A Method for Meta-Analysis of Epidemiological Studies

1988 ◽  
Vol 22 (10) ◽  
pp. 813-824 ◽  
Author(s):  
Thomas R. Einarson ◽  
J. Steven Leeder ◽  
Gideon Koren
Keyword(s):  
Confidence Interval ◽  
Odds Ratio ◽  
Meta Analysis ◽  
A Priori ◽  
Epidemiological Studies ◽  
Percent Confidence Interval ◽  
Case Control Studies ◽  
Chi Square ◽  
The Impact ◽  
Summary Odds Ratio

This article presents a stepwise approach for conducting a meta-analysis of epidemiological studies based on proposed guidelines. This systematic method is recommended for practitioners evaluating epidemiological studies in the literature to arrive at an overall quantitative estimate of the impact of a treatment. Bendectin is used as an illustrative example. Meta-analysts should establish a priori the purpose of the analysis and a complete protocol. This protocol should be adhered to, and all steps performed should be recorded in detail. To aid in developing such a protocol, we present methods the researcher can use to perform each of 22 steps in six major areas. The illustrative meta-analysis confirmed previous traditional narrative literature reviews that Bendectin is not related to teratogenic outcomes in humans. The overall summary odds ratio was 1.01 (χ2 = 0.05, p = 0.815) with a 95 percent confidence interval of 0.66–1.55. When the studies were separated according to study type, the summary odds ratio for cohort studies was 0.95 with a 95 percent confidence interval of 0.62–1.45. For case-control studies, the summary odds ratio was 1.27 with a 95 percent confidence interval of 0.83–1.94. The corresponding chi-square values were not statistically significant at the p = 0.05 level.

scholarly journals Circulating Insulin-Like Growth Factor-1 Level and Ovarian Cancer Risk

2016 ◽  
Vol 38 (2) ◽  
pp. 589-597 ◽  
Author(s):  
Yiyang Li ◽  
Yang Li ◽  
Jialing Zhang ◽  
Changjun Zheng ◽  
He Zhu ◽  
...  
Keyword(s):  
Ovarian Cancer ◽  
Growth Factor ◽  
Cancer Risk ◽  
Confidence Interval ◽  
Odds Ratio ◽  
Meta Analysis ◽  
Epidemiological Studies ◽  
Ovarian Cancer Risk ◽  
Insulin Like Growth Factor ◽  
Summary Odds Ratio

Background/Aims: Insulin-like growth factor-1 (IGF-1) has an important role in cells' proliferation, differentiation and apoptosis, and it may be involved in carcinogenesis. Several epidemiological studies assessed the association between circulating IGF-1 level and ovarian cancer risk, but there was still no conclusive finding. Methods: A meta-analysis of published studies was performed to assess the association between circulating IGF-1 level and ovarian cancer risk. The summary odds ratio (OR) with 95% confidence interval (95%CI) was calculated through meta-analysis to evaluate the strength of the association. Results: Five eligible studies were included into the meta-analysis, which involved a total of 2,028 cases of ovarian cancer and 4,625 controls. Meta-analysis of total 5 studies showed that high circulating IGF-1 level was correlated with decreased risk of ovarian cancer (OR = 0.84, 95%CI 0.74-0.97, P = 0.013). After adjusting for heterogeneity, high circulating IGF-1 level was still correlated with decreased risk of ovarian cancer (OR = 0.83, 95%CI 0.72-0.95, P = 0.007). Subgroup analysis by age showed that circulating IGF-1 level was not correlated with ovarian cancer risk in women both less than 55 years and more than 55 years. However, after adjusting for heterogeneity, high circulating IGF-1 level was correlated with decreased ovarian cancer risk in women less than 55 years (OR = 0.82, 95%CI 0.72-0.94, P = 0.004). Conclusion: Our meta-analysis suggests that high circulating IGF-1 level may be correlated with decreased ovarian cancer risk, especially in women less than 55 years. More studies are needed to further assess the association between circulating IGF-1 level and ovarian cancer risk in the future.

Association Between Chiropractic Use and Opioid Receipt Among Patients with Spinal Pain: A Systematic Review and Meta-analysis

Pain Medicine ◽  
2019 ◽  
Author(s):  
Kelsey L Corcoran ◽  
Lori A Bastian ◽  
Craig G Gunderson ◽  
Catherine Steffens ◽  
Alexandria Brackett ◽  
...  
Keyword(s):  
Systematic Review ◽  
Confidence Interval ◽  
Odds Ratio ◽  
Meta Analysis ◽  
Spinal Pain ◽  
Chiropractic Care ◽  
Current Evidence ◽  
Inverse Association ◽  
Case Control Studies ◽  
Opioid Prescription

Abstract Objective To investigate the current evidence to determine if there is an association between chiropractic use and opioid receipt. Design Systematic review and meta-analysis. Methods The protocol for this review was registered on PROSPERO (CRD42018095128). The MEDLINE, PubMed, EMBASE, AMED, CINAHL, and Web of Science databases were searched for relevant articles from database inception through April 18, 2018. Controlled studies, cohort studies, and case–control studies including adults with noncancer pain were eligible for inclusion. Studies reporting opioid receipt for both subjects who used chiropractic care and nonusers were included. Data extraction and risk of bias assessment were completed independently by pairs of reviewers. Meta-analysis was performed and presented as an odds ratio with 95% confidence interval. Results In all, 874 articles were identified. After detailed selection, 26 articles were reviewed in full, and six met the inclusion criteria. Five studies focused on back pain and one on neck pain. The prevalence of chiropractic care among patients with spinal pain varied between 11.3% and 51.3%. The proportion of patients receiving an opioid prescription was lower for chiropractic users (range = 12.3–57.6%) than nonusers (range = 31.2–65.9%). In a random-effects analysis, chiropractic users had a 64% lower odds of receiving an opioid prescription than nonusers (odds ratio = 0.36, 95% confidence interval = 0.30–0.43, P < 0.001, I2 = 92.8%). Conclusions This review demonstrated an inverse association between chiropractic use and opioid receipt among patients with spinal pain. Further research is warranted to assess this association and the implications it may have for case management strategies to decrease opioid use.

scholarly journals Traumatic Injury and Multiple Sclerosis: A Systematic Review and Meta-Analysis

2013 ◽  
Vol 40 (2) ◽  
pp. 168-176 ◽  
Author(s):  
Sharon A. Warren ◽  
Susan Armijo Olivo ◽  
Jorge Fuentes Contreras ◽  
Karen V. L. Turpin ◽  
Douglas P. Gross ◽  
...  
Keyword(s):  
Multiple Sclerosis ◽  
Systematic Review ◽  
Confidence Interval ◽  
Cohort Studies ◽  
Odds Ratio ◽  
Meta Analysis ◽  
Traumatic Injury ◽  
Case Control ◽  
Case Control Studies ◽  
Newcastle Ottawa Scale

A systematic review/meta-analysis of literature addressing a possible association between traumatic injury and onset of multiple sclerosis was conducted. Medline, Embase, Cochrane DSR, Ovid HealthStar, CINAHL, ISI Web of Science and Scopus were searched for analytical studies from 1950 to 2011. Two investigators independently reviewed articles for inclusion, assessing their quality using the Newcastle-Ottawa Scale. Of the 13 case-control studies included, 8 were moderate quality and 5 low; of the 3 cohort studies 2 were high and 1 moderate. Meta-analysis including moderate and low quality case-control studies produced a modest but significant odds ratio: 1.41 (95% confidence interval: 1.03, 1.93). However, when low quality studies were excluded, the resulting odds ratio was non-significant. Cohort studies produced a non-significant standardized incidence ratio of 1.00 (95% confidence interval: 0.86, 1.16). These findings support the conclusion that there is no association between traumatic injury and multiple sclerosis onset; more high quality cohort studies would help to confirm this observation.

Association between FSAP 1601G>A polymorphism and venous thromboembolism risk: A meta-analysis

2019 ◽  
Vol 35 (5) ◽  
pp. 345-353
Author(s):  
Li Da ◽  
Zhao Jiahui ◽  
Li Xiaoqiang
Keyword(s):  
Venous Thromboembolism ◽  
Confidence Interval ◽  
Odds Ratio ◽  
Web Of Science ◽  
Meta Analysis ◽  
Factor Vii ◽  
Case Control Studies ◽  
China National Knowledge Infrastructure ◽  
Bias Assessment ◽  
Knowledge Infrastructure

Objective Previous several studies have shown that factor VII-activating protease (FSAP) gene 1601G>A polymorphism is related to the occurrence of venous thromboembolism, but the results are inconsistent and controversial. Therefore, we conducted a meta-analysis to explore the association between FSAP 1601G>A polymorphism and venous thromboembolism susceptibility. Methods We managed a systematic literature search through Pubmed, Embase, Web of Science, China National Knowledge Infrastructure, and WanFang databases to collect research data related to FSAP gene 1601G>A polymorphism and susceptibility to venous thromboembolism published before May 2019. Data analysis was performed through Revman 5.3 and Stata 12.0 software, the pooled odd ratios and 95% confidence intervals were calculated. Additionally, the sensitivity analysis and publication bias assessment were also performed. Results A total of seven case–control studies were included and evaluated, including 2411 venous thromboembolism cases and 2850 controls. The meta-analysis results revealed that the FSAP 1601G>A mutation is associated with venous thromboembolism risk, and statistically significance was observed under three genetic comparison models (A: G, odds ratio: 1.33, 95% confidence interval: 1.07–1.66; GA: GG, odds ratio: 1.34, 95% confidence interval: 1.06–1.68; and GA + AA: GG, odds ratio: 1.33, 95% confidence interval: 1.06–1.66). Conclusion This study demonstrated that the FSAP 1601G>A polymorphism may be associated with venous thromboembolism susceptibility.

scholarly journals The impact of atrial fibrillation type on the risks of thromboembolic recurrence, mortality and major haemorrhage in patients with previous stroke: A systematic review and meta-analysis of observational studies

2020 ◽  
Vol 5 (2) ◽  
pp. 155-168
Author(s):  
Antonia Mentel ◽  
Terence J Quinn ◽  
Alan C Cameron ◽  
Kennedy R Lees ◽  
Azmil H Abdul-Rahim
Keyword(s):  
Atrial Fibrillation ◽  
Systematic Review ◽  
Confidence Interval ◽  
Odds Ratio ◽  
Observational Studies ◽  
Meta Analysis ◽  
Major Haemorrhage ◽  
Risk Of Bias ◽  
Previous Stroke ◽  
The Impact

Introduction There is conflicting evidence on the impact of atrial fibrillation (AF) type, i.e. non-paroxysmal AF or paroxysmal AF, on thromboembolic recurrence. The consensus of risk equivalence is greatly based on historical evidence, focussing on initial stroke risks. We conducted a systematic review and meta-analysis to describe the impact of AF type on the risk of thromboembolic recurrence, mortality and major haemorrhage in patients with previous stroke. Methods We systematically searched four multidisciplinary databases from inception to December 2018. We selected observational studies investigating clinical outcomes in patients with ischaemic stroke and AF, stratified by AF type. We assessed all included studies for risk of bias using the ‘Risk of Bias In Non-randomised Studies – of Exposures’ tool. The Comprehensive Meta-Analysis Software was used to calculate odds ratios from crude event rates. Results After reviewing 14,127 citations, we selected 108 studies for full-text screening. We extracted data from a total of 26 studies, reporting outcomes on 23,054 patients. Overall, risk of bias was moderate. The annual incidence rates of thromboembolism in patients with non-paroxysmal AF and paroxysmal AF were 7.1% (95% confidence interval: 4.2–11.7) and 5.2% (95% confidence interval: 3.2–8.2), respectively. The odds ratio for thromboembolism in patients with non-paroxysmal AF versus paroxysmal AF was 1.47 (95% confidence interval: 1.08–1.99, p = 0.013). The annual mortality rates in patients with non-paroxysmal AF and paroxysmal AF were 20.0% (95% confidence interval: 13.2–28.0) and 10.1% (95% confidence interval: 5.4–17.3), respectively, and odds ratio was 1.90 (95% confidence interval: 1.43–2.52, p < 0.001). There was no difference in rates of major haemorrhage, odds ratio  = 1.01 (95% confidence interval: 0.61–1.69, p = 0.966). Conclusion In patients with prior stroke, non-paroxysmal AF is associated with significantly higher risk of thromboembolic recurrence and mortality than paroxysmal AF. Although current guidelines make no distinction between non-paroxysmal AF and paroxysmal AF for secondary stroke prevention, future guidance and risk stratification tools may need to consider this differential risk (PROSPERO ID: CRD42019118531).

scholarly journals A Meta-Analysis for Association of Maternal Smoking with Childhood Refractive Error and Amblyopia

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Li Li ◽  
Ya Qi ◽  
Wei Shi ◽  
Yuan Wang ◽  
Wen Liu ◽  
...  
Keyword(s):  
Risk Factor ◽  
Confidence Interval ◽  
Publication Bias ◽  
Refractive Error ◽  
Odds Ratio ◽  
Maternal Smoking ◽  
Meta Analysis ◽  
Significant Heterogeneity ◽  
Chi Square ◽  
The Difference

Background. We aimed to evaluate the association between maternal smoking and the occurrence of childhood refractive error and amblyopia.Methods. Relevant articles were identified from PubMed and EMBASE up to May 2015. Combined odds ratio (OR) corresponding with its 95% confidence interval (CI) was calculated to evaluate the influence of maternal smoking on childhood refractive error and amblyopia. The heterogeneity was evaluated with the Chi-square-basedQstatistic and theI2test. Potential publication bias was finally examined by Egger’s test.Results. A total of 9 articles were included in this meta-analysis. The pooled OR showed that there was no significant association between maternal smoking and childhood refractive error. However, children whose mother smoked during pregnancy were 1.47 (95% CI: 1.12–1.93) times and 1.43 (95% CI: 1.23-1.66) times more likely to suffer from amblyopia and hyperopia, respectively, compared with children whose mother did not smoke, and the difference was significant. Significant heterogeneity was only found among studies involving the influence of maternal smoking on children’s refractive error (P<0.05;I2=69.9%). No potential publication bias was detected by Egger’s test.Conclusion. The meta-analysis suggests that maternal smoking is a risk factor for childhood hyperopia and amblyopia.

scholarly journals High parity is associated with increased risk of cervical cancer: Systematic review and meta-analysis of case-control studies

2021 ◽  
Author(s):  
Yohannes Tekalegn ◽  
Biniyam Sahiledengle ◽  
Demelash Woldeyohannes ◽  
Daniel Atlaw ◽  
Fikreab Desta ◽  
...  
Keyword(s):  
Systematic Review ◽  
Cervical Cancer ◽  
Odds Ratio ◽  
Meta Analysis ◽  
Random Effect ◽  
Epidemiological Studies ◽  
Analysis Model ◽  
Case Control Studies ◽  
High Parity ◽  
Increased Risk

Abstract Background: Cervical cancer is the fourth most common cancer among women. High parity has long been suspected with an increased risk of cervical cancer. Evidence from the existing epidemiological studies regarding the association between parity and cervical cancer is variable and inconsistent. Therefore, the objective of this systematic review and meta-analysis was to synthesize the best available evidence on the epidemiological association between parity and cervical cancer. Methods: MEDLINE/PubMed, HINARI, Google scholar, Science direct, and Cochrane Libraries were systematically searched. Cochrane Q statistics and I2 tests were performed to assess heterogeneity among included studies. Begg's test and egger's regression analysis were performed to assess publication bias. A random-effect meta-analysis model was used to compute pooled odds ratio of the association between parity and cervical cancer. Results: A total of 6975 participants (1998 patients; 4977 controls) were incorporated in the 13 articles included in the final meta-analysis. The meta-analysis revealed that women with parity greater than or equal to three had 2.4 times higher odds of developing cervical cancer compared to women with parity less than three [pooled odds ratio (POR) = 2.4, 95% CI: 1.9-3.2]. Conclusion: High parity is associated with an increased risk of cervical cancer. Strong epidemiological studies are recommended to further explore the mechanisms and role of parity in the causation of cervical cancer.

scholarly journals The risk of being culpable for or involved in a road crash after using cannabis: A systematic review and meta-analyses

2021 ◽  
Vol 7 ◽  
pp. 205032452110553
Author(s):  
Michael A. White ◽  
Nicholas R. Burns
Keyword(s):  
Odds Ratio ◽  
Meta Analysis ◽  
Case Control ◽  
Odds Ratios ◽  
Case Control Studies ◽  
Directional Bias ◽  
Increased Risk ◽  
Meta Analyses ◽  
Summary Odds Ratio ◽  
Average Measure

Background The development of drug driving policies should rest on sound epidemiological evidence as to the crash risks of driving after using psychoactive drugs. The findings from individual studies of the increased risk of crashing from the acute use of cannabis range in size from no increase (and perhaps even a protective effect) to a 10-fold increase. Coherent cannabis-driving policies cannot readily be developed from such an incoherent evidence base. A weighted average measure of risk, as provided by a meta-analysis, might be useful. However, if the range of risks found in the cannabis-crash studies reflects the different ways that a variety of biases are being expressed, then the simple application of a meta-analysis might provide little more than an average measure of bias. In other words, if the biases were predominantly inflationary, the meta-analysis would give an inflated estimate of crash risk; and if the biases were predominantly deflationary, the meta-analysis would give a deflated estimate of risk. Review We undertook a systematic search of electronic databases, and identified 13 culpability studies and 4 case–control studies from which cannabis-crash odds ratios could be extracted. Random-effects meta-analyses gave summary odds ratios of 1.37 (1.10–1.69) for the culpability studies and 1.45 (0.94–2.25) for the case–control studies. A tool was designed to identify and score biases arising from: confounding by uncontrolled covariates; inappropriate selection of cases and controls; and the inappropriate measurement of the exposure and outcome variables. Each study was scrutinised for the presence of those biases, and given a total ‘directional bias score’. Most of the biases were inflationary. A meta-regression against the total directional bias scores was performed for the culpability studies, giving a bias-adjusted summary odds ratio of 0.68 (0.45–1.05). The same analysis could not be performed for the case–control studies because there were only four such studies. Nonetheless, a monotonic relationship was found between the total bias scores and the cannabis-crash odds ratios, with Spearman's rho  =  0.95, p  =  0.05, indicating that the summary odds ratio of 1.45 is an overestimate. It is evident that the risks from driving after using cannabis are much lower than from other behaviours such as drink-driving, speeding or using mobile phones while driving. With the medical and recreational use of cannabis becoming more prevalent, the removal of cannabis-presence driving offences should be considered (while impairment-based offences would remain).

SIDE EFFECTS OF PTU AND MMI IN THE TREATMENT OF HYPERTHYROIDISM: A SYSTEMATIC REVIEW AND META-ANALYSIS

2020 ◽  
Vol 26 (2) ◽  
pp. 207-217 ◽  
Author(s):  
Wenshu Yu ◽  
Na Wu ◽  
Ling Li ◽  
Junwu Wang ◽  
Hong OuYang ◽  
...  
Keyword(s):  
Confidence Interval ◽  
Odds Ratio ◽  
Meta Analysis ◽  
Age Groups ◽  
Antithyroid Drug ◽  
Late Pregnancy ◽  
First Trimester ◽  
Group Differences ◽  
Antithyroid Drugs ◽  
The Impact

Objective: The present study aimed to investigate the adverse effects of the antithyroid drugs propylthiouracil (PTU) and methimazole (MMI)/carbimazole (CMZ) in treating hyperthyroidism. Methods: Qualitative analysis was performed for studies identified in a literature search up to April 20, 2019, and 30 studies were selected for meta-analysis. The study designs included case-control, randomized controlled, and retrospective cohort. Patients were in four age groups: childhood, gestating mothers, older adults, and other ages, and all were receiving PTU or MMI/CMZ. Adverse reactions to MMI/CMZ and PTU were evaluated and compared. Results: Odds of liver function injury were higher in the PTU group than in the MMI/CMZ group (odds ratio [OR], 2.40; 95% confidence interval [CI], 1.16 to 4.96; P = .02). Odds of elevated transaminase were much higher in the PTU group than in the MMI/CMZ group (OR, 3.96; 95% CI, 2.49 to 6.28; P<.00001). No significant between-group differences were found in odds of elevated bilirubin, agranulocytosis, rash, or urticaria; incidence of other adverse events; or in children. Odds of birth defects during the first trimester of pregnancy were higher in the MMI/CMZ group than in the PTU group (OR, 1.29; 95% CI, 1.09 to 1.53; P = .003). Conclusion: The impact of PTU on liver injury and transaminase levels is greater than that of MMI/CMZ, but no significant between-group differences are found in the drugs' effects on bilirubin, agranulocytosis and rash, urticaria, or in children. In treating pregnancy-related hyperthyroidism, PTU should be used in the first trimester and MMI reserved for use in late pregnancy. Abbreviations: ALT = alanine aminotransferase; ATD = antithyroid drug; CI = confidence interval; CMZ = carbimazole; GD = Graves disease; MMI = methimazole; MTU = methylthiouracil; NOS = Newcastle-Ottawa Scale; OR = odds ratio; PTU = propylthiouracil; RAI = radioactive iodine

Revascularisation in older adult patients with non-ST-segment elevation acute coronary syndrome: effect and impact on 6-month mortality

2019 ◽  
Vol 9 (4) ◽  
pp. 358-366 ◽  
Author(s):  
Alfredo Bardaji ◽  
José A Barrabés ◽  
Aida Ribera ◽  
Héctor Bueno ◽  
Antonio Fernández-Ortiz ◽  
...  
Keyword(s):  
Acute Coronary Syndrome ◽  
Confidence Interval ◽  
Older Adult ◽  
Odds Ratio ◽  
Meta Analysis ◽  
Two Stage ◽  
St Segment Elevation ◽  
Coronary Syndrome ◽  
St Segment ◽  
The Impact

Although revascularisation in non-ST-segment elevation acute coronary syndrome (NSTEACS) is associated with better outcomes, its impact in older adult patients is unclear. This is a retrospective analyses of three national NSTEACS registries conducted during the past decade in Spain. Patients aged 75 years and older were included: DESCARTES (DES; year 2002; n=534), MASCARA (MAS; 2005; n=1736) and DIOCLES (DIO; 2012; n=593). The adjusted association between revascularisation and total (inhospital and 6-month) mortality was estimated by two-stage meta-analysis (pooled effect across the three registries with inverse-variability weights) and one-stage meta-analysis (multilevel model with random effects across studies). The impact of revascularisation was assessed comparing the observed and the expected mortality based on a logistic regression model in the pooled database. Although revascularisation was associated with a lower risk of mortality in meta-analyses (two-stage: odds ratio 0.44, 95% confidence interval 0.29–0.67; one-stage: odds ratio 0.54, 95% confidence interval 0.36–0.81) and the revascularisation rate increased steadily from 2002 (DES 14.2%) to 2012 (DIO 43.7%), its impact was not patent across registries, probably because this increase was concentrated in low and medium-risk GRACE strata (tertile 1, 2 and 3: MAS 59%, 20% and 6%; DIO 64%, 39% and 19%, respectively). In conclusion, a consistent increase of revascularisation in NSTEACS in older adults was not followed by a decrease in mortality at 6 months, probably because the impact of this strategy is limited to the higher risk population, the stratum with the lowest revascularisation rate in real life.

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