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Journal of Exposure Science &... Feb 2021Systematic reviews are powerful tools for drawing causal inference for evidence-based decision-making. Published systematic reviews and meta-analyses of environmental... (Review)
Review
Systematic reviews are powerful tools for drawing causal inference for evidence-based decision-making. Published systematic reviews and meta-analyses of environmental and occupational epidemiology studies have increased dramatically in recent years; however, the quality and utility of published reviews are variable. Most methodologies were adapted from clinical epidemiology and have not been adequately modified to evaluate and integrate evidence from observational epidemiology studies assessing environmental and occupational hazards, especially in evaluating the quality of exposure assessments. Although many reviews conduct a systematic and transparent assessment for the potential for bias, they are often deficient in subsequently integrating across a body of evidence. A cohesive review considers the impact of the direction and magnitude of potential biases on the results, systematically evaluates important scientific issues such as study sensitivity and effect modifiers, identifies how different studies complement each other, and assesses other potential sources of heterogeneity. Given these challenges of conducting informative systematic reviews of observational studies, we provide a series of specific recommendations based on practical examples for cohesive evidence integration to reach an overall conclusion on a body of evidence to better support policy making in public health.
Topics: Causality; Epidemiologic Studies; Humans; Observational Studies as Topic; Occupational Health; Public Health
PubMed: 32415298
DOI: 10.1038/s41370-020-0228-0 -
Systematic Reviews Dec 2014Pharmacological thromboprophylaxis in the peri-operative period involves a trade-off between reduction in venous thromboembolism (VTE) and an increase in bleeding.... (Review)
Review
BACKGROUND
Pharmacological thromboprophylaxis in the peri-operative period involves a trade-off between reduction in venous thromboembolism (VTE) and an increase in bleeding. Baseline risks, in the absence of prophylaxis, for VTE and bleeding are known to vary widely between urological procedures, but their magnitude is highly uncertain. Systematic reviews and meta-analyses addressing baseline risks are uncommon, needed, and require methodological innovation. In this article, we describe the rationale and methods for a series of systematic reviews of the risks of symptomatic VTE and bleeding requiring reoperation in urological surgery.
METHODS/DESIGN
We searched MEDLINE from January 1, 2000 until April 10, 2014 for observational studies reporting on symptomatic VTE or bleeding after urological procedures. Additional studies known to experts and studies cited in relevant review articles were added. Teams of two reviewers, independently assessed articles for eligibility, evaluated risk of bias, and abstracted data. We derived best estimates of risk from the median estimates among studies rated at the lowest risk of bias. The primary endpoints were 30-day post-operative risk estimates of symptomatic VTE and bleeding requiring reoperation, stratified by procedure and patient risk factors.
DISCUSSION
This series of systematic reviews will inform clinicians and patients regarding the trade-off between VTE prevention and bleeding. Our work advances standards in systematic reviews of surgical complications, including assessment of risk of bias, criteria for arriving at best estimates of risk (including modeling of timing of events and dealing with suboptimal data reporting), dealing with subgroups at higher and lower risk of bias, and use of the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach to rate certainty in estimates of risk. The results will be incorporated in the upcoming European Association Urology Guideline on Thromboprophylaxis.
SYSTEMATIC REVIEW REGISTRATION
PROSPERO CRD42014010342.
Topics: Hemorrhage; Humans; Observational Studies as Topic; Postoperative Complications; Research Design; Thromboembolism; Urologic Surgical Procedures
PubMed: 25540016
DOI: 10.1186/2046-4053-3-150 -
Scientific Reports Mar 2021The limited availability of randomized controlled trials (RCTs) in nephrology undermines causal inferences in meta-analyses. Systematic reviews of observational studies... (Meta-Analysis)
Meta-Analysis
The limited availability of randomized controlled trials (RCTs) in nephrology undermines causal inferences in meta-analyses. Systematic reviews of observational studies have grown more common under such circumstances. We conducted systematic reviews of all comparative observational studies in nephrology from 2006 to 2016 to assess the trends in the past decade. We then focused on the meta-analyses combining observational studies and RCTs to evaluate the systematic differences in effect estimates between study designs using two statistical methods: by estimating the ratio of odds ratios (ROR) of the pooled OR obtained from observational studies versus those from RCTs and by examining the discrepancies in their statistical significance. The number of systematic reviews of observational studies in nephrology had grown by 11.7-fold in the past decade. Among 56 records combining observational studies and RCTs, ROR suggested that the estimates between study designs agreed well (ROR 1.05, 95% confidence interval 0.90-1.23). However, almost half of the reviews led to discrepant interpretations in terms of statistical significance. In conclusion, the findings based on ROR might encourage researchers to justify the inclusion of observational studies in meta-analyses. However, caution is needed, as the interpretations based on statistical significance were less concordant than those based on ROR.
Topics: Female; Humans; Kidney Diseases; Male; Nephrology; Observational Studies as Topic; Randomized Controlled Trials as Topic
PubMed: 33731727
DOI: 10.1038/s41598-021-85519-5 -
Hemodialysis International.... Jan 2023We conducted a systematic review of studies investigating lock solutions for use in non-tunneled hemodialysis catheters.
BACKGROUND
We conducted a systematic review of studies investigating lock solutions for use in non-tunneled hemodialysis catheters.
METHODS
We searched PubMed and Cochrane databases from inception to June 11, 2021. Study inclusion criteria were: randomized trial or observational study, adults (>18 years), with acute kidney injury (AKI); and temporary non-tunneled catheters. We recorded bleeding events, catheter dysfunction and complications.
RESULTS
Of 649 studies identified, 6 were included (4 randomized, 1 non-randomized trial, 1 retrospective cohort study; sample sizes 78-1496 patients). Citrate was compared to heparin in 4 studies, to saline in 1, and ethanol versus saline in 1. Event-free survival of non-tunneled catheters did not differ between groups. Catheter-related infections and adverse events were less frequent with citrate locks, but reached statistical significance in only two studies.
CONCLUSION
Existing data are too heterogeneous to enable recommending one type of catheter lock over any other for non-tunneled hemodialysis catheters.
Topics: Adult; Humans; Retrospective Studies; Central Venous Catheters; Renal Dialysis; Catheterization; Heparin; Catheter-Related Infections; Citric Acid; Citrates; Catheters, Indwelling; Observational Studies as Topic
PubMed: 36203330
DOI: 10.1111/hdi.13047 -
International Journal of Environmental... Aug 2019We conducted a systematic review to describe and summarize possible associations between the walkability index, overweight, and obesity. Systematic searches using seven...
We conducted a systematic review to describe and summarize possible associations between the walkability index, overweight, and obesity. Systematic searches using seven electronic databases and reference lists were conducted to identify papers published until December 2017. Observational studies, describing associations using regression-based statistical methods, published in English and Portuguese, reporting markers of overweight and obesity, and involving adults (≥18 years) were included. Of the 2469 references initially retrieved, ten were used for the descriptive synthesis. Seven studies showed significant inverse associations between walkability and overweight and obesity, however, all were cross-sectional studies. High risk of bias scores were observed in "selection bias" and "withdrawals and dropouts". All studies were published in high-income countries with sample sizes ranging among 75 to 649,513 participants. Weight and height as measures for determining BMI tended to be self-reported. Indicators of walkability, such as land-use mix, street connectivity and residential density were used as components of the indices. Based on this review, more studies should be conducted in low, middle, and middle-high income countries, using longitudinal designs that control neighborhood self-selection; other indicators of the neighborhood environment, such as food access, physical activity facilities, sidewalks, and safety and crime prevention should be considered.
Topics: Adult; Humans; Observational Studies as Topic; Overweight; Residence Characteristics; Walking
PubMed: 31466371
DOI: 10.3390/ijerph16173135 -
Aging Clinical and Experimental Research Sep 2023Accumulating evidence suggests that fatty acids (FAs) play an essential role in regulating skeletal muscle mass and function throughout life. This systematic review and... (Meta-Analysis)
Meta-Analysis Review
Accumulating evidence suggests that fatty acids (FAs) play an essential role in regulating skeletal muscle mass and function throughout life. This systematic review and meta-analysis aimed to examine the relationship between dietary or circulatory levels of monounsaturated FAs (MUFAs) and sarcopenia in observational studies. A comprehensive literature search was performed in three databases (PubMed, Scopus, and Web of Science) from inception until August 2022. Of 414 records, a total of 12 observational studies were identified for this review. Ten studies were meta-analysed, comprising a total of 3704 participants. The results revealed that MUFA intake is inversely associated with sarcopenia (standardized mean difference = - 0.28, 95% CI - 0.46 to - 0.11; p < 0.01). Despite the limited number of studies, our results suggest that lower MUFA intake is associated with a higher risk of sarcopenia. However, the available evidence is still insufficient and further investigations are needed to demonstrate this relationship.
Topics: Humans; Fatty Acids, Monounsaturated; Sarcopenia; Fatty Acids; Diet; Observational Studies as Topic
PubMed: 37340168
DOI: 10.1007/s40520-023-02465-0 -
Neurology India 2016Several chronic inflammatory disorders, such as rheumatoid arthritis and systemic lupus erythematosus, have been linked to an increased risk of cerebrovascular accident... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Several chronic inflammatory disorders, such as rheumatoid arthritis and systemic lupus erythematosus, have been linked to an increased risk of cerebrovascular accident (CVA), but the data on polymyalgia rheumatica (PMR) remains unclear.
MATERIALS AND METHODS
We conducted a systematic review and meta-analysis of observational studies that reported odds ratio, relative risk, hazard ratio, or standardized incidence ratio comparing the risk of CVA in patients with PMR versus non-PMR controls. Pooled risk ratio and 95% confidence interval (CI) were calculated using a random-effect, generic inverse variance method of DerSimonian and Laird.
RESULTS
Three retrospective cohort studies and one cross-sectional study were identified and included in the data analysis. We found a significantly elevated CVA risk in patients with PMR, with the pooled risk ratio of 1.87 (95% CI, 1.43-2.43). The statistical heterogeneity was high, with an I2 of 91%.
CONCLUSIONS
Our study demonstrated a statistically significantly increased CVA risk among patients with PMR.
Topics: Humans; Observational Studies as Topic; Polymyalgia Rheumatica; Risk Factors; Stroke
PubMed: 27625227
DOI: 10.4103/0028-3886.190273 -
Geriatric Nursing (New York, N.Y.) 2021The purpose of this study was to systematically examine the association between dementia and mortality among older adults with COVID-19. To do so, we conducted a search... (Meta-Analysis)
Meta-Analysis
The purpose of this study was to systematically examine the association between dementia and mortality among older adults with COVID-19. To do so, we conducted a search of 7 databases for relevant full-text articles. A cohort study and case-control study were included. A meta-analysis was performed to synthesize the pooled odds ratio with a random-effects model. We identified studies that reported mortality among older adults with dementia and non-dementia who have COVID-19. The pooled mortality rates of dementia and non-dementia older adults infected with COVID-19 were 39% (95% CI: 0.23-0.54%, I = 83.48%) and 20% (95% CI: 0.16-0.25%, I = 83.48%), respectively. Overall, dementia was the main factor influencing poor health outcomes and high rates of mortality in older adults with COVID-19 infection (odds ratio 2.96; 95% CI 2.00-4.38, I = 29.7%), respectively. Our results show that older adults with dementia with COVID-19 infection have a higher risk of mortality compared with older adults without dementia. This current study further highlights the need to provide focused care to the older adults with dementia or cognitive impairment who have COVID-19.
Topics: Aged; COVID-19; Case-Control Studies; Cohort Studies; Dementia; Humans; Observational Studies as Topic; SARS-CoV-2
PubMed: 33824009
DOI: 10.1016/j.gerinurse.2021.03.007 -
Advances in Nutrition (Bethesda, Md.) Oct 2022Gastroparesis (Gp) is a delay in gastric emptying in the absence of a mechanical obstruction and has the capacity to cause symptoms that significantly impact a patient's...
Gastroparesis (Gp) is a delay in gastric emptying in the absence of a mechanical obstruction and has the capacity to cause symptoms that significantly impact a patient's quality of life. Dietary interventions are the first-line treatment in Gp, but the efficacy of different diets is unclear. This systematic review seeks to determine the effectiveness of dietary interventions on clinical outcomes in Gp. A literature search of MEDLINE Ovid from 1 March 2008 to 1 October 2021 was conducted to identify randomized controlled trials, cohort studies, and cross-sectional studies that reported dietary interventions in Gp. From the initial search, 2789 studies resulted. These were assessed by 2 independent reviewers and selected based on the primary outcomes of interest: changes in symptom-specific patient-reported outcomes and changes in gastric emptying time. A third reviewer resolved any discrepancies. Six adult studies (185 subjects) met the inclusion criteria, whereas no pediatric study did. Five of the included studies were randomized controlled trials and one was an observational study. The systematic review suggested low-fat diets, small-particle diets, diets with isoflavones, and foods considered bland, starchy, sweet, and salty did not exacerbate Gp symptoms. Small-particle diets and diets with isoflavones were found to improve gastric emptying time in patients. Additionally, small-particle diets were shown to reduce anxiety in comparison to large-particle diets. Of the randomized controlled trials, 80% were low risk of bias and 20% were fair risk of bias. The observational study was considered fair quality. The data presented in this review suggest specific dietary interventions could potentially improve Gp symptoms and gastric emptying in adult patients, particularly low-fat and small-particle diets. For pediatric Gp, data are lacking. The limited data available highlights a critical gap in the literature.
Topics: Adult; Cross-Sectional Studies; Diet; Gastroparesis; Humans; Isoflavones; Observational Studies as Topic; Quality of Life
PubMed: 35425953
DOI: 10.1093/advances/nmac037 -
Journal of Global Health Nov 2022The association between adverse childhood experiences (ACEs) and diabetes is unclear. This systematic review and meta-analysis aims to quantify the association between... (Meta-Analysis)
Meta-Analysis
BACKGROUND
The association between adverse childhood experiences (ACEs) and diabetes is unclear. This systematic review and meta-analysis aims to quantify the association between the number and types of ACEs and diabetes during adulthood based on available observational studies.
METHODS
A comprehensive literature search of studies exploring the association between ACEs and diabetes was conducted in PubMed, Medline, and Embase databases until 15 April 2022. A random-effects model was used to pool odds ratios (ORs) and 95% confidence intervals (CIs) for the number and types of ACEs with diabetes. Regarding the association between the number of ACEs and diabetes, we used funnel plots to examine publication bias, subgroup analysis to explore sources of heterogeneity, and sensitivity analysis to explore the robustness of the pooled results.
RESULTS
A total of 49 studies were included. Individuals with higher continuous ACEs (per each additional ACE: OR = 1.06, 95% CI = 1.02-1.10), any ACE (OR = 1.22, 95% CI = 1.16-1.28), or ≥4 ACEs (OR = 1.44, 95% CI = 1.27-1.63) were at an increased risk of diabetes in adulthood when compared with individuals without ACEs. Across specific ACE types, childhood economic adversity (OR = 1.11, 95% CI = 1.04-1.19), physical abuse (OR = 1.14, 95% CI = 1.07-1.21), sexual abuse (OR = 1.25, 95% CI = 1.12-1.39), verbal abuse (OR = 1.11, 95% CI = 1.03-1.20), and incarceration (OR = 1.22, 95% CI = 1.03-1.45) were associated with diabetes. However, neglect, emotional abuse, domestic violence, parental divorce or separation, parental death, and living with a family member with substance abuse or mental disorders were not significantly associated with diabetes.
CONCLUSIONS
Individuals with ACEs may have a cumulative risk for diabetes in adulthood. It is critical to prevent ACEs and build resilience in individuals affected by ACEs.
Topics: Humans; Adult; Adverse Childhood Experiences; Risk Factors; Domestic Violence; Divorce; Diabetes Mellitus; Observational Studies as Topic
PubMed: 36318589
DOI: 10.7189/jogh.12.04082