Sources Of Between-study Heterogeneity Research Articles

Augmentation of cognitive-behavioural therapy for obsessive-compulsive and anxiety disorders: a protocol for a systematic review and meta-analysis.

While cognitive-behavioural therapy (CBT) for obsessive-compulsive disorder (OCD) and anxiety disorders (ADs) has been proven to be effective and is commonly recommended, a considerable proportion of patients remain symptomatic, do not respond to treatment or discontinue it. Thus, augmentation strategies aimed at enhancing CBT outcomes are essential to reduce the burden of OCD and ADs on patients and society. Various augmentation strategies for CBT in OCD and ADs have been investigated, yet it remains unclear if they show robust beneficial effects beyond first-line CBT. With this systematic review and meta-analysis, we will provide an overview and critically assess the efficacy of non-pharmacological augmentation strategies in addition to first-line CBT treatment for symptom reduction, response rates and dropout rates in individuals with OCD or ADs. We will screen PubMed, Embase, PsycArticles, PsycInfo, CINAHL, PSYNDEX and Cochrane Register of Controlled Trials without restrictions on publication dates or languages. Additionally, forward, and backward searches of included studies and systematic reviews will be conducted. Two reviewers will independently screen the studies, extract data and assess the methodological quality of the studies. We will exclusively include randomised controlled trials. The primary outcomes will be symptom severity and response rates. Dropout rates will serve as a secondary outcome. Moreover, we will provide a narrative review of the results. We will use subgroup and meta-regression analyses to identify potential moderators and sources of between-study heterogeneity. We will use the Grading of Recommendations Assessment, Development and Evaluation system to assess the overall quality of evidence. Ethical approval is not required. Results will be published in a peer-reviewed journal. CRD42024561027.

Intraprocedural Cortisol Measurement Increases Adrenal Vein Cannulation Success Rate in Primary Aldosteronism: A Systematic Review and Meta-analysis.

This study aimed to explore the effectiveness of intraprocedural cortisol measurement (IPCM) for the technical success rates of bilateral adrenal vein, right adrenal vein (RAV), and left adrenal vein (LAV) cannulation during adrenal vein sampling (AVS). Systematic searches of PubMed, Embase, Cochrane Library, and ClinicalTrials.gov were performed from database inception to May 10, 2023, without any restrictions. We estimated the overall effect estimates of outcomes using the Mantel-Haenszel random-effects model. We conducted subgroup analyses, meta-regression, and sensitivity analysis to explore the possible sources of between-study heterogeneity. In total, 3,485 patients from 11 studies (three prospective and eight retrospective) were enrolled. Bilateral selectivity in patients who underwent IPCM during AVS was significantly higher than that in patients who underwent a routine AVS procedure (84% vs. 64%, RR 1.42, 95% confidence interval [CI]: 1.27-1.59, P < 0.01), with significant heterogeneity (I2 = 68%). A 42% relative risk reduction in the failure rate of bilateral adrenal vein cannulation was found in the IPCM group. Moreover, pooled analysis showed a significant increase in the success rates of RAV cannulation (84% vs. 72%, RR 1.21, 95% CI 1.12-1.31, P < 0.01, I2 = 33%) and LAV cannulation (89% vs. 84%, RR 1.05, 95% CI 1.02-1.08, P < 0.01, I2 = 4%) when IPCM was implemented during the AVS procedure compared to the routine AVS procedure. An IPCM-based strategy during AVS appears to have a significant beneficial effect on improving the success rate of bilateral cannulation, RAV cannulation and LAV cannulation.

An Invited Reply to: A Comment on: The exploitation of sexual signals by predators: a meta-analysis (2022) White et al.

An Invited Reply to: A Comment on: The exploitation of sexual signals by predators: a meta-analysis (2022) White et al.

Population Characteristics, Symptoms, and Risk Factors of Idiopathic Chilblains: A Systematic Review, Meta-Analysis, and Meta-Regression.

Chilblains/perniosis is a non-freezing cold injury causing painful inflammatory skin lesions. Its pathogenesis remains poorly understood because it is often studied as secondary to other underlying conditions. We systematically investigated the population characteristics, symptoms, and predisposing factors of chilblains in healthy adults exposed to cool/cold environments. We screened PubMed, Embase, and Cochrane Library, and we adopted PRISMA reporting guidelines (PROSPERO: CRD42021245307). The risk of bias was assessed by two independent reviewers (RTI item bank). Random-effects model meta-analyses were performed to calculate the pooled prevalence of histopathological features. Mixed-effects meta-regressions were used to assess other sources of between-study heterogeneity. Thirteen studies (477 patients) were included. Chilblains affect more women than men, up to 12% of the body skin surface, and most frequently, the hands and fingers. Meta-analyses of nine studies (303 patients) showed a frequent presence of perivascular lymphocytic infiltrate (81%), basal epidermal-cell layer vacuolation (67%), papillary dermal edema (66%), and perieccrine lymphocytic infiltrate (57%). Meta-regressions (p ≤ 0.05) showed that smoking and frequent occupational exposure to water increase the likelihood of histopathological features. The population characteristics, symptoms, and predisposing factors of chilblains revealed in this analysis should be incorporated in medical care to improve the condition's diagnosis and management.

Mindfulness for internet use disorder: a study protocol of a systematic review and meta-analysis

IntroductionInternet use disorder (IUD) is on the rise and is associated with detrimental health consequences. Growing evidence suggests that mindfulness—either as a trait or cultivated in mindfulness-based programmes (MBPs)—is promising...

Global, regional, and country estimates of metabolic syndrome burden in children and adolescents in 2020: a systematic review and modelling analysis

Halting the rise in cardiometabolic risk factors in children and adolescents is crucial to curb the global burden of cardiovascular diseases. We aim to provide global, regional, and national estimates of the prevalence of metabolic syndrome in children and adolescents to support the development of evidence-based prevention strategies. In this systematic review with modelling analysis, we searched PubMed, Embase, Africa Journal Online, and Global Index Medicus from database inception to Jan 30, 2021, with no restriction on language or geographical location. We included community-based and school-based cross-sectional studies and cross-sectional analysis of cohort studies that reported prevalence of metabolic syndrome in the general population of children (6-12 years) and adolescents (13-18 years). Only studies with a low risk of bias were considered. Eligible studies included at least 200 participants and used probabilistic-based sampling. Diagnosis of metabolic syndrome had to meet at least three of the following criteria: high systolic or diastolic blood pressure (≥90th percentile for age, sex, and height); waist circumference in at least the 90th percentile for age, sex, and ethnic group; fasting plasma glucose 5·6 mmol/L or greater; fasting plasma triglycerides 1·24 mmol/L or greater; and fasting plasma high density lipoprotein cholesterol 1·03 mmol/L or less. Independent investigators selected eligible studies and extracted relevant data. The primary outcome was a crude estimate of metabolic syndrome prevalence, assessed using a Bayesian hierarchical model. Our search yielded 6808 items, of which 169 studies were eligible for analysis, including 306 prevalence datapoints, with 550 405 children and adolescents from 44 countries in 13 regions. The between-study variance (τ2) was 0·52 (95% CI 0·42-0·67), which could reflect the measurement of each component of the metabolic syndrome and covariates as sources of between-study heterogeneity. We estimated the global prevalence of metabolic syndrome in 2020 at 2·8% (95% uncertainty interval [UI] 1·4-6·7) for children and 4·8% (2·9-8·5) for adolescents, equating to around 25·8 (12·6-61·0) million children and 35·5 (21·3-63·0) million adolescents living with metabolic syndrome. In children, the prevalence of metabolic syndrome was 2·2% (95% UI 1·4-3·6) in high-income countries, 3·1% (2·5-4·3) in upper-middle-income countries, 2·6% (0·9-8·3) in lower-middle-income countries, and 3·5% (1·0-8·0) in low-income countries. In adolescents, the prevalence of metabolic syndrome was 5·5% (4·1-8·4) in high-income countries, 3·9% (3·1-5·4) in upper-middle-income countries, 4·5% (2·6-8·4) in lower-middle-income countries, and 7·0% (2·4-15·7) in low-income countries. Prevalence in children varied from 1·4% (0·6-3·1) in northwestern Europe to 8·2% (6·9-10·1) in Central Latin America. Prevalence for adolescents ranged from 2·9% (95% UI 2·6-3·3) in east Asia to 6·7% (5·9-8·3) in high-income English-speaking countries. The three countries with the highest prevalence estimates in children were Nicaragua (5·2%, 2·8-10·4), Iran (8·8%, 8·0-9·6), and Mexico (12·3%, 11·0-13·7); and the three countries with the highest prevalence estimates in adolescents were Iran (9·0%, 8·4-9·7), United Arab Emirates (9·8%, 8·5-10·3), and Spain (9·9%, 9·1-10·8). In 2020, about 3% of children and 5% of adolescents had metabolic syndrome, with some variation across countries and regions. The prevalence of metabolic syndrome was not consistently higher with increasing level of development, suggesting that the problem is not mainly driven by country wealth. The high number of children and adolescents living with metabolic syndrome globally highlights the urgent need for multisectoral interventions to reduce the global burden of metabolic syndrome and the conditions that lead to it, including childhood overweight and obesity. None.

Distinctive prosodic features of people with autism spectrum disorder: a systematic review and meta-analysis study

In this systematic review, we analyzed and evaluated the findings of studies on prosodic features of vocal productions of people with autism spectrum disorder (ASD) in order to recognize the statistically significant, most confirmed and reliable prosodic differences distinguishing people with ASD from typically developing individuals. Using suitable keywords, three major databases including Web of Science, PubMed and Scopus, were searched. The results for prosodic features such as mean pitch, pitch range and variability, speech rate, intensity and voice duration were extracted from eligible studies. The pooled standard mean difference between ASD and control groups was extracted or calculated. Using I2 statistic and Cochrane Q-test, between-study heterogeneity was evaluated. Furthermore, publication bias was assessed using funnel plot and its significance was evaluated using Egger’s and Begg’s tests. Thirty-nine eligible studies were retrieved (including 910 and 850 participants for ASD and control groups, respectively). This systematic review and meta-analysis showed that ASD group members had a significantly larger mean pitch (SMD = − 0.4, 95% CI [− 0.70, − 0.10]), larger pitch range (SMD = − 0.78, 95% CI [− 1.34, − 0.21]), longer voice duration (SMD = − 0.43, 95% CI [− 0.72, − 0.15]), and larger pitch variability (SMD = − 0.46, 95% CI [− 0.84, − 0.08]), compared with typically developing control group. However, no significant differences in pitch standard deviation, voice intensity and speech rate were found between groups. Chronological age of participants and voice elicitation tasks were two sources of between-study heterogeneity. Furthermore, no publication bias was observed during analyses (p > 0.05). Mean pitch, pitch range, pitch variability and voice duration were recognized as the prosodic features reliably distinguishing people with ASD from TD individuals.

Measurement errors in control risk regression: Acomparison of correction techniques.

Control risk regression is a diffuse approach for meta‐analysis about the effectiveness of a treatment, relating the measure of risk with which the outcome occurs in the treated group to that in the control group. The severity of illness is a source of between‐study heterogeneity that can be difficult to measure. It can be approximated by the rate of events in the control group. Since the estimate is a surrogate for the underlying risk, it is prone to measurement error. Correction methods are necessary to provide reliable inference. This article illustrates the extent of measurement error effects under different scenarios, including departures from the classical normality assumption for the control risk distribution. The performance of different measurement error corrections is examined. Attention will be paid to likelihood‐based structural methods assuming a distribution for the control risk measure and to functional methods avoiding the assumption, namely, a simulation‐based method and two score function methods. Advantages and limits of the approaches are evaluated through simulation. In case of large heterogeneity, structural approaches are preferable to score methods, while score methods perform better for small heterogeneity and small sample size. The simulation‐based approach has a satisfactory behavior whichever the examined scenario, with no convergence issues. The methods are applied to a meta‐analysis about the association between diabetes and risk of Parkinson disease. The study intends to make researchers aware of the measurement error problem occurring in control risk regression and lead them to the use of appropriate correction techniques to prevent fallacious conclusions.

Prognostic models for radiation-induced complications after radiotherapy in head and neck cancer patients

Objectives: This is a protocol for a Cochrane Review (prognosis). The objectives are as follows:. Primary objective The review question is “Which prognostic models are available to predict the risk of radiation-induced side effects after radiation exposure to patients with head and neck cancer, what is their quality, and what is their predictive performance?”. Investigation of sources of heterogeneity between studies We will assess sources of heterogeneity among the prognostic models developed in the eligible studies. The potential sources are study population (e.g. site/stage of cancer, the use of other treatment [surgery and chemotherapy]), predictors, definition and incidence of the predicted outcomes, and prediction horizons. If there are multiple validation studies for the same model, the same sources of between-study heterogeneity will be investigated.

A systematic review and meta-analysis of the prognostic role of age in oral tongue cancer.

While evidence suggests an increasing incidence of tongue cancer in young adults, published findings regarding the prognostic role of age at diagnosis are inconsistent. We performed a meta‐analysis of the literature to highlight key points that might help in understanding the association between age of oral tongue cancer patients at diagnosis and their prognosis. According to age at diagnosis, a systematic literature review of all published cohort studies assessing the recurrence risks and mortality associated with tongue cancer was conducted. We compared the risk estimates between patients aged >45 years and those aged <45 years at diagnosis. Random‐effects models were used to calculate summary relative risk estimates (SRRs) according to different clinical outcomes and sources of between‐study heterogeneity (I2) and bias. We included 31 independent cohort studies published between 1989 and 2019; these studies included a total of 28,288 patients. When risk estimations were not adjusted for confounders, no significant association was found between age at diagnosis and overall survival (OS). Conversely, after adjustment for confounders, older age at diagnosis was associated with a significantly increased risk of mortality. The difference between SRRs for adjusted and unadjusted estimates was significant (p < 0.01). Younger patients had a significantly higher risk of local recurrence. Younger patients with oral tongue cancer have better OS but a greater risk of recurrence than older patients. These findings should be validated in a large prospective cohort study which considers all confounders and prognostic factors.

UMBRELLA protocol: systematic reviews of multivariable biomarker prognostic models developed to predict clinical outcomes in patients with heart failure

BackgroundHeart failure (HF) is a chronic and common condition with a rising prevalence, especially in the elderly. Morbidity and mortality rates in people with HF are similar to those with common forms of cancer. Clinical guidelines highlight the need for more detailed prognostic information to optimise treatment and care planning for people with HF. Besides proven prognostic biomarkers and numerous newly developed prognostic models for HF clinical outcomes, no risk stratification models have been adequately established. Through a number of linked systematic reviews, we aim to assess the quality of the existing models with biomarkers in HF and summarise the evidence they present. MethodsWe will search MEDLINE, EMBASE, Web of Science Core Collection, and the prognostic studies database maintained by the Cochrane Prognosis Methods Group combining sensitive published search filters, with no language restriction, from 1990 onwards. Independent pairs of reviewers will screen and extract data. Eligible studies will be those developing, validating, or updating any prognostic model with biomarkers for clinical outcomes in adults with any type of HF. Data will be extracted using a piloted form that combines published good practice guidelines for critical appraisal, data extraction, and risk of bias assessment of prediction modelling studies. Missing information on predictive performance measures will be sought by contacting authors or estimated from available information when possible. If sufficient high quality and homogeneous data are available, we will meta-analyse the predictive performance of identified models. Sources of between-study heterogeneity will be explored through meta-regression using pre-defined study-level covariates. Results will be reported narratively if study quality is deemed to be low or if the between-study heterogeneity is high. Sensitivity analyses for risk of bias impact will be performed.DiscussionThis project aims to appraise and summarise the methodological conduct and predictive performance of existing clinically homogeneous HF prognostic models in separate systematic reviews.Registration: PROSPERO registration number CRD42019086990

Systematic review and meta-analysis of the epidemiology of Lassa virus in humans, rodents and other mammals in sub-Saharan Africa

Accurate data on the Lassa virus (LASV) human case fatality rate (CFR) and the prevalence of LASV in humans, rodents and other mammals are needed for better planning of actions that will ultimately reduce the burden of LASV infection in sub-Saharan Africa. In this systematic review with meta-analysis, we searched PubMed, Scopus, Africa Journal Online, and African Index Medicus from 1969 to 2020 to obtain studies that reported enough data to calculate LASV infection CFR or prevalence. Study selection, data extraction, and risk of bias assessment were conducted independently. We extracted all measures of current, recent, and past infections with LASV. Prevalence and CFR estimates were pooled using a random-effect meta-analysis. Factors associated with CFR, prevalence, and sources of between-study heterogeneity were determined using subgroup and metaregression analyses. This review was registered with PROSPERO, CRD42020166465. We initially identified 1,399 records and finally retained 109 reports that contributed to 291 prevalence records from 25 countries. The overall CFR was 29.7% (22.3–37.5) in humans. Pooled prevalence of LASV infection was 8.7% (95% confidence interval: 6.8–10.8) in humans, 3.2% (1.9–4.6) in rodents, and 0.7% (0.0–2.3) in other mammals. Subgroup and metaregression analyses revealed a substantial statistical heterogeneity explained by higher prevalence in tissue organs, in case-control, in hospital outbreak, and surveys, in retrospective studies, in urban and hospital setting, in hospitalized patients, and in West African countries. This study suggests that LASV infections is an important cause of death in humans and that LASV are common in humans, rodents and other mammals in sub-Saharan Africa. These estimates highlight disparities between sub-regions, and population risk profiles. Western Africa, and specific key populations were identified as having higher LASV CFR and prevalence, hence, deserving more attention for cost-effective preventive interventions.

Epidemiology of Treponema pallidum, Chlamydia trachomatis, Neisseria gonorrhoeae, Trichomonas vaginalis, and herpes simplex virus type 2 among female sex workers in the Middle East and North Africa: systematic review and meta-analytics.

BackgroundThe epidemiology of sexually transmitted infections (STIs) and the role of commercial heterosexual sex networks in driving STI transmission in the Middle East and North Africa (MENA) region remain largely unknown.ObjectiveTo characterize the epidemiology of Treponema pallidum (syphilis), Chlamydia trachomatis, Neisseria gonorrhoeae, Trichomonas vaginalis, and herpes simplex virus type 2 (HSV-2) among female sex workers (FSWs) in MENA using an in-depth quantitative assessment.MethodsA systematic review on ten international, regional, and country-level databases was conducted, and reported following PRISMA guidelines. Pooled prevalences of current and/or ever infection for each STI were estimated using random-effects meta-analyses. Sources of between-study heterogeneity were investigated through random-effects meta-regressions.ResultsOne T. pallidum incidence study and 144 STI prevalence studies were identified for 45 812 FSWs in 13 MENA countries. The pooled prevalence of current infection was 12.7% (95% confidence interval (CI) = 8.5%-17.7%) for T. pallidum, 14.4% (95% CI = 8.2%-22.0%) for C. trachomatis, 5.7% (95% CI = 3.5%-8.4%) for N. gonorrhoeae, and 7.1% (95% CI = 4.3%-10.5%) for T. vaginalis. The pooled prevalence of ever infection (seropositivity using antibody testing) was 12.8% (95% CI = 9.4%-16.6%) for T. pallidum, 80.3% (95% CI = 53.2%-97.6%) for C. trachomatis, and 23.7% (95% CI = 10.2%-40.4%) for HSV-2. The multivariable meta-regression for T. pallidum infection demonstrated strong subregional differences, with the Horn of Africa and North Africa showing, respectively 6-fold (adjusted odds ratio (AOR): 6.4; 95% CI = 2.5-16.7) and 5-fold (AOR = 5.0; 95% CI = 2.5-10.6) higher odds of infection than Eastern MENA. There was also strong evidence for declining T. pallidum odds of infection at 7% per year (AOR = 0.93; 95% CI = 0.88-0.98). Study-specific factors including diagnostic method, sample size, sampling methodology, and response rate, were not associated with syphilis infection. The multivariable model explained 48.5% of the variation in T. pallidum prevalence.ConclusionsSTI infection levels among FSWs in MENA are considerable, supporting a key role for commercial heterosexual sex networks in transmission dynamics, and highlighting the health needs of this neglected and vulnerable population. Syphilis prevalence in FSWs appears to have been declining for at least three decades. Gaps in evidence persist for multiple countries.

Mindfulness-based interventions to reduce burnout and stress in physicians: a study protocol for a systematic review and meta-analysis

IntroductionPhysicians often suffer from burnout and stress, not only affecting themselves, but also their patients and the healthcare system in general. An increasing number of studies suggest that mindfulness-based interventions...

Epidemiology of Chlamydia trachomatis in the Middle East and north Africa: a systematic review, meta-analysis, and meta-regression

The epidemiology of Chlamydia trachomatis in the Middle East and north Africa is poorly understood. We aimed to provide a comprehensive epidemiological assessment of C trachomatis infection in the Middle East and north Africa. We did a systematic review of C trachomatis infection as well as a meta-analysis and meta-regression of C trachomatis prevalence. We searched PubMed and Embase, as well as regional and national databases up to March 13, 2019, using broad search terms with no language or year restrictions. Any document or report including biological measures for C trachomatis prevalence or incidence was eligible for inclusion. We extracted all measures of current (genital or rectal), recent, and ever infection with C trachomatis. We estimated pooled average prevalence in different populations using random-effects meta-analysis. Factors associated with prevalence and sources of between-study heterogeneity were determined using meta-regression. We identified a total of 1531 citations, of which 255 reports contributed to 552 C trachomatis prevalence measures from 20 countries. No incidence measures were identified. Pooled prevalence of current genital infection was 3·0% (95% CI 2·3-3·8) in general populations, 2·8% (1·0-5·2) in intermediate-risk populations, 13·2% (7·2-20·7) in female sex workers, 11·3% (9·0-13·7) in infertility clinic attendees, 12·4% (7·9-17·7) in women with miscarriage, 12·4% (9·4-15·7) in symptomatic women, and 17·4% (12·5-22·8) in symptomatic men. Pooled prevalence of current rectal infection was 7·7% (4·2-12·0) in men who have sex with men. Substantial between-study heterogeneity was found. Multivariable meta-regression explained 29·0% of variation. Population type was most strongly associated with prevalence. Additional associations were found with assay type, sample size, country, and sex, but not with sampling methodology or response rate (about 90% of studies used convenience sampling and >75% had unclear response rate). There was no evidence for temporal variation in prevalence between 1982 and 2018. C trachomatis prevalence in the Middle East and north Africa is similar to other regions, but higher than expected given its sexually conservative norms. High prevalence in infertility clinic attendees and in women with miscarriage suggests a potential role for C trachomatis in poor reproductive health outcomes in this region. National Priorities Research Program from the Qatar National Research Fund (a member of Qatar Foundation).

Association between serum osteocalcin and body mass index: a systematic review and meta-analysis.

Osteocalcin is considered as a bone-derived hormone affecting on the body fat distribution and body mass index. Several cross-sectional studies have investigated the association between serum osteocalcin and body mass index. The aim of this study was to summarize the evidence on the relationship between serum osteocalcin and body mass index. We conducted a complete search up to November 2016 in PubMed and SCOPUS and reviewed reference list of all relevant articles and reviews. The DerSimonian-Laird method were used to pool effect sizes of eligible studies. The potential sources of heterogeneity were assessed using the standard χ 2 test.To find possible the sources of between-study heterogeneity, we carried out subgroup analyses based on sex, and type of study population. There was a significant inverse association in the overall result of this study between serum osteocalcin levels and BMI(r = -0.161; 95% CI: -0.197, -0.124, p < 0.000). In the subgroup analysis to find the sources of significant heterogeneity between-study, we observed that the type of the study population may be the source of between-study heterogeneity and the most correlation was seen in metabolic syndrome studies (r = -0.265; p = 0.000). Findings from the available data indicated an overall significant inverse association between serum osteocalcin and body mass index. Further studies based on the type of study population are needed to better clarify these associations.

Abstract 2301: Genital use of talc and risk of ovarian cancer: A meta-analysis

Abstract Some epidemiological studies suggest an association between genital use of talc powders and increased risk of ovarian cancer, but the evidence is not consistent. We performed a meta-analysis of epidemiologic studies to formally evaluate this suspected association. A systematic search was conducted in Medline, Embase and Scopus, leading to the identification of 24 case-control studies and 3 cohort studies, including 302,705 women with ovarian cancer. In the meta-analysis, we used a random-effect model to calculate summary estimates of the association between genital use of talc and occurrence of ovarian cancer. We assessed potential sources of between-study heterogeneity and presence of publication bias. The summary relative risk (RR) for ever use of genital talc and ovarian cancer was 1.22 (95% confidence interval [CI] 1.13-1.30). The RR for case-control studies was 1.26 (95% CI 1.17-1.35) and for cohort studies was 1.02 (95% CI 0.85-1.20, p heterogeneity=0.007). Serous carcinoma was the only histologic type for which an association was detected (RR 1.24; 95% CI 1.15-1.34). There was no trend in RR with either duration or frequency of genital talc use. This meta-analysis resulted in a weak but statistically significant association between genital use of talc and ovarian cancer, which appears to be limited to serous carcinoma. The heterogeneity of results by study design and the lack of a trend for duration and frequency of use, however, detract from a causal interpretation of this association. Note: This abstract was not presented at the meeting. Citation Format: Paolo Boffetta, Wera Berge. Genital use of talc and risk of ovarian cancer: A meta-analysis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2301. doi:10.1158/1538-7445.AM2017-2301

The effects of weight loss approaches on bone mineral density in adults: a systematic review and meta-analysis of randomized controlled trials.

We assessed the impact of weight loss strategies including calorie restriction and exercise training on BMD in adults using a systematic review of randomized controlled trials. Weight reduction results in reduced BMD at the hip, but has less effect on the spine. Both calorie restriction and a combination of calorie restriction and exercise result in a decrease in hip bone density, whereas weight loss response to exercise training without dietary restriction leads to increased hip BMD. Findings are not consistent on the effect of weight loss on bone mineral density (BMD). We conducted a systematic review on the randomized controlled trials to assess the effect of weight loss strategies, including calorie restriction and exercise programs on BMD in adults. A structured and comprehensive search of MEDLINE and EMBASE databases was undertaken up to March 2016. Study-specific mean differences (MD) were pooled using a random-effects model. Subgroup analysis and meta-regression were used to find possible sources of between-study heterogeneity. Thirty-two randomized controlled trials met predetermined inclusion criteria. The meta-analysis revealed no significant difference on total BMD (MD 0.007, 95% CI -0.020-0.034, p = 0.608). In contrast, the pooled data of studies showed a significant effect of weight loss on hip BMD (MD -0.008, 95% CI -0.09 to -0.006g/cm(2), p < 0.001) and also lumbar spine BMD (MD -0.018g/cm(2), 95% CI -0.019 to -0.017, p < 0.001). BMD in the hip site decreased after more than 4months, especially in those who were obese. Moreover, calorie restriction interventions longer than 13months showed a significant decreased in lumbar spine BMD. Weight loss led to significant decreases at the hip and lumbar spine BMD but not at the total. Weight loss response following calorie restriction resulted in a decrease in hip and lumbar spine bone density especially more than 1year; whereas an exercise-induced weight loss did not.

The SNP rs931794 in 15q25.1 Is Associated with Lung Cancer Risk: A Hospital-Based Case-Control Study and Meta-Analysis

BackgroundLung cancer is one of the most common human malignant diseases and the leading cause of cancer death worldwide. The rs931794, a SNP located in 15q25.1, has been suggested to be associated with lung cancer risk. Nevertheless, several genetic association studies yielded controversial results.Methods and FindingsA hospital-based case-control study involving 611 cases and 1062 controls revealed the variant of rs931794 was related to increased lung cancer risk. Stratified analyses revealed the G allele was significantly associated with lung cancer risk among smokers. Following meta-analysis including 6616 cases and 7697 controls confirmed the relevance of rs931794 variant with increased lung cancer risk once again. Heterogeneity should be taken into account when interpreting the consequences. Stratified analysis found ethnicity, histological type and genotyping method were not the sources of between-study heterogeneity. Further sensitivity analysis revealed that the study “Hsiung et al (2010)” might be the major contributor to heterogeneity. Cumulative meta-analysis showed the trend was increasingly obvious with adding studies, confirming the significant association.ConclusionsResults from our current case-control study and meta-analysis offered insight of association between rs931794 and lung cancer risk, suggesting the variant of rs931794 might be related with increased lung cancer risk.

The relationship between angiotensin-converting enzyme gene insertion/deletion polymorphism and digestive cancer risk: Insights from a meta-analysis.

The gene encoding angiotensin-converting enzyme (ACE) has been implicated in the development of several malignancies. We aimed to meta-analyze the association of ACE gene insertion/deletion (I/D) polymorphism with digestive cancer risk and seek possible sources of between-study heterogeneity. Two authors independently assessed eligibility of each retrieved publication and gathered relevant data. Risk estimates were expressed as odds ratio (OR) and 95% confidence interval (CI). Sixteen publications were qualified for analysis, involving 2903 digestive cancer cases and 10,833 controls. Overall analyses failed to show any significance for digestive cancer risk. There was moderate heterogeneity and lower publication bias for overall comparisons. In subgroup analyses, ACE gene II genotype was associated with a 15% reduced risk (OR=0.85, 95% CI: 0.57-1.27, p=0.434) for gastric cancer, but a 16% increased risk (OR=1.16, 95% CI: 0.89-1.52, p=0.273) for colorectal cancer. By source of controls, the I allele appeared to be a protective factor against digestive cancer in population-based studies (OR=0.87, 95% CI: 0.75-1.00, p=0.055) but a risk-conferring factor in hospital-based studies (OR=1.17, 95% CI: 1.01-1.35, p=0.033). Our findings suggested that ACE gene I allele might be a protective factor against gastric cancer, necessitating further confirmation in large, population-based studies.