Evaluation of the efficacy of systemic therapy for advanced uterine leiomyosarcoma: A systematic review, meta-analysis, and meta-regression analysis

Uterine leiomyosarcoma (uLMS) is an aggressive mesenchymal neoplasm associated with a poor prognosis. Systemic chemotherapy is the standard therapy for patients with uLMS. However, it is unclear which treatment regimen results in the most favorable clinical outcome. We performed a meta-analysis and meta-regression analysis to assess the efficiency of different treatments received by patients with advanced, metastatic, and relapsing uLMS by evaluating the objective response rate (ORR) and disease control rate (DCR) as primary endpoints. The frequentist random effects meta-analysis model was used to compare the outcomes of different treatment regimens for advanced uLMS. A meta-regression analysis was performed to estimate the association between the study-specific hazard ratios and specific demographic variables. A meta-analysis of 51 reports including 1664 patients was conducted. Among patients who received adjuvant chemotherapy (916 patients; 55%), gemcitabine and docetaxel were the most frequently used drugs. First-line monotherapy with alkylating agents (pooled ORR = 0.48; 95% confidence interval [CI]: 0.44-0.52) and second-line monotherapy with protein kinase inhibitors (pooled ORR = 0.45; 95% CI: 0.39-0.52) resulted in favorable prognoses. The combinations of anthracycline plus alkylating therapy (pooled DCR = 0.74; 95% CI: 0.67-0.79) and of gemcitabine plus docetaxel (pooled DCR = 0.70; 95% CI: 0.63-0.75) showed the greatest benefits when used as first-line and second-line chemotherapies, respectively. Subgroup meta-analysis results revealed that dual-regimen therapies comprising anthracycline plus alkylating therapy and gemcitabine plus docetaxel are practical therapeutic choices for International Federation of Gynecology and Obstetrics stages III-IVb with distant metastases when assessed by computed tomography (p = 0.001). Furthermore, neoadjuvant chemotherapy and local radiotherapy resulted in favorable outcomes for patients with earlier stages of distant relapsed uLMS (p < 0.001). Our findings provide a basis for designing new therapeutic strategies and can potentially guide clinical practice toward better prognoses for uLMS patients with advanced, metastatic, and relapsing disease.

Effects of Changes in Body Fat Mass as a Result of Regular Exercise on Hemoglobin A1c in Patients With Type 2 Diabetes Mellitus: A Meta-Analysis

An increase in visceral fat is associated with an increase in insulin resistance, so reducing body fat mass through exercise may help alleviate type 2 diabetes mellitus (T2DM). The current meta-analysis evaluated the effect of changes in body fat via an intervention of regular exercise on hemoglobin A1c (HbA1c) in patients with T2DM. The inclusion criteria were randomized controlled trials involving adults with T2DM, intervention involving exercise alone, an overall duration of intervention ≥12 weeks, and reporting HbA1c and body fat mass. The mean differences (MDs) were defined as the MD between the exercise group and the control group, and the MDs in HbA1c (in percentage) and body fat mass (in kilograms) were calculated. All MDs in HbA1c were pooled as overall effects. A meta-regression analysis was performed to evaluate the relationship between the MD in the body fat mass (in kilograms) and the MD in HbA1c. Twenty studies (1,134 subjects) were analyzed. The pooled MD in HbA1c (in percentage) decreased significantly (-0.4; 95% confidence interval [-0.5, -0.3]) but contained significant heterogeneity (Q = 52.7, p < .01; I2 = 41.6%). A meta-regression analysis showed that a decrease in the MD in body fat mass was significantly associated with a decrease in the MD in HbA1c (R2 = 80.0%) and heterogeneity decreased (Q = 27.3, p = .61; I2 = 11.9%), and a reduction in body fat mass of 1 kg was estimated to decrease the HbA1c (%) by approximately 0.2. The current study suggested that a decrease in HbA1c due to regular exercise depends on a reduction in body fat mass in patients with T2DM.

Serum afamin levels in predicting gestational diabetes mellitus and preeclampsia: A systematic review and meta-analysis

OBJECTIVES

The association between biomarkers and the risk of gestational diabetes mellitus (GDM) or preeclampsia (PE) has been extensively studied. However, there is still a lack of convenient, specific, and sensitive indicators for early identification of GMD and PE. Therefore, we conducted a meta-analysis of published articles to investigate the value of afamin circulating levels in the early diagnosis of GDM and PE.

METHODS

We searched the PubMed, Embase, Cochrane Library, and Web of Science databases for English studies published before November 16, 2022, that examined the association between afamin and GDM or PE. In addition, we searched Clinicaltrials.gov for the relevant completed and ongoing clinical trials. Pooled standard mean differences (SMDs) and weighted mean differences (WMDs) with 95% confidence intervals (CIs) were used to compare the levels of afamin in different groups.

RESULTS

Eleven studies were included in our analysis (N = 3047 participants: 1195 GDM, 1407 non-GDM, 195 PE, and 250 non-PE). Subgroup analysis based on different blood collection periods found that the plasma afamin levels in pregnant women with GDM in the first trimester were significantly higher than those in healthy pregnant women (SMD = 0.481, 95% CI: 0.280-0.682), but the analysis showed the opposite results in the second and late stages (SMD = 0.292, 95% CI: -0.092-0.676). The plasma afamin levels of pregnant women with PE in the first trimester (SMD = 0.808, 95% CI: 0.558-1.059) and second/third trimesters (SMD = 0.904, 95% CI: 0.570-1.239) were significantly higher than those in healthy pregnant women.

CONCLUSION

The plasma afamin levels in pregnant women with GDM in the first trimester were significantly higher than those in healthy pregnant women, but the analysis showed the opposite results in the second and third trimesters. The plasma afamin levels in pregnant women with PE in the first, second, and third trimesters were significantly higher than those in healthy pregnant women. Additional large-scale prospective studies are desired to verify these findings, and it is recommended that afamin should be included as a routine diagnostic test for women with GDM and PE.

SYSTEMATIC REVIEW REGISTRATION

https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=339171, identifier CRD42022339171.

Study on Chinese Farmland Ecosystem Service Value Transfer Based on Meta Analysis

An analytic database was built based on meta-regression analysis (MRA) method, mainly including ecosystem service type, farmland division, cultivated land type, value assessment method, and farmland characteristics. The feasible weighted least square (FWLS) method was adopted to comprehensively investigate the seventy observations from empirical studies. The results indicate that: (1) except the negative impact of farmland area on farmland value, such factors as paddy field, good soil conservation function, mainly providing agricultural products, and using market value method for assessment all produce positive effect on the promotion of farmland value. (2) In meta-regression analysis, the average transfer error is 36.74%, and the median transfer error is 14.59%. (3) Under the A1B, A2, B1, and B2 scenarios of IPCC SRES, it is discovered from calculation that the value changes under different scenarios have some differences, in which, the total value rises significantly under A2 scenario and will reach to 15,220 billion yuan until the year of 2100; while the total value loss is the greatest under B1 scenario and will fall to 6320 billion yuan until the year of 2100. Finally, this paper gives some suggestions for scholars to deeply study the service value of farmland ecosystem as well as for the government to formulate differentiation policies.

The Effect of Endogenous Cushing Syndrome on All-cause and Cause-specific Mortality

OBJECTIVE

We aimed to perform a systematic review and meta-analysis of all-cause and cause-specific mortality of patients with benign endogenous Cushing syndrome (CS).

METHODS

The protocol was registered in PROSPERO (CRD42017067530). PubMed, EMBASE, CINHAL, Web of Science, and Cochrane Central searches were undertaken from inception to January 2021. Outcomes were the standardized mortality ratio (SMR), proportion, and cause of deaths. The I2 test, subgroup analysis, and meta-regression were used to assess heterogeneity across studies.

RESULTS

SMR was reported in 14 articles including 3691 patients (13 Cushing disease [CD] and 7 adrenal CS [ACS] cohorts). Overall SMR was 3.0 (95% CI, 2.3-3.9; I2 = 80.5%) for all CS, 2.8 (95% CI, 2.1-3.7; I2 = 81.2%) for CD and 3.3 (95% CI, 0.5-6.6; I2 = 77.9%) for ACS. Proportion of deaths, reported in 87 articles including 19 181 CS patients (53 CD, 24 ACS, and 20 combined CS cohorts), was 0.05 (95% CI, 0.03-0.06) for all CS subtypes with meta-regression analysis revealing no differences between CS subtypes (P = .052). The proportion of deaths was 0.1 (10%) in articles published before 2000 and 0.03 (3%) in 2000 until the last search for CS (P < .001), CD (P < .001), and ACS (P = .01). The causes of death were atherosclerotic diseases and thromboembolism (43.4%), infection (12.7%), malignancy (10.6%), active disease (3.5%), adrenal insufficiency (3.0%), and suicide (2.2%). Despite improved outcomes in recent years, increased mortality from CS persists. The causes of death highlight the need to prevent and manage comorbidities in addition to treating hypercortisolism.

Association of Obesity With COVID-19 Severity and Mortality: An Updated Systemic Review, Meta-Analysis, and Meta-Regression

Background

Obesity affects the course of critical illnesses. We aimed to estimate the association of obesity with the severity and mortality in coronavirus disease 2019 (COVID-19) patients.

Data Sources

A systematic search was conducted from the inception of the COVID-19 pandemic through to 13 October 2021, on databases including Medline (PubMed), Embase, Science Web, and Cochrane Central Controlled Trials Registry. Preprint servers such as BioRxiv, MedRxiv, ChemRxiv, and SSRN were also scanned.

Study Selection and Data Extraction

Full-length articles focusing on the association of obesity and outcome in COVID-19 patients were included. Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines were used for study selection and data extraction. Our Population of interest were COVID-19 positive patients, obesity is our Intervention/Exposure point, Comparators are Non-obese vs obese patients The chief outcome of the study was the severity of the confirmed COVID-19 positive hospitalized patients in terms of admission to the intensive care unit (ICU) or the requirement of invasive mechanical ventilation/intubation with obesity. All-cause mortality in COVID-19 positive hospitalized patients with obesity was the secondary outcome of the study.

Results

In total, 3,140,413 patients from 167 studies were included in the study. Obesity was associated with an increased risk of severe disease (RR=1.52, 95% CI 1.41-1.63, p<0.001, I2 = 97%). Similarly, high mortality was observed in obese patients (RR=1.09, 95% CI 1.02-1.16, p=0.006, I2 = 97%). In multivariate meta-regression on severity, the covariate of the female gender, pulmonary disease, diabetes, older age, cardiovascular diseases, and hypertension was found to be significant and explained R2 = 40% of the between-study heterogeneity for severity. The aforementioned covariates were found to be significant for mortality as well, and these covariates collectively explained R2 = 50% of the between-study variability for mortality.

Conclusions

Our findings suggest that obesity is significantly associated with increased severity and higher mortality among COVID-19 patients. Therefore, the inclusion of obesity or its surrogate body mass index in prognostic scores and improvement of guidelines for patient care management is recommended.

Factors that Influence the Reported Sensitivity of Rapid Antigen Testing for SARS-CoV-2

Tests that detect the presence of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) antigen in clinical specimens from the upper respiratory tract can provide a rapid means of coronavirus disease 2019 (COVID-19) diagnosis and help identify individuals who may be infectious and should isolate to prevent SARS-CoV-2 transmission. This systematic review assesses the diagnostic accuracy of SARS-CoV-2 antigen detection in COVID-19 symptomatic and asymptomatic individuals compared to quantitative reverse transcription polymerase chain reaction (RT-qPCR) and summarizes antigen test sensitivity using meta-regression. In total, 83 studies were included that compared SARS-CoV-2 rapid antigen-based lateral flow testing (RALFT) to RT-qPCR for SARS-CoV-2. Generally, the quality of the evaluated studies was inconsistent; nevertheless, the overall sensitivity for RALFT was determined to be 75.0% (95% confidence interval: 71.0-78.0). Additionally, RALFT sensitivity was found to be higher for symptomatic vs. asymptomatic individuals and was higher for a symptomatic population within 7 days from symptom onset compared to a population with extended days of symptoms. Viral load was found to be the most important factor for determining SARS-CoV-2 antigen test sensitivity. Other design factors, such as specimen storage and anatomical collection type, also affect the performance of RALFT. RALFT and RT-qPCR testing both achieve high sensitivity when compared to SARS-CoV-2 viral culture.

Correlation Between Early Endpoints and Overall Survival in Non-Small-Cell Lung Cancer: A Trial-Level Meta-Analysis

Early endpoints, such as progression-free survival (PFS), are increasingly used as surrogates for overall survival (OS) to accelerate approval of novel oncology agents. Compiling trial-level data from randomized controlled trials (RCTs) could help to develop a predictive framework to ascertain correlation trends between treatment effects for early and late endpoints. Through trial-level correlation and random-effects meta-regression analysis, we assessed the relationship between hazard ratio (HR) OS and (1) HR PFS and (2) odds ratio (OR) PFS at 4 and 6 months, stratified according to the mechanism of action of the investigational product. Using multiple source databases, we compiled a data set including 81 phase II-IV RCTs (35 drugs and 156 observations) of patients with non-small-cell lung cancer. Low-to-moderate correlations were generally observed between treatment effects for early endpoints (based on PFS) and HR OS across trials of agents with different mechanisms of action. Moderate correlations were seen between treatment effects for HR PFS and HR OS across all trials, and in the programmed cell death-1/programmed cell death ligand-1 and epidermal growth factor receptor trial subsets. Although these results constitute an important step, caution is advised, as there are some limitations to our evaluation, and an additional patient-level analysis would be needed to establish true surrogacy.

Temporal trends in semen concentration and count among 327 373 Chinese healthy men from 1981 to 2019: a systematic review

STUDY QUESTION

Are there temporal trends of sperm concentration (SC) and total sperm count (TSC) in Chinese healthy males from 1981 to 2019?

SUMMARY ANSWER

Our result indicated a temporal decrease in SC and TSC among 327 373 healthy Chinese men in the recent four decades.

WHAT IS KNOWN ALREADY

A review of 61 papers reported a temporal decline in SC and TSC from 1938 to 1990. This trend was later confirmed by a systematic review of 185 published papers from 1981 to 2013. However, the majority of the included individuals were from western countries. In China, whether SC and TSC have declined remains controversial.

STUDY DESIGN, SIZE, DURATION

This systematic review of published articles used data extracted from Pubmed, Science Direct, Embase, China-National-Knowledge-Infrastructure (CNKI) and Wanfang Data to assess changes in SC and TSC in China from 1981 to 2019.

PARTICIPANTS/MATERIALS, SETTING, METHODS

A total of 111 studies including 327 373 individuals who provided semen samples from 1981 to 2019 were extracted for the present analysis. Study selection and data extraction were performed by two independent researchers. The trends in SC and TSC were analysed using liner-regression and meta-regression before and after adjusting for potential covariates. Moreover, subgroups, categorised based on geographic region, fertility status or recruitment source, were also analysed.

MAIN RESULTS AND THE ROLE OF CHANCE

SC declined significantly (slope liner-regression = -0.748 million/ml/year; P = 0.005; slope meta-regression = -0.824 million/ml/year; P < 0.001) between 1981 and 2019 in China. Trends for TSC was similar to that for SC (slope liner-regression = -2.073 million/year; P = 0.032; slope meta-regression = -2.188 million/year; P = 0.003). In subgroup meta-regression analyses, males with definite fertility had continuous declines in SC (slope northern group=-2.268, P = 0.009; slope southern group=-1.014, P = 0.009) and TSC (slope northern group=-9.675, P = 0.010; slope southern group=-3.215, P = 0.042). However, in the unselected group, where fertility status was unknown, the obvious downward trend in SC was only seen in males from Northern regions (slope = -0.836, P = 0.003). Another subgroup analysis demonstrated that obvious decreases in SC (slope = -1.432, P < 0.001) and TSC (slope=-4.315, P = 0.001) were only seen in volunteer groups but not in pre-pregnancy examination groups and other recruitment groups. The results changed minimally in multiple sensitivity analyses.

LIMITATIONS, REASONS FOR CAUTION

The validity of the meta-analysis results was limited mainly by the quality of the included studies. Additionally, our study spanned many decades and the recommended criteria for some semen parameter assessments have significantly changed, which may bring about some unavoidable bias. Moreover, the data remain insufficient especially in some provinces of China.

WIDER IMPLICATIONS OF THE FINDINGS

The present study is the first study to report significant decreases in SC and TSC in 327 373 healthy Chinese men between 1981 and 2019, indicating a serious reproductive health warning. Further studies on the causes of the declines are urgently needed.

STUDY FUNDING/COMPETING INTEREST(S)

D.Z. is supported by the National Natural Science Funding of China, Natural Science Funding of Shaanxi Province, Science Funding of Health Department, Shaanxi Province, Fundamental Research Funds for the Central University and the Project of Independent Innovative Experiment for Postgraduates in Medicine in Xi'an Jiaotong University. The authors have no conflicts of interests to declare.

TRIAL REGISTRATION NUMBER

N/A.

Evaluating the Efficacy of Therapeutic Programs on Improving Cognitive Function and Depression among Older Adults Living with Dementia in Korea

The purpose of this study was to evaluate the effect size of programs for enhancing cognition and alleviating depression in older adults with dementia. This study selected 45 cognition and 37 depression programs, which conducted pre- and post-tests and had a treatment group and a control group comprising older adults living in Korea. This study conducted a meta-regression analysis to examine the moderating effect of the program location, number of sessions, intervals, group activities, and curriculum on cognition and depression. Most programs improved cognitive function and lowered depression symptoms. The heterogeneity of the effect size was large. The effect size of the number of sessions on a cognitive function significantly increased with an increasing number of sessions. The effect size of the group activity program on cognitive function was higher. The effect of healthcare institutions on depression was lower compared to other locations. To make more effective interventions for cognition and depression, long-term and group activity programs following a comprehensive curriculum will be required. The programs of healthcare institutions are encouraged to accept the advantages of other institutions and apply them to improve the effects of the programs on depression. Future studies shall focus on establishing concrete measures to enable healthcare institutions to connect older adults with dementia with various other institutions that offer long-term group programs.

Association of lowering apolipoprotein B with cardiovascular outcomes across various lipid-lowering therapies: Systematic review and meta-analysis of trials

AIMS

The effect of therapeutic lowering of apolipoprotein B (apoB) on mortality and major adverse cardiovascular events is uncertain. It is also unclear whether these potential effects vary by different lipid-lowering strategies.

METHODS

A total of 29 randomized controlled trials were selected using PubMed, Cochrane Library and EMBASE through 2018. We selected trials of therapies which ultimately clear apolipoprotein B particles by upregulating low-density lipoprotein receptor (LDL-R) expression (statins, ezetimibe, proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors, bile acid sequestrants) or therapies which reduce apolipoprotein B independent of LDL-R (cholesteryl ester transfer protein inhibitor, fibrates, niacin, omega-3 fatty acids) with sample size of ≥1000 patients and follow-up of ≥1 year. The meta-regression and meta-analyses were constructed using a random effects model.

RESULTS

In 332,912 patients, meta-regression analyses showed relative risks of 0.95 for all-cause mortality (95% confidence interval 0.92-0.99) and 0.93 (0.88-0.98) for cardiovascular mortality for every 10 mg/dL decrease in apolipoprotein B by all interventions combined. Reduction in all-cause mortality was limited to statins (0.92 (0.86-0.98)). For MACE, the relative risk per 10 mg/dL reduction in apolipoprotein B was 0.93 (0.90-0.97) for all therapies combined, with both statin (0.88 (0.83-0.93)) and non-statin therapies (0.96 (0.94-0.99)). which clear apolipoprotein B by upregulating LDL-R showing significant reductions; whereas interventions which lower apolipoprotein B independent of LDL-R did not demonstrate this effect (1.02 (0.81-1.30)).

CONCLUSION

While both statin and established non-statin therapies (PCSK9 inhibitor and ezetimibe) reduced cardiovascular risk per decrease in apolipoprotein B, interventions which reduce apolipoprotein B independently of LDL-R were not associated with cardiovascular benefit.

Hip Osteoarthritis and Physical Workload: Influence of Study Quality on Risk Estimations-A Meta-Analysis of Epidemiological Findings

In this paper, we critically evaluate the quality of epidemiological evidence on hip osteoarthritis and workload published so far. The influence of study quality on risk estimations was analyzed in sensitivity meta-analyses and meta-regression analyses. Comprehensive searches for epidemiological studies of hip osteoarthritis and occupational workload were performed in literature databases and current reviews. All studies were assessed on the basis of study design, defined quality scores, and relevant confounders considered. In total, 34 suitable studies were identified for critical evaluation. Of these, 20 are prevalence studies and 14 incidence studies. Strong heterogeneity is observed in study design, quality level, and estimated exposure parameters. A consistent positive association between heavy physical workload and hip osteoarthritis was observed only among the male populations, not among the female populations. In general, cohort studies provided lower effect estimates than cross-sectional and population-based case-control studies. Studies with high quality scores also produced lower effect estimates than studies with low quality scores. Consideration of BMI as a confounder in published studies also yielded lower effect estimates than studies without consideration of BMI as a confounder. Our analyses indicate that high-quality studies of the association between occupational workload and hip osteoarthritis provide lower effect estimates than studies of lower quality.

Exploratory analysis of comparative clinical trials used for marketing approval in patients with type 2 diabetes in Japan

Background/objectives:

The results of phase 2 and 3 clinical trials, which justify decisions regarding marketing approval for new drugs, are used for comparison of drugs in the post-marketing phase. A number of meta-analyses of approved antidiabetics have been performed, but the heterogeneity of trials has not been fully examined. The aim of this study was to explore factors that may influence baseline HbA1c in trial samples and treatment outcomes (i.e. HbA1c reductions and effect sizes), with the goal of providing unbiased and fair retrospective comparisons between different antidiabetics.

Method:

We conducted three meta-regression analyses using 78 randomized or non-randomized comparative phase 2 or 3 trials of 24 approved antidiabetics in Japan, conducted from 1987 to 2012.

Results:

Baseline HbA1c of each arm was higher in phase 2 trials, trials with a greater number of subjects, trials with a lower proportion of male subjects, trials of combination therapy, or trials with longer subject disease duration. Entry criteria were different among drug classes and caused variations in baseline HbA1c. HbA1c reductions were larger in non-randomized trials, trials with a shorter treatment period, or trials with a lower proportion of male subjects. Effect sizes were larger in phase 2 trials, or trials of combination therapy. Larger effect sizes were observed in drugs with later market entry for alpha-glucosidase inhibitors and glinides.

Conclusion:

Baseline HbA1c, an important characteristic of subjects enrolled in trials of antidiabetics, differed significantly across trials. Differences in features of study subjects were caused by explicit stipulations in eligibility criteria of HbA1c and also by other conditions (e.g. trial design, regulatory guidance, treatment guideline) and/or interventions of investigators and pharmaceutical companies that were specific to drugs and trials. Healthcare professionals should carefully consider these heterogeneities in trials used for marketing approval review when making a retrospective comparison to select the best treatment option for patients.

Chimeric Antigen Receptor T-cell (CAR T) Therapy for Hematologic and Solid Malignancies: Efficacy and Safety-A Systematic Review with Meta-Analysis

Chimeric antigen receptors T cells (CAR T) had been used for treating various tumor patients in clinic, and owned an incredible efficacy in part of malignancies. However, CAR T therapy remains controversial due to doubts about its efficacy and safety in the clinical treatment of various malignancies. A total of 997 tumor patients from 52 studies were included in this review. Eligible studies were searched and reviewed from the databases of PubMed, Web of Science, Wanfang and Clinicaltrials.gov. Then meta-analysis and subgroup analysis were used to investigate the overall response rate (ORR), complete response rate (CRR), common side effect rate (CSER) and relapse rate (RR) of CAR T therapy for patients in clinical researches, respectively. The results further confirmed that CAR T therapy had a higher response rate for hematologic malignancies. More importantly, CAR T therapy had a higher CSER in patients with hematologic malignancies, and it had a similar RR in patients with different malignancies. Cell cultured without the addition of IL-2 and total administration less than 10⁸ cells were recommended. This study offers a reference for future research regarding the application in solid and hematologic malignancies, side effects and relapse, and even the production processes of CAR T cells.

Apolipoprotein E Gene Polymorphisms Affect the Efficacy of Thiazolidinediones for Alzheimer's Disease: A Systematic Review and Meta-Analysis

Although several studies have evaluated the efficacy of thiazolidinediones (TZD) for the treatment of Alzheimer's disease (AD), investigation of the impact of apolipoprotein E (ApoE) gene polymorphisms on the efficacy of TZD remains insufficient. We investigated the impact by conducting a systematic review and meta-analysis. MEDLINE, Cochrane Library, and Japana Centra Revuo Medicina were searched to identify relevant studies based on eligibility criteria. Mean differences (MD) of Alzheimer's Disease Assessment Scale-cognitive subscale (ADAS-Cog) total score with 95% confidence intervals (CI) were calculated for subgroups stratified by ApoE genotype. To evaluate the impact of ApoE gene polymorphisms, meta-regression analysis was also conducted to calculate the regression coefficient (Coef) of ApoE expression status with 95% CI. Three randomized controlled studies comparing rosiglitazone and placebo, with a total of 2381 subjects met the eligibility criteria. ApoE expression status was reported in 983 individuals (ApoE4-positive, 141; ApoE4-negative, 842). When compared to placebo, rosiglitazone significantly decreased ADAS-Cog score in ApoE4-negative individuals (MD, -1.37; 95% CI, -2.09 to -0.65), but significantly increased ADAS-Cog score in ApoE4-positive individuals (MD, 2.18; 95% CI, 0.52 to 3.85). The meta-regression analysis showed a significant association between efficacy and ApoE expression status (Coef, 3.55; 95% CI, 1.42 to 5.68). Although the present results should be interpreted with caution because of the limited number of studies, our findings suggest that ApoE gene polymorphisms impact the efficacy of rosiglitazone for AD patients. This finding would provide useful information for the development of new agents for AD.

Heterogeneous estimates of influenza virus types A and B in the elderly: Results of a meta-regression analysis

Influenza has many age‐dependent characteristics. A previous systematic review of randomized controlled trials showed that the detection rate of influenza B was higher in children than in non‐elderly adults. However, no comprehensive reviews have targeted the elderly, who carry the main burden of disease. We aimed to quantify the relative detection rates of virus types A and B among the elderly, to identify factors affecting these proportions, and to compare type distribution among seniors and younger age‐classes. A comprehensive literature search was conducted to identify multiseason studies reporting A and B virus type distributions in the elderly. A random‐effects meta‐analysis was planned to quantify the prevalence of type B among elderly subjects with laboratory‐confirmed influenza. Meta‐regression was then applied to explain the sources of heterogeneity. Across 27 estimates identified, the type B detection rate among seniors varied from 5% to 37%. Meta‐analysis was not feasible owing to high heterogeneity (I² = 98.5%). Meta‐regression analysis showed that study characteristics, such as number of seasons included, hemisphere, and setting, could have contributed to the heterogeneity observed. The final adjusted model showed that studies that included both outpatients and inpatients reported a significantly (P = .024) lower proportion than those involving outpatients only. The detection rate of type B among the elderly was generally lower than in children/adolescents, but not non‐elderly adults. Influenza virus type B has a relatively low detection rate in older adults, especially in settings covering both inpatients and outpatients. Public health implications are discussed.

Helicobacter pylori vacuolating cytotoxin genotypes and preneoplastic lesions or gastric cancer risk: a meta-analysis

BACKGROUND AND AIM

Disease progression to gastric cancer (GC) occurs in only a small proportion of Helicobacter pylori (H.  pylori) infected patients. The bacterium vacuolating cytotoxin A (vacA) gene polymorphisms may determine the clinical consequences. We examined the strength of this association in adult-infected populations and modeled the impact of mean age-standardized incidence rates (ASRs) of GC as a hypothesized moderator variable.

METHODS

Pooled relative risk (RR) estimates were calculated. Subgroup, sensitivity, and meta-regression analyses were conducted.

RESULTS

Totally, 33 studies (1446 cases/2697 controls) were analyzed. The vacA-s1 genotype was significantly associated with an increased risk of atrophic gastritis(AG), intestinal metaplasia(IM), and GC (RR = 1.116, 95% CI, 1.019-1.222; RR = 1.418, 95% CI, 1.035-1.942; and RR = 1.333, 95% CI, 1.115-1.593, respectively); however, the vacA m1 genotype strongly increased the risk of IM and GC, but not AG (RR = 1.571, 95% CI, 1.247-1.980 and RR = 1.431, 95% CI, 1.180-1.735, respectively). The vacA s1m1 allelic combination was linked to an increased risk of GC. The m1-type of vacA was more potent than s1 for predicting the risk of GC within the subgroups with the mean ASRs of 11/100,000-19/100,000 and less than 10/100,000. The meta-regression analysis indicated that the ASR of GC modified the association between H.  pylori genotypes and GC risk, where the estimated risk was significantly decreased with increasing the mean ASRs of GC (P-values = 0.025, 0.00009, and 0.0005 for s1, m1, and s1m1, respectively).

CONCLUSIONS

The H. pylori vacA-s1 and vacA-m1 allelic variants strongly increased susceptibility to IM and GC; however, only s1 showed an association with AG. These associations were largely influenced by geographic variations in the GC incidence rate.

Long-term outcomes of ductal carcinoma in situ of the breast: a systematic review, meta-analysis and meta-regression analysis

BACKGROUND

To summarize data on long-term ipsilateral local recurrence (LR) and breast cancer death rate (BCDR) for patients with ductal carcinoma in situ (DCIS) who received different treatments.

METHODS

Systematic review and study-level meta-analysis of prospective (n = 5) and retrospective (n = 21) studies of patients with pure DCIS and with median or mean follow-up time of ≥10 years. Meta-regression was performed to assess and adjust for effects of potential confounders - the average age of women, period of initial treatment, and of bias - follow-up duration on recurrence- and death-rates in each treatment group. LR and BCDR rates by local treatment used were reported. Outside of randomized trials, remaining studies were likely to have tailored patient treatment according to the clinical situation.

RESULTS

Nine thousand four hundred and four DCIS cases in 9391 patients with 10-year follow-up were included. The adjusted meta-regression LR rate for mastectomy was 2.6 % (95 % CI, 0.8-4.5); breast-conserving surgery with radiotherapy (RT), 13.6 % (95 % CI, 9.8-17.4); breast-conserving surgery without RT, 25.5 % (95 % CI, 18.1-32.9); and biopsy-only (residual predominately low-grade DCIS following inadequate excision), 27.8 % (95 % CI, 8.4-47.1). RT + tamoxifen (TAM) in conservation surgery (CS) patients resulted in lower LR compared to one or no adjuvant treatments: LR rate for CS + RT + TAM, 9.7 %; CS + RT(no TAM), 14.1 %; CS + TAM(no RT), 24.7 %; CS(alone), 25.1 % (linear trend for treatment P < 0.0001). Compared to CS + RT + TAM, a significantly higher invasive LR was observed for CS(alone), odds ratio (OR) 2.61 (P < 0.0001); CS + TAM(no RT), OR 2.52 (P = 0.001); CS + RT(no TAM), OR 1.59 (P = 0.022). BCDR was similar for mastectomy, breast-conserving surgery with or without RT (1.3-2.0 %) and non-significantly higher for biopsy-only (2.7 %). Additionally, the 15-year follow-up was reported where all like-studies had ≥ 15-year data sets; the biopsy-only patients had a meta-analysed total LR rate of 40.2 % and the invasive LR rate was 28.1 %. The biopsy-only patients had a ≥ 15-year BCDR (that included women with metastatic disease) of 17.9 %; the ≥ 15-year BCDR was 55.2 % for those with invasive LR.

CONCLUSIONS

More local intervention was associated with greater local control for patients with DCIS at long-term follow-up. For patients undergoing breast-conservation, invasive LR was significantly lower when two rather than one adjuvant treatment modalities were given.

Circumcision as a primary HIV preventive: extrapolating from the available data

Billions of dollars to circumcise millions of African males as an HIV infection prevention have been sought, yet the effectiveness of circumcision has not been demonstrated. Data from 109 populations comparing HIV prevalence and incidence in men based on circumcision status were evaluated using meta-regression. The impact on the association between circumcision and HIV incidence/prevalence of the HIV risk profile of the population, the circumcision rates within the population and whether the population was in Africa were assessed. No significant difference in the risk of HIV infection based on the circumcision status was seen in general populations. Studies of high-risk populations and populations with a higher prevalence of male circumcision reported significantly greater odds ratios (odds of intact man having HIV) (p < .0001). When adjusted for the impact of a high-risk population and the circumcision rate of the population, the baseline odds ratio was 0.78 (95% CI = 0.56-1.09). No consistent association between presence of HIV infection and circumcision status of adult males in general populations was found. When adjusted for other factors, having a foreskin was not a significant risk factor. This undermines the justification for using circumcision as a primary preventive for HIV infection.

Predictors of pain relief following spinal cord stimulation in chronic back and leg pain and failed back surgery syndrome: a systematic review and meta-regression analysis

We sought to assess the extent to which pain relief in chronic back and leg pain (CBLP) following spinal cord stimulation (SCS) is influenced by patient-related factors, including pain location, and technology factors. A number of electronic databases were searched with citation searching of included papers and recent systematic reviews. All study designs were included. The primary outcome was pain relief following SCS, we also sought pain score (pre- and post-SCS). Multiple predictive factors were examined: location of pain, history of back surgery, initial level of pain, litigation/worker's compensation, age, gender, duration of pain, duration of follow-up, publication year, continent of data collection, study design, quality score, method of SCS lead implant, and type of SCS lead. Between-study association in predictive factors and pain relief were assessed by meta-regression. Seventy-four studies (N = 3,025 patients with CBLP) met the inclusion criteria; 63 reported data to allow inclusion in a quantitative analysis. Evidence of substantial statistical heterogeneity (P < 0.0001) in level of pain relief following SCS was noted. The mean level of pain relief across studies was 58% (95% CI: 53% to 64%, random effects) at an average follow-up of 24 months. Multivariable meta-regression analysis showed no predictive patient or technology factors. SCS was effective in reducing pain irrespective of the location of CBLP. This review supports SCS as an effective pain relieving treatment for CBLP with predominant leg pain with or without a prior history of back surgery. Randomized controlled trials need to confirm the effectiveness and cost-effectiveness of SCS in the CLBP population with predominant low back pain.

Correlation of the BACH1 Pro919Ser polymorphism with breast cancer risk: A literature-based meta-analysis and meta-regression analysis

Recent investigations have suggested that common genetic polymorphisms in BRCA1-associated C-terminal helicase 1 (BACH1) are important in the development of breast cancer. However, individually published studies and previous meta-analyses have demonstrated inconclusive results. The aim of this meta-analysis was to derive a more precise estimation of the correlation between a common polymorphism [proline (Pro) 919 serine (Ser); rs4986764 C>T] in the BACH1 gene and susceptibility to breast cancer. A literature search of PubMed, Embase, Web of Science and Chinese BioMedicine (CBM) databases was conducted on articles published prior to March 1, 2013. Crude odds ratios (ORs) with 95% confidence intervals (CIs) were calculated. Eleven case-control studies were included with a total of 6,903 breast cancer cases and 8,154 healthy controls. The meta-analysis results revealed that the BACH1 919Ser polymorphism may be correlated with a decreased risk of breast cancer among Caucasian populations (Ser allele versus Pro allele: OR=0.90, 95% CI=0.86–0.95; Pro/Ser + Ser/Ser versus Pro/Pro: OR=0.90, 95% CI=0.84–0.98; Ser/Ser versus Pro/Pro + Pro/Ser: OR=0.84, 95% CI=0.76–0.92; Ser/Ser versus Pro/Pro: OR=0.81, 95% CI=0.73–0.91; Ser/Ser versus Pro/Ser: OR=0.86, 95% CI=0.78–0.95), although not among Asian populations. Further subgroup analyses indicated that there were significant correlations between the BACH1 919Ser polymorphism and a decreased risk of breast cancer in postmenopausal females, females with a family history of breast cancer and females without BRCA1/2 mutations. Univariate and multivariate meta-regression analyses revealed that none of the factors explained the heterogeneity (all P>0.05). The present meta-analysis suggested that the BACH1 919Ser polymorphism may decrease the risk of breast cancer among Caucasian populations, particularly in postmenopausal females with a family history of breast cancer and without BRCA1/2 mutations.

Meta-regression analysis of high-frequency ventilation vs conventional ventilation in infant respiratory distress syndrome

OBJECTIVE

There is considerable heterogeneity among randomized trials comparing high-frequency ventilation (HFV) with conventional mechanical ventilation (CMV) in premature neonates with respiratory distress syndrome. We investigated what factors explained differences in outcome among these trials.

DESIGN

Meta-regression analysis of 15 randomized trials.

MEASUREMENTS AND RESULTS

Variables were extracted to explain heterogeneity: year of publication; use of Sensormedics 3100A ventilator for HFV; time on CMV prior to start of study; gestational age; use of surfactant; high lung volume strategy in HFV; and lung protective ventilation strategy in CMV and baseline risk. Chronic lung disease (CLD) and death or CLD were outcome measures. Relative risk ratios were calculated to estimate effect sizes of explanatory variables on reported relative risks. Adjusted estimates of relative risk ratios of high lung volume strategy and lung protective ventilation strategy were 0.42 (95% CI 0.06-2.48) and 2.02 (95% CI 0.18-23.12) for CLD, respectively. The effect of gestational age was less pronounced (RRR=1.17 (95% CI 0.16-8.32) for CLD, respectively). Use of Sensormedics and prior time on CMV had the smallest effects [RRR=0.96 (95% CI 0.47-1.94) and RRR=0.85 (95% CI 0.58-1.24) for CLD, respectively)]. The same results applied to CLD or death as outcome.

CONCLUSIONS

Variation in ventilation strategies that were used in trials comparing HFV with CMV in premature neonates offered the most likely explanation for the observed differences in the outcome of these trials compared with other explanatory factors.