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PubMed1991

Strategies for the advancement of surgical methods in cleft lip and palate.

This paper examines the clinical research methodologies used for the evaluation of cleft lip and palate therapies. A survey of clinical reports in the Cleft Palate Journal between 1964 and 1988 revealed that almost all used retrospective methods (96%). The authors examine the merits and biases associated with retrospective evaluation of therapies and compared these to prospective randomized clinical trials. The strengths and weaknesses of clinical trials are discussed in relation to the long-term evaluation of primary surgery in cleft patients. For these to be successful, further work is needed to investigate questions such as sample size, possible predictors of long-term outcome, and improved methods of presurgical assessment. The authors conclude that if the uncertainties associated with the choice of primary cleft surgery are to be resolved, the challenge of multicenter prospective clinical trials must be faced by the various disciplines involved in cleft palate clinical research.

Cleft Lip↗
PubMed2005

Safety of transvenous cardiac resynchronization system implantation in patients with chronic heart failure: combined results of over 2,000 patients from a multicenter study program.

OBJECTIVES: The purpose of this study was to evaluate the safety of implanting a cardiac resynchronization therapy (CRT) system. BACKGROUND: Clinicians and patients require data on the safety of the CRT implant procedure to estimate procedural risk. METHODS: We evaluated outcomes of transvenous CRT system implantation in 2,078 patients from the Multicenter InSync Randomized Clinical Evaluation (MIRACLE) study, the MIRACLE Implantable Cardioverter-Defibrillator (ICD) study, and the InSync III study. We compared the MIRACLE study to the InSync III study and the MIRACLE ICD study randomized phase to its general phase to evaluate the effect of new technologies. RESULTS: The implant attempt succeeded in 1,903 of 2,078 (91.6%) patients. Implant time decreased from 2.7 h in the MIRACLE study to 2.3 h in the InSync III study (p < 0.001), and from 2.8 h in the MIRACLE ICD study randomized phase to 2.4 h in the general phase (p < 0.001). The implant procedure produced 62 perioperative complications in 53 (9.3%) MIRACLE trial patients; 159 in 135 (21.1%) MIRACLE ICD study randomized phase patients and 71 in 62 (13.9%) general phase patients (p < 0.05 vs. randomized); and 41 in 37 (8.8%) InSync III study patients (p = NS vs. the MIRACLE study). We observed 73 postoperative complications in 62 (11.7%) MIRACLE trial patients, 77 in 68 (11.9%) MIRACLE ICD study randomized phase patients and 56 in 45 (11.0%) general phase patients (p = NS), and 37 in 34 (8.6%) InSync III study patients (p = NS). A total of 8% of patients required reoperation to treat lead dislodgement, extracardiac stimulation, or infection during follow-up. CONCLUSIONS: Transvenous CRT system implantation appears safe, well-tolerated, has a high success rate, and improves with operator experience and the addition of new technologies.

Aged↗
PubMed2003

Update on Novo Nordisk's clinical trial programme on NovoSeven.

Recombinant coagulation factor VIIa (rFVIIa; Novoseven, Novo Nordisk A/S, Bagsvaerd, Denmark) is registered in most regions of the world for the treatment of bleeding episodes in haemophilia patients with inhibitors to factor VIII or IX. Since its initial availability, there have been several case stories on the investigational use of rFVIIa as a haemostatic agent in a variety of bleeding patients. Novo Nordisk recognizes the need to establish clinical guidance, and when possible, regulatory approvals for indications with bleeding episodes of various aetiologies. Currently, the safety and efficacy of rFVIIa is being investigated in 11 multinational, phase II trials, involving more than 1500 patients. Most of these trials have been designed to establish the efficacy of rFVIIa as a rescue treatment in episodes of severe life-threatening (upper gastrointestinal bleeding, stem cell transplantation, intra-cerebral haemorrhage and trauma). The remaining focus is on the prophylactic use of rFVIIa to improve haemostasis during surgery (orthotopic liver transplantation and liver resection), with the aim of avoiding or reducing the need for blood transfusions. In addition, Novo Nordisk is also continuing studies in haemophilia patients with inhibitors to increase therapeutic knowledge within this indication. Studies addressing dosages and regimens in subpopulations are presently ongoing.

Blood Coagulation Disorders↗
PubMed2004

Update on the management of hypertension: recent clinical trials and the JNC 7.

The following issues are highlighted: Emphasis is placed on the importance of systolic blood pressure elevations in estimating risk and in determining prognosis. A review of placebo-controlled clinical trials indicates that cardiovascular events are statistically significantly reduced with diuretic- or b blocker-based treatment regimens. The question of whether blood pressure lowering alone or specific medications make the difference in outcome is discussed. Based on the results of numerous trials, it is apparent that blood pressure lowering itself is probably of greater importance in reducing cardiovascular events than the specific medication used. Meta-analyses suggest, however, that the use of an agent that blocks the renin-angiotensin aldosterone system is probably more effective in diabetics and in patients with nephropathy than a regimen based on calcium channel blocker therapy. The Antihypertensive and Lipid-Lowering treatment to Prevent Heart Attack Trial (ALLHAT) reported no overall difference in coronary heart disease outcome among patients treated with a diuretic-based compared to a calcium channel blocker- or an angiotensin-converting enzyme inhibitor-based treatment program. However, patients in the diuretic group experienced fewer episodes of heart failure than in the calcium channel blocker group and fewer episodes of heart failure and strokes than those in the angiotensin-converting enzyme inhibitor group. Results were similar in diabetics and nondiabetics. Possible reasons for this outcome are discussed. The Australian National Blood Pressure 2 study, which was unblinded, reported a marginally significantly better outcome only in male patients receiving an angiotensin-converting enzyme inhibitor-based regimen compared to those receiving a diuretic-based program. Finally, the Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC 7) is reviewed. Highlights of this report include the new designation of prehypertension, i.e., blood pressures of 120-139 mm Hg/80-89 mm Hg. The JNC 7 suggested that diuretics should be the first-step drug of choice in most patients, but listed numerous specific reasons why other agents should be used in special situations. The report stressed that the majority of patients will require two or more medications to achieve goal blood pressure.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed1995

Exploratory or analytic meta-analysis: should we distinguish between them?

Meta-analysis has been defined as a study and "statistical analysis which combines or integrates the results of several independent studies." Included in this definition are other terms, such as systematic overviews, pooling data, pooling study results, and quantitative literature reviews. Like any study, the questions being asked will influence the design and the method of analysis of the meta-analysis. Since a meta-analysis is a study based on a literature review, it is inherently observational rather than experimental in nature. This idea is supported by the fact that the meta-analyst has limited control over the availability of studies or the information collected and reported in the individual studies. Meta-analysis has been applied to clinical trials and epidemiology. At first glance the potential for bias appears greater in epidemiology than in clinical trials. But this may depend on the question being asked. If randomized clinical trials are limited to improving an estimate of effect or testing a hypothesis in a relatively homogeneous set of effect sizes, the clinical trial will tend to be less prone to bias than a comparable set of epidemiologic studies. In this context, the issue of combinability may dominate the meta-analysis. We refer to this type of meta-analysis as an "analytic" meta-analysis. On the other hand when the goal is to resolve controversy, or pose and answer new questions the main concern of the meta-analysis is to explain the variation in the effect sizes. We refer to this application of a meta-analysis as an "exploratory" meta-analysis. In this second type of meta-analysis the characteristics of the different studies become the focus of the analysis. This leads to the idea that protocols for a meta-analysis should reflect its goals and how the results are to be used. Finally, we will consider whether there is a role of meta-analysis in the field of drug development.

Bias↗
PubMed1997

Ten years of improvement in the standard of randomised controlled clinical trials in four international journals.

One hundred reports of randomised controlled clinical trials in BMJ, Lancet, N Engl J Med, and Br J Surg in 1996 were compared with 100 reports published worldwide in 1979 to 1984 in terms of design and conduct, analysis, and presentation. In all these respects the recently published trials were significantly better than those of 12 to 17 years ago. There is, however, room for further improvement.

Evaluation Studies as Topic↗
PubMed1998

The role of self-treatment guidelines in self-management education for adult asthmatics.

Guidelines on asthma management have changed considerably in the last two decades. Patient education has gained in popularity and especially asthma self-management training is thought to be essential in the treatment of adult asthma. Since 1989 many researchers have added self-treatment guidelines to self-management programmes and several studies have found improvements in health outcomes, such as lung function, quality of life, use of health care facilities and asthma symptoms. However, because of the lack of proper control groups, it is not clear whether this has to be attributed to self-treatment guidelines or to, for example, more education or more medical attention. The only two studies that were placebo controlled did not show an effect of self-treatment. To assess the added benefit of self-treatment guidelines to a self-management programme, randomized 'placebo' controlled trials of sufficient size with sufficient follow-up time are necessary. The only difference between intervention and control groups should be guidelines for self-treatment.

Adult↗
PubMed2004

Poststroke epilepsy: epidemiology, pathophysiology and management.

Seizures and status epilepticus can be a presenting feature of acute stroke. They may occur in its early (<7 days) clinical course or be a remote (>7 days) complication. Most seizures are single, either partial or generalised. Early and remote seizures seem to have different predictors and pathogenesis. Seizures are more frequent in severe and disabling strokes, haemorrhagic strokes and those with cortical involvement. The risk of epilepsy is higher for patients with early seizures, cortical infarctions and lobar haemorrhages and in dependent patients. Early or remote seizures do not have a significant influence on dependency or mortality, although seizures and status epilepticus can be a direct cause of death. Treatment can be started after a first or a recurrent seizure. Treatment options include phenytoin, carbamazepine, valproic acid (valproate sodium) and the new antiepileptic drugs (AEDs). New AEDs can be used to decrease the likelihood of drug interactions and adverse effects in patients who do not tolerate the classic AEDs and in treatment failures with classic AEDs. Large observational studies to define prognostic factors for poststroke seizures in specific stroke subtypes are needed. Randomised controlled trials of AED prophylaxis for acute and remote seizures are essential to improve the evidence level of current guidelines and recommendations.

Anticonvulsants↗