaemia, insulin concentrations and lipid parameters in adult patients with overweight or obesity

BACKGROUND & AIMS

Several studies have reported the effects of prebiotics and synbiotics supplementation in lipid profile and glucose homeostasis, however a pooled analysis of clinical trials that assessed these parameters has not been performed in overweight or obese individuals. The aim of this study was to evaluate the effects of prebiotics and synbiotics on plasma lipid profile, fasting insulin and fasting glucose in adults with overweight or obesity.

METHODS

Randomized controlled trials were systematically searched before May 2014 in electronic databases and screening reference lists. Combined and stratified (diabetics and non-diabetics trials) meta-analyzes were performed.

RESULTS

Thirteen trials, representing 513 adult participants with Body Mass Index ≥25 kg/m² were included. Prebiotic supplementation reduced plasma total cholesterol (SMD -0.25; 95% CI -0.48, -0.02) and LDL-c (SMD -0.22; 95% CI -0.44, -0.00) concentrations in overall analysis, and reduced triglycerides (SMD -0.72; 95% CI -1.20, -0.23) and increased HDL-c (SMD 0.49; 95% CI 0.01, 0.97) concentrations in diabetic trials. Synbiotic supplementation reduced plasma fasting insulin (SMD -0.39; 95% CI -0.75, -0.02) and triglycerides (SMD -0.43; 95% CI -0.70, -0.15) concentrations.

CONCLUSIONS

The improvement of the evaluated parameters supports prebiotics and synbiotics supplementation as an adjuvant therapy in obesity-related comorbidities, such as dyslipidemia and insulin resistance.

The WHO Health Promoting School framework for improving the health and well-being of students and their academic achievement

BACKGROUND

The World Health Organization's (WHO's) Health Promoting Schools (HPS) framework is an holistic, settings-based approach to promoting health and educational attainment in school. The effectiveness of this approach has not been previously rigorously reviewed.

OBJECTIVES

To assess the effectiveness of the Health Promoting Schools (HPS) framework in improving the health and well-being of students and their academic achievement.

SEARCH METHODS

We searched the following electronic databases in January 2011 and again in March and April 2013: Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, PsycINFO, CINAHL, Campbell Library, ASSIA, BiblioMap, CAB Abstracts, IBSS, Social Science Citation Index, Sociological Abstracts, TRoPHI, Global Health Database, SIGLE, Australian Education Index, British Education Index, Education Resources Information Centre, Database of Education Research, Dissertation Express, Index to Theses in Great Britain and Ireland, ClinicalTrials.gov, Current controlled trials, and WHO International Clinical Trials Registry Platform. We also searched relevant websites, handsearched reference lists, and used citation tracking to identify other relevant articles.

SELECTION CRITERIA

We included cluster-randomised controlled trials where randomisation took place at the level of school, district or other geographical area. Participants were children and young people aged four to 18 years, attending schools or colleges. In this review, we define HPS interventions as comprising the following three elements: input to the curriculum; changes to the school's ethos or environment or both; and engagement with families or communities, or both. We compared this intervention against schools that implemented either no intervention or continued with their usual practice, or any programme that included just one or two of the above mentioned HPS elements.

DATA COLLECTION AND ANALYSIS

At least two review authors identified relevant trials, extracted data, and assessed risk of bias in the trials. We grouped different types of interventions according to the health topic targeted or the approach used, or both. Where data permitted, we performed random-effects meta-analyses to provide a summary of results across studies.

MAIN RESULTS

We included 67 eligible cluster trials, randomising 1443 schools or districts. This is made up of 1345 schools and 98 districts. The studies tackled a range of health issues: physical activity (4), nutrition (12), physical activity and nutrition combined (18), bullying (7), tobacco (5), alcohol (2), sexual health (2), violence (2), mental health (2), hand-washing (2), multiple risk behaviours (7), cycle-helmet use (1), eating disorders (1), sun protection (1), and oral health (1). The quality of evidence overall was low to moderate as determined by the GRADE approach. 'Risk of bias' assessments identified methodological limitations, including heavy reliance on self-reported data and high attrition rates for some studies. In addition, there was a lack of long-term follow-up data for most studies.We found positive effects for some interventions for: body mass index (BMI), physical activity, physical fitness, fruit and vegetable intake, tobacco use, and being bullied. Intervention effects were generally small but have the potential to produce public health benefits at the population level. We found little evidence of effectiveness for standardised body mass index (zBMI) and no evidence of effectiveness for fat intake, alcohol use, drug use, mental health, violence and bullying others; however, only a small number of studies focused on these latter outcomes. It was not possible to meta-analyse data on other health outcomes due to lack of data. Few studies provided details on adverse events or outcomes related to the interventions. In addition, few studies included any academic, attendance or school-related outcomes. We therefore cannot draw any clear conclusions as to the effectiveness of this approach for improving academic achievement.

AUTHORS' CONCLUSIONS

The results of this review provide evidence for the effectiveness of some interventions based on the HPS framework for improving certain health outcomes but not others. More well-designed research is required to establish the effectiveness of this approach for other health topics and academic achievement.

Characterization of local complex structures in a recurrence plot to improve nonlinear dynamic discriminant analysis

Structures in recurrence plots (RPs), preserving the rich information of nonlinear invariants and trajectory characteristics, have been increasingly analyzed in dynamic discrimination studies. The conventional analysis of RPs is mainly focused on quantifying the overall diagonal and vertical line structures through a method, called recurrence quantification analysis (RQA). This study extensively explores the information in RPs by quantifying local complex RP structures. To do this, an approach was developed to analyze the combination of three major RQA variables: determinism, laminarity, and recurrence rate (DLR) in a metawindow moving over a RP. It was then evaluated in two experiments discriminating (1) ideal nonlinear dynamic series emulated from the Lorenz system with different control parameters and (2) data sets of human heart rate regulations with normal sinus rhythms (n = 18) and congestive heart failure (n = 29). Finally, the DLR was compared with seven major RQA variables in terms of discriminatory power, measured by standardized mean difference (DSMD). In the two experiments, DLR resulted in the highest discriminatory power with DSMD = 2.53 and 0.98, respectively, which were 7.41 and 2.09 times the best performance from RQA. The study also revealed that the optimal RP structures for the discriminations were neither typical diagonal structures nor vertical structures. These findings indicate that local complex RP structures contain some rich information unexploited by RQA. Therefore, future research to extensively analyze complex RP structures would potentially improve the effectiveness of the RP analysis in dynamic discrimination studies.

Metabolic benefits of dietary prebiotics in human subjects: a systematic review of randomised controlled trials

Complex relationships exist between the gut microflora and their human hosts. Emerging evidence suggests that bacterial dysbiosis within the colon may be involved in the pathogenesis of the metabolic syndrome, type 2 diabetes and CVD. The use of dietary prebiotic supplements to restore an optimal balance of intestinal flora may positively affect host metabolism, representing a potential treatment strategy for individuals with cardiometabolic disorders. The present review aimed to examine the current evidence supporting that dietary prebiotic supplementation in adults has beneficial effects on biochemical parameters associated with the development of metabolic abnormalities including obesity, glucose intolerance, dyslipidaemia, hepatic steatosis and low-grade chronic inflammation. Between January 2000 and September 2013, eight computer databases were searched for randomised controlled trials published in English. Human trials were included if at least one group received a dietary prebiotic intervention. In the present review, twenty-six randomised controlled trials involving 831 participants were included. Evidence indicated that dietary prebiotic supplementation increased self-reported feelings of satiety in healthy adults (standardised mean difference -0.57, 95% CI -1.13, -0.01). Prebiotic supplementation also significantly reduced postprandial glucose (-0.76, 95% CI -1.41, -0.12) and insulin (-0.77, 95% CI -1.50, -0.04) concentrations. The effects of dietary prebiotics on total energy intake, body weight, peptide YY and glucagon-like peptide-1 concentrations, gastric emptying times, insulin sensitivity, lipids, inflammatory markers and immune function were contradictory. Dietary prebiotic consumption was found to be associated with subjective improvements in satiety and reductions in postprandial glucose and insulin concentrations. Additional evidence is required before recommending prebiotic supplements to individuals with metabolic abnormalities. Large-scale trials of longer duration evaluating gut microbial growth and activity are required.

Community engagement to reduce inequalities in health: a systematic review, meta-analysis and economic analysis

Background

Community engagement has been advanced as a promising way of improving health and reducing health inequalities; however, the approach is not yet supported by a strong evidence base.

Objectives

To undertake a multimethod systematic review which builds on the evidence that underpins the current UK guidance on community engagement; to identify theoretical models underpinning community engagement; to explore mechanisms and contexts through which communities are engaged; to identify community engagement approaches that are effective in reducing health inequalities, under what circumstances and for whom; and to determine the processes and costs associated with their implementation.

Data sources

Databases including the Cochrane Database of Systematic Reviews (CDSR), The Campbell Library, the Database of Abstracts of Reviews of Effects (DARE), the Health Technology Assessment (HTA) database, the NHS Economic Evaluation Database (NHS EED) and EPPI-Centre’s Trials Register of Promoting Health Interventions (TRoPHI) and Database of Promoting Health Effectiveness Reviews (DoPHER) were searched from 1990 to August 2011 for systematic reviews and primary studies. Trials evaluating community engagement interventions reporting health outcomes were included.

Review methods

Study eligibility criteria: published after 1990; outcome, economic, or process evaluation; intervention relevant to community engagement; written in English; measured and reported health or community outcomes, or presents cost, resource, or implementation data characterises study populations or reports differential impacts in terms of social determinants of health; conducted in an Organisation for Economic Co-operation and Development (OECD) country. Study appraisal: risk of bias for outcome evaluations; assessment of validity and relevance for process evaluations; comparison against an economic evaluation checklist for economic evaluations. Synthesis methods: four synthesis approaches were adopted for the different evidence types: theoretical, quantitative, process, and economic evidence.

Results

The theoretical synthesis identified key models of community engagement that are underpinned by different theories of changes. Results from 131 studies included in a meta-analysis indicate that there is solid evidence that community engagement interventions have a positive impact on health behaviours, health consequences, self-efficacy and perceived social support outcomes, across various conditions. There is insufficient evidence – particularly for long-term outcomes and indirect beneficiaries – to determine whether one particular model of community engagement is likely to be more effective than any other. There are also insufficient data to test the effects on health inequalities, although there is some evidence to suggest that interventions that improve social inequalities (as measured by social support) also improve health behaviours. There is weak evidence from the effectiveness and process evaluations that certain implementation factors may affect intervention success. From the economic analysis, there is weak but inconsistent evidence that community engagement interventions are cost-effective. By combining findings across the syntheses, we produced a new conceptual framework.

Limitations

Differences in the populations, intervention approaches and health outcomes made it difficult to pinpoint specific strategies for intervention effectiveness. The syntheses of process and economic evidence were limited by the small (generally not rigorous) evidence base.

Conclusions

Community engagement interventions are effective across a wide range of contexts and using a variety of mechanisms. Public health initiatives should incorporate community engagement into intervention design. Evaluations should place greater emphasis on long-term outcomes, outcomes for indirect beneficiaries, process evaluation, and reporting costs and resources data. The theories of change identified and the newly developed conceptual framework are useful tools for researchers and practitioners. We identified trends in the evidence that could provide useful directions for future intervention design and evaluation.

Funding

The National Institute for Health Research Public Health Research programme.

Accuracy and Precision of an Effect Size and Its Variance From a Multilevel Model for Cluster Randomized Trials: A Simulation Study

This article investigates an effect size (MLM ES) and its variance for cluster randomized trials based on parameter estimates from multilevel modeling analysis. Accuracy and precision of MLM ES were evaluated using Monte Carlo simulation methods and compared with the performance of an effect size, computed from summary statistics, proposed by Hedges (2007; Hedges' dB ). Simulation results indicated that MLM ES had acceptable accuracy in all conditions, also demonstrating efficiency and consistency. With small sample sizes, MLM ES did not suffer from the same negative bias as Hedges' dB due to overestimation of between-cluster variance. With large sample sizes, MLM ES and Hedges' dB were comparable for accuracy and efficiency. Both MLM ES and Hedges' dB showed considerable bias in some conditions when cluster sizes were unequal. An illustrative example using real data was provided.

Efficacy and safety of local anaesthetics for premature ejaculation: a systematic review and meta-analysis

To assess the efficacy and safety of local anaesthetics for premature ejaculation (PE), a systematic review of the literature was performed using the Cochrane Library, PUBMED and EMBASE. We screened and retrieved the randomized controlled trials on the treatment of PE with local anaesthetics. End points included intravaginal ejaculation latency time (IELT), patient-reported outcome assessments and adverse events. Meta-analyses were conducted with Stata 11.0. In total, seven publications involving 566 patients with local anaesthetics and 388 with placebos strictly met our eligibility criteria. Meta-analyses showed that after the patients were treated with the local anaesthetics, the value of the standardized mean difference of the changes in IELT was 5.02 (95% CI: 3.03-7.00). A higher rate of adverse events occurred compared with placebos (odds ratio: 3.30, 95% CI: 1.71-6.36), but these events were restricted to local side effects. In addition, significantly greater improvement was observed in patient-reported outcomes. In summary, local anaesthetics can prolong IELT and improve ejaculatory control and sexual satisfaction.

Estimating within-study covariances in multivariate meta-analysis with multiple outcomes

Multivariate meta-analysis allows the joint synthesis of effect estimates based on multiple outcomes from multiple studies, accounting for the potential correlations among them. However, standard methods for multivariate meta-analysis for multiple outcomes are restricted to problems where the within-study correlation is known or where individual participant data are available. This paper proposes an approach to approximating the within-study covariances based on information about likely correlations between underlying outcomes. We developed methods for both continuous and dichotomous data and for combinations of the two types. An application to a meta-analysis of treatments for stroke illustrates the use of the approximated covariance in multivariate meta-analysis with correlated outcomes.

Evidence-based sample size estimation based upon an updated meta-regression analysis

A traditional meta-analysis examines the overall effectiveness of an intervention by producing a pooled estimate of treatment efficacy. In contrast to this, a meta-regression model seeks to determine whether a study-level covariate (X) is a plausible source of heterogeneity in a set of treatment effects. Upon performing such an analysis, the results may suggest the presence of a meaningful amount of variation in the treatment effects because of the covariate; however, the current set of trials may not provide sufficient statistical power for such a conclusion. The proposed approach provides quantitative insight into the amount of support that a new trial may provide to the hypothesis that X is a meaningful source of variation in an updated meta-regression model, which includes both the previously completed and the proposed trial. This empirical algorithm allows examination of the potential feasibility of a planned study of various sizes to further support or refute the hypothesis that X is a statistically significant source of variation. A detailed example illustrates the sample size estimation algorithm for both a planned individually or cluster randomized trial to investigate the now commonly accepted impact of geographical latitude on the observed effectiveness of the Bacillus Calmette-Guérin vaccine in the prevention of tuberculosis. Copyright © 2012 John Wiley & Sons, Ltd.

Efficacy of directional preference management for low back pain: a systematic review

BACKGROUND

Providing specific treatment based on symptom response for people with low back pain (LBP) and a directional preference (DP) is a widely used treatment approach. The efficacy of treatment using the principles of directional preference management (DPM) for LBP is unclear.

OBJECTIVE

The purpose of this study was to determine the efficacy of treatment using the principles of DPM for people with LBP and a DP.

METHODS

Computer databases were searched for randomized controlled trials (RCTs) published in English up to January 2010. Only RCTs investigating DPM for people with LBP and a DP were included. Outcomes for pain, back specific function, and work participation were extracted.

RESULTS

Six RCTs were included in this review. Five were considered high quality. Clinical heterogeneity of the included trials prevented meta-analysis. GRADE quality assessment revealed mixed results; however, moderate evidence was identified that DPM was significantly more effective than a number of comparison treatments for pain, function, and work participation at short-term, intermediate-term, and long-term follow-ups. No trials found that DPM was significantly less effective than comparison treatments.

CONCLUSIONS

Although this systematic review showed mixed results, some evidence was found supporting the effectiveness of DPM when applied to participants with a DP, particularly at short-term and intermediate-term follow-ups. Further high-quality RCTs are warranted to evaluate the effect of DPM applied to people with LBP and a DP.

Designing clinical trials to test disease-modifying agents: application to the treatment trials of Alzheimer's disease

BACKGROUND

Therapeutic trials of disease-modifying agents on Alzheimer's disease (AD) require novel designs and analyses involving switch of treatments for at least a portion of subjects enrolled. Randomized start and randomized withdrawal designs are two examples of such designs. Crucial design parameters such as sample size and the time of treatment switch are important to understand in designing such clinical trials.

PURPOSE

The purpose of this article is to provide methods to determine sample sizes and time of treatment switch as well as optimum statistical tests of treatment efficacy for clinical trials of disease-modifying agents on AD.

METHODS

A general linear mixed effects model is proposed to test the disease-modifying efficacy of novel therapeutic agents on AD. This model links the longitudinal growth from both the placebo arm and the treatment arm at the time of treatment switch for these in the delayed treatment arm or early withdrawal arm and incorporates the potential correlation on the rate of cognitive change before and after the treatment switch. Sample sizes and the optimum time for treatment switch of such trials as well as optimum test statistic for the treatment efficacy are determined according to the model.

RESULTS

Assuming an evenly spaced longitudinal design over a fixed duration, the optimum treatment switching time in a randomized start or a randomized withdrawal trial is half way through the trial. With the optimum test statistic for the treatment efficacy and over a wide spectrum of model parameters, the optimum sample size allocations are fairly close to the simplest design with a sample size ratio of 1:1:1 among the treatment arm, the delayed treatment or early withdrawal arm, and the placebo arm. The application of the proposed methodology to AD provides evidence that much larger sample sizes are required to adequately power disease-modifying trials when compared with those for symptomatic agents, even when the treatment switch time and efficacy test are optimally chosen.

LIMITATIONS

The proposed method assumes that the only and immediate effect of treatment switch is on the rate of cognitive change.

CONCLUSIONS

Crucial design parameters for the clinical trials of disease-modifying agents on AD can be optimally chosen. Government and industry officials as well as academia researchers should consider the optimum use of the clinical trials design for disease-modifying agents on AD in their effort to search for the treatments with the potential to modify the underlying pathophysiology of AD.

Protocol for a systematic review of the effects of schools and school-environment interventions on health: evidence mapping and syntheses

BACKGROUND

Schools may have important effects on students' and staff's health. Rather than treating schools merely as sites for health education, 'school-environment' interventions treat schools as settings which influence health. Evidence concerning the effects of such interventions has not been recently synthesised.

METHODS/DESIGN

Systematic review aiming to map and synthesise evidence on what theories and conceptual frameworks are most commonly used to inform school-environment interventions or explain school-level influences on health; what effects school-environment interventions have on health/health inequalities; how feasible and acceptable are school-environment interventions; what effects other school-level factors have on health; and through what processes school-level influences affect health.We will examine interventions aiming to promote health by modifying schools' physical, social or cultural environment via actions focused on school policies and practices relating to education, pastoral care and other aspects of schools beyond merely providing health education. Participants are staff and students age 4-18 years.We will review published research unrestricted by language, year or source. Searching will involve electronic databases including Embase, ERIC, PubMed, PsycInfo and Social Science Citation Index using natural-language phrases plus reference/citation checking.Stage 1 will map studies descriptively by focus and methods. Stage 2 will involve additional inclusion criteria, quality assessment and data extraction undertaken by two reviewers in parallel. Evidence will be synthesised narratively and statistically where appropriate (undertaking subgroup analyses and meta-regression and where no significant heterogeneity of effect sizes is found, pooling these to calculate a final effect size).

DISCUSSION

We anticipate: finding a large number of studies missed by previous reviews; that non-intervention studies of school effects examine a greater breadth of determinants than are addressed by intervention studies; and that intervention effect estimates are greater than for school-based health curriculum interventions without school-environment components.

Conservative management of lumbar disc herniation with associated radiculopathy: a systematic review

STUDY DESIGN

A systematic review of randomized controlled trials.

OBJECTIVE

To determine the efficacy and adverse effects of conservative treatments for people who have lumbar disc herniation with associated radiculopathy (LDHR).

SUMMARY OF BACKGROUND DATA

Although conservative management is commonly used for people who have LDHR, the efficacy and adverse effects of conservative treatments for this condition are unclear.

METHODS

We searched 10 computer databases for trials published in English between 1971 and 2008. Trials focusing on people with referred leg symptoms and radiologic confirmation of a lumbar disc herniation were included if at least 1 group received a conservative and noninjection treatment.

RESULTS

Eighteen trials involving 1671 participants were included. Seven (39%) trials were considered of high quality. Meta-analysis on 2 high-quality trials revealed that advice is less effective than microdiscectomy surgery at short-term follow-up, but equally effective at long-term follow-up. Individual high-quality trials provided moderate evidence that stabilization exercises are more effective than no treatment, that manipulation is more effective than sham manipulation for people with acute symptoms and an intact anulus, and that no difference exists among traction, laser, and ultrasound. One trial showed some additional benefit from adding mechanical traction to medication and electrotherapy methods. Adverse events were associated with traction (pain, anxiety, lower limb weakness, and fainting) and ibuprofen (gastrointestinal events).

CONCLUSION

Advice is less effective than microdiscectomy in the short term but equally effective in the long term for people who have LDHR. Moderate evidence favors stabilization exercises over no treatment, manipulation over sham manipulation, and the addition of mechanical traction to medication and electrotherapy. There was no difference among traction, laser, and ultrasound. Adverse events were associated with traction and ibuprofen. Additional high-quality trials would allow firmer conclusions regarding adverse effects and efficacy.

Systematic prevention of overweight and obesity in adults: a qualitative and quantitative literature analysis

To date, most interventions aimed at preventing obesity have underemphasized the application of systematic intervention development, implementation and evaluation. The present review provides a thorough insight in factors promoting implementation and/or effectiveness in interventions aimed at preventing overweight/obesity among adults. A total of 46 studies evaluating interventions aimed at preventing obesity were reviewed, followed by both qualitative and quantitative analyses. The Intervention Mapping protocol and the Environmental Research framework for weight Gain prevention (EnRG) were applied to analyse and classify the included studies. The interventions were categorized by setting (workplace, community, health care) and target group (ethnic minorities, pregnant women, [pre]menopausal women, smokers, people with intellectual disabilities). Generally, interventions were found to have potential in changing energy balance-related behaviours and anthropometric outcomes. Effect sizes for changes in body mass index ranged between -0.09 and 0.45. When the programme goal specifically aimed at weight management, the intervention was found to be more successful than interventions with programme goals that were aimed at preventing cardiovascular disease or improving general health status. Although a considerable part of studies included motivational interventions, only some actually assessed the effects on potential cognitive mediators. A general lack of reporting underlying theoretical models for behaviour change was observed as well as the inclusion of linkage groups and strategies to promote empowerment.

Cluster randomized trials produced similar results to individually randomized trials in a meta-analysis of enhanced care for depression

OBJECTIVES

To examine whether cluster randomized trials (1) produce baseline imbalances between intervention and control conditions; (2) give results that are substantially different individually randomized trials; and (3) give different results when adjusted for unit of analysis error.

STUDY DESIGN AND SETTING

We used 14 cluster randomized trials and 20 individualized trials of the same intervention (collaborative care for depression). We conducted a random effects meta-analysis to examine imbalance in baseline depression scores. We used meta-regression to test for differential effect size and heterogeneity between clustered and individualized studies. Unit of analysis error was corrected using a range of plausible published intraclass correlation coefficients (ICCs).

RESULTS

There were no baseline imbalances in either cluster randomized (P=0.837) or individually randomized (P=0.737) studies. Cluster randomized studies gave almost identical estimates of effect size when compared to individually randomized studies (standardized mean difference, SMDcluster=0.25, 95% confidence interval [CI]: 0.17, 0.33; SMDindividual=0.24; 95% CI: 0.13, 0.36). Adjustment for clustering had minimal effect on clinical and statistical significance (pooled SMDICC 0.02=0.249 [95% CI: 0.174, 0.325] to SMDICC 0.05=0.258 [95% CI: 0.172, 0.345]).

CONCLUSION

The additional effort and expense involved in cluster randomized trials needs to be justified when individualized studies might produce robust and believable results.

The merits of breaking the matches: a cautionary tale

Matched-pair cluster randomization trials are frequently adopted as the design of choice for evaluating an intervention offered at the community level. However, previous research has demonstrated that a strategy of breaking the matches and performing an unmatched analysis may be more efficient than performing a matched analysis on the resulting data, particularly when the total number of communities is small and the matching is judged as relatively ineffective. The research concerning this question has naturally focused on testing the effect of intervention. However, a secondary objective of many community intervention trials is to investigate the effect of individual-level risk factors on one or more outcome variables. Focusing on the case of a continuous outcome variable, we show that the practice of performing an unmatched analysis on data arising from a matched-pair design can lead to bias in the estimated regression coefficient, and a corresponding test of significance which is overly liberal. However, for large-scale community intervention trials, which typically recruit a relatively small number of large clusters, such an analysis will generally be both valid and efficient. We also consider other approaches to testing the effect of an individual-level risk factor in a matched-pair cluster randomization design, including a generalized linear model approach that preserves the matching, a two-stage cluster-level analysis, and an approach based on generalized estimating equations.

Using goal attainment scaling to improve the quality of long-term care: a group-randomized trial

OBJECTIVE

To assess the effect of a 6-month interdisciplinary customized intervention based on goal attainment scaling and aimed at improving the quality of care provided by long-term care facilities to frail older adults.

DESIGN

A pair-matched group-randomized trial with quality of care measurements taken before and after the intervention and 6 months later.

SETTING

Forty unregulated small-to-medium sized long-term care facilities delivering inadequate care to at least one resident. Facilities were matched on baseline quality of care, health district, and size. One member of each pair was then randomly allocated to the intervention, the other acting as a control.

STUDY PARTICIPANTS

The trial involved 201 frail older adults randomly selected from the 40 participating facilities.

INTERVENTION

The intervention was tailored to the main quality problems identified at baseline in the facility. The first task of the intervention team was to set weighted quality improvement goals with the facility manager, which were then recorded on a goal attainment follow-up guide. Subsequent monthly on-site visits, interspersed with frequent telephone calls, were meant to assist the manager and staff to implement permanent changes in the areas of care targeted for improvement. Main outcome measure. Quality of care measured with the Quality of Care (QUALCARE) Scale, a multidimensional instrument that uses a 5-point scale to assess six subdimensions of care: environmental, physical, medical management, psychosocial, human rights, and financial. A score greater than 2 is considered indicative of inadequate care.

RESULTS

The intervention effect on the overall quality of care was neither clinically nor statistically significant. Change from baseline to the end of the intervention averaged .21 and .22 in the experimental and control conditions, respectively (P = 0.86).

CONCLUSION

Attainment of preset quality improvement objectives did not translate into detectable improvements in the care provided to residents.