Ethnic differences in metabolic syndrome in high-income countries: A systematic review and meta-analysis.

This review aimed to systematically quantify the differences in Metabolic Syndrome (MetS) prevalence across various ethnic groups in high-income countries by sex, and to evaluate the overall prevalence trends from 1996 to 2022. We conducted a systematic literature review using MEDLINE, Web of Science Core Collection, CINAHL, and the Cochrane Library, focusing on studies about MetS prevalence among ethnic groups in high-income countries. We pooled 23 studies that used NCEP-ATP III criteria and included 147,756 healthy participants aged 18 and above. We calculated pooled prevalence estimates and 95% confidence intervals (CI) using both fixed-effect and random-effect intercept logistic regression models. Data were analysed for 3 periods: 1996-2005, 2006-2009, and 2010-2021. The pooled prevalence of MetS in high-income countries, based on the NCEP-ATP III criteria, was 27.4% over the studied period, showing an increase from 24.2% in 1996-2005 to 31.9% in 2010-2021, with men and women having similar rates. When stratified by ethnicity and sex, ethnic minority women experienced the highest prevalence at 31.7%, while ethnic majority women had the lowest at 22.7%. Notably, MetS was more prevalent in ethnic minority women than men. Among ethnic minorities, women had a higher prevalence of MetS than men, and the difference was highest in Asians (about 15 percentage points). Among women, the prevalence of MetS was highest in Asians (41.2%) and lowest in Blacks/Africans (26.7%). Among men, it was highest in indigenous minority groups (34.3%) and lowest among in Blacks/Africans (19.8%). MetS is increasing at an alarming rate in high-income countries, particularly among ethnic minority women. The burden of MetS could be effectively reduced by tailoring interventions according to ethnic variations and risk profiles.

CAT HPPR: a critical appraisal tool to assess the quality of systematic, rapid, and scoping reviews investigating interventions in health promotion and prevention.

BACKGROUND: For over three decades researchers have developed critical appraisal tools (CATs) for assessing the scientific quality of research overviews. Most established CATs for reviews in evidence-based medicine and evidence-based public health (EBPH) focus on systematic reviews (SRs) with studies on experimental interventions or exposure included. EBPH- and implementation-oriented organisations and decision-makers, however, often seek access to rapid reviews (RRs) or scoping reviews (ScRs) for rapid evidence synthesis and research field exploration. Until now, no CAT is available to assess the quality of SRs, RRs, and ScRs following a unified approach. We set out to develop such a CAT. METHODS: The development process of the Critical Appraisal Tool for Health Promotion and Prevention Reviews (CAT HPPR) included six phases: (i) the definition of important review formats and complementary approaches, (ii) the identification of relevant CATs, (iii) prioritisation, selection and adaptation of quality criteria using a consensus approach, (iv) development of the rating system and bilingual guidance documents, (v) engaging with experts in the field for piloting/optimising the CAT, and (vi) approval of the final CAT. We used a pragmatic search approach to identify reporting guidelines/standards (n = 3; e.g. PRISMA, MECIR) as well as guidance documents (n = 17; e.g. for reviews with mixed-methods approach) to develop working definitions for SRs, RRs, ScRs, and other review types (esp. those defined by statistical methods or included data sources). RESULTS: We successfully identified 14 relevant CATs, predominantly for SRs (e.g. AMSTAR 2), and extracted 46 items. Following consensual discussions 15 individual criteria were included in our CAT and tailored to the review types of interest. The CAT was piloted with 14 different reviews which were eligible to be included in a new German database looking at interventions in health promotion and prevention in different implementation settings. CONCLUSIONS: The newly developed CAT HPPR follows a unique uniformed approach to assess a set of heterogeneous reviews (e.g. reviews from problem identification to policy evaluations) to assist end-users needs. Feedback of external experts showed general feasibility and satisfaction with the tool. Future studies should further formally test the validity of CAT HPPR using larger sets of reviews.

Searching two or more databases decreased the risk of missing relevant studies: a metaresearch study.

BACKGROUND AND OBJECTIVES: Assessing changes in coverage, recall, review, conclusions and references not found when searching fewer databases. METHODS: In randomly selected 60 Cochrane reviews, we checked included study publications' coverage (indexation) and recall (findability) using different search approaches with MEDLINE, Embase, and CENTRAL and related them to authors' conclusions and certainty. We assessed characteristics of unfound references. RESULTS: Overall 1989/2080 included references, were indexed in ≥1 database (coverage = 96%). In reviews where using one of our search approaches would not change conclusions and certainty (n = 44-54), median coverage and recall were highest (range 87.9%-100.0% and 78.2%-93.3%, respectively). Here, searching ≥2 databases reached >95% coverage and ≥87.9% recall. In reviews with unchanged conclusions but less certainty (n = 2-8): 63.3%-79.3% coverage and 45.0%-75.0% recall. In reviews with opposite conclusions (n = 1-3): 63.3%-96.6% and 52.1%-78.7%. In reviews where a conclusion was no longer possible (n = 3-7): 60.6%-86.0% and 20.0%-53.8%. The 265 references that were indexed but unfound were more often abstractless (30% vs. 11%) and older (28% vs. 17% published before 1991) than found references. CONCLUSION: Searching ≥2 databases improves coverage and recall and decreases the risk of missing eligible studies. If researchers suspect that relevant articles are difficult to find, supplementary search methods should be used.

Dissemination of Evidence by Cochrane Public Health Europe in German-Speaking Countries: An Online Stakeholder Survey.

Objectives: To investigate the reach and impact of "Infomails", email summaries of Cochrane reviews in German, regularly disseminated by Cochrane Public Health Europe (CPHE) to stakeholders in Austria, Germany and Switzerland. Methods: We analysed email campaign reports from 15 Infomails delivered until November 2020. Furthermore, we invited all previous Infomail recipients to participate in an online survey on the impact and perceptions regarding our Infomails in November 2020. We analysed the results using descriptive statistics. Results: The Infomails' open rate ranged from 10.9% to 39.3% (median 26.0%), and the median click rate on the embedded links was 28.0% (range 8.6-53.8%), highest for nutrition and prevention topics. Out of 1259 recipients, 267 (21.2%) completed our survey. Infomails were most used in discussions, writing reports or statements, for policy or strategy development or programme or guideline development. Persons who remembered receiving Infomails rated them as useful, comprehensible or informative. Conclusion: Infomails summarising recent Cochrane reviews were considered useful for the daily work of public health stakeholders in German-speaking countries. Regular targeted messaging may increase the perceived usefulness.

Effects of n-3 Polyunsaturated Fatty Acid Supplementation in the Prevention and Treatment of Depressive Disorders-A Systematic Review and Meta-Analysis.

N-3 polyunsaturated fatty acids (PUFAs) have been suggested to affect depressive disorders. This review aims to determine the effect of n-3 PUFAs on depressive symptoms in people with or without diagnosed depression. Medline, PsycINFO, and Cochrane CENTRAL databases were searched for randomized controlled trials (RCTs) assessing the association between n-3 PUFAs and depressive symptoms or disorders as outcomes. A random-effects meta-analysis of standardized mean difference (SMD) with 95% confidence intervals (CI) was performed. Twenty-five studies (7682 participants) were included. Our meta-analysis (20 studies) indicated that n-3 PUFA supplementation lowered depressive symptomology as compared with placebo: SMD = -0.34, 95% CI: -0.55, -0.12, I2 = 86%, n = 5836, but a possible publication bias cannot be ruled out. Subgroup analyses indicated no statistically significant difference by treatment duration of <12 vs. ≥12 weeks, presence of comorbidity, or severity of depressive symptoms. Nevertheless, beneficial effects were seen in the subgroups of studies with longer treatment duration and with no depression and mild to moderate depression. Subgroup analysis by eicosapentaenoic acid (EPA) dosage revealed differences in favor of the lower EPA dosage. Sensitivity analysis including studies with low risk of bias seems to confirm the overall result. Supplementation of n-3 PUFA appears to have a modest beneficial effect on depressive symptomology, although the quality of evidence is still insufficient.

[Insights for healthy settings: a database to support the translation of findings from systematic reviews into practice]. / Wissen für gesunde Lebenswelten: Eine Datenbank zum Praxistransfer von Erkenntnissen aus systematischen Übersichtsarbeiten.

The database "Insights for healthy settings" was developed by the GKV-Bündnis für Gesundheit, a joint initiative of all health insurance funds for developing and implementing setting-based health promotion and prevention measures. It aims to support health insurance funds and other practice partners in planning and implementing evidence-based health promotion and prevention measures in different settings. The database complements existing intervention databases by providing insights based on findings from systematic reviews. This article aims to present the database, describe possible applications, and discuss options for further development.The database contains findings on the effectiveness and strategies for implementation of setting-based health promotion and prevention measures. In addition to structured summaries of systematic reviews, it includes summaries of scoping reviews and rapid reviews. Different search options (e.g., free text search, subject headings, and search filters) can be used to find database entries (currently n = 13). Quality-assured database entries are created by means of a standardized form and based on the four-eyes principle. To allow for easy access, key findings are presented briefly, and technical terms are clarified. Experts from health insurance funds are continuously involved in the development process of the database.As part of the database's further development, new reviews of the GKV-Bündnis für Gesundheit as well as from other sources will be added. Additionally, quality assessments of included reviews will be depicted and supporting activities developed to further encourage translation of scientific knowledge into practice.

Taxation of the fat content of foods for reducing their consumption and preventing obesity or other adverse health outcomes.

BACKGROUND: Overweight and obesity are increasing worldwide and are considered to be a major public health issue of the 21st century. Introducing taxation of the fat content in foods is considered a potentially powerful policy tool to reduce consumption of foods high in fat or saturated fat, or both. OBJECTIVES: To assess the effects of taxation of the fat content in food on consumption of total fat and saturated fat, energy intake, overweight, obesity, and other adverse health outcomes in the general population. SEARCH METHODS: We searched CENTRAL, Cochrane Database of Systematic Reviews, MEDLINE, Embase, and 15 other databases and trial registers on 12 September 2019. We handsearched the reference lists of all records of included studies, searched websites of international organizations and institutions (14 October 2019), and contacted review advisory group members to identify planned, ongoing, or unpublished studies (26 February 2020). SELECTION CRITERIA: In line with Cochrane Effective Practice and Organisation of Care Group (EPOC) criteria, we included the following study types: randomized controlled trials (RCTs), cluster-randomized controlled trials (cRCTs), non-randomized controlled trials (nRCTs), controlled before-after (CBA) studies, and interrupted time series studies. We included studies that evaluated the effects of taxes on the fat content in foods. Such a tax could be expressed as sales, excise, or special value added tax (VAT) on the final product or an intermediary product. Eligible interventions were taxation at any level, with no restriction on the duration or the implementation level (i.e. local, regional, national, or multinational). Eligible study populations were children (zero to 17 years) and adults (18 years or older) from any country and setting. We excluded studies that focused on specific subgroups only (e.g. people receiving pharmaceutical intervention; people undergoing a surgical intervention; ill people who are overweight or obese as a side effect, such as those with thyroiditis and depression; and people with chronic illness). Primary outcomes were total fat consumption, consumption of saturated fat, energy intake through fat, energy intake through saturated fat, total energy intake, and incidence/prevalence of overweight or obesity. We did not exclude studies based on country, setting, comparison, or population. DATA COLLECTION AND ANALYSIS: We used standard Cochrane methods for all phases of the review. Risk of bias of the included studies was assessed using the criteria of Cochrane's 'Risk of bias' tool and the EPOC Group's guidance. Results of the review are summarized narratively and the certainty of the evidence was assessed using the GRADE approach. These steps were done by two review authors, independently. MAIN RESULTS: We identified 23,281 records from searching electronic databases and 1173 records from other sources, leading to a total of 24,454 records. Two studies met the criteria for inclusion in the review. Both included studies investigated the effect the Danish tax on saturated fat contained in selected food items between 2011 and 2012. Both studies used an interrupted time series design. Neither included study had a parallel control group from another geographic area. The included studies investigated an unbalanced panel of approximately 2000 households in Denmark and the sales data from a specific Danish supermarket chain (1293 stores). Therefore, the included studies did not address individual participants, and no restriction regarding age, sex, and socioeconomic characteristics were defined. We judged the overall risk of bias of the two included studies as unclear. For the outcome total consumption of fat, a reduction of 41.8 grams per week per person in a household (P < 0.001) was estimated. For the consumption of saturated fat, one study reported a reduction of 4.2% from minced beef sales, a reduction of 5.8% from cream sales, and an increase of 0.5% to sour cream sales (no measures of statistical precision were reported for these estimates). These estimates are based on a restricted number of food types and derived from sales data; they do not measure individual intake. Moreover, these estimates do not account for other relevant sources of fat intake (e.g. packaged or processed food) or other food outlets (e.g. restaurants or cafeterias); hence, we judged the evidence on the effect of taxation on total fat consumption or saturated fat consumption to be very uncertain. We did not identify evidence on the effect of the intervention on energy intake or the incidence or prevalence of overweight or obesity. AUTHORS' CONCLUSIONS: Given the very low quality of the evidence currently available, we are unable to reliably establish whether a tax on total fat or saturated fat is effective or ineffective in reducing consumption of total fat or saturated fat. There is currently no evidence on the effect of a tax on total fat or saturated fat on total energy intake or energy intake through saturated fat or total fat, or preventing the incidence or reducing the prevalence of overweight or obesity.

Abbreviated and comprehensive literature searches led to identical or very similar effect estimates: a meta-epidemiological study.

OBJECTIVES: The objective of this study was to assess the agreement of treatment effect estimates from meta-analyses based on abbreviated or comprehensive literature searches. STUDY DESIGN AND SETTING: This was a meta-epidemiological study. We abbreviated 47 comprehensive Cochrane review searches and searched MEDLINE/Embase/CENTRAL alone, in combination, with/without checking references (658 new searches). We compared one meta-analysis from each review with recalculated ones based on abbreviated searches. RESULTS: The 47 original meta-analyses included 444 trials (median 6 per review [interquartile range (IQR) 3-11]) with 360045 participants (median 1,371 per review [IQR 685-8,041]). Depending on the search approach, abbreviated searches led to identical effect estimates in 34-79% of meta-analyses, to different effect estimates with the same direction and level of statistical significance in 15-51%, and to opposite effects (or effects could not be estimated anymore) in 6-13%. The deviation of effect sizes was zero in 50% of the meta-analyses and in 75% not larger than 1.07-fold. Effect estimates of abbreviated searches were not consistently smaller or larger (median ratio of odds ratio 1 [IQR 1-1.01]) but more imprecise (1.02-1.06-fold larger standard errors). CONCLUSION: Abbreviated literature searches often led to identical or very similar effect estimates as comprehensive searches with slightly increased confidence intervals. Relevant deviations may occur.

Racial/ethnic differences in the prevalence and incidence of metabolic syndrome in high-income countries: a protocol for a systematic review.

BACKGROUND: Metabolic syndrome is a constellation of various cardiovascular and type 2 diabetes risk factors, such as abdominal obesity, atherogenic dyslipidemia, high blood pressure, and high blood glucose, but its prevalence varies widely by geographical region, sex, and race/ethnicity. The objective of this study is to examine the prevalence and incidence of metabolic syndrome among adults of different racial/ethnic origins in high-income countries. METHODS: We designed and registered a study protocol for a systematic review of descriptive epidemiological data. Observational studies (e.g., cross sectional and cohort studies) reporting morbidity data of metabolic syndrome and conducted in a wide range of adult people (e.g., different racial/ethnic origins, including migrants) will be included. The primary outcome will be the prevalence and incidence of metabolic syndrome. Secondary outcomes will be the prevalence and incidence of individual components of metabolic syndrome (e.g., abdominal obesity, dyslipidemia, high blood pressure, and high blood glucose). Literature searches will be conducted in several electronic databases (from inception onwards), including MEDLINE, Web of Science Core Collection (Science Citation Index and Social Science Citation Index), CINAHL, and Cochrane Library. Two investigators will independently screen all reference titles, abstracts, and full-text articles. The methodological quality (or potential bias) of selected studies will be appraised using an appropriate tool. Our results will be described narratively. Random-effects meta-analysis will be conducted, if feasible and appropriate. Additional analyses will be conducted to explore the potential sources of heterogeneity. CONCLUSION: This systematic review will identify, evaluate, and integrate prevalence and incidence data of metabolic syndrome, with focus on racial/ethnic differences in high-income countries. We anticipate our findings may guide policy formulation and identify knowledge gaps in the literature that future research should address. SYSTEMATIC REVIEW REGISTRATION: PROSPERO, CRD42020157189.

Taxation of unprocessed sugar or sugar-added foods for reducing their consumption and preventing obesity or other adverse health outcomes.

BACKGROUND: Global prevalence of overweight and obesity are alarming. For tackling this public health problem, preventive public health and policy actions are urgently needed. Some countries implemented food taxes in the past and some were subsequently abolished. Some countries, such as Norway, Hungary, Denmark, Bermuda, Dominica, St. Vincent and the Grenadines, and the Navajo Nation (USA), specifically implemented taxes on unprocessed sugar and sugar-added foods. These taxes on unprocessed sugar and sugar-added foods are fiscal policy interventions, implemented to decrease their consumption and in turn reduce adverse health-related, economic and social effects associated with these food products. OBJECTIVES: To assess the effects of taxation of unprocessed sugar or sugar-added foods in the general population on the consumption of unprocessed sugar or sugar-added foods, the prevalence and incidence of overweight and obesity, and the prevalence and incidence of other diet-related health outcomes. SEARCH METHODS: We searched CENTRAL, Cochrane Database of Systematic Reviews, MEDLINE, Embase and 15 other databases and trials registers on 12 September 2019. We handsearched the reference list of all records of included studies, searched websites of international organisations and institutions, and contacted review advisory group members to identify planned, ongoing or unpublished studies. SELECTION CRITERIA: We included studies with the following populations: children (0 to 17 years) and adults (18 years or older) from any country and setting. Exclusion applied to studies with specific subgroups, such as people with any disease who were overweight or obese as a side-effect of the disease. The review included studies with taxes on or artificial increases of selling prices for unprocessed sugar or food products that contain added sugar (e.g. sweets, ice cream, confectionery, and bakery products), or both, as intervention, regardless of the taxation level or price increase. In line with Cochrane Effective Practice and Organisation of Care (EPOC) criteria, we included randomised controlled trials (RCTs), cluster-randomised controlled trials (cRCTs), non-randomised controlled trials (nRCTs), controlled before-after (CBA) studies, and interrupted time series (ITS) studies. We included controlled studies with more than one intervention or control site and ITS studies with a clearly defined intervention time and at least three data points before and three after the intervention. Our primary outcomes were consumption of unprocessed sugar or sugar-added foods, energy intake, overweight, and obesity. Our secondary outcomes were substitution and diet, expenditure, demand, and other health outcomes. DATA COLLECTION AND ANALYSIS: Two review authors independently screened all eligible records for inclusion, assessed the risk of bias, and performed data extraction.Two review authors independently assessed the certainty of the evidence using the GRADE approach. MAIN RESULTS: We retrieved a total of 24,454 records. After deduplicating records, 18,767 records remained for title and abstract screening. Of 11 potentially relevant studies, we included one ITS study with 40,210 household-level observations from the Hungarian Household Budget and Living Conditions Survey. The baseline ranged from January 2008 to August 2011, the intervention was implemented on September 2011, and follow-up was until December 2012 (16 months). The intervention was a tax - the so-called 'Hungarian public health product tax' - on sugar-added foods, including selected foods exceeding a specific sugar threshold value. The intervention includes co-interventions: the taxation of sugar-sweetened beverages (SSBs) and of foods high in salt or caffeine. The study provides evidence on the effect of taxing foods exceeding a specific sugar threshold value on the consumption of sugar-added foods. After implementation of the Hungarian public health product tax, the mean consumption of taxed sugar-added foods (measured in units of kg) decreased by 4.0% (standardised mean difference (SMD) -0.040, 95% confidence interval (CI) -0.07 to -0.01; very low-certainty evidence). The study was at low risk of bias in terms of performance bias, detection bias and reporting bias, with the shape of effect pre-specified and the intervention unlikely to have any effect on data collection. The study was at unclear risk of attrition bias and at high risk in terms of other bias and the independence of the intervention. We rated the certainty of the evidence as very low for the primary and secondary outcomes. The Hungarian public health product tax included a tax on sugar-added foods but did not include a tax on unprocessed sugar. We did not find eligible studies reporting on the taxation of unprocessed sugar. No studies reported on the primary outcomes of consumption of unprocessed sugar, energy intake, overweight, and obesity. No studies reported on the secondary outcomes of substitution and diet, demand, and other health outcomes. No studies reported on differential effects across population subgroups. We could not perform meta-analyses or pool study results. AUTHORS' CONCLUSIONS: There was very limited evidence and the certainty of the evidence was very low. Despite the reported reduction in consumption of taxed sugar-added foods, we are uncertain whether taxing unprocessed sugar or sugar-added foods has an effect on reducing their consumption and preventing obesity or other adverse health outcomes. Further robustly conducted studies are required to draw concrete conclusions on the effectiveness of taxing unprocessed sugar or sugar-added foods for reducing their consumption and preventing obesity or other adverse health outcomes.

Satisfaction of Nigerian patients with health services: a protocol for a systematic review.

BACKGROUND: Patient-based assessment of health services is becoming popular in measuring the standard of care. Both quantitative and qualitative methods are available. Patient satisfaction surveys are commonly used to record the experiences of patients in hospitals, whereas qualitative designs (e.g., interviews and focus group discussions) are used less frequently. To date, there has been no systematic review published devoted to patient satisfaction with health services in Nigeria. We aim to (1) systematically analyze relevant quantitative studies to pinpoint excellent procedures in measuring patient satisfaction with health services, (2) to investigate if a reference method (gold standard method) exists, and (3) to identify relevant topics which are recognized by patients as important for the delivery of a high-quality health service in Nigeria. METHODS: Searches of eight electronic journal databases, including MEDLINE, EMBASE, CINAHL, PsycINFO, AJOL, CDSR, DARE, and HTA will be conducted to identify studies assessing patient satisfaction with health services in Nigeria. The searches will be supported by manual searches in reference lists of relevant primary studies and systematic reviews. The review will be limited to studies published since 2007. After a stepwise screening process by two reviewers, data from included studies will be extracted and reviewed. The COSMIN RoB checklist will be used to critically appraise included studies. We will carry out an extensive data synthesis to answer the review questions. DISCUSSION: The intended systematic review will provide information on how the satisfaction of patients with health services has earlier been described and assessed in Nigerian studies. It will establish if a gold standard method exists and synthesize information on topics which might be of special interest to patients. Review findings will enrich the debate on patient-centered care and overall performance of health quality standards in Nigeria. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42018108140.

Naswar (Smokeless Tobacco) Use and the Risk of Oral Cancer in Pakistan: A Systematic Review With Meta-Analysis.

Introduction: With an annual increase of 16000 new cases each year, oral cancer is the second most common cancer in Pakistan. There is conflicting evidence regarding the carcinogenicity of different forms of smokeless tobacco (SLT) from different countries. This difference in evidence may be attributed to the varied composition of SLT products used around the world, necessitating the establishment of individual risks related to each SLT product. Methods: An electronic search in relevant databases yielded 119 publications, out of which six were included in this review. Effect estimates (odds ratios (ORs)) were abstracted or calculated from the given data. A fixed effects meta-analysis was performed to assess the risk of oral cancer with the use of Naswar. Population attributable fractions (PAF) were also calculated. Results: The Meta Odds Ratio (mOR) for oral cancer associated with the "ever use" of Naswar compared to "never use" was 11.8 (95% CI = 8.4-16.4), I2 = 67%. The pooled estimate for oral cancer in "Ever-users" of Naswar compared to "Never-users," in the Khyber Pakhtunkhwa province was 18.3 (95% CI = 8.7-38.5), I2 = 0%. The PAF for oral cancer associated with the use of Naswar in Pakistan was 44% (95% CI = 35-53). Discussion: This review highlights a strong relationship between oral cancer incidence and the use of Naswar in Pakistan and adds to the evidence base on the carcinogenicity of SLT products in humans. Although the synthesized evidence may not be of a high quality, it represents the "best available evidence" which can be used to inform policy. Implications: The carcinogenicity of Naswar, a form of smokeless tobacco used extensively in Pakistan, Afghanistan, and Central Asia, has yet to be recognized by the International Agency for Research on Cancer (IARC), partly due to the lack of evidence on the association of Naswar use and cancer. Additionally, Naswar is yet un-regulated in Pakistan and evades the tax net, resulting in it being freely available to both adults and children at very cheap prices compared to cigarettes, which has been the main focus of tobacco control in Pakistan. This review provides ample evidence for the IARC to declare Naswar as carcinogenic, as well as the Government of Pakistan to regulate the production and sale of Naswar.

Comparison of three meta-analytic methods using data from digital interventions on type 2 diabetes.

AIMS: Pooling the effect sizes of randomized controlled trials (RCTs) from continuous outcomes, such as glycated hemoglobin level (HbA1c), is an important method in evidence syntheses. However, due to challenges related to baseline imbalances and pre/post correlations, simple analysis of change scores (SACS) and simple analysis of final values (SAFV) meta-analyses result in under- or overestimation of effect estimates. This study was aimed to compare pooled effect sizes estimated by Analysis of Covariance (ANCOVA), SACS, and SAFV meta-analyses, using the example of RCTs of digital interventions with HbA1c as the main outcome. MATERIALS AND METHODS: Three databases were systematically searched for RCTs published from 1993 through June 2017. Two reviewers independently assessed titles and abstracts using predefined eligibility criteria, assessed study quality, and extracted data, with disagreements resolved by arbitration from a third reviewer. RESULTS: ANCOVA, SACS, and SAFV resulted in pooled HbA1c mean differences of -0.39% (95% CI: [-0.51, -0.26]), -0.39% (95% CI: [-0.51, -0.26]), and -0.34% (95% CI: [-0.48-0.19]), respectively. Removing studies with both high baseline imbalance (≥±0.2%) and pre/post correlation of ≥±0.6 resulted in a mean difference of -0.39% (95% CI: [-0.53, -0.26]), -0.40% (95% CI: [-0.54, -0.26]), and -0.33% (95% CI: [-0.48, -0.18]) with ANCOVA, SACS, and SAFV meta-analyses, respectively. Substantial heterogeneity was noted. Egger's test for funnel plot symmetry did not indicate evidence of publication bias for all methods. CONCLUSION: By all meta-analytic methods, digital interventions appear effective in reducing HbA1c in type 2 diabetes. The effort to adjust for baseline imbalance and pre/post correlation using ANCOVA relies on the level of detail reported from individual studies. Reporting detailed summary data and, ideally, access to individual patient data of intervention trials are essential.

Effectiveness of Digital Interventions for Improving Glycemic Control in Persons with Poorly Controlled Type 2 Diabetes: A Systematic Review, Meta-analysis, and Meta-regression Analysis.

BACKGROUND: Digital interventions may assist patients with type 2 diabetes in improving glycemic control. We aimed to synthesize effect sizes of digital interventions on glycated hemoglobin (HbA1c) levels and to identify effective features of digital interventions targeting patients with poorly controlled type 2 diabetes. MATERIALS AND METHODS: MEDLINE, ISI Web of Science, and PsycINFO were searched for randomized controlled trials (RCTs) comparing the effects of digital interventions with usual care. Two reviewers independently assessed studies for eligibility and determined study quality, using the Cochrane Risk of Bias Assessment Tool. The Behavioral Change Technique Taxonomy V1 (BCTTv1) was used to identify BCTs used in interventions. Mean HbA1c differences were pooled using analysis of covariance to adjust for baseline differences and pre-post correlations. To examine effective intervention features and to evaluate differences in effect sizes across groups, meta-regression and subgroup analyses were performed. RESULTS: Twenty-three arms of 21 RCTs were included in the meta-analysis (n = 3787 patients, 52.6% in intervention arms). The mean HbA1c baseline differences ranged from -0.2% to 0.64%. The pooled mean HbA1c change was statistically significant (-0.39 {95% CI: [-0.51 to -0.26]} with substantial heterogeneity [I2 statistic, 80.8%]) and a significant HbA1c reduction was noted for web-based interventions. A baseline HbA1c level above 7.5%, ß = -0.44 (95% CI: [-0.81 to -0.06]), the BCTs "problem solving," ß = -1.30 (95% CI: [-2.05 to -0.54]), and "self-monitoring outcomes of behavior," ß = -1.21 (95% CI: [-1.95 to -0.46]) were significantly associated with reduced HbA1c levels. CONCLUSIONS: Digital interventions appear effective for reducing HbA1c levels in patients with poorly controlled type 2 diabetes.

Abbreviated literature searches were viable alternatives to comprehensive searches: a meta-epidemiological study.

OBJECTIVE: To assess the effects of abbreviated literature searches on evidence syntheses conclusions. STUDY DESIGN AND SETTING: We randomly selected 60 Cochrane reviews of clinical interventions and repeated literature searches using 14 abbreviated approaches (combinations of MEDLINE, Embase, CENTRAL with and without searches of reference lists). If abbreviated searches missed included studies, we recalculated meta-analyses. Cochrane authors determined whether the new evidence base would change conclusions. We assessed the noninferiority of abbreviated searches allowing for a maximum of 10% changed conclusions. RESULTS: We conducted 840 abbreviated literature searches. Noninferiority varied based on the definition of "changed conclusion". When the reduction of the certainty of a conclusion was of concern, all abbreviated searches were inferior. Searching Embase only rendered the greatest proportion of changed conclusions (27%, 95% confidence interval [CI]: 16%-40%); combining MEDLINE, Embase, CENTRAL with searches of references lists the lowest (8%, 95% CI 3%-18%). When falsely reaching an opposite conclusion was of concern, combining one database with another or with searches of reference lists was noninferior to comprehensive searches (2%, 95% CI: 0%-9%). CONCLUSION: If decision-makers are willing to accept less certainty and a small risk for opposite conclusions, some abbreviated searches are viable options for rapid evidence syntheses. Decisions demanding high certainty require comprehensive searches.

External validation of type 2 diabetes computer simulation models: definitions, approaches, implications and room for improvement-a protocol for a systematic review.

BACKGROUND: Type 2 diabetes mellitus (T2DM), a highly prevalent chronic disease, puts a large burden on individual health and health care systems. Computer simulation models, used to evaluate the clinical and economic effectiveness of various interventions to handle T2DM, have become a well-established tool in diabetes research. Despite the broad consensus about the general importance of validation, especially external validation, as a crucial instrument of assessing and controlling for the quality of these models, there are no systematic reviews comparing such validation of diabetes models. As a result, the main objectives of this systematic review are to identify and appraise the different approaches used for the external validation of existing models covering the development and progression of T2DM. METHODS: We will perform adapted searches by applying respective search strategies to identify suitable studies from 14 electronic databases. Retrieved study records will be included or excluded based on predefined eligibility criteria as defined in this protocol. Among others, a publication filter will exclude studies published before 1995. We will run abstract and full text screenings and then extract data from all selected studies by filling in a predefined data extraction spreadsheet. We will undertake a descriptive, narrative synthesis of findings to address the study objectives. We will pay special attention to aspects of quality of these models in regard to the external validation based upon ISPOR and ADA recommendations as well as Mount Hood Challenge reports. All critical stages within the screening, data extraction and synthesis processes will be conducted by at least two authors. This protocol adheres to PRISMA and PRISMA-P standards. DISCUSSION: The proposed systematic review will provide a broad overview of the current practice in the external validation of models with respect to T2DM incidence and progression in humans built on simulation techniques. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42017069983 .

Effectiveness of behavioral change techniques employed in eHealth interventions designed to improve glycemic control in persons with poorly controlled type 2 diabetes: a systematic review and meta-analysis protocol.

BACKGROUND: The incorporation of Behavioral Change Techniques (BCTs) in eHealth interventions for the management of non-communicable diseases (NCDs), such as type 2 diabetes mellitus (T2DM), might be a promising approach to improve clinical and behavioral outcomes of NCDs in the long run. This 3paper reports a protocol for a systematic review that aims to (a) identify the effects of individual BCTs in eHealth interventions for lowering glycated hemoglobin levels (HbA1c) and (b) investigate which additional intervention features (duration of intervention, tailoring, theory-base, and mode of delivery) affect levels of HbA1c in this population. The protocol follows the Preferred Reporting Items for Systematic review and Meta-Analysis Protocols (PRISMA-P) 2015 guideline. METHODS/DESIGN: To identify eligible studies, an extensive systematic database search (PubMed, Web of Science, and PsycINFO) using keywords will be conducted. This review will include randomized controlled trials examining the effects of eHealth interventions on HbA1c in persons with poorly controlled T2DM over a minimum follow-up period of 3 months. Relevant data will be extracted from the included studies using Microsoft Excel. The content of the interventions will be extracted from the description of interventions and will be classified according to the BCT taxonomy v1 tool. The quality of studies will be independently assessed by two reviewers using the Cochrane risk of bias tool. If the studies have adequate homogeneity, meta-analysis will be considered. The effect sizes of each BCT will be calculated using the random effect model. The quality of the synthesized evidence will be evaluated employing the Grading of the Recommendations Assessment, Development and Evaluation (GRADE) criteria. DISCUSSION: This systematic review is one of the firsts to appraise the effectiveness of eHealth interventions employing BCTs which aimed at improving glycemic control in persons with poorly controlled T2DM. The review will aggregate the effect sizes of BCTs on HbA1c levels. The results may inform future eHealth interventions targeting poorly controlled T2DM populations. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42016049940.

Community gardening, community farming and other local community-based gardening interventions to prevent overweight and obesity in high-income and middle-income countries: protocol for a systematic review.

INTRODUCTION: The worldwide prevalence of overweight/obesity has continued to rise over the last decades. To reverse this trend, public health authorities are exploring cost-effective interventions, especially in high-income and middle-income countries. Community gardening offers a unique opportunity for individuals to enhance physical activity levels and improve their diet. However, synthesised evidence on the short-term or long-term effectiveness and on the costs of community gardening interventions to prevent overweight/obesity remains limited. Therefore, this review will investigate: (1) the effectiveness of voluntary participation in community gardening compared with no or a control intervention on overweight/obesity and associated health outcomes, (2) effects on different subgroups of populations and (3) the costs of community gardening interventions. METHODS AND ANALYSIS: We will conduct a systematic review, limited to evaluations of community gardening interventions with controlled quantitative and interrupted time series designs. To identify relevant articles, we will systematically search 12 academic and 5 grey literature databases, as well as 2 trial registers and 6 websites. Articles will then be assessed for eligibility based on a predefined set of criteria. At least two independent reviewers will assess each article for relevance, before evaluating the methodological quality and potential bias of the studies. Data relevant to the objectives of this review will be extracted and cross-validated. Any disagreements will be mediated by a third reviewer. If feasible, meta-analyses of primary outcomes (overweight/obesity, physical activity, food intake, energy intake) will be conducted. We will use the Grading of Recommendations Assessment, Development and Evaluation method to assess the overall quality of evidence. ETHICS AND DISSEMINATION: For this review, no ethical approval is required as we will only extract and analyse secondary data. We aim to submit the final review manuscript to an open access journal for publication and disseminate results via conferences and social media. TRIAL REGISTRATION NUMBER: International Prospective Register of Systematic Reviews (PROSPERO)(CRD42017043696).