Simon G Thompson
Datos Biográficos
| ID | 6161601 |
|---|---|
| NOMBRE | Simon G Thompson |
| NOMBRES | Simon G |
| APELLIDO | Thompson |
| FIRMA | THOMPSON S G |
| AFILIACIONES | MRC Biostatistics Unit |
| ORCID | 0000-0002-5274-7814 |
| VERIFICADO | Sí |
| TOTAL DE OBRAS | 16 |
| TOTAL DE CITAS | 53 |
| TOTAL COMO AUTOR | 16 |
| TOTAL COMO EDITOR | 0 |
| PRIMER AÑO DE PUBLICACIÓN | 1987 |
| AÑO MÁS RECIENTE DE PUBLICACIÓN | 2018 |
| ÍNDICE H | 2 |
Risk thresholds for alcohol consumption
BACKGROUND: Low-risk limits recommended for alcohol consumption vary substantially across different national guidelines. To define thresholds associated with lowest risk for all-cause mortality and cardiovascular disease, we studied individual-participant data from 599 912 current drinkers without previous cardiovascular disease. METHODS: We did a combined analysis of individual-participant data from three large-scale data sources in 19 high-inco…
Interpreting findings from Mendelian randomization using the MR-Egger method
Mendelian randomization-Egger (MR-Egger) is an analysis method for Mendelian randomization using summarized genetic data. MR-Egger consists of three parts: (1) a test for directional pleiotropy, (2) a test for a causal effect, and (3) an estimate of the causal effect. While conventional analysis methods for Mendelian randomization assume that all genetic variants satisfy the instrumental variable assumptions, the MR-Egger method is able to assess…
Body-mass index and all-cause mortality
Association of Cardiometabolic Multimorbidity With Mortality
IMPORTANCE The prevalence of cardiometabolic multimorbidity is increasing. OBJECTIVE To estimate reductions in life expectancy associated with cardiometabolic multimorbidity. DESIGN, SETTING, AND PARTICIPANTS Age-and sex-adjusted mortality rates and hazard ratios (HRs) were calculated using individual participant data from the Emerging Risk Factors Collaboration (689 300 participants; 91 cohorts; years of baseline surveys: 1960-2007; latest morta…
Mendelian Randomization Analysis With Multiple Genetic Variants Using Summarized Data
Genome‐wide association studies, which typically report regression coefficients summarizing the associations of many genetic variants with various traits, are potentially a powerful source of data for Mendelian randomization investigations. We demonstrate how such coefficients from multiple variants can be combined in a Mendelian randomization analysis to estimate the causal effect of a risk factor on an outcome. The bias and efficiency of estima…
Using natural experiments to evaluate population health interventions
Natural experimental studies are often recommended as a way of understanding the health impact of policies and other large scale interventions. Although they have certain advantages over planned experiments, and may be the only option when it is impossible to manipulate exposure to the intervention, natural experimental studies are more susceptible to bias. This paper introduces new guidance from the Medical Research Council to help researchers a…
A Re-Evaluation of Random-Effects Meta-Analysis
Meta-analysis in the presence of unexplained heterogeneity is frequently undertaken by using a random-effects model, in which the effects underlying different studies are assumed to be drawn from a normal distribution. Here we discuss the justification and interpretation of such models, by addressing in turn the aims of estimation, prediction and hypothesis testing. A particular issue that we consider is the distinction between inference on the m…
The DYD-RCT protocol
International Standard Randomised Controlled Trial Number Register ISRCTN31070347
Controlling the risk of spurious findings from meta‐regression
Meta‐regression has become a commonly used tool for investigating whether study characteristics may explain heterogeneity of results among studies in a systematic review. However, such explorations of heterogeneity are prone to misleading false‐positive results. It is unclear how many covariates can reliably be investigated, and how this might depend on the number of studies, the extent of the heterogeneity and the relative weights awarded to the…
Poorer self assessed health in a prospective study of men with screen detected abdominal aortic aneurysm
Study objectives: To assess the extent to which poorer self assessed health in men in whom an abdominal aortic aneurysm (AAA) is detected at screening is a consequence or a predictor of screening outcome. Design: Prospective study. Setting: Community based screening. Participants: 23 654 men who attended for AAA screening as part of the UK multicentre aneurysm screening study completed a measure of self assessed health before screening. A total o…
Measuring inconsistency in meta-analyses
Cochrane Reviews have recently started including the quantity I2 to help readers assess the consistency of the results of studies in meta-analyses. What does this new quantity mean, and why is assessment of heterogeneity so important to clinical practice?
How should meta‐regression analyses be undertaken and interpreted?
Appropriate methods for meta‐regression applied to a set of clinical trials, and the limitations and pitfalls in interpretation, are insufficiently recognized. Here we summarize recent research focusing on these issues, and consider three published examples of meta‐regression in the light of this work. One principal methodological issue is that meta‐regression should be weighted to take account of both within‐trial variances of treatment effects …
Quantifying heterogeneity in a meta‐analysis
The extent of heterogeneity in a meta‐analysis partly determines the difficulty in drawing overall conclusions. This extent may be measured by estimating a between‐study variance, but interpretation is then specific to a particular treatment effect metric. A test for the existence of heterogeneity exists, but depends on the number of studies in the meta‐analysis. We develop measures of the impact of heterogeneity on a meta‐analysis, from mathemat…
The potential and limitations of meta-analysis
We are currently wimessing an "epidemic" of meta-analyses and overviews in the scientific literature. This is a relatively new phenomenon and this article addresses some of the important issues raised by their increasing use. In particular the differing applications and limitations of meta- analysis are discussed, with a review of the analytic methods used and the problems and biases encountered
Primary prevention trials in cardiovascular disease
potential benefit of any primary prevention policy for reducing the risk of cardiovascular disease in the community. Observational epidemiology can lead to the development of hypotheses regarding which primary interventions ought to work, but one can argue that only by comparative (and usually long term and large scale) experimentation can one achieve scientifically acceptable evidence that intervention really does (or does not) work. Clinical tr…
Relation between cigarette smoking and use of hormonal replacement therapy for menopausal symptoms
The aim of this study was to characterise new users of hormonal replacement therapy (HRT) for the relief of menopausal symptoms and to compare these women with never-users of HRT; 402 new users and 804 never-users were studied. Hot flushes were the most common symptom in both users and non-users and were the most frequent reason for prescribing HRT. The prevalence of menopausal symptoms in non-users of HRT was high although substantially lower th…
Using natural experiments to evaluate population health interventions
Natural experimental studies are often recommended as a way of understanding the health impact of policies and other large scale interventions. Although they have certain advantages over planned experiments, and may be the only option when it is impossible to manipulate exposure to the intervention, natural experimental studies are more susceptible to bias. This paper introduces new guidance from the Medical Research Council to help researchers a…
Poorer self assessed health in a prospective study of men with screen detected abdominal aortic aneurysm
Study objectives: To assess the extent to which poorer self assessed health in men in whom an abdominal aortic aneurysm (AAA) is detected at screening is a consequence or a predictor of screening outcome. Design: Prospective study. Setting: Community based screening. Participants: 23 654 men who attended for AAA screening as part of the UK multicentre aneurysm screening study completed a measure of self assessed health before screening. A total o…
The potential and limitations of meta-analysis
We are currently wimessing an "epidemic" of meta-analyses and overviews in the scientific literature. This is a relatively new phenomenon and this article addresses some of the important issues raised by their increasing use. In particular the differing applications and limitations of meta- analysis are discussed, with a review of the analytic methods used and the problems and biases encountered
Relation between cigarette smoking and use of hormonal replacement therapy for menopausal symptoms
The aim of this study was to characterise new users of hormonal replacement therapy (HRT) for the relief of menopausal symptoms and to compare these women with never-users of HRT; 402 new users and 804 never-users were studied. Hot flushes were the most common symptom in both users and non-users and were the most frequent reason for prescribing HRT. The prevalence of menopausal symptoms in non-users of HRT was high although substantially lower th…
Relation between cigarette smoking and use of hormonal replacement therapy for menopausal symptoms
The aim of this study was to characterise new users of hormonal replacement therapy (HRT) for the relief of menopausal symptoms and to compare these women with never-users of HRT; 402 new users and 804 never-users were studied. Hot flushes were the most common symptom in both users and non-users and were the most frequent reason for prescribing HRT. The prevalence of menopausal symptoms in non-users of HRT was high although substantially lower th…
Primary prevention trials in cardiovascular disease
potential benefit of any primary prevention policy for reducing the risk of cardiovascular disease in the community. Observational epidemiology can lead to the development of hypotheses regarding which primary interventions ought to work, but one can argue that only by comparative (and usually long term and large scale) experimentation can one achieve scientifically acceptable evidence that intervention really does (or does not) work. Clinical tr…
The potential and limitations of meta-analysis
We are currently wimessing an "epidemic" of meta-analyses and overviews in the scientific literature. This is a relatively new phenomenon and this article addresses some of the important issues raised by their increasing use. In particular the differing applications and limitations of meta- analysis are discussed, with a review of the analytic methods used and the problems and biases encountered
How should meta‐regression analyses be undertaken and interpreted?
Appropriate methods for meta‐regression applied to a set of clinical trials, and the limitations and pitfalls in interpretation, are insufficiently recognized. Here we summarize recent research focusing on these issues, and consider three published examples of meta‐regression in the light of this work. One principal methodological issue is that meta‐regression should be weighted to take account of both within‐trial variances of treatment effects …
Quantifying heterogeneity in a meta‐analysis
The extent of heterogeneity in a meta‐analysis partly determines the difficulty in drawing overall conclusions. This extent may be measured by estimating a between‐study variance, but interpretation is then specific to a particular treatment effect metric. A test for the existence of heterogeneity exists, but depends on the number of studies in the meta‐analysis. We develop measures of the impact of heterogeneity on a meta‐analysis, from mathemat…
Measuring inconsistency in meta-analyses
Cochrane Reviews have recently started including the quantity I2 to help readers assess the consistency of the results of studies in meta-analyses. What does this new quantity mean, and why is assessment of heterogeneity so important to clinical practice?
Controlling the risk of spurious findings from meta‐regression
Meta‐regression has become a commonly used tool for investigating whether study characteristics may explain heterogeneity of results among studies in a systematic review. However, such explorations of heterogeneity are prone to misleading false‐positive results. It is unclear how many covariates can reliably be investigated, and how this might depend on the number of studies, the extent of the heterogeneity and the relative weights awarded to the…
Poorer self assessed health in a prospective study of men with screen detected abdominal aortic aneurysm
Study objectives: To assess the extent to which poorer self assessed health in men in whom an abdominal aortic aneurysm (AAA) is detected at screening is a consequence or a predictor of screening outcome. Design: Prospective study. Setting: Community based screening. Participants: 23 654 men who attended for AAA screening as part of the UK multicentre aneurysm screening study completed a measure of self assessed health before screening. A total o…
The DYD-RCT protocol
International Standard Randomised Controlled Trial Number Register ISRCTN31070347
A Re-Evaluation of Random-Effects Meta-Analysis
Meta-analysis in the presence of unexplained heterogeneity is frequently undertaken by using a random-effects model, in which the effects underlying different studies are assumed to be drawn from a normal distribution. Here we discuss the justification and interpretation of such models, by addressing in turn the aims of estimation, prediction and hypothesis testing. A particular issue that we consider is the distinction between inference on the m…
Using natural experiments to evaluate population health interventions
Natural experimental studies are often recommended as a way of understanding the health impact of policies and other large scale interventions. Although they have certain advantages over planned experiments, and may be the only option when it is impossible to manipulate exposure to the intervention, natural experimental studies are more susceptible to bias. This paper introduces new guidance from the Medical Research Council to help researchers a…
Mendelian Randomization Analysis With Multiple Genetic Variants Using Summarized Data
Genome‐wide association studies, which typically report regression coefficients summarizing the associations of many genetic variants with various traits, are potentially a powerful source of data for Mendelian randomization investigations. We demonstrate how such coefficients from multiple variants can be combined in a Mendelian randomization analysis to estimate the causal effect of a risk factor on an outcome. The bias and efficiency of estima…
Association of Cardiometabolic Multimorbidity With Mortality
IMPORTANCE The prevalence of cardiometabolic multimorbidity is increasing. OBJECTIVE To estimate reductions in life expectancy associated with cardiometabolic multimorbidity. DESIGN, SETTING, AND PARTICIPANTS Age-and sex-adjusted mortality rates and hazard ratios (HRs) were calculated using individual participant data from the Emerging Risk Factors Collaboration (689 300 participants; 91 cohorts; years of baseline surveys: 1960-2007; latest morta…
Body-mass index and all-cause mortality
Interpreting findings from Mendelian randomization using the MR-Egger method
Mendelian randomization-Egger (MR-Egger) is an analysis method for Mendelian randomization using summarized genetic data. MR-Egger consists of three parts: (1) a test for directional pleiotropy, (2) a test for a causal effect, and (3) an estimate of the causal effect. While conventional analysis methods for Mendelian randomization assume that all genetic variants satisfy the instrumental variable assumptions, the MR-Egger method is able to assess…
Risk thresholds for alcohol consumption
BACKGROUND: Low-risk limits recommended for alcohol consumption vary substantially across different national guidelines. To define thresholds associated with lowest risk for all-cause mortality and cardiovascular disease, we studied individual-participant data from 599 912 current drinkers without previous cardiovascular disease. METHODS: We did a combined analysis of individual-participant data from three large-scale data sources in 19 high-inco…
Medicine (11 obras) · Computer Science (7 obras) · Meta-analysis (6 obras) · Meta-analysis and systematic reviews (6 obras) · Econometrics (5 obras) · Mathematics (5 obras) · Internal Medicine (4 obras) · Statistics (4 obras) · Confidence interval (3 obras) · Environmental health (3 obras)