scholarly journals Design and implementation of observational studies to measure disease burden with a focus on stroke

2017 ◽  
Vol 13 (2) ◽  
pp. 157-165
Author(s):  
George Howard ◽  
Virginia J Howard
Keyword(s):  
Cohort Studies ◽  
Study Design ◽  
Observational Studies ◽  
Disease Burden ◽  
Epidemiological Studies ◽  
Cross Sectional ◽  
Surveillance Studies ◽  
Design And Implementation ◽  
Design Considerations ◽  
Cross Sectional Studies

Observational epidemiological studies have the dual goals of measuring disease burden and assessing the association between exposures and outcomes. This report focuses on the first of these goals and provides an overview of design considerations of commonly used approaches, specifically community surveillance studies, cross-sectional studies, and longitudinal cohort studies. Each of these designs has strengths and weaknesses, with no study design being superior in all cases. Rather, these designs are complementary to achieve a better understanding of the burden of stroke.

scholarly journals Evidence-Based Medicine, Systematic Reviews, and Guidelines in Interventional Pain Management: Part 4: Observational Studies

2009 ◽  
Vol 1;12 (1;1) ◽  
pp. 73-108 ◽  
Author(s):  
Laxmaiah Manchikanti
Keyword(s):  
Cohort Studies ◽  
Medical Research ◽  
Evidence Based Medicine ◽  
Observational Studies ◽  
Randomized Trials ◽  
Evidence Based ◽  
Cross Sectional ◽  
Cross Sectional Studies ◽  
Based Medicine ◽  
Strobe Statement

Evidence-based medicine (EBM) stresses the examination of evidence from clinical research and describes it as a shift in medical paradigms, in contrast to intuition, unsystematic clinical experience, and pathophysiologic rationale. While the importance of randomized trials has been created by the concept of the hierarchy of evidence in guiding therapy, much of the medical research is observational. There is competition, contrast, and a feeling of inferiority and uselessness for observational studies, created by a lack of understanding of medical research. However, observational studies and randomized clinical trials (RCTs) can be viewed as the steps of observation and experimentation that form the basis of the scientific methodology. Further, rational healthcare practices require knowledge about the etiology and pathogenesis, diagnosis, prognosis, and treatment of disorders. The reporting of observational research is often not detailed and clear enough with insufficient quality and poor reporting, which hampers the assessment of strengths and weaknesses of the study and the generalizability of the mixed results. Thus, design, implementation, and reporting of observational studies is crucial. The biased interpretation of results from observational studies, either in favor of or opposed to a treatment, and lack of proper understanding of observational studies, leads to a poor appraisal of the quality. Similar to the Consolidated Standards of Reporting Trials (CONSORT) statement for the reporting of randomized trials, the Strengthening of the Reporting of Observational Studies in Epidemiology (STROBE) statement was developed with recommendations to improve the quality of reporting observational studies. The STROBE statement consists of a checklist of 22 items, which relate to the title, abstract, introduction, methods, results, and discussion sections of articles. Multiple types of observational studies are conducted; however, 3 types have been highlighted in the STROBE document and also in the present review, which include cohort studies, case-controlled studies, and cross-sectional studies. This comprehensive review provides an introduction and rationale, types, design, and reporting of observational studies; outcomes assessment and data presentation and analysis; statistical analysis, results, and a discussion of observational studies. Key words: Observational studies, cohort studies, case control studies, cross-sectional studies, allocation bias, sample size, Strengthening of the Reporting of Observational Studies in Epidemiology (STROBE)

scholarly journals Associations of Whole Grain and Refined Grain Consumption With Metabolic Syndrome. A Meta-Analysis of Observational Studies

2021 ◽  
Vol 8 ◽  
Author(s):  
Hongbin Guo ◽  
Jun Ding ◽  
Jieyu Liang ◽  
Yi Zhang
Keyword(s):  
Metabolic Syndrome ◽  
Cohort Studies ◽  
Prospective Cohort ◽  
Observational Studies ◽  
Meta Analysis ◽  
Epidemiological Studies ◽  
Whole Grain ◽  
Cross Sectional ◽  
Prospective Cohort Studies ◽  
Embase Database

Background: The associations of whole grain and refined grain consumption with metabolic syndrome (MetS) has been evaluated in several epidemiological studies with conflicting results. This meta-analysis was therefore employed to further investigate the above associations.Method: We searched the PubMed, Web of Science and Embase database until March 2021 (without restriction for inclusion time), for observational studies on the associations of whole grain and refined grain consumption with MetS. The pooled relative risk (RR) of MetS for the highest vs. lowest category of whole grain and refined grain consumption, as well as their corresponding 95% confidence interval (CI) were calculated.Results: A total of 14 observational studies, which involved seven cross-sectional and seven prospective cohort studies, were identified. Specifically, nine studies were related to whole grain consumption, and the overall multi-variable adjusted RR demonstrated that the whole grain consumption was inversely associated with MetS (RR = 0.80, 95%CI: 0.67–0.97; P = 0.021). With regard to refined grain consumption, 13 studies were included. The overall multi-variable adjusted RR indicated that refined grain consumption was positively associated with MetS (RR = 1.37, 95%CI: 1.02–1.84; P = 0.036).Conclusions: The existing evidence suggests that whole grain consumption is negatively associated with MetS, whereas refined grain consumption is positively associated with MetS. Our result might be helpful to better consider the diet effect on MetS. However, more well-designed prospective cohort studies are needed to elaborate the concerned issues further.

scholarly journals Fruit and vegetable consumption and risk of depression: accumulative evidence from an updated systematic review and meta-analysis of epidemiological studies

2018 ◽  
Vol 119 (10) ◽  
pp. 1087-1101 ◽  
Author(s):  
Faezeh Saghafian ◽  
Hanieh Malmir ◽  
Parvane Saneei ◽  
Alireza Milajerdi ◽  
Bagher Larijani ◽  
...  
Keyword(s):  
Cohort Studies ◽  
Observational Studies ◽  
Vegetable Intake ◽  
Vegetable Consumption ◽  
Meta Analysis ◽  
Fruit And Vegetable Consumption ◽  
Fruit And Vegetable Intake ◽  
Fruit And Vegetable ◽  
Cross Sectional ◽  
Cross Sectional Studies

AbstractFindings from observational studies investigating the association between fruit and vegetable consumption and risk of depression were inconsistent. We conducted a systematic review and meta-analysis to summarise available data on the association between fruit and vegetable intake and depression. A systematic literature search of relevant reports published in Medline/PubMed, ISI (Web of Science), SCOPUS and Google Scholar until Oct 2017 was conducted. Data from 27 publications (sixteen cross-sectional, nine cohort and two case–control studies) on fruit, vegetables and/or total fruit and vegetable consumption in relation to depression were included in the systematic review. A total of eighteen studies that reported relative risks (RR), hazard ratios or OR for the relationship were included in the meta-analysis. The pooled RR for depression in the highest v. the lowest category of fruit intake was 0·83 (95 % CI 0·71, 0·98) in cohort studies and 0·76 (95 % CI 0·63, 0·92) in cross-sectional studies. Consumption of vegetables was also associated with a 14 % lower risk of depression (overall RR=0·86; 95 % CI 0·75, 0·98) in cohort studies and a 25 % lower risk of depression (overall RR=0·75; 95 % CI 0·62, 0·91) in cross-sectional studies. Moreover, an inverse significant association was observed between intake of total fruit and vegetables and risk of depression (overall RR=0·80; 95 % CI 0·65, 0·98) in cross-sectional studies. In a non-linear dose–response association, we failed to find any significant association between fruit or vegetable intake and risk of depression (fruit (cross-sectional studies): Pnon-linearty=0·12; vegetables (cross-sectional studies): Pnon-linearty<0·001; (cohort studies) Pnon-linearty=0·97). Meta-regression of included observational studies revealed an inverse linear association between fruit or vegetable intake and risk of depression, such that every 100-g increased intake of fruit was associated with a 3 % reduced risk of depression in cohort studies (RR=0·97; 95 % CI 0·95, 0·99). With regard to vegetable consumption, every 100-g increase in intake was associated with a 3 % reduced risk of depression in cohort studies (RR=0·97; 95 % CI 0·95, 0·98) and 5 % reduced odds in cross-sectional studies (RR=0·95; 95 % CI 0·91, 0·98). This meta-analysis of observational studies provides further evidence that fruit and vegetable intake was protectively associated with depression. This finding supports the current recommendation of increasing fruit and vegetable intake to improve mental health.

scholarly journals Caffeine Intake from Coffee or Tea and Cognitive Disorders: A Meta-Analysis of Observational Studies

2015 ◽  
Vol 44 (1) ◽  
pp. 51-63 ◽  
Author(s):  
Young-Seok Kim ◽  
Sang Mi Kwak ◽  
Seung-Kwon Myung
Keyword(s):  
Cohort Studies ◽  
Meta Analysis ◽  
Cognitive Disorders ◽  
Epidemiological Studies ◽  
Case Control ◽  
Caffeine Intake ◽  
Case Control Studies ◽  
Coffee Intake ◽  
Cross Sectional ◽  
Cross Sectional Studies

Background: Observational epidemiological studies such as cross-sectional, case-control, and cohort studies have reported inconsistent findings regarding the association between caffeine intake from coffee or tea and the risk of cognitive disorders such as dementia, Alzheimer's disease, cognitive impairment, and cognitive decline. Methods: We searched PubMed and EMBASE in September 2014. Three evaluators independently extracted and reviewed articles, based on predetermined selection criteria. Results: Out of 293 articles identified through the search and bibliographies of relevant articles, 20 epidemiological studies from 19 articles, which involved 31,479 participants (8,398 in six cross-sectional studies, 4,601 in five case-control studies, and 19,918 in nine cohort studies), were included in the final analysis. The pooled odds ratio (OR) or relative risk (RR) of caffeine intake from coffee or tea for cognitive disorders (dementia, Alzheimer's disease, cognitive impairment, and cognitive decline) was 0.82 (95% confidence interval [CI], 0.67-1.01, I2 = 63.2%) in a random-effects meta-analysis. In the subgroup meta-analysis by caffeine sources, the summary OR or RR of coffee intake was 0.83 (95% CI, 0.70-0.98; I2 = 44.8%). However, in the subgroup meta-analysis by study design, the summary estimates (RR or OR) of coffee intake for cognitive disorders were 0.70 (95% CI, 0.50-0.98; I2 = 42.0%) for cross-sectional studies, 0.82 (95% CI, 0.55-1.24; I2 = 33.4%) for case-control studies, and 0.90 (95% CI, 0.59-1.36; I2 = 60.0%) for cohort studies. Conclusions: This meta-analysis found that caffeine intake from coffee or tea was not associated with the risk of cognitive disorders.

scholarly journals Dietary patterns and CVD: a systematic review and meta-analysis of observational studies

2015 ◽  
Vol 114 (9) ◽  
pp. 1341-1359 ◽  
Author(s):  
Míriam Rodríguez-Monforte ◽  
Gemma Flores-Mateo ◽  
Emília Sánchez
Keyword(s):  
Cohort Studies ◽  
Dietary Patterns ◽  
Observational Studies ◽  
Protective Factor ◽  
Meta Analysis ◽  
Epidemiological Studies ◽  
Case Control ◽  
Case Control Studies ◽  
Chd Risk ◽  
Control Comparison

AbstractEpidemiological studies show that diet is linked to the risk of developing CVD. The objective of this meta-analysis was to estimate the association between empirically derived dietary patterns and CVD. PubMed was searched for observational studies of data-driven dietary patterns that reported outcomes of cardiovascular events. The association between dietary patterns and CVD was estimated using a random-effects meta-analysis with 95 % CI. Totally, twenty-two observational studies met the inclusion criteria. The pooled relative risk (RR) for CVD, CHD and stroke in a comparison of the highest to the lowest category of prudent/healthy dietary patterns in cohort studies was 0·69 (95 % CI 0·60, 0·78; I2=0 %), 0·83 (95 % CI 0·75, 0·92; I2=44·6 %) and 0·86 (95 % CI 0·74, 1·01; I2=59·5 %), respectively. The pooled RR of CHD in a case–control comparison of the highest to the lowest category of prudent/healthy dietary patterns was 0·71 (95 % CI 0·63, 0·80; I2=0 %). The pooled RR for CVD, CHD and stroke in a comparison of the highest to the lowest category of western dietary patterns in cohort studies was 1·14 (95 % CI 0·92, 1·42; I2=56·9 %), 1·03 (95 % CI 0·90, 1·17; I2=59·4 %) and 1·05 (95 % CI 0·91, 1·22; I2=27·6 %), respectively; in case–control studies, there was evidence of increased CHD risk. Our results support the evidence of the prudent/healthy pattern as a protective factor for CVD.

Abstract P269: Cardio-Ankle Vascular Index and the Risk of Cardiovascular Outcomes and All-cause Mortality: A Systematic Review

Circulation ◽  
2018 ◽  
Vol 137 (suppl_1) ◽  
Author(s):  
Kunihiro Matsushita ◽  
Ning Ding ◽  
Esther Kim
Keyword(s):  
Systematic Review ◽  
Arterial Stiffness ◽  
Cohort Studies ◽  
Statistical Significance ◽  
Risk Of Bias ◽  
Cvd Risk ◽  
Cross Sectional ◽  
Stiffness Evaluation ◽  
All Cause Mortality ◽  
Cross Sectional Studies

Introduction: Arterial stiffness is widely used as an index of arteriosclerosis and is associated with cardiovascular disease (CVD). Recently, cardio-ankle vascular index (CAVI) was developed as a measurement of arterial stiffness that is independent of blood pressure at the time of arterial stiffness evaluation. The associations of CAVI with CVD events and all-cause mortality have not been extensively assessed. We therefore systematically reviewed the studies reporting CAVI and relevant outcomes. Methods: We searched for both prospective and cross-sectional studies using MEDLINE, Embase, and Cochrane from inception to April 11, 2017. Two independent reviewers screened the retrieved papers, extracted relevant data and assessed the risk of bias. Any discrepancy was solved by discussion or a third reviewer. Heterogeneity among studies was assessed using the I 2 statistic. We pooled the results of studies that were sufficiently homogeneous. Results: Among 1,519 records, we identified 9 cohort studies (n=5,292) and 17 cross-sectional eligible studies (n=7,309). All 9 cohort studies reported the outcome of composited CVD (498 cases), but the categorization/modeling of CAVI was not consistent across those studies. The pooled hazard ratio (HR) of CVD for the highest vs. lowest CAVI category in 3 studies was borderline significant (pooled HR=1.34 [0.95, 1.87], p=0.092) (I 2 = 25.2%, p=0.263). For 3 studies examining the continuous association between CAVI and CVD, 1standard deviation (SD) increment of CAVI was significantly associated with CVD risk (pooled HR=1.22 [1.03, 1.45], p=0.023) (I 2 = 27.1%, p=0.253). Only 3 cohort studies investigated CAVI and all-cause mortality, and none of them reported a significant association. All 17 cross-sectional studies reported higher CAVI values in patients with CVD compared to those without CVD, with statistical significance in most studies. Conclusions: CAVI was generally higher in patients with CVD compared to their counterparts. In terms of the prospective prognostic value of CAVI, we found a limited number of studies, but they indicated a modest association between CAVI and CVD risk. Our systematic review highlighted the need for large prospective studies to assess the usefulness of CAVI as a predictor of CVD and mortality.

scholarly journals Neighbourhood socioeconomic status and overweight/obesity: a systematic review and meta-analysis of epidemiological studies

BMJ Open ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. e028238 ◽  
Author(s):  
Shimels Hussien Mohammed ◽  
Tesfa Dejenie Habtewold ◽  
Mulugeta Molla Birhanu ◽  
Tesfamichael Awoke Sissay ◽  
Balewgizie Sileshi Tegegne ◽  
...  
Keyword(s):  
Systematic Review ◽  
Socioeconomic Status ◽  
Observational Studies ◽  
Data Extraction ◽  
Meta Analysis ◽  
Epidemiological Studies ◽  
Cochrane Library ◽  
Eligibility Criteria ◽  
Cross Sectional ◽  
Neighbourhood Socioeconomic Status

ObjectiveLow neighbourhood socioeconomic status (NSES) has been linked to a higher risk of overweight/obesity, irrespective of the individual’s own socioeconomic status. No meta-analysis study has been done on the association. Thus, this study was done to synthesise the existing evidence on the association of NSES with overweight, obesity and body mass index (BMI).DesignSystematic review and meta-analysis.Data sourcesPubMed, Embase, Scopus, Cochrane Library, Web of Sciences and Google Scholar databases were searched for articles published until 25 September 2019.Eligibility criteriaEpidemiological studies, both longitudinal and cross-sectional ones, which examined the link of NSES to overweight, obesity or BMI, were included.Data extraction and synthesisData extraction was done by two reviewers, working independently. The methodological quality of included studies was assessed using the Newcastle-Ottawa Scale for the observational studies. The summary estimates of the relationships of NSES with overweight, obesity and BMI statuses were calculated with random-effects meta-analysis models. Heterogeneity was assessed by Cochran’s Q and I2 statistics. Subgroup analyses were done by age categories, continents, study designs and NSES measures. Publication bias was assessed by visual inspection of funnel plots and Egger’s regression test.ResultA total of 21 observational studies, covering 1 244 438 individuals, were included in this meta-analysis. Low NSES, compared with high NSES, was found to be associated with a 31% higher odds of overweight (pooled OR 1.31, 95% CI 1.16 to 1.47, p<0.001), a 45% higher odds of obesity (pooled OR 1.45, 95% CI 1.21 to 1.74, p<0.001) and a 1.09 kg/m2 increase in mean BMI (pooled beta=1.09, 95% CI 0.67 to 1.50, p<0.001).ConclusionNSES disparity might be contributing to the burden of overweight/obesity. Further studies are warranted, including whether addressing NSES disparity could reduce the risk of overweight/obesity.PROSPERO registration numberCRD42017063889

scholarly journals The International Classification of Functioning, Disability and Health: a systematic review of observational studies

2014 ◽  
Vol 17 (2) ◽  
pp. 437-451 ◽  
Author(s):  
Luciana Castaneda ◽  
Anke Bergmann ◽  
Ligia Bahia
Keyword(s):  
Systematic Review ◽  
Observational Studies ◽  
Qualitative Methodology ◽  
Epidemiological Studies ◽  
International Classification ◽  
International Classification Of Functioning ◽  
Disability And Health ◽  
Cross Sectional ◽  
Core Set

Objective: To systematically review the use of the International Classification of Functioning, Disability and Health (ICF) in observational studies. Methods: This study is a systematic review of articles that use the ICF in observational studies. We took into account the observational design papers available in databases such as PubMed, Lilacs and SciELO, published in English and Portuguese from January 2001 to June 2011. We excluded those in which the samples did not comprise individuals, those about children and adolescents, and qualitative methodology articles. After reading the abstracts of 265 identified articles, 65 met the inclusion criteria. Of these, 18 were excluded. The STROBE (Strengthening the Reporting of Observational Studies in Epidemiology) adapted Checklist, with 15 items needed for observational studies, was applied to the 47 remaining articles. Any paper that met 12 of these criteria was included in this systematic review. Results: 29 articles were reviewed. Regarding the ICF application methodology, the checklist was used in 31% of the articles, the core set in 31% and the ICF categories in 31%. In the remaining 7%, it was not possible to define the applied methodology. In most papers (41%), qualifiers were used in their original format. As far as the area of knowledge is concerned, most of the studies were related to Rheumatology (24%) and Orthopedics (21%). Regarding the study design, 83% of the articles used cross-sectional studies. Conclusion: Results indicate a wide scientific production related to ICF over the past 10 years. Different areas of knowledge are involved in the debate on the improvement of information on morbidity. However, there are only a few quantitative epidemiological studies involving the use of ICF. Future studies are needed to improve data related to functioning and disability.

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