PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Clinical Trials”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources
PubMed1991

Cancer clinical trials. Clinical trials programs.

The National Cancer Institute (NCI) is the largest single sponsor of studies using anti-neoplastic agents with over 100 compounds currently in various stages of clinical testing. Most of the clinical trials are conducted by the NCI sponsored cooperative oncology groups and community oncology programs, cancer centers, and the pharmaceutical industry. These organizations conduct studies both independently as well as in a collaborative fashion.

Clinical Protocols↗
PubMed1991

A decade of progress in statistical methodology for clinical trials.

Clinical trials played a dominant and expanding role in the evaluation of new treatments during the decade of the 1980s. There were major improvements in the quality of clinical trials in many medical fields. There were also important developments in the methodology of designing, monitoring, conducting, analysing, reporting and interpreting clinical trials. This paper attempts to review some of these developments. A comprehensive review is beyond the abilities of any one individual. Consequently, this paper attempts to offer a broad stroke description of this area and to highlight specific topics of importance based on my particular experience. An extensive, but non-comprehensive bibliography is included to provide entry points to the literature of methodologic developments for clinical trials in the 1980s.

Clinical Trials as Topic↗
PubMed1987

Should the elderly hypertensive be treated? Evidence from clinical trials.

Clinical trials for over 15 years have addressed the therapeutic utility of treating elderly hypertensives. Many early trials showed no treatment effects. Because of the recent publication of new information, a review of available evidence concerning this issue was undertaken. Eight randomized clinical trials were assessed regarding trial design. The studies varied according to generalizability, diagnostic criteria, choice of therapy, outcome measures assessed, evaluation of compliance, methods of analysis, duration of follow-up, determination of side effects, and ability to exclude a type 2 error. While many of the earlier studies found no treatment effects, they lacked methodologic rigor; more recent studies demonstrated positive treatment effects. Pooling of results from similar trials supports a notable treatment effect in the prevention of stroke. There is also evidence that the elderly are not more susceptible to side effects of antihypertensive drugs, as is generally believed. The best evidence suggests the hypertensive elderly should be treated.

Aged↗
PubMed1992

Modulation of fluorouracil with recombinant alfa interferon: M. D. Anderson Clinical trial.

Clinical trials have been initiated examining the combination of fluorouracil (5-FU) and recombinant interferon alfa-2a (rIFN-2a) in the treatment of advanced colorectal carcinomas. An early trial reported a response rate of 76%, encouraging further investigation. Clinical trials have used 5-FU administered as a continuous intravenous infusion, 750 mg/m2 per day for 5 consecutive days, followed by weekly bolus administration of 5-FU 750 mg/m2. Recombinant interferon alfa-2a, 9 million units, was administered subcutaneously three times weekly. Of 45 evaluable patients treated at The University of Texas M. D. Anderson Cancer Center, a response rate of 35% (95% confidence interval, 22%, 50%) was observed. Twenty-five percent of patients developed grade 4 toxicity and 82% developed grade 3 toxicity. The median survival was 16 months. Investigation of this combination will require randomized trials to further assess activity in relation to alternative treatments.

Antineoplastic Combined Chemotherapy Protocols↗
PubMedDate not supplied

[Ethics and clinical trials].

Clinical research is indispensable for determining the safety and efficacy of drugs in human. It provides the scientific basis for rational drug usage. Methodology of clinical trials can raise some ethical issues. As an example the use of a placebo is described in this paper. Generally the ethical issues may be solved by the adequate information of every individual assigned to clinical investigation in agreement with the Declaration of Helsinki and the Huriet law. This information must be approved by an ethical committee. Finally an information about the general provisions of clinical trials must be destined to the general public.

Clinical Trials as Topic↗
PubMedDate not supplied

Clinical trials.

Clinical trials are a relatively underused form of investigation in family medicine. This paper presents an overview of those considering conducting or assessing a clinical trial. A bibliography for further reading is also provided. Topics covered include aspects of: the development of a protocol; design such as randomization and binding; the special role of non-drug studies in family medicine; measurement--especially combating bias; analysis--particularly the management of drop-outs; and, the problem of generalizability.

Clinical Protocols↗
PubMed1990

Interim analyses in clinical trials.

Clinical trials of new cancer treatments often involve multiple analyses of the data to address concerns related to medical ethics and the costs and efficiency of medical research. Failure to account for such interim analyses can introduce significant bias into the results of a study. The authors discuss the role of interim analyses in clinical trials and describe the factors that need to be considered in the planning, monitoring, and reporting of a study involving group sequential hypothesis tests.

Bias↗
PubMed1989

Optimising oral rehydration solution composition for the children of Europe: clinical trials.

Clinical trials testing different oral rehydration solutions (ORS) are reviewed. The effects of individual components and their concentrations are analysed in order to establish margins of safety for the composition of the ideal ORS for children in Europe. Glucose is the solute of choice for ORS and concentrations of 70-140 mmol/l are adequate. Glucose may be replaced by sucrose or glucose polymers. "Low" sodium concentrations (35-60 mmol/l) are advised for rehydration and maintenance in acute non-cholera diarrhoea, for children of all ages, including neonates, and for any degree of dehydration except shock. Although intended for children who are not malnourished, the European ORS should have an adequate potassium concentration (20-30 mmol/l), namely the same concentration as found in WHO-ORS. Chloride concentration depends upon other constituents of ORS, namely sodium and potassium, but the range of 30-90 mmol/l is considered to be adequate. Base or base precursors are not required for correction of acidosis except in the severe cases that always need intravenous replacement. A relatively low osmolality seems advisable.

Carbohydrates↗
PubMed1989

The trials of clinical trials.

Controlled clinical trials are becoming increasingly frequent in neurology. A review of the literature indicates that several trials have serious flaws in study design and conduct that render the results questionable or uninterpretable. These reports, together with my own experience with the trial of plasmapheresis in the treatment of acute Guillain-Barré syndrome, have led me to conclude that while the formulation of the crucial research question and the definition of outcomes as a measure of efficacy are extremely important, the availability of a compliant patient population of appropriate size and the compliance by the study physicians are essential. Moreover, close cooperation with the statistician in planning the trial and the statistical strategy for analysis is also critical. Suggestions are made to aid the clinician in setting up the most efficacious trial and reporting the results.

Clinical Trials as Topic↗
PubMed1989

The analysis of titration studies in phase III clinical trials.

Clinical trials commonly employ the titration design for certain drugs such as antihypertensives. In a Phase III trial the design has purposes distinct from those of a Phase I or II trial, as well as from those of a trial with a parallel design. In this paper we compare the titration design with the usual parallel design in their respective purposes for Phase III trials, explore the relevant questions addressed, and examine typical data from such trials. We also discuss work which focuses primarily on the Phase I or II titration trials. We formulate the problem in the framework of one-way contingency table augmented with incomplete data and obtain the maximum likelihood estimates of the parameters and their estimated variances/covariances via the EM algorithm. An example of a Phase III study of an antihypertensive agent illustrates the proposed procedure.

Analysis of Variance↗
PubMed1991

Approximate multinormal probabilities applied to correlated multiple endpoints in clinical trials.

Clinical trials with multiple endpoints incur increased familywise type I errors. The Bonferroni correction is a common method used to modify the p-values to account for multiple significance testing. For independent endpoints the Bonferroni method is slightly conservative whereas with high correlation the conservatism is extreme, as demonstrated by Pocock et al. This paper presents a procedure which allows for the correlation present, whilst adjusting the multiple p-values. The method is based on an approximation derived for multinormal probabilities.

Analysis of Variance↗
PubMed1991

Combination antihypertensive therapy with terazosin and other antihypertensive agents: results of clinical trials.

Clinical trials in which the selective alpha 1-adrenergic receptor blocker terazosin was given in combination with other antihypertensive agents are reviewed. Results of a recent study examining the effects of combination terazosin and verapamil therapy on blood pressure and heart rate are also presented. In several studies of the combination of terazosin plus a diuretic (hydrochlorothiazide, methyclothiazide, chlorthalidone, furosemide, amiloride, triamterene, metolazone, or spironolactone), significant decreases in one or more of the blood pressure variables studied were demonstrated (compared with diuretic plus placebo). In a placebo-controlled, double-blind study of terazosin plus atenolol, supine and standing blood pressures decreased significantly from baseline (atenolol monotherapy) after the addition of terazosin but not placebo. In a study of terazosin added to background therapy (including beta-blockers, diuretics, methyldopa, clonidine, captopril, guanethidine, hydralazine, and nifedipine), the addition of terazosin resulted in significant decreases in supine and standing diastolic blood pressures compared with baseline values (background therapy alone). Combination antihypertensive therapy with terazosin and verapamil reduced blood pressure to a significantly greater extent than either agent alone. Preliminary pharmacokinetic results indicate that terazosin did not alter the metabolism of verapamil. No significant abnormal laboratory test results have been reported for patients taking terazosin in combination with other antihypertensive agents; in fact some evidence suggests that terazosin may attenuate adverse lipid, glucose, and potassium changes associated with thiazide diuretics. Adverse experiences associated with terazosin combination therapy are usually mild to moderate. Results from all these studies suggest that terazosin effectively controls mild-to-moderate hypertension when it is used in combination with other antihypertensive agents without cumulative adverse effects.

Adrenergic alpha-Antagonists↗
PubMed1988

[Clinical effects of oxybutynin hydrochloride in the treatment of unstable bladder and overactive neurogenic bladder: a long-term clinical trial].

Clinical effects and therapeutic usefulness of oxybutynin hydrochloride were evaluated in a long-term clinical trial on patients with unstable bladders and neurogenic bladders. Of the 46 patients entered into the trial, 37 were those diagnosed with an unstable bladder and 9 with a neurogenic bladder with overactive detrusor. In 37 of the cases (80%), the period of drug administration reached up to 12 weeks and in 16 cases (34%) the drugs were administered for more than 24 weeks. The average administration period was 165.9 days. The average total given dose was 1776.9 mg and average dose per day was 10.7 mg. Excellent and good responses were obtained in 76.3, 88.9 and 69.6% at 12 and 24 weeks after start of administration and at the time of discontinuing the drug, respectively. The cystometric changes at pre- and post-administration were evaluated on 23 cases and revealed a significant increase in volume at first sensation and maximum desire to void. Maximum resting intravesical pressure was significantly declined and uninhibited detrusor contractions were significantly suppressed. Side effects were noted in 11 of the 46 cases (23.9%), most of which were well tolerated by the patients. In 4 cases the drug had to be discontinued because of the side effects. Dry mouth was the most common side effect, occupying almost half of the incidents. No significant abnormality was noted on blood laboratory data, blood pressure or heart rate, following the drug administration. In one case slight increase in serum glutamic-oxalacetic transaminase and glutamic-pyruvic transaminase was encountered, but its relationship with the drug was obscure. The clinical usefulness of this drug (excellent and good) was 78.9, 88.9 and 69.6% at 12 and 24 weeks after start of administration, and at the time of drug discontinuation, respectively. The present long-term trial proved that oxybutynin hydrochloride is an exceedingly effective and safe agent for clinical management of unstable bladder and overactive neurogenic bladder.

Adolescent↗
PubMed1990

The marriage of clinical trials and clinical decision science.

Clinical decision science is concerned with rational clinical decisions. All branches of medical research contribute here, but controlled clinical trials of the pragmatic variety carry a particular responsibility. Usually, however, they are not conducted and reported so that they can be used directly as input to a decision analysis. We suggest that the forces of the two methodologies should be united, and point out some areas where this 'marriage' will have a non-trivial impact: choice of end points, style of outcome recording, adaptive designs, and style of result presentation. Special attention is given to the decision-analytic setting of research priorities, the role of utility calculus in quantifying the ethical dilemmas that surround clinical trials, and the use of patient attitude towards outcomes of treatment as a covariate in its own right.

Clinical Protocols↗
PubMedDate not supplied

Efficient use of endpoints in clinical trials: a clinical perspective.

Efficiencies in the use of endpoints in clinical trials are hard won, not easy. They depend upon the shifting of study resources among clinical centres and central units, as well as between numbers of participants and the costs of the endpoint measurement. Costs of endpoint measurement and evaluation do not tell the whole story; nor do costs multiplied by the total number of patients to be recruited; other costs generated by a particular endpoint must also be taken into account. Each clinical trial must be considered separately for the efficient use of endpoints.

Cost Control↗
PubMed1990

Effect of patients' expectations of benefit with standard breast cancer adjuvant chemotherapy on participation in a randomized clinical trial: a clinical vignette study.

Patients frequently overestimate the benefit of standard breast cancer adjuvant therapy. This is due in part to vague doctor-patient communication. To examine how the doctor's description and patient's expectations of the benefit of standard therapy affect clinical trial participation, we randomized 282 female cancer patients to one of two versions of a clinical vignette describing a choice between standard cyclophosphamide, methotrexate, and fluorouracil (5FU) (CMF) and a randomized trial comparing CMF with cyclophosphamide, doxorubicin, and 5FU (CAF). The vignettes differed only on whether results with CMF were described verbally or numerically in terms of disease-free survival (DFS). After selecting CMF or the trial, patients estimated their 10-year DFS with CMF. Patients were randomized 3:1 to the verbal vignette. The trial was selected by 110 of 210 (52.4%) verbal vignette patients versus 25 of 72 (34.7%) numeric vignette patients (P = .01). Estimates of 10-year DFS with CMF varied considerably; many were inaccurate. When patients in the verbal vignette group were divided into thirds according to DFS estimate, 22 of 64 (34.4%) in the top third selected the trial versus 38 of 64 (59.4%) and 38 of 65 (58.5%) in the middle and bottom third, respectively (P = .005). Younger age, college education, and previous participation in a trial also predicted trial selection. Multivariate logistic regression suggested that the benefit expected from CMF was more important than how benefit was described in treatment selection. Assuring realistic patient expectations of standard adjuvant therapy benefit is likely to be important during discussion of clinical trials.

Adult↗