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Results for “Randomized Controlled Trials as Topic”

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PubMed1997

Are community health interventions evaluated appropriately? A review of six journals.

OBJECTIVES: To determine if Randomized Controlled Trial (RCT) methodology was used appropriately in community health, we: (1) determined the proportion of non-randomized studies that should have been RCTs, and (2) assessed the quality of the RCTs. METHODS: The 1992 issues of six community health journals were manually searched. Intervention studies were analyzed. Studies that did not use randomization were analyzed for feasibility and practicality of RCT methods; RCTs were analyzed for quality using a checklist. RCTs were compared with community health RCTs from The New England Journal of Medicine. The proportion of studies meeting each criterion was determined. RESULTS: Fourteen percent of 603 studies were interventions and 4% were RCTs. Of those not using randomization, 42% should have. Mean RCT scores were significantly lower for the community health journals than for The New England Journal of Medicine. Many criteria important to quality scored poorly. CONCLUSIONS: RCTs are underused and lack methodologic rigor in community health. Conclusions regarding the effectiveness of interventions are therefore suspect.

Community Medicine↗

PubMed1999

Asthma management: evidence based studies and their implications for cost-efficacy.

This review attempts to infer a cost-effective strategy for the management of bronchial asthma based on evidence from randomized controlled trials. Acute severe asthma should be treated with short-acting inhaled beta-agonists followed by a short course of oral steroids. Decisions on hospital admission should be made within 1 to 2 hours and prolonged treatment in emergency departments avoided. A comprehensive educational and drug optimizing program will prevent chronic illness and relapse. Educational programs should be brief but intensive, supervised by asthma specialists and incorporate self monitoring of symptoms plus written action plans. Peak expiratory flow monitoring should not be mandated for all patients. Inhaled corticosteroids (ICS) are the most cost-effective drugs for the long term prevention of asthma. ICS should be started at low doses. If the symptoms of asthma are not well controlled by moderate doses of ICS, high dose ICS treatment should be avoided and add on medication prescribed instead. Oral bronchodilators are less expensive add on medication than long-acting inhaled beta-agonists.

Anti-Asthmatic Agents↗

PubMed2002

The influence of hyperhomocysteinemia on graft patency after infrainguinal bypass surgery in the Dutch BOA Study.

OBJECTIVE: Hyperhomocysteinemia has been identified as a risk factor for (cardio)vascular disease. Whether hyperhomocysteinemia contributes to graft failure after peripheral bypass surgery remains unclear. The present study evaluated the influence of hyperhomocysteinemia on graft patency after infrainguinal bypass surgery. DESIGN: The present study was designed as a nested case-control study. METHOD: In this study (nested in the Dutch Bypass Oral anticoagulants or Aspirin Study), 150 patients with graft occlusion were each matched with two randomly selected controls with patent grafts (N = 299) from the same trial. Venous blood samples were drawn from cases and controls, and total plasma homocysteine (tHcy) was determined. Mean serum homocysteine levels and the presence of hyperhomocysteinemia (>95th percentile in healthy individuals) were compared between cases and controls. RESULTS: No significant differences were found between serum levels of homocysteine in patients with and without graft occlusion. The mean plasma homocysteine levels were 14.4 micromol/L and 14.9 micromol/L in the case and control groups, respectively. The resulting mean difference was -0.4 (95% confidence interval [CI], -1.8-0.9). The odds ratio of hyperhomocysteinemia was 0.81 (95% CI, 0.49-1.33). Adjustment for risk factors of graft occlusion did not change these results. CONCLUSIONS: Postoperative raised serum levels of homocysteine proved not to be a risk factor for graft occlusion after infrainguinal bypass grafting.

Aged↗

PubMed2005

Comparison of ezetimibe plus simvastatin versus simvastatin monotherapy on atherosclerosis progression in familial hypercholesterolemia. Design and rationale of the Ezetimibe and Simvastatin in Hypercholesterolemia Enhances Atherosclerosis Regression (ENHANCE) trial.

BACKGROUND: Lipid lowering through statin therapy significantly reduces the risk of cardiovascular events. The ENHANCE study is an international 2-year, randomized, double-blind, controlled trial designed to test the hypothesis that treatment of hypercholesterolemia by use of 2 complementary agents, ezetimibe (a specific cholesterol absorption inhibitor) and simvastatin (a 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor), will result in larger beneficial effects on carotid artery intima-media thickness (CA IMT) than simvastatin monotherapy. METHODS: The study will recruit 725 men and women with heterozygous familial hypercholesterolemia. After a placebo washout period, participants are randomized to receive daily administration of either simvastatin 80 mg and ezetimibe 10 mg or simvastatin 80 mg and placebo. The ENHANCE trial uses novel state-of-the-art single-frame digital image acquisition and rigorous quality assurance and control. RESULTS: The primary end point is mean change from baseline to 2 years in CA IMT, using composite measures from the right and left far wall common carotid artery, carotid bulb, and internal carotid artery. Secondary end points include (1) the proportion of participants who exhibit reductions in CA IMT, (2) the change in maximum far wall IMT, (3) the proportion of participants who develop new carotid artery plaques, and (4) the changes in carotid plus common femoral artery IMT. CONCLUSIONS: This study addresses the question of whether a regimen that uses drugs with different mechanisms of action will be of further benefit in terms of atherosclerosis reduction compared to statin monotherapy.

Adult↗

PubMed2002

Classic or Bayesian research design and analysis. Does it make a difference?

OBJECTIVE: The role of classical and Bayesian statistical approaches remains in dispute in health services research and policy. The goal of this study was to determine if results differ when both analytic techniques are used with the same data set. DESIGN: We searched MEDLINE and related databases for English-language articles published January 1, 1978 through August 31, 1999. We combined Bayesian and classical statistics search terms and their variants with randomized control trials (RCTs) and meta-analyses. RESULTS: Searches found 18 studies in 14 publications that met all review criteria--nine RCTs, eight meta-analyses, and one epidemiologic estimate. Statistical analyses using both methods agreed in five RCTs, four meta-analyses, and for the epidemiologic estimates. For four RCTs where results disagreed, classical analysis found the experimental intervention was efficacious compared with the control, and Bayesian reanalysis concluded the intervention was not proven efficacious. Classical meta-analyses of the four studies where results disagreed concluded the experimental intervention was not better than the control; Bayesian reanalysis concluded it was efficacious. CONCLUSION: Classical and Bayesian methods in this review exhibited important divergence of results. Disagreement on many fundamental beliefs between classical and Bayesian statistics means continuing debate. One way to resolve this debate is for proponents of each technique to decide together the circumstances for use of each method and analytic framework. If the experts do not agree on the methodologic requirements, other decision makers likely will force their own views.

Bayes Theorem↗

PubMed2006

Information and low back pain management: a systematic review.

STUDY DESIGN: A systematic search of three electronic databases was done to identify randomized controlled trials on the effect of written or audiovisual information in low back pain. OBJECTIVES: To determine whether information is an effective preventive action and/or therapy for low back pain and which type of information is most effective. SUMMARY OF BACKGROUND DATA: Information is commonly used in the primary care of low back pain and mostly delivered by booklets. METHODS: A systematic computer-aided search of the Medline, PsyclInfo, and Embase database. A rating system was used to assess the strength of the evidence, based on the methodologic quality of the randomized controlled trials, the relevance of the outcome measures, and the consistency of the results. RESULTS: Eleven randomized controlled trials were selected, including seven trials of high methodologic quality, as well as one parallel group controlled survey and one longitudinal study. Only three of the seven high-quality studies showed favorable results for information. There is strong evidence that a booklet increases knowledge and moderate evidence that physician-related cues increase the confidence in a booklet and adherence to exercises. There is limited evidence that a biopsychosocial booklet is more efficient than a biomedical booklet to shift patient's beliefs about physical activity, pain, and consequences of low back trouble. There is strong evidence that booklets are not efficient on absenteeism and conflicting evidence that they are efficient on healthcare use. There is no evidence that e-mail discussion or video programs alone are effective to reduce low back pain, disability, and healthcare costs. CONCLUSIONS: Information based on a biopsychosocial model is recommended in primary care to shift patient beliefs on low back pain. Nevertheless, information delivery alone is not sufficient to prevent absenteeism and reduce healthcare costs.

Databases, Factual↗

PubMed1998

Implementing guidelines and innovations in general practice: which interventions are effective?

BACKGROUND: It is crucial that research findings are implemented in general practice if high-quality care is to be achieved. Multifaceted interventions are usually assumed to be more effective than single interventions, but this hypothesis has yet to be tested for general practice care. This review evaluates the effectiveness of interventions in influencing the implementation of guidelines and adoption of innovations in general practice. A systematic literature study was carried out using MEDLINE searches for the period from January 1980 until June 1994, and 21 medical journals were searched manually. Randomized controlled trials and controlled before and after studies (with pre- and post-intervention measurements in all groups) were selected for the analysis. Clinical area, interventions used, methodological characteristics and effects on clinical behaviour were noted independently by two researchers using a standardized scoring form. Of 143 studies found, 61 were selected for the analysis, covering 86 intervention groups that could be compared with a control group without the intervention. Information transfer alone was effective in two out of 18 groups, whereas combinations of information transfer and learning through social influence or management support were effective in four out of eight and three out of seven groups respectively. Information linked to performance was effective in 10 out of 15 groups, but the combination of information transfer and information linked to performance was effective in only three out of 20 groups. Some, but not all, multifaceted interventions are effective in inducing change in general practice. Social influence and management support can improve the effectiveness of information transfer, but information linked to performance does not necessarily do so. The variation in the effectiveness of interventions needs further analysis.

Family Practice↗

PubMed1999

New primary prevention trials of sudden cardiac death in patients with left ventricular dysfunction: SCD-HEFT and MADIT-II.

Primary prevention of sudden arrhythmic death in patients with organic heart disease with poor left ventricular function and/or heart failure is currently a major challenge in cardiology. Amiodarone (with or without beta blockers) and the implantable cardioverter defibrillator (ICD) are considered the 2 major therapeutic tools to prevent sudden arrhythmic death in these patients. Two large trials have been launched to define the prophylactic benefit of the ICD or amiodarone on total mortality in patients that receive optimal heart failure and anti-ischemic treatment but remain at high risk of dying suddenly. The Sudden Cardiac Death in Heart Failure Trial (SCD-Heft) is designed to determine whether amiodarone or the ICD will decrease overall mortality in patients with coronary artery disease or nonischemic cardiomyopathy who are in heart failure New York Heart Association (NYHA) class II or III and have a left ventricular ejection fraction < 35%. The primary endpoint is total mortality; secondary objectives are comparison of arrhythmic and nonarrhythmic mortality and morbidity in the 3 arms as well as quality of life, cost-effectiveness, and incidence of episodes of ventricular tachyarrhythmias. The Multicenter Automatic Defibrillator Implantation Trial (MADIT) II is a follow-up study to the MADIT trial. It examines the prophylactic benefit in coronary artery disease patients with a left ventricular ejection fraction of < 30%, who have had at least 1 myocardial infarction but require no further risk stratification. MADIT II is a sequential design trial that compares ICD versus no ICD therapy. Programmed electrical stimulation to test inducibility of ventricular tachycardia is performed during ICD implantation, and various noninvasive risk markers are tested after randomization. Primary endpoint is total mortality, and secondary objectives are quality-of-life issues as well as cost-effectiveness ratio.

Adult↗

PubMed2002

Clinical practice guideline on the use of manipulation or mobilization in the treatment of adults with mechanical neck disorders.

PURPOSE: An evidence-based clinical practice guideline was developed to ascertain the risks and benefits for manipulation or mobilization in treating mechanical neck disorders with or without radicular findings or cerviogenic headache. Pain, function, patient satisfaction and adverse events were appraised. METHODS: The practice guideline development cycle/model and Cochrane reviewing process, critiquing past reviews, randomized trials and surveys were used. RESULTS: Manipulation and mobilization alone showed similar effects as placebo, wait period, or control group, and appeared similar in benefit for pain relief. While high-technology exercises were superior to manipulation alone for improving long-term pain scores, manipulation plus low-technology exercise had the same effect. Patient satisfaction scores favoured manipulation plus low-technology exercise over manipulation alone, and high-technology exercise alone. Multi-modal care including some combination of manipulation or mobilizations and exercise was superior to control, other physical medicine methods, and rest. Based on weak evidence, estimates for serious complication for manipulation ranged from one in 20,000 to five in 10,000,000. RECOMMENDATIONS: Stronger evidence suggests a multi-modal management strategy using mobilization or manipulation plus exercise is beneficial for relief of mechanical neck pain. Weaker evidence suggest less benefit to either manipulation/mobilization done alone than when used with exercise. The risk rate is uncertain.

Evidence-Based Medicine↗

PubMed2005

ISAT and ISUIA: the impact on informed consent.

The International Subarachnoid Aneurysm Trial (ISAT) was a multicenter randomized trial that compared the safety and efficacy of endovascular coil treatment versus surgical clipping for the treatment of ruptured brain aneurysms. To be eligible for enrollment in the ISAT trial, each patient had to be deemed equally suitable for either coiling or clipping. The investigators used the term "clinical equipoise" to describe this balance. This study more than any other has set the playing field for the future of interventional radiology/endovascular neurosurgery politics.

Aneurysm, Ruptured↗

PubMed2004

Atrial fibrillation and cardioembolic stroke.

The most disabling consequence of atrial fibrillation (AF) is stroke. In the elderly, AF is the single most important cause of stroke. The risk of stroke is increased at least 6-fold in subjects with AF. Strokes in patients with AF are in general severe, associated with higher risk of fatality and prone to early and long-term recurrence. The cardiac origin of stroke can be strongly suspected by anamnesis, clinical examination and findings on neuroimaging. Paroxysmal AF is an important cause of brain embolism, that is often difficult to document. Risk factors for stroke in AF include: previous embolism (including previous transient ischaemic attack (TIA), or ischaemic stroke), age >65 years, structural cardiac disease, rheumatic or other significant valvular heart disease, valvular artificial prosthesis, hypertension, heart failure and significant left ventricular systolic dysfunction, diabetes and coronary disease. All AF patients with TIA or stroke have a formal indication for long-term anticoagulation. Only patients without risk factors or with contraindications to warfarin should be put on aspirin. Treating 1 000 patients with AF for 1 year with oral anticoagulants rather than aspirin would prevent 23 ischaemic strokes while causing 9 major bleedings. Despite its enormous preventive potential, oral anticoagulants are underused in AF, because treating physicians often have lack of knowledge about trials and guidelines, underestimate the benefits and overestimate the risks associated with continuous oral anticoagulation. The introduction of anticoagulants that do not need frequent control tests, such as ximelagatran, will increase the proportion of AF patients with risk factors for stroke who are anticoagulated. There is no evidence to support routine immediate anticoagulation in acute ischeamic stroke associated with AF.

Adult↗

PubMed1995

The need for evidence-based medicine.

As physicians, whether serving individual patients or populations, we always have sought to base our decisions and actions on the best possible evidence. The ascendancy of the randomized trial heralded a fundamental shift in the way that we establish the clinical bases for diagnosis, prognosis, and therapeutics. The ability to track down, critically appraise (for its validity and usefulness), and incorporate this rapidly growing body of evidence into one's clinical practice has been named 'evidence-based medicine' (EBM).

Clinical Medicine↗

PubMedDate not supplied

Meta-analysis of randomized educational and behavioral interventions in type 2 diabetes.

PURPOSE: This meta-analysis was conducted to assess the effect of educational and behavioral interventions on body weight and glycemic control in type 2 diabetes. METHODS: Studies selected for analysis were published randomized controlled trials that evaluated educational and behavioral interventions (no drug interventions) in type 2 diabetes (sample size > or = 10). These criteria were applied to searches of electronic databases and relevant bibliographies. Data were independently abstracted by 2 reviewers and adjudicated by consensus. RESULTS: Of the 63 articles that met the inclusion criteria, 18 provided enough information for pooled estimates of glycohemoglobin (total Ghb, HbA1, or HbA1C). These 18 studies yielded 2720 participants (sample sizes of 18 to 749). Interventions ranged from 1 to 19 months; follow-up ranged from 1 to 26 months. Glycohemoglobin was reduced by a mean of 0.43%. When results were stratified by quality score, glycohemoglobin was -0.50% and -0.38% for studies with high and low quality scores, respectively. When weighting studies by sample size, fasting blood glucose was reduced by 24 mg/dL and weight by 3 lbs. CONCLUSIONS: Previous educational and behavioral interventions in type 2 diabetes have produced modest improvements in glycemic control. Future research should refine such interventions and improve methodology.

Blood Glucose↗

PubMed2000

Bipolar disorder therapeutics: maintenance treatment.

Although most of the care received by bipolar patients occurs during the maintenance phase, relatively little empirical data is available to guide long-term treatment decisions. We review literature pertaining to key questions related to use of pharmacotherapy in the maintenance phase of bipolar disorder. The few double-blind trials with a reasonable sample size are restricted to bipolar I patients and address a modest range of questions mostly related to use of lithium. One rigorous multicenter trial found valproate to have prophylactic benefit. Other studies with valproate alone and in combination suggest efficacy equivalent to lithium and perhaps greater than carbamazepine. Data available for combination treatment are sparse but moderately encouraging. Maintenance treatment with standard antidepressant medications appears destabilizing for some bipolar patients, particularly following a mixed episode. Although some bipolar patients may benefit from combined treatment with a mood stabilizer and a standard antidepressant medication, current knowledge does not allow confident selection of the bipolar patients who might benefit. Clozapine and perhaps other atypical antipsychotics are promising options for maintenance treatment but have not been evaluated in double-blind trials. The numerous other agents used in maintenance treatment are primarily adjuncts to lithium, valproate, or carbamazepine, and information about them is largely anecdotal and uncontrolled. Study design for maintenance trials remains an imperfect art. Conclusions must be drawn cautiously, given the limited generalizability of study designs that accession samples enriched with presumed treatment responders, randomize patients after brief periods of partial remission, abruptly taper prior treatment, make no attempt to distinguish relapse from recurrence, use no formal outcome assessments, or report hospitalization as the only outcome criterion.

Antidepressive Agents↗

PubMed2001

Intercenter variance in clinical trials of head trauma--experience of the National Acute Brain Injury Study: Hypothermia.

OBJECT: In a recently conducted trial of hypothermia in patients with severe brain injury, differences were found in the effects of hypothermia treatment among various centers. This analysis explores the reasons for such differences. METHODS: The authors reviewed data obtained in 392 patients treated for severe brain injury. Prerandomization variables, critical physiological variables, treatment variables, and accrual methodologies were investigated among various centers. Hypothermia was found to be detrimental in patients older than the age of 45 years, beneficial in patients younger than 45 years of age in whom hypothermia was present on admission, and without effect in those in whom normothermia was documented on admission. Marginally significant differences (p < 0.054) in the intercenter outcomes of hypothermia-treated patients were likely the result of wide differences in the percentage of patients older than 45 years of age and in the percentage of patients in whom hypothermia was present on admission among centers. The trial sensitivity was likely diminished by significant differences in the incidence of mean arterial blood pressure (MABP) less than 70 mm Hg (p < 0.001) and cerebral perfusion pressure (CPP) less than 50 mm Hg (p < 0.05) but not intracranial pressure (ICP) greater than 25 mm Hg (not significant) among patients in the various centers. Hours of vasopressor usage (p < 0.03) and morphine dose (p < 0.001) and the percentage of dehydrated patients varied significantly among centers (p < 0.001). The participation of small centers increased intercenter variance and diminished the quality of data. CONCLUSIONS: For Phase III clinical trials we recommend: 1) a detailed protocol specifying fluid and MABP, ICP, and CPP management: 2) continuous monitoring of protocol compliance; 3) a run-in period for new centers to test accrual and protocol adherence; and 4) inclusion of only centers in which patients are regularly randomized.

Adult↗

PubMed2006

Cautionary tales in the interpretation of systematic reviews of therapy trials.

This is the second in a series of articles emphasizing the cautions in the interpretation of health-care studies. Systematic reviews are presented as comprehensive, unbiased summaries of evidence and are often referred to by clinicians, guideline developers and health policy-makers. Their strengths and limitations, and how their results can be subject to bias and misinterpretation, are discussed.

Humans↗

PubMed2002

Innovation in surgery: the rules of evidence.

The intellectual infrastructures of evidence-based medicine (EBM) are the levels of evidence and the grades of recommendation for the following types of research articles: therapy/prevention, etiology/harm, prognosis, diagnosis, differential diagnosis/symptom prevalence study, economic analysis/decision analysis. The levels of evidence for therapy (1 to 5) progress from systematic reviews (with homogeneity) of randomized control trials (RCT) of high quality, level 1, to level 5-expert opinion without explicit critical appraisal, or based on physiology, bench research, or "first principles." The grades of recommendation (A, B, C, D) are founded on the quality of the evidence defined by its level. These grades are aimed at helping clinicians understand the source from whence came statements in, for example, guidelines. The development of surgical procedures and their introduction into practice has not depended upon the RCT but rather upon an enthusiast performing a case series, sometimes with clearly defined results. Should all operations and procedures be evaluated by an RCT? Clearly not, and the levels of evidence support this quite clearly with the "all or none" research category as level 1c. This relates to frequent clinical situations requiring a solution often immediate, eg, pus, a ruptured aneurysm, a sucking chest wound, that do not lend themselves to a trial, as the control regimen (doing nothing) would lead to death. Techniques evolve with experience usually based on an understanding of pathophysiology. At what point should an RCT enter into the resolution of surgical therapies? Can observational studies correctly designed and carried out do the job? Two new study classifications have been introduced: in level 1, category c "all or none" studies; and in level 2, category c "outcomes" research. In neither is there much definition. Are these the areas into which the evaluation of new surgical procedures and technology should be placed? The surgical community is faced with dramatic changes in technology and evolving techniques, and needs to define the rules of evidence applicable to their discipline with the same rigor that the EBM gurus have used, in order for surgeons to define evidence-based surgical practice.

Evidence-Based Medicine↗

PubMed2001

Treatment of multiple sclerosis with hyperbaric oxygen therapy.

Despite considerable research effort there is little controlled evidence that a course of hyperbaric oxygen therapy (HBO2T) results in any benefit for patients with multiple sclerosis (MS). The great majority of randomized trials involved investigating a course of 20 treatments at pressures between 1.75 and 2.5 atm abs daily for 60-120 min over 4 wk against a placebo regimen. None has tested the efficacy of HBO2T against alternative current best practice. A systematic review of this randomized evidence suggests there is no significant benefit from the administration of HBO2T (Improved EDSS after HBO2T: OR = 2.02, 95% CI 0.63-6.43. Improved sphincter function: OR = 1.3, 95% CI 0.8-2.11). On average, 42 patients would need to be treated before we could expect one individual to benefit with an improved disability status score; however, we cannot be confident that the number we would need to treat is less than infinite (NNT = 42, 95% CI 15 to infinity). There is some case for further investigation of possible therapeutic effects in selected sub-groups of patients and for the response to prolonged courses of HBO2T at more modest pressures; however, the case is not strong. At this time, we cannot recommend the routine treatment of MS with HBO2T.

Evidence-Based Medicine↗