Abstract:
BACKGROUND:Our systematic review has demonstrated that antioxidant supplements may increase mortality. We have now updated this review. OBJECTIVES:To assess the beneficial and harmful effects of antioxidant supplements for prevention of mortality in adults. SEARCH METHODS:We searched The Cochrane Library, MEDLINE, EMBASE, LILACS, the Science Citation Index Expanded, and Conference Proceedings Citation Index-Science to February 2011. We scanned bibliographies of relevant publications and asked pharmaceutical companies for additional trials. SELECTION CRITERIA:We included all primary and secondary prevention randomised clinical trials on antioxidant supplements (beta-carotene, vitamin A, vitamin C, vitamin E, and selenium) versus placebo or no intervention. DATA COLLECTION AND ANALYSIS:Three authors extracted data. Random-effects and fixed-effect model meta-analyses were conducted. Risk of bias was considered in order to minimise the risk of systematic errors. Trial sequential analyses were conducted to minimise the risk of random errors. Random-effects model meta-regression analyses were performed to assess sources of intertrial heterogeneity. MAIN RESULTS:Seventy-eight randomised trials with 296,707 participants were included. Fifty-six trials including 244,056 participants had low risk of bias. Twenty-six trials included 215,900 healthy participants. Fifty-two trials included 80,807 participants with various diseases in a stable phase. The mean age was 63 years (range 18 to 103 years). The mean proportion of women was 46%. Of the 78 trials, 46 used the parallel-group design, 30 the factorial design, and 2 the cross-over design. All antioxidants were administered orally, either alone or in combination with vitamins, minerals, or other interventions. The duration of supplementation varied from 28 days to 12 years (mean duration 3 years; median duration 2 years). Overall, the antioxidant supplements had no significant effect on mortality in a random-effects model meta-analysis (21,484 dead/183,749 (11.7%) versus 11,479 dead/112,958 (10.2%); 78 trials, relative risk (RR) 1.02, 95% confidence interval (CI) 0.98 to 1.05) but significantly increased mortality in a fixed-effect model (RR 1.03, 95% CI 1.01 to 1.05). Heterogeneity was low with an I(2)- of 12%. In meta-regression analysis, the risk of bias and type of antioxidant supplement were the only significant predictors of intertrial heterogeneity. Meta-regression analysis did not find a significant difference in the estimated intervention effect in the primary prevention and the secondary prevention trials. In the 56 trials with a low risk of bias, the antioxidant supplements significantly increased mortality (18,833 dead/146,320 (12.9%) versus 10,320 dead/97,736 (10.6%); RR 1.04, 95% CI 1.01 to 1.07). This effect was confirmed by trial sequential analysis. Excluding factorial trials with potential confounding showed that 38 trials with low risk of bias demonstrated a significant increase in mortality (2822 dead/26,903 (10.5%) versus 2473 dead/26,052 (9.5%); RR 1.10, 95% CI 1.05 to 1.15). In trials with low risk of bias, beta-carotene (13,202 dead/96,003 (13.8%) versus 8556 dead/77,003 (11.1%); 26 trials, RR 1.05, 95% CI 1.01 to 1.09) and vitamin E (11,689 dead/97,523 (12.0%) versus 7561 dead/73,721 (10.3%); 46 trials, RR 1.03, 95% CI 1.00 to 1.05) significantly increased mortality, whereas vitamin A (3444 dead/24,596 (14.0%) versus 2249 dead/16,548 (13.6%); 12 trials, RR 1.07, 95% CI 0.97 to 1.18), vitamin C (3637 dead/36,659 (9.9%) versus 2717 dead/29,283 (9.3%); 29 trials, RR 1.02, 95% CI 0.98 to 1.07), and selenium (2670 dead/39,779 (6.7%) versus 1468 dead/22,961 (6.4%); 17 trials, RR 0.97, 95% CI 0.91 to 1.03) did not significantly affect mortality. In univariate meta-regression analysis, the dose of vitamin A was significantly associated with increased mortality (RR 1.0006, 95% CI 1.0002 to 1.001, P = 0.002). AUTHORS' CONCLUSIONS:We found no evidence to support antioxidant supplements for primary or secondary prevention. Beta-carotene and vitamin E seem to increase mortality, and so may higher doses of vitamin A. Antioxidant supplements need to be considered as medicinal products and should undergo sufficient evaluation before marketing.
journal_name
Cochrane Database Syst Revjournal_title
The Cochrane database of systematic reviewsauthors
Bjelakovic G,Nikolova D,Gluud LL,Simonetti RG,Gluud Cdoi
10.1002/14651858.CD007176.pub2subject
Has Abstractpub_date
2012-03-14 00:00:00pages
CD007176issue
3issn
1469-493Xpub_type
杂志文章,meta分析,评审abstract:BACKGROUND:Post-extraction bleeding (PEB) is a recognised, frequently encountered complication in dental practice, which is defined as bleeding that continues beyond 8 to 12 hours after dental extraction. The incidence of post-extraction bleeding varies from 0% to 26%. If post-extraction bleeding is not managed, compli...
journal_title:The Cochrane database of systematic reviews
pub_type: 杂志文章,评审
doi:10.1002/14651858.CD011930.pub2
更新日期:2016-06-10 00:00:00
abstract:BACKGROUND:Electroconvulsive therapy (ECT) involves the induction of a seizure (fit) for therapeutic purposes by the administration of a variable frequency electrical stimulus shock via electrodes applied to the scalp. The effects of its use in people with schizophrenia are unclear. OBJECTIVES:To determine whether ele...
journal_title:The Cochrane database of systematic reviews
pub_type: 杂志文章,评审
doi:10.1002/14651858.CD000076
更新日期:2002-01-01 00:00:00
abstract:BACKGROUND:Charcot-Marie-Tooth disease (CMT) comprises a large variety of different forms of motor and sensory neuropathies. The most frequent are demyelinating forms (CMT1) and axonal forms (CMT2). The molecular basis of several CMT forms has been clarified during the last 15 years. Since muscle wasting and sensory di...
journal_title:The Cochrane database of systematic reviews
pub_type: 杂志文章,评审
doi:10.1002/14651858.CD006052.pub2
更新日期:2008-01-23 00:00:00
abstract:BACKGROUND:Lead poisoning is associated with physical, cognitive and neurobehavioural impairment in children, and trials have tested many household interventions to prevent lead exposure. This is an update of the original review, first published in 2008. OBJECTIVES:To assess the effects of household interventions for ...
journal_title:The Cochrane database of systematic reviews
pub_type: 杂志文章,meta分析,评审
doi:10.1002/14651858.CD006047.pub5
更新日期:2016-10-16 00:00:00
abstract:BACKGROUND:Pulmonary rehabilitation has become a cornerstone in the management of patients with stable Chronic Obstructive Pulmonary Disease (COPD). Systematic reviews have shown large and important clinical effects of pulmonary rehabilitation in these patients. In unstable COPD patients who have suffered from an exace...
journal_title:The Cochrane database of systematic reviews
pub_type: 杂志文章,meta分析,评审
doi:10.1002/14651858.CD005305.pub2
更新日期:2009-01-21 00:00:00
abstract:BACKGROUND:Individuals with chronic bronchitis or chronic obstructive pulmonary disease (COPD) may suffer recurrent exacerbations with an increase in volume and/or purulence of sputum. Because of the personal and healthcare costs associated with exacerbations, any therapy that reduces the number of exacerbations is use...
journal_title:The Cochrane database of systematic reviews
pub_type: 杂志文章,meta分析,评审
doi:10.1002/14651858.CD001287.pub3
更新日期:2010-02-17 00:00:00
abstract:BACKGROUND:Cardiotocography (CTG) is a continuous recording of the fetal heart rate obtained via an ultrasound transducer placed on the mother's abdomen. CTG is widely used in pregnancy as a method of assessing fetal well-being, predominantly in pregnancies with increased risk of complications. OBJECTIVES:To assess th...
journal_title:The Cochrane database of systematic reviews
pub_type: 杂志文章,meta分析,评审
doi:10.1002/14651858.CD007863.pub3
更新日期:2012-12-12 00:00:00
abstract:BACKGROUND:In general, surgery is believed to offer the best prospects for cure for early stage non-small cell lung cancer (NSCLC). In spite of the intention to consider all patients with stage I-II disease for surgery, there are those who, although technically operable, either refuse surgery or are considered inoperab...
journal_title:The Cochrane database of systematic reviews
pub_type: 杂志文章,评审
doi:10.1002/14651858.CD002935
更新日期:2001-01-01 00:00:00
abstract:BACKGROUND:There have been recent advances in chemotherapy-induced nausea and vomiting using 5-HT(3) inhibitors and dexamethasone. However, many still experience these symptoms, and expert panels encourage additional methods to reduce these symptoms. OBJECTIVES:The objective was to assess the effectiveness of acupunct...
journal_title:The Cochrane database of systematic reviews
pub_type: 杂志文章,meta分析,评审
doi:10.1002/14651858.CD002285.pub2
更新日期:2006-04-19 00:00:00
abstract:BACKGROUND:Post-thrombotic syndrome (PTS) is a long-term complication of deep vein thrombosis (DVT) characterised by chronic pain, swelling and skin changes in the affected limb. One in every three patients with DVT will develop post-thrombotic complications within five years. OBJECTIVES:To determine the relative effe...
journal_title:The Cochrane database of systematic reviews
pub_type: 杂志文章,评审
doi:10.1002/14651858.CD004174.pub2
更新日期:2004-01-01 00:00:00
abstract:BACKGROUND:Chronic pain following mesh-based inguinal hernia repair is frequently reported, and has a significant impact on quality of life. Whether mesh fixation with glue can reduce chronic pain without increasing the recurrence rate is still controversial. OBJECTIVES:To determine whether tissue adhesives can reduce...
journal_title:The Cochrane database of systematic reviews
pub_type: 杂志文章,meta分析,评审
doi:10.1002/14651858.CD010814.pub2
更新日期:2017-02-07 00:00:00
abstract:BACKGROUND:Intravenous thrombolytic therapy is the standard care for patients with acute myocardial infarction, based upon its widespread availability and ability to reduce patient mortality well demonstrated in randomised trials. Despite its proven efficacy, thrombolytic therapy has limitations. Many patients are inel...
journal_title:The Cochrane database of systematic reviews
pub_type: 杂志文章,meta分析,评审
doi:10.1002/14651858.CD001560
更新日期:2003-01-01 00:00:00
abstract:BACKGROUND:Many people with cancer experience moderate to severe pain that requires treatment with strong opioids, such as oxycodone and morphine. Strong opioids are, however, not effective for pain in all people, neither are they well-tolerated by all people. The aim of this review was to assess whether oxycodone is a...
journal_title:The Cochrane database of systematic reviews
pub_type: 杂志文章,meta分析,评审
doi:10.1002/14651858.CD003870.pub6
更新日期:2017-08-22 00:00:00
abstract:BACKGROUND:Nausea and vomiting are common symptoms of patients with terminal, incurable illnesses and can be distressing. OBJECTIVES:The primary objective of the review was to evaluate the efficacy and adverse events associated with the use of haloperidol for the treatment of nausea and vomiting in palliative care pat...
journal_title:The Cochrane database of systematic reviews
pub_type: 杂志文章,评审
doi:10.1002/14651858.CD006271.pub2
更新日期:2009-04-15 00:00:00
abstract:BACKGROUND:There is increasing evidence that diabetic retinopathy is caused by the action of free radicals. Radical scavengers like vitamin C and superoxide dismutase (SOD) may influence the outcome and progression of diabetic retinopathy, but no systematic review of the literature has been published to examine this hy...
journal_title:The Cochrane database of systematic reviews
pub_type: 杂志文章,评审
doi:10.1002/14651858.CD006695.pub2
更新日期:2008-01-23 00:00:00
abstract:BACKGROUND:Concerns regarding the safety of transfused blood, have prompted reconsideration of the use of allogeneic (blood from an unrelated donor) red blood cell (RBC) transfusion, and a range of techniques to minimise transfusion requirements. OBJECTIVES:To examine the evidence for the efficacy of cell salvage in r...
journal_title:The Cochrane database of systematic reviews
pub_type: 杂志文章,meta分析,评审
doi:10.1002/14651858.CD001888
更新日期:2003-01-01 00:00:00
abstract:BACKGROUND:Knee osteoarthritis is a leading cause of chronic pain, disability, and decreased quality of life. Despite the long-standing use of intra-articular corticosteroids, there is an ongoing debate about their benefits and safety. This is an update of a Cochrane review first published in 2005. OBJECTIVES:To deter...
journal_title:The Cochrane database of systematic reviews
pub_type: 杂志文章,meta分析,评审
doi:10.1002/14651858.CD005328.pub3
更新日期:2015-10-22 00:00:00
abstract:BACKGROUND:Medications used to treat inflammatory bowel disease (IBD) have significantly improved patient outcomes and delayed time to surgery. However, some of these therapies are recognized to increase the general risk of infection and have an unclear impact on postoperative infection risk. OBJECTIVES:To assess the ...
journal_title:The Cochrane database of systematic reviews
pub_type: 杂志文章,meta分析
doi:10.1002/14651858.CD013256.pub2
更新日期:2020-10-24 00:00:00
abstract:BACKGROUND:Glaucoma is the international leading cause of irreversible blindness. Intraocular pressure (IOP) is the only currently known modifiable risk factor; it can be reduced by medications, incisional surgery, or laser trabeculoplasty (LTP). LTP reduces IOP by 25% to 30% from baseline, but early acute IOP elevatio...
journal_title:The Cochrane database of systematic reviews
pub_type: 杂志文章,meta分析,评审
doi:10.1002/14651858.CD010746.pub2
更新日期:2017-02-23 00:00:00
abstract:BACKGROUND:Early childhood vaccination is an essential global public health practice that saves two to three million lives each year, but many children do not receive all the recommended vaccines. To achieve and maintain appropriate coverage rates, vaccination programmes rely on people having sufficient awareness and a...
journal_title:The Cochrane database of systematic reviews
pub_type: 杂志文章,meta分析,评审
doi:10.1002/14651858.CD010038.pub3
更新日期:2018-05-08 00:00:00
abstract:BACKGROUND:In the intrinsic system of controlling airway calibre, the cholinergic (muscarinic) sympathetic nervous system has an important role. Anticholinergic, anti muscarinic bronchodilators such as ipratropium bromide are frequently used in the management of childhood airway disease. In asthma, ipratropium is a les...
journal_title:The Cochrane database of systematic reviews
pub_type: 杂志文章,meta分析,评审
doi:10.1002/14651858.CD003535
更新日期:2003-01-01 00:00:00
abstract:BACKGROUND:Atherosclerotic cardiovascular disease (ASCVD) is the leading cause of death and disability worldwide, yet ASCVD risk factor control and secondary prevention rates remain low. A fixed-dose combination of blood pressure- and cholesterol-lowering and antiplatelet treatments into a single pill, or polypill, has...
journal_title:The Cochrane database of systematic reviews
pub_type: 杂志文章,meta分析,评审
doi:10.1002/14651858.CD009868.pub3
更新日期:2017-03-06 00:00:00
abstract:BACKGROUND:Pain following brain surgery can compromise recovery. Several pharmacological interventions have been used to prevent pain after craniotomy; however, there is currently a lack of evidence regarding which interventions are most effective. OBJECTIVES:The objectives are to assess the effectiveness of pharmacol...
journal_title:The Cochrane database of systematic reviews
pub_type: 杂志文章,meta分析
doi:10.1002/14651858.CD011931.pub2
更新日期:2019-11-21 00:00:00
abstract:BACKGROUND:Methadone maintenance was the first widely used form of opioid replacement therapy developed to treat heroin dependence, and it remains the best-researched treatment for this problem. Despite the widespread use of methadone in maintenance treatment for opioid dependence in many countries, it is a controversi...
journal_title:The Cochrane database of systematic reviews
pub_type: 杂志文章,meta分析,评审
doi:10.1002/14651858.CD002209
更新日期:2003-01-01 00:00:00
abstract:BACKGROUND:There is considerable variation in use of pain relief for managing pain or discomfort of femoral sheath removal. Efficacy of pain relief to promote comfort during this procedure or to reduce the incidence of vascular and procedural complications has not been established. OBJECTIVES:Assess efficacy of pain r...
journal_title:The Cochrane database of systematic reviews
pub_type: 杂志文章,meta分析,评审
doi:10.1002/14651858.CD006043.pub2
更新日期:2008-10-08 00:00:00
abstract:BACKGROUND:This is an updated version of the original Cochrane review first published in Issue 9, 2010 on "Interventions for cough in cancer". Cough is a common symptom in patients with malignancies, especially in patients with lung cancer. Cough is not well controlled in clinical practice and clinicians have few manag...
journal_title:The Cochrane database of systematic reviews
pub_type: 杂志文章
doi:10.1002/14651858.CD007881.pub3
更新日期:2015-05-19 00:00:00
abstract:BACKGROUND:Both human menopausal gonadotropin (hMG) and human follicle stimulating hormone (hFSH) have been used successfully for ovarian stimulation, but the relative importance of FSH and luteinizing hormone (LH) in follicular growth and maturation has been the subject of much debate. OBJECTIVES:To conduct a systema...
journal_title:The Cochrane database of systematic reviews
pub_type: 杂志文章,评审
doi:10.1002/14651858.CD000061
更新日期:1996-04-22 00:00:00
abstract:BACKGROUND:Oral analgesia is a convenient and widely used form of pain relief following caesarean section. It includes various medications used at different doses alone or in adjunction to other form of analgesia. OBJECTIVES:To determine the effectiveness, safety and cost-effectiveness of oral analgesia for post-caesa...
journal_title:The Cochrane database of systematic reviews
pub_type: 杂志文章,meta分析,评审
doi:10.1002/14651858.CD010450.pub2
更新日期:2015-03-29 00:00:00
abstract:BACKGROUND:Therapeutic Touch (TT) is an alternative therapy that has gained popularity over the past two decades for helping wounds to heal. Practitioners enter a meditative state and pass their hands above the patient's body to find and correct any imbalances in the patient's 'life energy' or chi. Scientific instrumen...
journal_title:The Cochrane database of systematic reviews
pub_type: 杂志文章,meta分析,评审
doi:10.1002/14651858.CD002766.pub4
更新日期:2016-05-03 00:00:00
abstract:BACKGROUND:Misoprostol is a synthetic prostaglandin which has been used to induce labour. Oral use of the drug misoprostol may be convenient, but an overdose could cause uterine hyperstimulation and precipitate labour which may be life-threatening for both mother and fetus. OBJECTIVES:The objective of this review was ...
journal_title:The Cochrane database of systematic reviews
pub_type: 杂志文章,评审
doi:10.1002/14651858.CD001338
更新日期:2000-01-01 00:00:00