| 1. |
- Danesh, John, et al.
(författare)
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Plasma fibrinogen level and the risk of major cardiovascular diseases and nonvascular mortality: an individual participant meta-analysis
- 2005
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Ingår i: JAMA: The Journal of the American Medical Association. - : American Medical Association (AMA). - 1538-3598 .- 0098-7484. ; 294:14, s. 1799-1809
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Forskningsöversikt (refereegranskat)abstract
- CONTEXT: Plasma fibrinogen levels may be associated with the risk of coronary heart disease (CHD) and stroke. OBJECTIVE: To assess the relationships of fibrinogen levels with risk of major vascular and with risk of nonvascular outcomes based on individual participant data. DATA SOURCES: Relevant studies were identified by computer-assisted searches, hand searches of reference lists, and personal communication with relevant investigators. STUDY SELECTION: All identified prospective studies were included with information available on baseline fibrinogen levels and details of subsequent major vascular morbidity and/or cause-specific mortality during at least 1 year of follow-up. Studies were excluded if they recruited participants on the basis of having had a previous history of cardiovascular disease; participants with known preexisting CHD or stroke were excluded. DATA EXTRACTION: Individual records were provided on each of 154,211 participants in 31 prospective studies. During 1.38 million person-years of follow-up, there were 6944 first nonfatal myocardial infarctions or stroke events and 13,210 deaths. Cause-specific mortality was generally available. Analyses involved proportional hazards modeling with adjustment for confounding by known cardiovascular risk factors and for regression dilution bias. DATA SYNTHESIS: Within each age group considered (40-59, 60-69, and > or =70 years), there was an approximately log-linear association with usual fibrinogen level for the risk of any CHD, any stroke, other vascular (eg, non-CHD, nonstroke) mortality, and nonvascular mortality. There was no evidence of a threshold within the range of usual fibrinogen level studied at any age. The age- and sex- adjusted hazard ratio per 1-g/L increase in usual fibrinogen level for CHD was 2.42 (95% confidence interval [CI], 2.24-2.60); stroke, 2.06 (95% CI, 1.83-2.33); other vascular mortality, 2.76 (95% CI, 2.28-3.35); and nonvascular mortality, 2.03 (95% CI, 1.90-2.18). The hazard ratios for CHD and stroke were reduced to about 1.8 after further adjustment for measured values of several established vascular risk factors. In a subset of 7011 participants with available C-reactive protein values, the findings for CHD were essentially unchanged following additional adjustment for C-reactive protein. The associations of fibrinogen level with CHD or stroke did not differ substantially according to sex, smoking, blood pressure, blood lipid levels, or several features of study design. CONCLUSIONS: In this large individual participant meta-analysis, moderately strong associations were found between usual plasma fibrinogen level and the risks of CHD, stroke, other vascular mortality, and nonvascular mortality in a wide range of circumstances in healthy middle-aged adults. Assessment of any causal relevance of elevated fibrinogen levels to disease requires additional research.
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| 2. |
- Janiaud, Perrine, et al.
(författare)
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Association of Convalescent Plasma Treatment With Clinical Outcomes in Patients With COVID-19 : A Systematic Review and Meta-analysis
- 2021
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Ingår i: Journal of the American Medical Association (JAMA). - : American Medical Association (AMA). - 0098-7484 .- 1538-3598. ; 325:12, s. 1185-1195
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Forskningsöversikt (refereegranskat)abstract
- IMPORTANCE Convalescent plasma is a proposed treatment for COVID-19. OBJECTIVE To assess clinical outcomes with convalescent plasma treatment vs placebo or standard of care in peer-reviewed and preprint publications or press releases of randomized clinical trials (RCTs). DATA SOURCES PubMed, the Cochrane COVID-19 trial registry, and the Living Overview of Evidence platform were searched until January 29, 2021. STUDY SELECTION The RCTs selected compared any type of convalescent plasma vs placebo or standard of care for patients with confirmed or suspected COVID-19 in any treatment setting. DATA EXTRACTION AND SYNTHESIS Two reviewers independently extracted data on relevant clinical outcomes, trial characteristics, and patient characteristics and used the Cochrane Risk of Bias Assessment Tool. The primary analysis included peer-reviewed publications of RCTs only, whereas the secondary analysis included all publicly available RCT data (peer-reviewed publications, preprints, and press releases). Inverse variance-weighted meta-analyses were conducted to summarize the treatment effects. The certainty of the evidence was assessed using the Grading of Recommendations Assessment, Development, and Evaluation. MAIN OUTCOMES AND MEASURES All-cause mortality, length of hospital stay, clinical improvement, clinical deterioration, mechanical ventilation use, and serious adverse events. RESULTS A total of 1060 patients from 4 peer-reviewed RCTs and 10 722 patients from 6 other publicly available RCTs were included. The summary risk ratio (RR) for all-cause mortality with convalescent plasma in the 4 peer-reviewed RCTs was 0.93 (95% CI, 0.63 to 1.38), the absolute risk difference was -1.21% (95% CI, -5.29% to 2.88%), and there was low certainty of the evidence due to imprecision. Across all 10 RCTs, the summary RR was 1.02 (95% CI, 0.92 to 1.12) and there was moderate certainty of the evidence due to inclusion of unpublished data. Among the peer-reviewed RCTs, the summary hazard ratio was 1.17 (95% CI, 0.07 to 20.34) for length of hospital stay, the summary RR was 0.76 (95% CI, 0.20 to 2.87) for mechanical ventilation use (the absolute risk difference for mechanical ventilation use was -2.56%[95% CI, -13.16% to 8.05%]), and there was low certainty of the evidence due to imprecision for both outcomes. Limited data on clinical improvement, clinical deterioration, and serious adverse events showed no significant differences. CONCLUSIONS AND RELEVANCE Treatment with convalescent plasma compared with placebo or standard of care was not significantly associated with a decrease in all-cause mortality or with any benefit for other clinical outcomes. The certainty of the evidence was low to moderate for all-cause mortality and low for other outcomes.
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| 3. |
- Larsson, Susanna C., et al.
(författare)
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Vitamin B-6 and Risk of Colorectal Cancer A Meta-analysis of Prospective Studies
- 2010
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Ingår i: Journal of the American Medical Association (JAMA). - : AMER MEDICAL ASSOC. - 0098-7484 .- 1538-3598. ; 303:11, s. 1077-1083
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Forskningsöversikt (refereegranskat)abstract
- Context Mounting evidence indicates that vitamin B-6, a coenzyme involved in nearly 100 enzymatic reactions, may reduce the risk of colorectal cancer. Objective To conduct a systematic review with meta-analysis of prospective studies assessing the association of vitamin B-6 intake or blood levels of pyridoxal 5'-phosphate (PLP; the active form of vitamin B-6) with risk of colorectal cancer. Data Sources Relevant studies were identified by a search of MEDLINE and EMBASE databases to February 2010, with no restrictions. We also reviewed reference lists from retrieved articles. Study Selection We included prospective studies that reported relative risk (RR) estimates with 95% confidence intervals (CIs) for the association between vitamin B-6 intake or blood PLP levels and the risk of colorectal, colon, or rectal cancer. Data Extraction Two authors independently extracted data and assessed study quality. Study-specific RRs were pooled using a random-effects model. Data Synthesis Nine studies on vitamin B-6 intake and 4 studies on blood PLP levels were included in the meta-analysis. The pooled RRs of colorectal cancer for the highest vs lowest category of vitamin B-6 intake and blood PLP levels were 0.90 (95% CI, 0.75-1.07) and 0.52 (95% CI, 0.38-0.71), respectively. There was heterogeneity among studies of vitamin B-6 intake (P=.01) but not among studies of blood PLP levels (P=.95). Omitting 1 study that contributed substantially to the heterogeneity among studies of vitamin B-6 intake yielded a pooled RR of 0.80 (95% CI, 0.69-0.92). The risk of colorectal cancer decreased by 49% for every 100-pmol/mL increase (approximately 2 SDs) in blood PLP levels (RR, 0.51; 95% CI, 0.38-0.69). Conclusion Vitamin B-6 intake and blood PLP levels were inversely associated with the risk of colorectal cancer in this meta-analysis. JAMA. 2010; 303(11): 1077-1083
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| 4. |
- O'Donoghue, Michelle, et al.
(författare)
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Early invasive vs conservative treatment strategies in women and men with unstable angina and non-ST-segment elevation myocardial infarction : a meta-analysis
- 2008
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Ingår i: Journal of the American Medical Association (JAMA). - : American Medical Association (AMA). - 0098-7484 .- 1538-3598. ; 300:1, s. 71-80
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Forskningsöversikt (refereegranskat)abstract
- CONTEXT: Although an invasive strategy is frequently used in patients with non-ST-segment elevation acute coronary syndromes (NSTE ACS), data from some trials suggest that this strategy may not benefit women. OBJECTIVE: To conduct a meta-analysis of randomized trials to compare the effects of an invasive vs conservative strategy in women and men with NSTE ACS. DATA SOURCES: Trials were identified through a computerized literature search of the MEDLINE and Cochrane databases (1970-April 2008) using the search terms invasive strategy, conservative strategy, selective invasive strategy, acute coronary syndromes, non-ST-elevation myocardial infarction, and unstable angina. STUDY SELECTION: Randomized clinical trials comparing an invasive vs conservative treatment strategy in patients with NSTE ACS. DATA EXTRACTION: The principal investigators for each trial provided the sex-specific incidences of death, myocardial infarction (MI), and rehospitalization with ACS through 12 months of follow-up. DATA SYNTHESIS: Data were combined across 8 trials (3075 women and 7075 men). The odds ratio (OR) for the composite of death, MI, or ACS for invasive vs conservative strategy in women was 0.81 (95% confidence interval [CI], 0.65-1.01; 21.1% vs 25.0%) and in men was 0.73 (95% CI, 0.55-0.98; 21.2% vs 26.3%) without significant heterogeneity between sexes (P for interaction = .26). Among biomarker-positive women, an invasive strategy was associated with a 33% lower odds of death, MI, or ACS (OR, 0.67; 95% CI, 0.50-0.88) and a nonsignificant 23% lower odds of death or MI (OR, 0.77; 95% CI, 0.47-1.25). In contrast, an invasive strategy was not associated with a significant reduction in the triple composite end point in biomarker-negative women (OR, 0.94; 95% CI, 0.61-1.44; P for interaction = .36) and was associated with a nonsignificant 35% higher odds of death or MI (OR, 1.35; 95% CI, 0.78-2.35; P for interaction = .08). Among men, the OR for death, MI, or ACS was 0.56 (95% CI, 0.46-0.67) if biomarker-positive and 0.72 (95% CI, 0.51-1.01) if biomarker-negative (P for interaction = .09). CONCLUSIONS: In NSTE ACS, an invasive strategy has a comparable benefit in men and high-risk women for reducing the composite end point of death, MI, or rehospitalization with ACS. In contrast, our data provide evidence supporting the new guideline recommendation for a conservative strategy in low-risk women.
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| 5. |
- Smith-Warner, S A, et al.
(författare)
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Intake of fruits and vegetables and risk of breast cancer - A pooled analysis of cohort studies
- 2001
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Ingår i: Journal of the American Medical Association (JAMA). - Harvard Univ, Sch Publ Hlth, Dept Nutr, Ctr Canc Prevent, Boston, MA 02115 USA. Harvard Univ, Sch Publ Hlth, Dept Epidemiol, Ctr Canc Prevent, Boston, MA 02115 USA. Harvard Univ, Sch Publ Hlth, Dept Biostat, Ctr Canc Prevent, Boston, MA 02115 USA. Harvard Univ, Sch Publ Hlth, Dept Environm Hlth, Ctr Canc Prevent, Boston, MA 02115 USA. Brigham & Womens Hosp, Dept Med, Channing Lab, Boston, MA USA. Harvard Univ, Sch Med, Boston, MA 02115 USA. Karolinska Inst, Dept Med Epidemiol, Stockholm, Sweden. Loma Linda Univ, Sch Med, Ctr Hlth Res, Loma Linda, CA USA. Maastricht Univ, Dept Epidemiol, Maastricht, Netherlands. Univ Minnesota, Sch Publ Hlth, Div Epidemiol, Minneapolis, MN 55455 USA. SUNY Buffalo, Dept Social & Prevent Med, Buffalo, NY 14260 USA. TNO, Nutr & Food Res Inst, NL-3700 AJ Zeist, Netherlands. Deutsch Krebsforschungszentrum, Div Clin Epidemiol, D-6900 Heidelberg, Germany. Fred Hutchinson Canc Res Ctr, Canc Prevent Res Program, Seattle, WA 98104 USA. Albert Einstein Coll Med, Dept Epidemiol & Social Med, Bronx, NY 10467 USA. NYU, Sch Med, Dept Obstet & Gynecol, New York, NY USA. NYU, Sch Med, Nelson Inst Environm Med, New York, NY USA. NYU, Sch Med, Kaplan Canc Ctr, New York, NY USA. : AMER MEDICAL ASSOC. - 0098-7484 .- 1538-3598. ; 285:6, s. 769-776
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Forskningsöversikt (refereegranskat)abstract
- Context Some epidemiologic studies suggest that elevated fruit and vegetable consumption is associated with a reduced risk of breast cancer. However, most have been case-control studies in which recall and selection bias may influence the results. Additionally, publication bias may have influenced the literature on associations for specific fruit and vegetable subgroups. Objective To examine the association between breast cancer and total and specific fruit and vegetable group intakes using standardized exposure definitions. Data Sources/Study Selection Eight prospective studies that had at least 200 incident breast cancer cases, assessed usual dietary intake, and completed a validation study of the diet assessment method or a closely related instrument were included in these analyses. Data Extraction Using the primary data from each of the studies, we calculated study-specific relative risks (RRs) that were combined using a random-effects model. Data Synthesis The studies included 7377 incident invasive breast cancer cases occurring among 351825 women whose diet was analyzed at baseline. For comparisons of the highest vs lowest quartiles of intake, weak, nonsignificant associations were observed for total fruits (pooled multivariate RR, 0.93; 95% confidence interval [CI], 0.86-1.00; P for trend =.08), total vegetables (RR, 0.96; 95% CI, 0.89-1.04; P for trend=.54), and total fruits and vegetables (RR, 0.93; 95% CI, 0.86-1.00; P for trend=.12). No additional benefit was apparent in comparisons of the highest and lowest deciles of intake. No associations were observed for green leafy vegetables, 8 botanical groups, and 17 specific fruits and vegetables. Conclusion These results suggest that fruit and vegetable consumption during adulthood is not significantly associated with reduced breast cancer risk.
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| 6. |
- Demers, C., et al.
(författare)
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Impact of candesartan on nonfatal myocardial infarction and cardiovascular death in patients with heart failure
- 2005
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Ingår i: JAMA. - 1538-3598. ; 294:14, s. 1794-8
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Forskningsöversikt (refereegranskat)abstract
- CONTEXT: Angiotensin-converting enzyme (ACE) inhibitors reduce the risk of myocardial infarction (MI), but it is not known whether angiotensin receptor blockers have the same effect. OBJECTIVE: To assess the impact of the angiotensin receptor blocker candesartan on MI and other coronary events in patients with heart failure. DESIGN, SETTING, AND PARTICIPANTS: The Candesartan in Heart Failure: Assessment of Reduction in Mortality and Morbidity (CHARM) program, a randomized, placebo-controlled study enrolling patients (mean age, 66 [SD, 11] years) with New York Heart Association class II to IV symptoms who were randomly allocated to receive candesartan (target dose, 32 mg once daily) or matching placebo given in addition to optimal therapy for heart failure. Patients were enrolled from March 1999 through March 2001. Of 7599 patients allocated, 4004 (53%) had experienced a previous MI, and 1808 (24%) currently had angina. At baseline, 3125 (41%) were receiving an ACE inhibitor; 4203 (55%), a beta-blocker; 3153 (42%), a lipid-lowering drug; 4246 (56%), aspirin; and 6286 (83%), a diuretic. MAIN OUTCOME MEASURE: The primary outcome of the present analysis was the composite of cardiovascular death or nonfatal MI in patients with heart failure receiving candesartan or placebo. RESULTS: During the median follow-up of 37.7 months, the primary outcome of cardiovascular death or nonfatal MI was significantly reduced in the candesartan group (775 patients [20.4%]) vs the placebo group (868 [22.9%]) (hazard ratio [HR], 0.87; 95% confidence interval [CI], 0.79-0.96; P = .004; number needed to treat [NNT], 40). Nonfatal MI alone was also significantly reduced in the candesartan group (116 [3.1%]) vs the placebo group (148 [3.9%]) (HR, 0.77; 95% CI, 0.60-0.98; P = .03; NNT, 118). The secondary outcome of fatal MI, sudden death, or nonfatal MI was significantly reduced with candesartan (459 [12.1%]) vs placebo (522 [13.8%]) (HR, 0.86; 95% CI, 0.75-0.97; P = .02; NNT, 59). Risk reductions in cardiovascular death or nonfatal MI were similar across predetermined subgroups and the component CHARM trials. There was no impact on hospitalizations for unstable angina or coronary revascularization procedures with candesartan. CONCLUSION: In patients with heart failure, candesartan significantly reduces the risk of the composite outcome of cardiovascular death or nonfatal MI.
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