Evaluation of old and new tests of heterogeneity in epidemiologic meta-analysis

Impact of sarcopenia on outcomes following lumbar spine surgery for degenerative disease: an updated systematic review and meta-analysis

PURPOSE

This study aimed to consolidate the evidence regarding the prognostic influence of sarcopenia in degenerative lumbar spine surgeries.

METHODS

A literature search of public databases was conducted up to Nov 15, 2023 using combinations of the key words "sarcopenia" and "lumbar spine surgery". Eligible studies were those that focused on adults undergoing decompression or fusion surgery for degenerative lumbar spine diseases, and compared the outcomes between patients with and without preoperative sarcopenia. Primary outcomes were change in ODI and back and leg pain VAS pain scores. Secondary outcomes were changes in Eq. 5D, JOA, SFHS-p scores, and LOS.

RESULTS

Ultimately, nine retrospective studies with a total of 993 patients were included. Sarcopenic patients exhibited significantly worse functional improvement as assessed by ODI compared to non-sarcopenic patients (pooled standardized mean difference [pSMD] = 0.53, 95% confidence interval [CI]: 0.17-0.90). Back pain (pSMD = 0.31, 95% CI:0.15-0.47) and leg pain (pSMD = 0.21, 95% CI:0.02 - 0.39) improvement were also less in sarcopenic patients. Non-sarcopenic patients had greater improvements in Eq. 5D (pSMD = 0.25) and SFHS-p (pSMD = 0.39), and shorter LOS (pSMD = 0.62).

CONCLUSIONS

As compared to patients without sarcopenia, those with sarcopenia undergoing lumbar spine surgery for degenerative diseases have lower improvements in functional ability, quality of life, physical health, pain relief and extended hospitalization compared to those without sarcopenia.

Cervical Disc Arthroplasty (CDA) versus Anterior Cervical Discectomy and Fusion (ACDF) for Two-Level Cervical Disc Degenerative Disease: An Updated Systematic Review and Meta-Analysis

Background: Anterior cervical discectomy and fusion (ACDF) and cervical disc arthroplasty (CDA) are both considered to be efficacious surgical procedures for treating cervical spondylosis in patients with or without compression myelopathy. This updated systematic review and meta-analysis aimed to compare the outcomes of these procedures for the treatment of cervical degenerative disc disease (DDD) at two contiguous levels. Methods: The PubMed, EMBASE, and Cochrane CENTRAL databases were searched up to 1 May 2023. Studies comparing the outcomes between CDA and ACDF in patients with two-level cervical DDD were eligible for inclusion. Primary outcomes were surgical success rates and secondary surgery rates. Secondary outcomes were scores on the Neck Disability Index (NDI) and Visual Analogue Scale (VAS) for neck and arm pain, as well as the Japanese Orthopaedic Association (JOA) score for the severity of cervical compression myelopathy and complication rates. Results: In total, eight studies (two RCTs, four retrospective studies, and two prospective studies) with a total of 1155 patients (CDA: 598; ACDF: 557) were included. Pooled results revealed that CDA was associated with a significantly higher overall success rate (OR, 2.710, 95% CI: 1.949-3.770) and lower secondary surgery rate (OR, 0.254, 95% CI: 0.169-0.382) compared to ACDF. In addition, complication rates were significantly lower in the CDA group than in the ACDF group (OR, 0.548, 95% CI: 0.326 to 0.919). CDA was also associated with significantly greater improvements in neck pain VAS than ACDF. No significant differences were found in improvements in the arm VAS, NDI, and JOA scores between the two procedures. Conclusions: CDA may provide better postoperative outcomes for surgical success, secondary surgery, pain reduction, and postoperative complications than ACDF for treating patients with two-level cervical DDD.

Differences in Smoking Behavior by Nativity, Race/Ethnicity, and Education among Women Diagnosed with Breast Cancer

BACKGROUND

We evaluated smoking differences across nativity and race/ethnicity among women diagnosed with breast cancer.

METHODS

In our Northern Californian pooled population of 5,653 [670 Asian, 690 Hispanic, and 4,300 non-Hispanic White (White)] women diagnosed with breast cancer, we evaluated smoking differences across nativity, race/ethnicity, and acculturation and effect modification of nativity by race/ethnicity and education.

RESULTS

Foreign-born women currently smoked less than US-born women [odds ratio (OR) = 0.46, 95% confidence limit (CL): 0.29-0.72]. Hispanic (OR = 0.50; 95% CL: 0.32-0.78) women currently smoked less than White women. Among those who ever smoked (n = 2,557), foreign-born women smoked 5.23 fewer pack-years (PY) than US-born women (95% CL: -2.75 to -7.70). Furthermore, Asian (-4.60, 95% CL: -0.81 to -8.39) and Hispanic (-6.79, 95% CL: -4.14 to -9.43) women smoked fewer PY than White women. Associations were generally suggestive of greater smoking with greater acculturation (immigration age, US years, survey language). Finally, associations for nativity differed by education but not race/ethnicity, with a higher likelihood of smoking in US-born women only among those with less than a bachelor's degree (OR = 2.84, 95% CL: 2.15-3.77; current smoking: P = 0.01, PY: P = 0.05).

CONCLUSIONS

Asian and Hispanic (vs. White) and foreign-born (vs. US-born) breast cancer survivors reported fewer smoking behaviors. Smoking differences across nativity and education were driven by higher rates of smoking in US-born women with lower educational attainment.

IMPACT

Smoking behavioral patterns were similar among breast cancer survivors and the general population, informing potential smoking interventions.

Comparison of plate versus screw internal fixation in the treatment of posterior malleolar fracture: A systematic review and meta-analysis

BACKGROUND

Treatment of posterior malleolar fracture with plate or screw fixation is still controversial. Plate fixation is considered to have better stability but more soft tissue damage; screw fixation is less invasive and may yields lesser blood loss and surgery time. We conducted this meta-analysis to explore intraoperative and postoperative efficacy between plate and screw fixation in posterior malleolar fractured patients.

METHODS

PubMed, Cochrane, Embase, Scopus and Chinese National Knowledge Infrastructure databases were searched in accordance with the Preferred Reporting Items for Systematic Review and Meta-analysis (PRISMA) guidelines. Random-effects model and 95% confidence intervals was used. The outcomes of interest were surgery time, blood loss, length of hospital stay, American Orthopedic Foot and Ankle Score (AOFAS), bone healing time, full weight bearing time, off bed ambulation time, Visual Analogue Scale (VAS), complication rate, and rate of use of syndesmosis screw etc. RESULTS: One randomized clinical trial and fifty-two retrospective cohort studies with a total of 3757 patients (1956 in screw group and 1801 in plate group) were included in the systematic review. Compared to screw group, plate group yielded significantly longer surgery time, more intraoperative blood loss, but shorter length of hospital stay, better AOFAS, better Baird Jackson score, better AOFAS and Baird Jackson excellent-good rate, shorter bone healing time, shorter time enabling full weight bearing, shorter time enabling off bed ambulation, lesser postoperative pain, lesser complication rate, lesser loosening rate, lesser malunion rate, and lesser postoperative osteoarthritis.

CONCLUSIONS

Plate fixation is a favorable alternative to screw fixation in posterior malleolar fractured patients. Although plate fixation was at risk of longer surgery time and more blood loss, it provided better postoperative functional outcome, shorter healing, weight bearing and off bed ambulation time and lesser pain compared to screw fixation.

Circulating biomarkers of oxidative stress in people with acne vulgaris: a systematic review and meta-analysis

The relationship between acne vulgaris and oxidative stress biomarkers lacks a clear consensus. This study aimed to explore the potential correlation between acne vulgaris and circulating oxidative stress biomarkers (superoxide dismutase [SOD], malondialdehyde [MDA], and total antioxidant capacity [TAC]). We searched the PubMed, Embase, and Cochrane Library databases for articles published before June 26, 2023. The literature search combined free words and the medical subject headings terms related to acne vulgaris, SOD, MDA, and TAC. Data were analyzed using Stata 15 software. Additionally, we conducted a subgroup analysis stratified by the severity of acne vulgaris. A total of 14 trials involving 1191 participants were included. Overall results revealed that acne vulgaris was associated with MDA concentrations (SMD = 1.73; 95% CI 1.05, 2.4; P < 0.001). Subgroup analyses indicated that the severity of acne vulgaris was correlated with levels of circulating biomarkers of oxidative stress. TAC concentrations were significantly lower in patients with moderate acne vulgaris compared to controls (SMD =  - 1.37; 95% CI =  - 2.15, - 0.58, P = 0.001). SOD concentrations were significantly lower (SMD =  - 2.92; 95% CI =  - 5.39, - 0.46, P = 0.02) and MDA concentrations were significantly higher (SMD = 2.26; 95% CI = 0.95, 3.57, P = 0.001) in patients with severe acne vulgaris compared to controls. Our results implied that oxidative stress may exist in acne vulgaris. Furthermore, the severity of acne vulgaris was also correlated with oxidative stress.

Combined Endoscopic Cyclophotocoagulation and Phacoemulsification Versus Phacoemulsification Alone in the Glaucoma Treatment: A Systematic Review and Meta-Analysis

The complete safety and efficacy of endoscopic cyclophotocoagulation (ECP) remain unclear in the literature and, to our knowledge, there are no current meta-analyses on phaco-ECP versus phacoemulsification alone to date. Thus, we conducted a systematic review and meta-analysis comparing these two strategies through studies, assessing the effectiveness and safety of outcomes in a population with glaucoma. The protocol for this systematic review was registered in the PROSPERO International Prospective Register of Systematic Reviews (CRD42023482376). We systematically searched PubMed, Embase, and Web of Science from inception to December 2023. A random-effects model was used for all analyses due to heterogeneity. Review Manager 5.3 (Cochrane Centre, The Cochrane Collaboration, Denmark) was used for statistical analysis. Finally, nine studies were included in this comprehensive review and a total of 5389 eyes were analyzed in our study. In comparison to the ECP and phacoemulsification group, those receiving phacoemulsification alone showed better results in best-corrected visual acuity (MD 0.09; CI 95% 0.03 to 0.16; I²=0%), but worse outcomes in intraocular pressure (IOP) (MD -1.49; 95% CI -2.29 to -0.68; I²=29%) and use medications (MD -0.75; 95% CI -0.94 to -0.56; I²=0%) in the last visit. Complication rates, both general and serious, were significantly different between the groups, indicating the potential impact of combined procedures on patient outcomes. Thus, combining ECP with phacoemulsification for glaucoma treatment showed sustained IOP reduction and decreased medication dependence. However, higher complication rates suggest careful consideration of risks. More extensive research with larger trials and longer follow-ups is needed to validate findings and address limitations, providing valuable insights into this treatment approach.

Endoscopic Versus Microscopic Type I Tympanoplasty: An Updated Systematic Review and Meta-analysis

OBJECTIVE

Our objective was to perform a systematic review and meta-analysis comparing the clinical outcomes after endoscopic and microscopic type I tympanoplasty.

STUDY DESIGN

Randomized controlled trials, two-arm prospective studies, and retrospective studies were included.

SETTING

Medline, Cochrane, EMBASE, and Google Scholar databases were searched until March 1, 2022 using the combinations of search terms: "endoscopic," "microscopic," and "tympanoplasty."

METHODS

Two independent reviewers utilized the abovementioned search strategy to identify eligible studies. If any uncertainty existed regarding eligibility, a third reviewer was consulted. Primary outcome measures were graft success rate, air-bone gap (ABG) improvement, and operative time. Secondary outcomes were the rate of need for canalplasty, the proportion of self-rated excellent cosmetic results, and pain visual analog scale (VAS).

RESULTS

Forty-three studies enrolled a total of 3712 patients who were undergoing type I tympanoplasty and were finally included. The pooled result showed endoscopic approach was significantly associated with shorter operative time (difference in means: -20.021, 95% confidence interval [CI]: -31.431 to -8.611), less need for canalplasty (odds ratio [OR]: 0.065, 95% CI: 0.026-0.164), more self-rated excellent cosmetic results (OR: 87.323, 95% CI: 26.750-285.063), and lower pain VAS (difference in means: -2.513, 95% CI: -4.737 to -0.228). No significant differences in graft success rate or ABG were observed between the two procedures.

CONCLUSION

Endoscopic type I tympanoplasty provides a similar graft success rate, improvement in ABG, and reperforation rate to microscopic tympanoplasty with a shorter operative time, better self-rated cosmetic results, and less pain. Unless contraindicated, the endoscopic approach should be the procedure of choice in type I tympanoplasty.

Efficacy and safety of iloprost in the treatment of pulmonary arterial hypertension: A systematic review and meta-analysis

BACKGROUND

The efficacy of iloprost in treating pulmonary arterial hypertension (PAH) is controversial. Adverse reactions such as hypotension may occur during treatment.

OBJECTIVES

Aim to evaluate the efficacy and safety of iloprost for PAH.

METHODS

Studies were obtained from an electronic search of the CNKI, Wanfang, VIP, SinoMed, PubMed, Medline, Embase, and Cochrane Library databases up to May 18, 2023. A meta-analysis of each study was performed using RevMan 5.4 with a 95 % confidence interval (CI). A randomized or fixed-effects model was applied according to a heterogeneity test.

RESULTS

Twelve trials involving 718 participants were selected, including 433 in five randomized controlled trials (RCTs) and 285 in seven prospective clinical trials. All the patients received iloprost inhalation. The short- and prolonged treatment groups significantly improved the 6-minute walking distance (6 MWD). The mortality and clinical deterioration incidences in the iloprost group were not significantly different from those in the control group. The mean pulmonary arterial pressure (mPAP) was reduced after 3 months of iloprost RCTs and 12 months of prospective treatment. Iloprost decreased pulmonary vascular resistance (PVR) by approximately 231.29 units, significantly increased cardiac output (CO), and improved the quality of life (QoL). The main adverse reactions to iloprost treatment were cough (17 %), headache (16.4 %), and flushing (12.4 %).

CONCLUSION

Iloprost, either used alone or as adjuvant therapy, can enhance exercise capacity, lower hemodynamic parameters, and improve long-term outcomes. However, the risk of mortality and clinical deterioration remains unknown.

The Relative Age Effect at Different Age Periods in Soccer: A Meta-Analysis

In the selection of young athletes, earlier-born adolescents often leverage their temporary biological advantage over their later-born peers from the same cohort, giving rise to the phenomenon known as the Relative Age Effect (RAE). In this study, we delved into the complexities of the RAE in soccer by reviewing 563 independent research samples across 90 articles. Our analysis showed that age period and performance level are pivotal factors influencing the magnitude of the RAE. The adolescent age period emerged as a significant RAE determinant, showcasing the highest effect size magnitudes in our findings. Among athletes of different performance levels, adult European soccer players have been extensively studied, and they have exhibited the most pronounced RAE magnitudes. Intriguingly, our findings reveal another compelling trend: the frequency of players born early versus late in the eligible birth year escalated as player performance levels increased, particularly during adolescence. Coaches and players appear to capitalize unconsciously on this maturational advantage, though this strategy wanes post-adolescence. While there are currently no penalties for this team selection practice, our findings stress the need for coaches to comprehend the ramifications of selecting athletes with an age bias We offer insights into RAE complexities, highlight the synergy of age and performance in these transitory advantages, and advance arguments for more fairly selecting and developing youth athletes.

A metabolomic investigation of serum perfluorooctane sulfonate and perfluorooctanoate

BACKGROUND

Exposures to perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA), environmentally persistent chemicals detectable in the blood of most Americans, have been associated with several health outcomes. To offer insight into their possible biologic effects, we evaluated the metabolomic correlates of circulating PFOS and PFOA among 3,647 participants in eight nested case-control serum metabolomic profiling studies from the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial.

METHODS

Metabolomic profiling was conducted by Metabolon Inc., using ultra high-performance liquid chromatography/tandem accurate mass spectrometry. We conducted study-specific multivariable linear regression analyses estimating the associations of metabolite levels with levels of PFOS or PFOA. For metabolites measured in at least 3 of 8 nested case-control studies, random effects meta-analysis was used to summarize study-specific results (1,038 metabolites in PFOS analyses and 1,100 in PFOA analyses).

RESULTS

The meta-analysis identified 51 and 38 metabolites associated with PFOS and PFOA, respectively, at a Bonferroni-corrected significance level (4.8x10-5 and 4.6x10-5, respectively). For both PFOS and PFOA, the most common types of associated metabolites were lipids (sphingolipids, fatty acid metabolites) and xenobiotics (xanthine metabolites, chemicals). Positive associations were commonly observed with lipid metabolites sphingomyelin (d18:1/18:0) (P = 2.0x10-10 and 2.0x10-8, respectively), 3-carboxy-4-methyl-5-pentyl-2-furanpropionate (P = 2.7x10-15, 1.1x10-17), and lignoceroylcarnitine (C24) (P = 2.6x10-8, 6.2x10-6). The strongest positive associations were observed for chemicals 3,5-dichloro-2,6-dihydroxybenzoic acid (P = 3.0x10-112 and 6.8x10-13, respectively) and 3-bromo-5-chloro-2,6-dihydroxybenzoic acid (P = 1.6x10-14, 2.3x10-6). Other metabolites positively associated with PFOS included D-glucose (carbohydrate), carotene diol (vitamin A metabolism), and L-alpha-aminobutyric acid (glutathione metabolism), while uric acid (purine metabolite) was positively associated with PFOA. PFOS associations were consistent even after adjusting for PFOA as a covariate, while PFOA associations were greatly attenuated with PFOS adjustment.

CONCLUSIONS

In this large metabolomic study, we observed robust positive associations with PFOS for several molecules. Further investigation of these metabolites may offer insight into PFOS-related biologic effects.

Cross-species comparative analysis of single presynapses

Comparing brain structure across species and regions enables key functional insights. Leveraging publicly available data from a novel mass cytometry-based method, synaptometry by time of flight (SynTOF), we applied an unsupervised machine learning approach to conduct a comparative study of presynapse molecular abundance across three species and three brain regions. We used neural networks and their attractive properties to model complex relationships among high dimensional data to develop a unified, unsupervised framework for comparing the profile of more than 4.5 million single presynapses among normal human, macaque, and mouse samples. An extensive validation showed the feasibility of performing cross-species comparison using SynTOF profiling. Integrative analysis of the abundance of 20 presynaptic proteins revealed near-complete separation between primates and mice involving synaptic pruning, cellular energy, lipid metabolism, and neurotransmission. In addition, our analysis revealed a strong overlap between the presynaptic composition of human and macaque in the cerebral cortex and neostriatum. Our unique approach illuminates species- and region-specific variation in presynapse molecular composition.

Effectiveness of real-time classroom interactive competition on academic performance: a systematic review and meta-analysis

In recent years, different tools have been introduced into the educational landscape to promote active participation and interaction between students and teachers through personal response systems. The evolution of this methodology has allowed students to participate in real-time by answering questions posed. Previous reviews on the effectiveness of real-time classroom interactive competition (RCIC) on academic performance have been performed; however, this research was based only on Kahoot, without considering other RCIC tools or programs. In addition, the RCIC effectiveness at different educational levels and its effect according to the duration of the intervention has not been meta-analytically analyzed until to date. The aim of this meta-analysis was to analyze the RCIC effectiveness in improving academic performance. A search focused on studies from the educational field published from 2010 until September 2022 was performed. Experimental studies with objective and valid data (scores based on tests or exams) were included. From a total of 397 studies considered potentially eligible, 23 studies met the inclusion criteria. The sample was n = 1,877 for the experimental group and n = 1,765 for the control group with an academic improvement in favor to experimental group (MD 7.34; CI [5.31-9.43]; p < 0.001). There was also significant improvement in academic performance when analyzing different educational levels and different tools. In addition, both short-term interventions (two weeks or less in duration) and long-term (from two weeks to one year in duration) were effective. Therefore, RCIC interventions seem to be an effective strategy to improve academic performance.

Impacts of long-term ambient particulate matter and gaseous pollutants on circulating biomarkers of inflammation in male and female health professionals

BACKGROUND

Systemic inflammation may serve as a biological mechanism linking air pollution to poor health but supporting evidence from studies of long-term pollutant exposure and inflammatory cytokines is inconsistent.

OBJECTIVE

We studied associations between multiple particulate matter (PM) and gaseous air pollutants and pro- and anti-inflammatory cytokines within two nationwide cohorts of men and women.

METHODS

Data were obtained from 16,151 women in the Nurses' Health Study and 7,930 men in the Health Professionals' Follow-up Study with at least one measure of circulating adiponectin, C-Reactive Protein (CRP), Interleukin-6 (IL-6) or soluble tumor necrosis-factor receptor-2 (sTNFR-2). Exposure to PM with aerodynamic diameter ≤2.5, 2.5-10, and ≤10 μm (PM2.5, PM2.5-10, PM10) and nitrogen dioxide (NO2) was estimated using spatio-temporal models and were linked to participants' addresses at the time of blood draw. Averages of the 1-, 3-, and 12-months prior to blood draw were examined. Associations between each biomarker and pollutant were estimated from linear regression models adjusted for individual and contextual covariates.

RESULTS

In adjusted models, we observed a 2.72% (95% CI: 0.43%, 5.95%), 3.11% (-0.12%, 6.45%), and 3.67% (0.19%, 7.26%) increase in CRP associated with a 10 μg/m3 increase in 1-, 3-, and 12- month averaged NO2 in women. Among men, there was a statistically significant 5.96% (95% CI: 0.07%, 12.20%), 6.99% (95% CI: 0.29%, 14.15%), and 8.33% (95% CI: 0.35%, 16.94%) increase in CRP associated with a 10 μg/m3 increase in 1-, 3-, and 12-month averaged PM2.5-10, respectively. Increasing PM2.5-10 was associated with increasing IL-6 and sTNFR-2 among men over shorter exposure durations. There were no associations with exposures to PM2.5 or PM10, or with adiponectin. Findings were robust to sensitivity analyses restricting to disease-free controls and non-movers.

CONCLUSIONS

Across multiple long-term pollutant exposures and inflammatory markers, associations were generally weak. Focusing on specific pollutant-inflammatory mechanisms may clarify pathways.

Effectiveness of Exercise in Patients with Overweight or Obesity Suffering from Knee Osteoarthritis: A Systematic Review and Meta-Analysis

OBJECTIVES

The main purpose of this study was to review the evidence about the effectiveness of exercise in patients with overweight or obesity suffering from knee osteoarthritis.

METHODS

Randomized clinical trials (RCTs) published between January 2002 and May 2022 were included.

RESULTS

A total of 64 articles were identified, of which six met the criteria for meta-analysis. The pain scale score was higher in the control group (mean difference 0.95; confidence interval 0.42-1.47; p < 0.001; I² = 44%). The physical function scale (lower scores indicate lower levels of symptoms or physical disability) presented a higher score in the control group (mean difference 3.74; confidence interval 0.85-6.53; p < 0.05; I² = 56%). Moreover, the intervention group achieved a greater distance (meters) walking in a 6 min interval (mean difference 38.18; confidence interval 20.01-56.35; p < 0.001; I² = 0%).

CONCLUSIONS

Exercise interventions seem effective in improving quality of life in people with overweight or obesity suffering from knee osteoarthritis, reducing pain and improving physical function.

The performance of using dried blood spot specimens for HIV-1 viral load testing: A systematic review and meta-analysis

BACKGROUND

Accurate routine HIV viral load testing is essential for assessing the efficacy of antiretroviral treatment (ART) regimens and the emergence of drug resistance. While the use of plasma specimens is the standard for viral load testing, its use is restricted by the limited ambient temperature stability of viral load biomarkers in whole blood and plasma during storage and transportation and the limited cold chain available between many health care facilities in resource-limited settings. Alternative specimen types and technologies, such as dried blood spots, may address these issues and increase access to viral load testing; however, their technical performance is unclear. To address this, we conducted a meta-analysis comparing viral load results from paired dried blood spot and plasma specimens analyzed with commonly used viral load testing technologies.

METHODS AND FINDINGS

Standard databases, conferences, and gray literature were searched in 2013 and 2018. Nearly all studies identified (60) were conducted between 2007 and 2018. Data from 40 of the 60 studies were included in the meta-analysis, which accounted for a total of 10,871 paired dried blood spot:plasma data points. We used random effects models to determine the bias, accuracy, precision, and misclassification for each viral load technology and to account for between-study variation. Dried blood spot specimens produced consistently higher mean viral loads across all technologies when compared to plasma specimens. However, when used to identify treatment failure, each technology compared best to plasma at a threshold of 1,000 copies/ml, the present World Health Organization recommended treatment failure threshold. Some heterogeneity existed between technologies; however, 5 technologies had a sensitivity greater than 95%. Furthermore, 5 technologies had a specificity greater than 85% yet 2 technologies had a specificity less than 60% using a treatment failure threshold of 1,000 copies/ml. The study's main limitation was the direct applicability of findings as nearly all studies to date used dried blood spot samples prepared in laboratories using precision pipetting that resulted in consistent input volumes.

CONCLUSIONS

This analysis provides evidence to support the implementation and scale-up of dried blood spot specimens for viral load testing using the same 1,000 copies/ml treatment failure threshold as used with plasma specimens. This may support improved access to viral load testing in resource-limited settings lacking the required infrastructure and cold chain storage for testing with plasma specimens.

Wide-Awake Local Anesthesia With no Tourniquet Versus General Anesthesia for the Plating of Distal Radius Fracture: A Systematic Review and Meta-Analysis

Background

Distal radius fractures are treated using open reduction and internal fixation and using general anesthesia (GA) or regional blocks. A new technique, wide-awake local anesthesia with no tourniquet (WALANT), allows this operation to be conducted in nonsedated patients without the use of tourniquets.

Objective

We analyzed whether WALANT yields better outcomes than GA in the treatment of patients with distal radius fractures.

Evidence Review

We searched the PubMed, Cochrane Library, Embase, and Scopus databases for cases of distal radius fractures treated using WALANT or GA. The outcomes of interest were duration of preparation for surgery, duration of surgery, blood loss, and length of postoperative hospitalization; visual analog scale (VAS), Mayo wrist score, and Quick Disabilities of the Arm, Shoulder and Hand (QuickDASH) questionnaire score on postoperative day 1; range of motion (ROM); time until bone union; and complication rate.

Findings

We systematically reviewed 4 studies with a total of 263 patients (128 with WALANT and 135 with GA). In comparison with GA, WALANT required less time for preparation for surgery, shorter postoperative hospitalization, and lower postoperative day 1 VAS scores; however, blood loss was greater. Functional outcomes (ROM, QuickDASH score, and Mayo wrist score), complication rates, and times until union did not differ considerably between the two methods.

Conclusion

The included studies demonstrated that durations of preparation for surgery and postoperative hospitalization were shorter and pain on postoperative day 1 was less severe with WALANT than with GA. Although blood loss in surgery was greater with WALANT, this technique is a novel and promising alternative to GA.

Serum antioxidant vitamins and respiratory morbidity and mortality: a pooled analysis

BACKGROUND

Oxidative stress plays a key role in the pathogenesis of respiratory diseases; however, studies on antioxidant vitamins and respiratory outcomes have been conflicting. We evaluated whether lower serum levels of vitamins A, C, D, and E are associated with respiratory morbidity and mortality in the U.S. adult population.

METHODS

We conducted a pooled analysis of data from the 1988-1994 and 1999-2006 National Health and Nutrition Examination Survey (participants aged ≥ 20 years). We estimated covariate-adjusted odds ratios (aOR) per interquartile decrease in each serum vitamin level to quantify associations with respiratory morbidity, and covariate-adjusted hazard ratios (aHR) to quantify associations with respiratory mortality assessed prospectively through 2015. Vitamin supplementation and smoking were evaluated as potential effect modifiers.

RESULTS

Lower serum vitamin C increased the odds of wheeze among all participants (overall aOR: 1.08, 95% CI: 1.01-1.16). Among smokers, lower serum α-tocopherol vitamin E increased the odds of wheeze (aOR: 1.11, 95% CI: 1.04-1.19) and chronic bronchitis/emphysema (aOR: 1.13, 95% CI: 1.03-1.24). Conversely, lower serum γ-tocopherol vitamin E was associated with lower odds of wheeze and chronic bronchitis/emphysema (overall aORs: 0.85, 95% CI: 0.79-0.92 and 0.85, 95% CI: 0.76-0.95, respectively). Lower serum vitamin C was associated with increased chronic lower respiratory disease (CLRD) mortality in all participants (overall aHR: 1.27, 95% CI: 1.07-1.51), whereas lower serum 25-hydroxyvitamin D (25-OHD) tended to increase mortality from CLRD and influenza/pneumonia among smokers (aHR range: 1.33-1.75). Mortality from influenza/ pneumonia increased with decreasing serum vitamin A levels in all participants (overall aHR: 1.21, 95% CI: 0.99-1.48). In pooled analysis, vitamin C deficiency and 25-OHD insufficiency were associated with mortality from influenza/pneumonia, increasing mortality risk up to twofold.

CONCLUSIONS

Our analysis of nationally representative data on over 34,000 participants showed that lower serum levels of vitamins A, C, D, and α-tocopherol vitamin E are associated with increased respiratory morbidity and/or mortality in U.S. adults. The results underscore the importance of antioxidant vitamins in respiratory health.

Prospective study of dietary intake of branched-chain amino acids and the risk of primary open-angle glaucoma

PURPOSE

Metabolomic and preclinical studies suggest that branched-chain amino acids (BCAA) may be inversely associated with neurodegenerative diseases including glaucoma. We therefore assessed the long-term association between dietary intake of BCAA and incident primary open-angle glaucoma (POAG) and POAG subtypes.

METHODS

We followed biennially participants of the Nurses' Health Study (NHS; 65 531 women: 1984-2016), Health Professionals Follow-up Study (42 254 men: 1986-2016) and NHSII (66 904 women; 1991-2017). Eligible participants were 40+ years old and reported eye examinations. Repeated validated food frequency questionnaires were used to assess dietary intake of BCAA. Incident cases of POAG and POAG subtypes defined by visual field (VF) loss and untreated intraocular pressure (IOP) were confirmed by medical record review. Multivariable-adjusted relative risks (MVRRs) and 95% confidence intervals (CIs) were estimated using Cox proportional hazards models.

RESULTS

We identified 1946 incident POAG cases. The pooled MVRRs of POAG for the highest quintile (Q5 = 17.1 g/day) versus lowest quintile (Q1 = 11.2 g/day) of total BCAA intake was 0.93 (95% CI, 0.73-1.19; p_trend  = 0.45; p_{heterogeneity by sex}  = 0.24). For subtypes of POAG defined by IOP level or POAG with only peripheral VF loss, no associations were observed for men or women (p_trend  ≥ 0.20); however, for the POAG subtype with early paracentral VF loss, there was a suggestion of an inverse association in women (MVRR_Q5versusQ1  = 0.80 [95% CI, 0.57-1.12; p_trend  = 0.12]) but not in men (MVRR_Q5versusQ1  = 1.38 [95% CI, 0.81-2.34; p_trend  = 0.28; p_{heterogeneity by sex}  = 0.06]).

CONCLUSION

Higher dietary intake of BCAA was not associated with POAG risk.

Association between miRNA-499 gene polymorphism and autoimmune diseases: A meta-analysis

Introduction

The association between miRNA-499 rs3746444 and a variety of autoimmune diseases has been reported. However, these results were contradictory and just focused on one or two autoimmune diseases. The present study aims to examine the possible association between rs3746444 polymorphism and the risk of autoimmune diseases.

Methods

The studies that evaluated the association between miRNA-499 gene polymorphism and autoimmune diseases were retrieved. Five different genetic models were used to evaluate the association. The random-effects model was used to pool the effect sizes. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated to estimate the associations. Stratification analyses were performed by ethnicity and type of autoimmune diseases. False-positive report probability (FPRP) was performed for determining noteworthy associations.

Results

Seventeen articles (twenty studies) involving 4,376 cases and 4,991 controls were identified and included in our meta-analysis. The pooled ORs of all eligible case-control studies indicated a significant association between miRNA-499 gene polymorphism and autoimmune diseases: (T vs. C: OR = 0.877; 95% CI: 0.774, 0.993; P = 0.039). Stratified analysis indicated a significant association across both Caucasian (TT vs. TC+CC: OR = 0.779; 95% CI: 0.622, 0.976; P = 0.030) and Asian (T vs. C: OR = 0.895; 95% CI: 0.808, 0.992; P = 0.035) populations. There was also a significant association in Behcet’s disease, rheumatoid arthritis, systemic lupus erythematosus, and ulcerative colitis populations.

Conclusions

Our meta-analysis suggested that the miRNA-499 rs3746444 polymorphism was associated with an elevated risk of autoimmune diseases in the overall analysis as well as Caucasian and Asian populations.

Does Hippocampal Volume in Patients with Posttraumatic Stress Disorder Vary by Trauma Type?

Posttraumatic stress disorder (PTSD) is a debilitating disorder that can develop after experiencing a traumatic event and is, in part, characterized by memory disturbances. Given its important role in learning and memory, the hippocampus has been studied extensively in PTSD using volumetric neuroimaging techniques. However, the results of these studies are mixed. The variability in findings across studies could arise from differences in samples with regard to trauma type, but this connection has not yet been formally assessed. To assess this question, we conducted (1) mixed-effects meta-analyses to replicate previous meta-analytic findings of significant differences in hippocampal volumes in PTSD groups versus two different types of control groups (trauma-exposed and -unexposed groups), and (2) mixed-effects subgroup and meta-regression analyses to determine whether trauma type moderated these hippocampal volume differences. Overall, the PTSD groups showed significantly smaller right hippocampal volumes than both control groups and significantly smaller left hippocampal volumes than trauma-unexposed control groups. Subgroup and meta-regression analyses revealed that trauma type did not moderate the effect seen between PTSD and trauma-exposed non-PTSD groups but did moderate the effect between the PTSD and trauma-unexposed control groups: studies that contained participants with PTSD related to combat trauma exhibited significantly smaller effect sizes for right hippocampal volumes compared to the interpersonal violence and "other" trauma-type groups with PTSD. These findings suggest that trauma type may moderate hippocampal volume in trauma-exposed individuals but not in those with PTSD.

Diagnostic Accuracy of Dried Plasma Spot Specimens for HIV-1 Viral Load Testing: A Systematic Review and Meta-analysis

BACKGROUND

Dried plasma spot specimens may be a viable alternative to traditional liquid plasma in field settings, but the diagnostic accuracy is not well understood.

METHODS

Standard databases (PubMed and Medline), conferences, and gray literature were searched until January 2019. The quality of evidence was evaluated using the Standards for Reporting Studies of Diagnostic Accuracy and Quality Assessment of Diagnostic Accuracy Studies-2 criteria. We used univariate and bivariate random effects models to determine misclassification, sensitivity, and specificity across multiple thresholds, overall and for each viral load technology, and to account for between-study variation.

RESULTS

We identified 23 studies for inclusion in the systematic review that compared the diagnostic accuracy of dried plasma spots with that of plasma. Primary data from 16 of the 23 studies were shared and included in the meta-analysis, representing 18 countries, totaling 1847 paired dried plasma spot:plasma data points. The mean bias of dried plasma spot specimens compared with that of plasma was 0.28 log10 copies/mL, whereas the difference in median viral load was 2.25 log10 copies/mL. More dried plasma spot values were undetectable compared with plasma values (43.6% vs. 29.8%). Analyzing all technologies together, the sensitivity and specificity of dried plasma spot specimens were >92% across all treatment failure thresholds compared and total misclassification <5.4% across all treatment failure thresholds compared. Some technologies had lower sensitivity or specificity; however, the results were typically consistent across treatment failure thresholds.

DISCUSSION

Overall, dried plasma spot specimens performed relatively well compared with plasma with sensitivity and specificity values greater than 90% and misclassification rates less than 10% across all treatment failure thresholds reviewed.

A penalization approach to random-effects meta-analysis

Systematic reviews and meta-analyses are principal tools to synthesize evidence from multiple independent sources in many research fields. The assessment of heterogeneity among collected studies is a critical step when performing a meta-analysis, given its influence on model selection and conclusions about treatment effects. A common-effect (CE) model is conventionally used when the studies are deemed homogeneous, while a random-effects (RE) model is used for heterogeneous studies. However, both models have limitations. For example, the CE model produces excessively conservative confidence intervals with low coverage probabilities when the collected studies have heterogeneous treatment effects. The RE model, on the other hand, assigns higher weights to small studies compared to the CE model. In the presence of small-study effects or publication bias, the over-weighted small studies from a RE model can lead to substantially biased overall treatment effect estimates. In addition, outlying studies may exaggerate between-study heterogeneity. This article introduces penalization methods as a compromise between the CE and RE models. The proposed methods are motivated by the penalized likelihood approach, which is widely used in the current literature to control model complexity and reduce variances of parameter estimates. We compare the existing and proposed methods with simulated data and several case studies to illustrate the benefits of the penalization methods.

Bootstrap-Based Between-Study Heterogeneity Tests in Meta-Analysis

Meta-analysis combines pertinent information from existing studies to provide an overall estimate of population parameters/effect sizes, as well as to quantify and explain the differences between studies. However, testing between-study heterogeneity is one of the most challenging tasks in meta-analysis research. Existing methods for testing heterogeneity, such as the Q test and likelihood ratio (LR) test, have been criticized for their failure to control Type I error rate and/or failure to attain enough statistical power. Although better reference distribution approximations have been proposed in the literature, their application is limited. Additionally, when the interest is to test whether the size of the heterogeneity is larger than a specific level, existing methods are far from mature. To address these issues, we propose new heterogeneity tests. Specifically, we combine bootstrap methods with existing heterogeneity tests (i.e., the maximum LR test, the restricted maximum LR test, and the Q test) to overcome the reference distribution issue and denote them as B-ML-LRT, B-REML-LRT, and B-Q, respectively. Simulation studies were conducted to examine and compare the performance of the proposed methods with the regular LR test, the regular Q test, and the Kulinskaya's improved Q test in both random- and mixed-effects meta-analyses. Based on the results of Type I error rates and statistical power, B-REML-LRT is recommended. Additionally, the improved Q test is also recommended when it is applicable. An R package boot.heterogeneity is provided to facilitate the implementation of the proposed tests.

Gastroesophageal reflux disease and asthma exacerbation: A systematic review and meta-analysis

BACKGROUND

Gastroesophageal reflux disease (GORD) is highly prevalent and often coexists with asthma exacerbation. Divergent findings about the association between the two diseases were reported. We conducted a systematic review and meta-analysis to determine whether there exists an association between GORD and asthma.

METHODS

We searched MEDLINE, EMBASE, and other databases and then performed a manual search, to identify eligible studies. Pooled odds ratios (ORs) and their 95% confidence intervals (CIs) were calculated using fixed- and random-effect models. We evaluated the quality of included studies, explored heterogeneity between studies, undertook subgroup analyses, assessed publication bias, and performed sensitivity analyses.

RESULTS

We identified 32 eligible studies, conducted in 14 countries and including a total of 1,612,361 patients of all ages. Overall, GORD shows a weak association with asthma exacerbation (OR = 1.27; 95% CI 1.18-1.35). This association was observed in cohort, case-control, and cross-sectional designs and in European as well as non-European populations. Subgroup analyses show that GORD is associated with frequent asthma exacerbations (≥3 exacerbations, OR = 1.59; 95% CI 1.13-2.24) and with exacerbations needing oral corticosteroid therapy (OR = 1.24; 95% CI 1.09-1.41). GORD pediatric patients are at higher odds of asthma exacerbation than adults. We did not detect any evidence of publication bias and the association between GORD and asthma exacerbation held in all undertaken sensitivity analyses.

CONCLUSIONS

Gastroesophageal reflux disease and asthma exacerbation are weakly associated.

Fracture-Dedicated Prosthesis Promotes the Healing Rate of Greater Tuberosity in Reverse Shoulder Arthroplasty: A Meta-Analysis

Introduction: Reverse shoulder arthroplasty (RSA) is becoming popular in the treatment of complex proximal humeral fractures (PHFs). Greater tuberosity healing may influence functional outcomes and range of motion (ROM) of shoulder after RSA. In addition, the design of prosthesis may impact the healing rate of greater tuberosity. The purpose of this study is to know: (1) does the healing of greater tuberosity affect the functional outcomes and ROM of shoulder? and (2) does the design of prosthesis affect the healing rate of greater tuberosity? Materials and Methods: PubMed, Ovid/Embase, and the Cochrane Library were searched for studies comparing the clinical outcomes between the healed groups and the non-healed groups after RSA. Results: For functional outcomes, the results showed that the healed group had better Constant scores (CSs) (p < 0.0001). For ROM, the healed group showed better flexion (p < 0.0001), abduction (p = 0.02), and external rotation (p < 0.00001) of shoulder. For the design of prosthesis, the mean healing rate of greater tuberosity (82.7%) in patients with fracture-dedicated prosthesis was higher than those (63.0%) in patients with standard prosthesis. Subgroup analyses showed that the CS (p = 0.12) and abduction (p = 0.96) of patients using fracture-dedicated prostheses were not different between the healed groups and the non-healed groups. Meta-regression showed that there was no significant relationship between the design of prosthesis and CS (p = 0.312), flexion (p = 0.422), or external rotation (p = 0.776). Conclusion: Our meta-analysis showed that the healed groups could obtain better functional outcomes and ROM than the non-healed groups. In addition, fracture-dedicated prostheses promoted the healing rate of greater tuberosity. Systematic Review Registration: https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42020157276, PROSPERO: CRD42020157276.

Association between apnea-hypopnea index and coronary artery calcification: a systematic review and meta-analysis

BACKGROUND

The present study aimed to evaluate the association between presence and severity of obstructive sleep apnoea (OSA) and the presence of subclinical coronary artery disease (CAD) as assessed by coronary calcium score.

METHODS

Medline, Cochrane, and Google Scholar databases were searched. The presence of coronary artery calcification (CAC) and CAC score were assessed.

RESULTS

Irrespective of the cut-off value of apnoea-hypopnea index (AHI) (5 or 15 events/h), patients in the OSA group had higher rate of CAC presence and mean CAC score than those in the control group. Subgroup analyses of patients monitored with home sleep apnoea testing (HSAT) or in-hospital/laboratory polysomnography showed that the OSA group had higher rate of CAC presence and mean CAC score than the control group, except in the comparison of mean CAC score between AHI ≥5 vs. <5 events/h for patients using HSAT, which was not significant. Pair-wise comparison showed that CAC score may increase with increased OSA severity.

CONCLUSIONS

In participants without symptomatic coronary disease, the presence of OSA was associated with the presence and extent of CAC. However, potential confounders such as age, gender, and BMI and the diversity of CAC scores may affect the association.

Effect of partial and total sleep deprivation on serum testosterone in healthy males: a systematic review and meta-analysis

BACKGROUND

Currently, there is no consensus on the effect of sleep deprivation on male serum testosterone. This systematic review and meta-analysis aimed to determine the association between partial/total sleep deprivation and male serum testosterone level.

METHODS

The literature related to sleep deprivation and male serum testosterone in the PubMed, Embase, and Cochrane Library databases were searched from their inception to July 15, 2021. Data were pooled using the Stata 15 software. The results were presented as standard mean differences (SMDs) with their 95% confidence intervals (CIs).

RESULTS

Eighteen studies involving 252 men were included in the systematic review and meta-analysis. The findings revealed that short-term partial sleep deprivation had no significant effect on male serum testosterone (SMD = -0.22; 95% CI: -0.5, 0.06; P = 0.13), while total sleep deprivation reduced the male testosterone levels (SMD = -0.64; 95% CI: -0.87, -0.42; P < 0.001). According to the intervention duration of total sleep deprivation, subgroup analysis was conducted by a fixed-effects model. The results revealed that the serum testosterone was significantly decreased after 24 h total sleep deprivation (SMD = - 0.67; 95% CI = - 0.93, -0.42, P < 0.001), as well as 40-48 h total sleep deprivation (SMD = - 0.74; 95% CI = - 1.22, -0.26, P = 0.002).

CONCLUSIONS

This meta-analysis revealed that total sleep deprivation (more than or equal to 24 h) reduces the male testosterone levels, while short-term partial sleep deprivation has no significant effect on male serum testosterone. Sleep duration plays a pivotal role in maintaining male serum testosterone levels.

Association between systemic lupus erythematosus and risk of cervical atypia: A meta-analysis

BACKGROUND

Previous studies showed conflicting results regarding the association between systemic lupus erythematosus (SLE) and risk of cervical atypia. Therefore, the present study aimed to make a meta-analysis to summarize results of studies regarding association between SLE and risk of cervical atypia.

METHODS

We searched for articles published before March 2021 in in the following databases: PubMed, EMBASE, Web of Science, Medline and Google Scholar. Odds ratios (ORs) and relative risks (RRs) with their 95% confidence intervals (CIs) were computed to create a pooled effect size and 95% CI using STATA 12.0 software.

RESULTS

The present meta-analysis showed that SLE was significantly associated with increased risks of cervical atypia (OR/RR = 2.94, 95% CI 2.22 to 3.89, I² = 92.1%, p < .001), cervical cancer (OR/RR = 3.13, 95% CI 2.09 to 4.70, I² = 84.7%, p < .001), squamous intraepithelial lesion (SIL) (OR/RR = 5.00, 95% CI 2.58 to 9.69, I² = 88.9%, p < .001) and low-grade SIL (OR/RR = 3.14, 95% CI 1.29 to 7.67, I² = 63.3%, p = .018) with random effects models.

CONCLUSION

In summary, findings of this meta-analysis demonstrated that SLE was associated with a higher risk of cervical pre-malignant lesions and carcinoma. It may be necessary for clinicians to remind women with SLE to screen human papillomavirus infection and be vaccinated as soon as possible. However, caution is required when interpreting our findings. Further studies, especially well-designed randomized controlled clinical trials are awaited to confirm the association between SLE and cervical atypia-associated diseases.

Association between obstructive sleep apnea and male serum testosterone: A systematic review and meta-analysis

BACKGROUND

Currently, there is no consensus on the effect of obstructive sleep apnea on male serum testosterone levels. This systematic review and meta-analysis aimed to determine the association between obstructive sleep apnea and male serum testosterone level.

METHODS

The literature related to obstructive sleep apnea and male serum testosterone in the PubMed, Embase, and Cochrane Library databases were searched from their inception to June 10, 2021. Data were pooled using the Stata 15 software. We performed a subgroup analysis of studies after matching the age and body mass index, as well as according to the severity of obstructive sleep apnea.

RESULTS

Eighteen studies involving 1823 men were included in the systematic review and meta-analysis. A significant inverse association between obstructive sleep apnea and male serum testosterone (SMD = -0.76; 95% CI: -1.18, -0.33; p = 0.001) was found. After adjusting for age and body mass index, this inverse association still existed (SMD = -0.8; 95% CI = -1.41, -0.18, p = 0.012). According to the subgroup analysis of obstructive sleep apnea severity, our results showed that serum testosterone was not significantly decreased in mild (SMD = -0.58; 95% CI = -1.88, 0.73, p = 0.386) and moderate obstructive sleep apnea patients (SMD = -0.94; 95% CI = -2.04, 0.15, p = 0.092), whereas it was significantly reduced in patients with severe obstructive sleep apnea (SMD = -1.21; 95% CI = -2.02, -0.41, p = 0.003).

CONCLUSIONS

Obstructive sleep apnea is inversely associated with male serum testosterone levels, independent of body mass index and age. Notably, the severity of obstructive sleep apnea is also correlated with male serum testosterone, which is significantly reduced in patients with severe obstructive sleep apnea.

The association of general obesity, central obesity and visceral body fat with the risk of gestational diabetes mellitus: Evidence from a systematic review and meta-analysis

BACKGROUND

Studies consistently reported that general obesity predicts gestational diabetes mellitus (GDM). However, whether other phenotypes of obesity such as central obesity and visceral adiposity might have differential associations as risk factors of GDM are less known. The objective of this study was to investigate the association of all these obesity phenotypes in developing GDM.

METHODS

PubMed, CINHAL, Embase, Scopus, Google Scholar and Web of Science were searched. Full-text research articles published in English from 1985 to February 2020 with cohort and cross-sectional studies design and reported an association between obesity and GDM were included. Case-control studies, case reports, conference abstract, women with previous metabolic disorders and articles considered general obesity only were excluded. A bias adjusted-quality effect meta-analysis was conducted to evaluate the association of these obesity phenotypes and GDM risk.

RESULTS

Twenty studies met the inclusion criteria representing data of ∼50 thousand women at the reproductive age with ∼7% prevalence of GDM. Meta-analysis of 14 datasets revealed that the three types of obesity were significantly associated with an increased risk of GDM. In addition, visceral adiposity was a stronger risk factor for GDM than other obesity phenotypes (odd ratio = 3.25, 95% confidence interval = 2.01-5.26) versus (odd ratio = 2.73, 95% confidence interval = 2.20-3.38) for general obesity and (odd ratio = 2.53, 95% confidence interval = 2.04-3.14) for central obesity.

CONCLUSION

The findings of this study suggest that general obesity, central obesity and visceral body fat were associated with an increased risk of GDM. Furthermore, the association with maternal visceral adiposity was more robust compared to general obesity and central obesity.

On ratio measures of heterogeneity for meta-analyses

As a measure of heterogeneity in meta-analysis, the coefficient of variation (CV) has been recently considered, providing researchers with a complement to the very popular I 2 measure. While I 2 measures the proportion of total variance that is due to variance of the random effects, the CV is the ratio of the standard deviation of the random effects to the effect of interest. Consequently, the CV provides a different measure of the extent of heterogeneity in a meta-analysis relative to the effect being measured. However, very large CV values can occur when the effect is small making interpretation difficult. The purpose of this article is two-fold. First, we consider variants of the CV that exist in the interval 0 , 1 which may be preferable for some researchers. Second, we provide interval estimators for the CV and its variants with excellent coverage properties. We perform simulation studies based on simulated and real data sets and draw comparisons between the methods. For both the CV and its transformations, we recommend confidence intervals using the propagating imprecision method or, as a simpler alternative but at the expense of slightly worse performance in terms of coverage, combining reduced-coverage confidence intervals for the two parameters. These interval estimators typically have better coverage properties for the CV measure than those previously considered.

Paracetamol Intake and Hematologic Malignancies: A Meta-Analysis of Observational Studies

Hematologic malignancies cause more than half a million deaths every year worldwide. Analgesics were suggested as chemopreventive agents for several cancers but so far, results from individual studies about the relationship between paracetamol (acetaminophen) use and hematologic malignancies are conflicting. Therefore, we decided to perform a systematic review and meta-analysis. We retrieved studies published in any language by systematically searching Medline, Embase, Conference Proceedings Citation Index, Open Access Theses and Dissertations, and the five regional bibliographic databases of the World Health Organization until December 2020. Pooled odds ratios (OR) and their 95% confidence intervals (CI) were calculated according to the inverse of their variances. We performed separate analyses by histologic type. We also evaluated publication bias and assessed quality. A total of 17 study units met our inclusion criteria. The results show an association of hematologic malignancies with any paracetamol intake (OR 1.49, 95% CI 1.23-1.80) and with high paracetamol intake (OR 1.77, 95% CI 1.45-2.16). By subtype, risk was higher for multiple myeloma (OR 2.13, 95% CI 1.54-2.94) for any use and OR 3.16, 95% CI 1.96-5.10 for high intake, while risk was lower and non-significant for non-Hodgkin lymphoma. This meta-analysis provides evidence that paracetamol intake may be associated with hematologic malignancies and suggests that a dose-response effect is plausible. These results are unlikely to be due to publication bias or low quality of studies. Future research should focus on assessing the dose-response relationship.

Diabetes mellitus and oral lichen planus: A systematic review and meta-analysis

OBJECTIVE

To undertake a meta-analysis of the association of Oral Lichen Planus (OLP) with diabetes, two diseases with an important impact on public health and the economy, but the evidence of which about their association is inconsistent.

METHODS

Relevant studies were localized by searching MEDLINE, EMBASE, Conference Proceedings, and other databases from inception to October 2020, without restrictions. The reference lists of included studies and of related reviews were also inspected. Global pooled odds ratios were calculated, and predefined subgroup analyses were performed. The heterogeneity between studies and publication bias was assessed and sensitivity analysis was carried out.

RESULTS

Thirty-two studies were included in the meta-analysis. Pooled ORs showed a moderate association between diabetes and OLP [OR: 1.87 (95%CI: 1.57, 2.34)]. The association is limited to studies carried out on adults only [OR: 2.12 (95%CI: 1.75, 2.57)] and is observed in all study designs. Globally, the heterogeneity was low to moderate. Studies carried out in European populations show a stronger association of diabetes and OLP than Asiatic studies [OR: 2.49 (95%CI: 1.87, 3.32) and 1.60 (95%CI: 1.25, 2.03), respectively].

CONCLUSIONS

Diabetes and OLP are moderately associated. Systematic diagnosis of diabetes in OLP patients could prove useful.

Blood eosinophil count as predictor of asthma exacerbation. A meta-analysis

BACKGROUND

Evidence about the association of high blood eosinophil count with asthma exacerbation is inconsistent and unclear. The objective of this meta-analysis was to determine whether elevated blood eosinophil count predicts asthma exacerbation.

METHODS

We searched MEDLINE, EMBASE, and additional databases, without any language restriction. We also checked the reference lists of the included studies and of relevant systematic reviews. The main outcome was the occurrence of asthma exacerbation. We calculated global pooled odds ratios (ORs) and their 95% confidence intervals (CIs) and performed predefined subgroup analyses. We appraised the quality of the studies using Newcastle-Ottawa Scale, examined the heterogeneity between studies, assessed publication bias, and carried out sensitivity analyses.

RESULTS

Among 1567 retrieved publications, 23 observational studies comprising 155,772 participants met the inclusion criteria. High blood eosinophil count was associated with higher odds of asthma exacerbation [OR: 1.31 (95% CI: 1.16, 1.49)], specifically with asthma-related outpatient visits [OR: 1.46 (95% CI: 1.25, 1.70)] and emergency department visits [OR: 1.63 (95% CI: 1.29, 2.07)]. A significant association was observed starting from an eosinophils' cutoff value of 200 cells/μl. The association was observed for cohort studies [OR: 1.30 (95%CI: 1.13, 1.49)], North American studies [OR: 1.43 (95%CI: 1.31, 1.57)], Asian populations [OR: 1.67 (95%CI: 1.34, 2.08)], children [OR: 1.38 (95%CI: 1.22, 1.56)], and studies that adjusted for inhaled corticosteroids therapy [OR: 1.42 (95%CI: 1.28, 1.56)].

CONCLUSIONS

Blood eosinophil counts ≥ 200 cells/µL are associated with asthma exacerbation. Blood eosinophil count is a modifiable factor that could be addressed in asthma management strategies.

A comparison of hypothesis tests for homogeneity in meta-analysis with focus on rare binary events

Analysis of rare binary events is an important problem for biomedical researchers. Due to the sparsity of events in such problems, meta-analysis that integrates information across multiple studies can be applied to increase the efficiency of statistical inference. Although it is critical to examine whether the effect sizes are homogeneous across all studies, a comprehensive review of homogeneity tests has been lacking, and in particular, no attention has been paid to infrequent dichotomous outcomes. We systematically review statistical methods for homogeneity testing. By conducting an extensive simulation analysis and two case studies, we examine the performance of 30 tests in meta-analysis of rare binary outcomes. When using log-odds ratio as the association measure, our simulation results suggest that there is no uniform winner. However, we recommend the test proposed by Kulinskaya and Dollinger (BMC Med Res Methodol, 2015, 15), which uses a gamma distribution to approximate the null distribution, for its generally good performance; for very rare events coupled with small within-study sample sizes, in addition to the Kulinskaya-Dollinger test, we further recommend the conditional score test based on the random-effects hypergeometric model proposed by Liang and Self (Biometrika, 1985, 72:353-358). One should be cautious about the use of the Wald tests, the Lipsitz tests (Biometrics, 1998, 54:148-160), and tests proposed by Bhaumik et al (J Am Stat Assoc, 2012, 107:555-567).

Socioeconomic status and occurrence of chronic pain: a meta-analysis

OBJECTIVE

To examine the association between socioeconomic status (SES) and the occurrence of chronic pain, defined as pain that persists or recurs for >3 months.

METHODS

We performed a structured search in Medline, Embase, WHO Global Index Medicus and Conference Proceedings Citation Index-Science databases to identify cohort and case-control studies on chronic pain and SES and its subgroups (SES combined index, educational level, income and occupational status). We extracted study characteristics, outcome measures and measures of association and their 95% CIs. Literature search, data extraction and risk of bias assessment were conducted by two independent researchers. We performed main and subgroup meta-analyses using random-effects model, and formally assessed heterogeneity and publication bias.

RESULTS

A total of 45 studies, covering a population of ∼175 000 individuals, were meta-analysed, yielding a pooled Odds Ratio (OR) of 1.32 (95% CI: 1.21, 1.44) and 1.16 (95% CI: 1.09, 1.23) for low and medium SES levels, respectively, compared with high level. We obtained similar results in all the subgroup analyses. Heterogeneity was generally moderate to high across strata, and some evidence of publication bias for low socioeconomic status was found.

CONCLUSION

Our results support a moderate increase in the risk of chronic pain for low and medium SES when compared with high SES, a feature that remained constant in all measures of exposure or outcome used. Further prospective research on populations from developing countries are needed to confirm our findings as the studies available for this meta-analysis were carried out exclusively in developed countries.

Methotrexate can prevent cardiovascular events in patients with rheumatoid arthritis: An updated meta-analysis

AIMS

The incidence of cardiovascular events (CVEs) in patients with rheumatoid arthritis (RA) is higher than that in people without RA. This may be because inflammation promotes the progression of atherosclerosis. Anti-inflammatory drugs might reduce the occurrence of CVEs in patients with RA. Methotrexate (MTX) is a conventional synthetic anti-rheumatic drug that is widely used in the treatment of RA. We performed a meta-analysis to determine whether MTX can prevent CVEs in RA patients. Then, we discussed the possibility of using MTX to prevent recurred CVEs in patients with coronary heart disease (CHD).

METHODS

We searched PubMed, Embase, Web of Science, and the Cochrane Library using the key words "methotrexate," "cardiovascular," "acute coronary syndrome," "coronary heart disease," "myocardial infarction," "angina pectoris," and "rheumatoid arthritis." The efficacy outcome was defined as a composite of CVEs, including stable angina, acute coronary syndrome, stroke, heart failure, and cardiac death.

RESULTS

A total of 10 studies and 195,416 RA patients were included in our meta-analysis, and the effect size of relative risk (RR) was pooled using a fixed effect model. The results showed that MTX prevented CVEs in RA patients (RR: 0.798, 95% CI 0.726-0.876, P = .001, I2 = 27. 9%).

CONCLUSION

MTX can prevent CVEs in RA patients, but there is not sufficient evidence for using MTX to treat patients with CHD.

On the finite sample distribution of the likelihood ratio statistic for testing heterogeneity in meta-analysis

In meta-analysis, hypothesis testing is one of the commonly used approaches for assessing whether heterogeneity exists in effects between studies. The literature concluded that the Q-statistic is clearly the best choice and criticized the performance of the likelihood ratio test in terms of the type I error control and power. However, all the criticism for the likelihood ratio test is based on the use of a mixture of two chi-square distributions with 0 and 1 degrees of freedom, which is justified only asymptotically. In this study, we develop a novel method to derive the finite sample distribution of the likelihood ratio test and restricted likelihood ratio test statistics for testing the zero variance component in the random effects model for meta-analysis. We also extend this result to the heterogeneity test when metaregression is applied. A numerical study shows that the proposed statistics have superior performance to the Q-statistic, especially when the number of studies collected for meta-analysis is small to moderate.

Prenatal Exposure to Macrolides and Risk of Congenital Malformations: A Meta-Analysis

INTRODUCTION

Macrolides are widely used during pregnancy; however, their fetal safety remains uncertain. We performed a meta-analysis to assess the relation between prenatal exposure to macrolides and occurrence of congenital malformations.

METHODS

We searched MEDLINE, EMBASE, and other databases until June 12, 2019. We assessed the quality of the studies and checked for heterogeneity and publication bias. We performed three different analyses and compared the effect of macrolides with each of the following unexposed populations: Group 1: babies unexposed to any medicine before birth, Group 2: babies exposed to non-macrolide antibiotics/non-teratogens, and Group 3: mixed population of the first and second comparators.

RESULTS

A weak association between macrolides and congenital malformation of any type was observed when macrolides were compared with the mixed population (OR_{group 3} 1.06 [95% CI 1.01-1.10]). Subgroup analysis showed that this weak association is restricted to fetus exposure in the first trimester of pregnancy (OR 1.06 [95% CI 1.01-1.11]) and to cohort studies (OR 1.07 [95% CI 1.02-1.13]). Digestive system malformations were found to be slightly associated with prenatal exposure to macrolides (OR_group 3 1.14 [95% CI 1.02-1.26]). The musculoskeletal system was also found to be potentially affected (OR_group 2 1.21 [95% CI 1.08-1.35] and OR_group 3 1.15 [95% CI 1.05-1.26]). European studies showed a slightly stronger association than American studies in these two comparisons.

CONCLUSIONS

Our study suggests a weak association between prenatal use of macrolides and congenital malformations, limited to exposure in early pregnancy, and musculoskeletal and digestive systems. In addition to studies with a larger control of confounding, risk-benefit research is needed to determine the usefulness of macrolides during pregnancy.

Higher Rate of Postoperative Complications in Delayed Achilles Tendon Repair Compared to Early Achilles Tendon Repair: A Meta-Analysis

BACKGROUND

Some authors found that delayed repair of Achilles tendon ruptures achieved similar functional outcomes when compared with acute repair of Achilles tendon ruptures. The purpose of our study was to compare functional outcomes and complication rates of acute repair to delayed repair after Achilles tendon ruptures.

METHODS

PubMed, Embase (Ovid) and the Cochrane Library were searched.

RESULTS

For Achilles tendon rupture score (ATRS), the overall result revealed that there was no significant difference in ATRS between acute repair groups and delayed repair groups (P = 0.59). For Tegner scores, Halasi scores and Achilles tendon resting angle (ATRA), there was no significant difference between the two groups (P = 0.28, P = 0.47 and P = 0.68). There was no significant difference in the subjective assessment between acute repair groups and delayed repair groups (P = 0.84). However, delayed repair groups showed a higher incidence of complications than acute repair groups (P = 0.01). Subgroup analyses showed that the mean time from injury to surgery of delayed repair groups affect the pooled result substantially. For mean time less than 28d, there was no difference in the incidence of complications between acute repair groups and delayed repair groups (P = 0.09). However, for mean time more than 28d, delayed repair groups showed a higher incidence of complications than acute repair groups (P = 0.05).

CONCLUSION

Our study showed delayed repair could obtain similar functional outcomes and subjective assessment when compared with acute repair. However, the rate of complications after delayed repair was higher than that of early repair. Further high-quality randomized controlled trials (RCT) are needed to evaluate the difference.

Allelic distribution of ABO gene in Chinese centenarians

Objective

Human ABO blood groups are determined by the alleles A, B, and O (O01 and O02) of the ABO gene and have been linked to the risks for cardiovascular diseases and cancers that affect lifespan.

We examined the genetic associations of the ABO gene and blood groups with longevity.

Methods

We inspected the frequencies of the A, B, O, and O02 alleles in a large Chinese centenarian population (n = 2201) and in middle‐aged controls (n = 2330). The single nucleotide polymorphisms were selected as allele A (rs507666), B (rs8176743, rs8176746, and rs8176749), O (rs687289), and O02 (rs688976, rs549446, and rs512770).

Results

Supported by allelic and genotypic association studies, the frequencies of blood types A, B, O, and AB in centenarian versus control participants were not statistically different: 0.2821 versus 0.2781 (χ² = 0.09, P = 0.76), 0.2867 versus 0.3060 (χ² = 2.03, P = 0.15), 0.3380 versus 0.3159 (χ² = 2.52, P = 0.11), and 0.0859 versus 0.0910 (χ² = 0.37, P = 0.54), respectively. Sex had little effect on these distributions.

Conclusion

Integrated with other previous reports, we conclude from this large Chinese cohort that genetic variants of the ABO gene and blood groups are not associated with longevity.

Frontal sinus fracture management: a systematic review and meta-analysis

A systematic review of the frontal sinus fracture management literature was undertaken to document measurable outcomes, with emphasis on complications associated with the various treatment strategies. A comprehensive electronic search was undertaken in October 2018. Randomized controlled trials (RCT), controlled clinical trials, retrospective and prospective studies describing the management of frontal sinus fractures and complications were included. Twenty-four publications were included: one reporting a prospective RCT and 23 reporting consecutive case series studies (four prospective, 19 retrospective). These included 2388 patients (84.1% male, average age 23-43 years); 50.7% of cases were due to motor vehicle accidents and 61.8% had a concomitant intracranial injury. There were six categories for anterior table reconstruction, three endoscopic surgery categories, 11 for obliteration, and six for cranialization. Forest plots demonstrating complications based on the Clavien-Dindo classification of 1 ('low') and >3 ('high') were determined for total, early, and late complications, with heterogeneous effect sizes. Fractures with a nasofrontal outflow tract (NFOT) injury without obstruction can be treated with reconstruction if displaced, or managed conservatively if undisplaced. Obliteration and cranialization should be considered when there is obstruction of the NFOT. A computed tomography scan should be performed at 6 months to evaluate re-ventilation of the sinus. Endoscopic sinus surgery is a reasonable salvage re-ventilation procedure.

Evaluation of Physical Activity and Lifestyle Interventions Focused on School Children with Obesity Using Accelerometry: A Systematic Review and Meta-Analysis

Despite the existence of global recommendations for physical activity and lifestyle to avoid childhood obesity, there are no specific recommendations for school-age children. The aim of this meta-analysis was to measure the effects of current interventions with a physical activity component on body mass index (BMI) Z-score and on the moderate and vigorous physical activity (MVPA) time, measured by accelerometry, and focused on children with obesity. Randomized controlled trial studies (RCTs) based on physical activity interventions focused on children with obesity (6 to 12 years old) from January 1991 to August 2018 were included. The post-intervention mean and standard deviation of the BMI Z-score and MVPA engaged time were extracted to calculate the results using random effects models. Of a total of 229 studies considered potentially eligible, only 10 RCTs met the inclusion criteria. There were improvements in the BMI Z-score for physical activity intervention groups, compared with non-intervention children in addition to a significant increase in time engaged in MVPA. In conclusion, interventions with a physical activity component in school-children with obesity seem to be effective at reducing BMI and producing an increase in time spent engaged in physical activity. Therefore, interventions based on physical activity should be considered one of the main strategies in treating childhood obesity.

Treating vaginitis with probiotics in non-pregnant females: A systematic review and meta-analysis

Vaginitis, also known as vulvovaginitis, is an inflammation of the vagina and vulva and a common disease in females. It is thought to be caused by vaginal dysbiosis and improved by probiotics. Bacterial vaginosis (BV) and vulvovaginal candidiasis (VVC) are the major types of vaginal infections. The present systematic review and meta-analysis aimed to clarify the efficacy of probiotics in the treatment of common vaginal infections in non-pregnant females. Literature on randomized controlled trials and two-armed prospective studies on any intervention with probiotics published until December 24th, 2018 was searched in the PubMed, Cochrane and EMBASE databases. The outcomes of interest were recurrence rate, cure rate, remission rate and normal vaginal flora restoration. Finally, a total of 30 studies on bacterial vaginosis (BV) and/or VVC were included and stratified into 3 study types based on treatment design as follows: Type I, antibiotic/probiotics vs. antibiotics/antifungals (22 studies); Type II, probiotics vs. placebo (5 studies); Type III, probiotics vs. antibiotics (3 studies). The type I studies comprised 1,788 non-pregnant females and had the highest inter-study comparability in post-treatment follow-up design and meta-analysis outcome data. Probiotics interventions were significantly associated with a lower recurrence rate of vaginitis [pooled odds ratio (OR)=0.27, 95% CI: 0.18-0.41, P<0.001] and higher cure/remission rate (pooled OR=2.28, 95% CI: 1.20-4.32, P=0.011). However, a significant increase in normal vaginal flora after probiotic treatment was observed only in BV (pooled OR=4.55, 95% CI: 1.44-14.35, P=0.01). In addition, supportive but heterogeneous results were obtained from the 6-month follow-up data of Type-I studies, different infection types and supplementary analysis of Type-II studies. In conclusion, probiotics have a significant short-term effect in the treatment of common vaginal infections in non-pregnant females. In order to evaluate the long-term effects of probiotics in common vaginal infections, it is worthwhile to perform higher-quality clinical trials in the future.

Association between pre-diagnostic leukocyte mitochondrial DNA copy number and survival among colorectal cancer patients

BACKGROUND

Mitochondrial DNA copy number (mtDNAcn) is considered a biomarker for mitochondrial function and oxidative stress. Although previous studies have suggested a potential relationship between mtDNAcn at the time of colorectal cancer (CRC) diagnosis and CRC prognosis, findings have been inconsistent, and no study has specifically investigated the association of pre-diagnostic mtDNAcn with CRC survival.

METHODS

We examined the association of pre-diagnostic leukocyte mtDNAcn (measured by qPCR) with overall and CRC-specific survival among 587 patients in Nurses' Health Study and Health Professionals Follow-Up Study. Cox models were constructed to estimate hazard ratios (HRs) and 95 % confidence intervals (95 % CIs).

RESULTS

During a mean follow-up of 10.5 years, 395 deaths were identified; 180 were due to CRC. Overall, we did not observe significant associations between mtDNAcn and either overall or CRC-specific survival among all cases or by cancer location, grade, or stage. In an exploratory stratified analysis, a suggestive inverse association of mtDNAcn and overall death risk appeared among current smokers [HR (95 % CI) for 1 SD decrease in mtDNAcn = 1.50 (0.98, 2.32), P-trend = 0.06]. Reduced mtDNAcn and lower CRC-specific death risk was observed among patients aged ≤ 70.5 at diagnosis [HR (95 % CI) for 1 SD decrease of mtDNAcn = 0.71 (0.52, 0.97), P-trend = 0.03], ≤ 5 years from blood collection to diagnosis [HR (95 % CI) for 1 SD decrease in mtDNAcn = 0.65 (0.44, 0.96), P-trend = 0.03] and those consuming a low-inflammatory diet [HR (95 % CI) for 1 SD decrease in mtDNAcn = 0.61 (0.42, 0.88), P-trend = 0.009].

CONCLUSION

no significant associations between pre-diagnostic leukocyte mtDNAcn and either overall or CRC-specific survival appeared but exploratory analysis identified potential sub-group associations.

Effect of methotrexate use on the development of type 2 diabetes in rheumatoid arthritis patients: A systematic review and meta-analysis

BACKGROUND

The high risk of cardiovascular disease is well recognized in rheumatoid arthritis. Type 2 diabetes also attributes to this increase in risk. Rheumatoid arthritis is a chronic inflammatory condition, which aggravates insulin resistance, placing the patients at a higher risk of type 2 diabetes and subsequent cardiovascular outcomes. Methotrexate treatment, as a gold standard anti-inflammatory drug in the treatment of rheumatoid arthritis has shown beneficial effects on cardiovascular health. However, its impact on type 2 diabetes is still unknown.

OBJECTIVE

To assess the strength of the association between exposure to methotrexate and the rate of development of type 2 diabetes in rheumatoid arthritis patients.

METHODS

All rheumatoid arthritis studies reporting the use of methotrexate as an exposure and type 2 diabetes as an outcome were searched until March 2020 using MEDLINE, Cochrane and Scopus databases. Studies were included if the diagnosis of rheumatoid arthritis was made according to current guidelines or by a rheumatologist, and if there was information about methotrexate exposure and the type 2 diabetes outcome. The author and an independent assessor evaluated the articles for eligibility. Meta-analyses combined relative risk estimates from each study where raw counts were available.

RESULTS

Sixteen studies reporting sufficient data for inclusion in the meta-analyses were identified. Methotrexate showed a promising effect on the risk of type 2 diabetes as this risk decreased in rheumatoid arthritis patients using methotrexate (Relative risk 0.48, 95% CI 0.16, 1.43).

CONCLUSION

Rheumatoid arthritis patients on methotrexate treatment had a lower risk of developing type 2 diabetes compared to rheumatoid arthritis patients not exposed to methotrexate. This finding highlights the need for future, randomized control trials to confirm the beneficial effect of methotrexate on type 2 diabetes in the rheumatoid arthritis population.

Cutaneous nevi and internal cancer risk: Results from two large prospective cohorts of US women

Elevated cutaneous nevus number has been linked to longer telomeres. Recently, a large systematic Mendelian randomization study identified a significant positive association between telomere length and risk of cancer. Here, we hypothesized that higher nevus count, as a phenotypic marker of longer telomere, may be associated with increased risk of internal cancer, and prospectively examined the association between nevus count and total as well as site-specific cancer risk among participants in the Nurses' Health Study (NHS, 1986-2012) and the Nurses' Health Study 2 (NHS2, 1989-2013) using Cox proportional hazards models. During 3,900,264 person-years of follow-up, we documented a total of 23,004 internal cancer cases (15,484 in the NHS and 7,520 in the NHS2). Compared to participants who had no nevi, the multivariate hazard ratios of total cancer (excluding skin cancer) were 1.06 (95% confidence interval [CI], 1.03-1.09) for women with 1-5 nevi, 1.08 (95% CI, 1.03-1.15) for those who had 6-14 nevi and 1.19 (95% CI, 1.05-1.35) for those with 15 or more nevi (p trend <0.0001). Moreover, because nevus count has been associated with risk of breast cancer previously, we conducted a secondary analysis by excluding breast cancer from the outcomes of interest. The results were very similar to those of our primary analysis. For individual cancer, most of the associations with nevus count were positive but not statistically significant. In conclusion, we identified the number of cutaneous nevi as a phenotypic marker associated with internal cancer risk, which may be explained by telomere biology.