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Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

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At least 145 records · Page 8Linked to original sources
PubMed1994

Comparison of chemotherapy and bone marrow transplants using two independent clinical databases.

Comparing the outcome of chemotherapy and bone marrow transplants in the absence of a randomized trial is difficult but necessary for diseases where small numbers of patients make such trials difficult if not impossible. To address this issue for adults with acute lymphoblastic leukemia in first remission, we created an empirical database using two separate datasets, one from the International Bone Marrow Transplant Registry and the other from two multicenter chemotherapy studies. Prior to combining the datasets, a study protocol was developed to define inclusion criteria, outcomes to be compared and statistical methods. The main problems of a non-randomized comparison are biases potentially introduced by differences in baseline composition of the two cohorts and differences in time-to-treatment. The source of the latter bias is different distributions of waiting times between achieving complete remission and receiving post-remission therapy. Several techniques to control these biases were evaluated; each gave qualitatively similar results. These methods can easily be applied to other clinical situations where randomized trials are not available.

Adolescent↗
PubMed2001

The use of evidence in pharmacovigilance. Case reports as the reference source for drug withdrawals.

OBJECTIVE: Withdrawal of a drug from the market for safety reasons is a serious and sometimes complex decision. The scientific evidence supporting drug withdrawals in the past years is critically appraised. METHODS: With data provided by the Spanish Medicines Agency, all drugs withdrawn from the Spanish market for safety reasons from January 1990 to December 1999 were identified. The adverse drug reactions (ADRs) were classified by the year of withdrawal, by the organ/system affected and by the alleged type of reaction (Rawlins and Thompson classification). A systematic review of the literature was performed. RESULTS: A total of 22 drugs were withdrawn from the market due to safety reasons. In 18 of 22 cases (82%), the evidence supporting the drug withdrawal came from individual case reports, cases series or the combination of data provided by randomised clinical trials and case reports. Hepatic (eight cases) and cardiac (five cases) reactions accounted for 59% (13 of 22) of the total withdrawals. In 10 of 22 (45%) cases, drug withdrawal was clearly due to type-B reactions. Only four withdrawals were based on evidence from observational studies including a comparison group. CONCLUSION: Case reports are the main source of information used to withdraw a drug from the market for safety reasons. It is necessary to improve the quality of evidence supporting the withdrawal process of drugs linked to unexpected and severe ADRs. The use of large databases to perform cohort or nested case-control analyses is the most efficient and reliable method to study type-A class effect ADRs. The implementation of such databases in different countries could increase the quality of the information on ADRs by allowing researchers to conduct efficiently these type of studies.

Adverse Drug Reaction Reporting Systems↗
PubMed1999

Twenty years of phase III trials for patients with extensive-stage small-cell lung cancer: perceptible progress.

PURPOSE: All cooperative group studies performed in North America for patients with extensive-stage small-cell lung cancer (SCLC) were evaluated to determine the pattern of the clinical trials and the outcome of patients over the past 20 years. PATIENTS AND METHODS: Phase III trials for patients with extensive-stage SCLC were identified through a search of the National Cancer Institute Cancer Therapy Evaluation Program database from 1972 to 1993. Patients with extensive-stage SCLC treated during a similar time interval listed in the Surveillance, Epidemiology, and End Results (SEER) database were also examined. Trends were tested in the number of trials over time, the number and sex of patients entered onto the trials, and the survival time of patients treated over time. RESULTS: Twenty-one phase III trials for patients with extensive-stage SCLC were initiated between 1972 and 1990. The median of the median survival times of patients treated on the control arms of the phase III trials initiated between 1972 and 1981 was 7.0 months; for those patients enrolled onto control arms between 1982 and 1990, the median survival time was 8.9 months (P =.001). Analysis of the SEER database of patients with extensive-stage SCLC over the same time period shows a similar 2-month prolongation in median survival time. CONCLUSION: Analysis of 21 phase III trials initiated in North America and the SEER database from 1972 to 1994 demonstrates that there has been a modest improvement in the survival time of patients with extensive-stage SCLC.

Carcinoma, Small Cell↗
PubMed1994

Breast cancer outcome and predictors of outcome: are there age differentials?

Several questions were addressed regarding breast cancer outcome, predictors of outcome, and young age at diagnosis. Is there evidence that outcome is worse in younger women compared with other age groups? Do younger patients have a greater frequency of adverse prognostic factors? If younger age is associated with a poor outcome, is it an intrinsic independent adverse predictor, or is the outcome worse due to poor prognostic factor profiles? Several methods were used to answer these questions and applied to those reports in which age categories were carefully defined: 1) detailed review of population-based breast cancer outcome literature, 2) synthesis of published cooperative group and single institution univariate and multivariate analyses, and 3) a new analysis of the 8738-patient San Antonio database. Overall, epidemiologic studies suggested that younger women have the worst survival outcome, when matched with similarly staged older cohorts. Univariate trends analyses confirmed that younger women more often had more positive lymph nodes, larger tumors, and negative steroid hormone receptors. Significantly more cancers in women less than 35 years of age had high S-phase fractions and abnormal expression of p53. Multivariate modeling confirmed that young age was an independent adverse predictor when a few standard factors were considered in the model, but other descriptors such as tumor grade or high S-phase fraction were more important when available. These data support the conclusion that "young age" serves as a surrogate for a greater frequency of adverse prognostic factor profiles and suggest important questions for future study.

Adult↗
PubMed2001

Use of internet technologies for data acquisition in large clinical trials.

Data acquisition for automated processing is a central aspect of clinical trials with large numbers of cases because of their extensive demand for manpower. Scientific data can be collected using data forms, which are created in Hypertext Markup Language and published on the Internet. The completed data form can be returned via E-mail or Common Gateway Interface-Script and forwarded into a study database. For the Internet-based data acquisition of a prospective multicenter trial (e.g., on endophthalmitis incidence after cataract extraction), we developed two special HTML forms that can be opened in the ophthalmology department's homepage. A large number of acquired anonymous data has been collected via Internet and automatically transferred into the trial database. The Internet provides a fast and easy avenue for the acquisition of scientific data. This method of data acquisition and data processing will become more common place in multicenter clinical trials.

Clinical Trials as Topic↗
PubMed1988

Report from the panel on the Case for Registers of Clinical Trials at the Eighth Annual Meeting of the Society for Clinical Trials.

A plenary session at the Eighth Annual Meeting of the Society for Clinical Trials addressed "The Case for Registers of Clinical Trials." There are a number of reasons for having registers of clinical trials: to promote collaboration and communication among investigators regarding new and ongoing clinical trials, to provide a basis for methodologic research, and to facilitate meta-analysis by the availability of a system of trial identification that is independent of the published literature. The experience gleaned by those involved with two existing trial registers, the International Committee on Thrombosis and Haemostasis Registry and the Oxford Database of Perinatal Trials, can be used to provide insight into the issues generic to trial registration. The time perspective to be used, inclusion and exclusion criteria, the practicability of comprehensive prospective registration, and funding are central considerations for these and other registers.

Clinical Trials as Topic↗
PubMed1990

Coordinating data management for multiple ongoing clinical trials and registries.

The Epidemiology Data Center at the University of Pittsburgh has developed a standard set of data management procedures, reports, and computing configurations for use on multicenter research projects. Based on budget restrictions and study design considerations, a project-specific data management system can be quickly constructed by utilizing appropriate components from the EDC tool kit: the PoP software system for the computerization of the database from paper forms to data entry screens; program shells for telecommunication and backup procedures; and procedural documents for providing the necessary training materials for centralized or decentralized processing environments. The EDC data flow specification provides quality control assurances from entry through statistical analysis.

Clinical Trials as Topic↗
PubMed1996

[EDMUS--a new European databank for multiple sclerosis. A brief introduction of ongoing and planned multicenter studies within the scope of the "European Concentrated Action for Multiple Sclerosis"].

EDMUS, the European Database for Multiple Sclerosis (MS), was established on the occasion of the first European Concerted Action for MS under the auspices of the European Community. The system is user-friendly and makes it possible to record and retrieve data relevant to MS. Within the framework of another European Concerted Action, several international multicenter trials are currently in progress. EVALUED, a validation of the EDMUS system, assesses the interrater variability; PRIMS examines the influence of pregnancy and the post-partum period on the course of MS; and PRESTIMUS investigates predictive factors in suspected MS. Further, planned studies include ERAZMUS (early azathioprine and interferon-beta treatment in MS) and AZASTOP, which is designed to evaluate the effect of stopping azathioprine treatment.

Azathioprine↗
PubMed1999

DBcat: a catalog of biological databases.

The DBcat (http://www.infobiogen.fr/services/dbcat) is a comprehensive catalog of biological databases, maintained and curated on a daily basis at GIS Infobiogen. It contains more than 400 databases classified by application domains. The DBcat is a structured flat file library, that can be searched by means of an SRS server or a dedicated Web interface. The files are available for downloading from Infobiogen anonymous ftp server.

Biology↗
PubMed2001

A qualitative assessment of the neurological safety of antipsychotic drugs; an analysis of a risperidone database.

BACKGROUND: Neurological side effects of antipsychotic agents limit the use of these drugs, and development of newer antipsychotic agents has been focused on a reduced risk of extrapyramidal symptoms (EPS) as well as effective symptom control. METHODS: A qualitative analysis of EPS was performed using Extrapyramidal Symptom Rating Scale (ESRS) data from 11 double-blind risperidone trials. An ESRS factor analysis and maximum changes in ESRS scores were compared for the risperidone, haloperidol, and placebo groups. RESULTS: The factor analysis revealed five factors. Between-group comparisons showed no differences between placebo and 1 to 2 mg/day-risperidone groups. Parkinsonism, tremor, akathisia, and sialorrhea were more likely to occur with haloperidol than with placebo or risperidone at 1 to 6 mg/day. Similar results were noted by maximum changes in ESRS scores. At risperidone doses of more than 8 mg/day, acute EPS severity lay between that of the placebo and haloperidol groups. The severity of tardive dyskinesia was greater in patients receiving placebo than in those receiving either active treatment. CONCLUSIONS: As the results described above were derived from a post hoc analysis of an existing database, conclusions must remain tentative. To provide more definitive answers, EPS assessments in future studies should be refined to more accurately predict the type of EPS expected with a given agent in clinical practice.

Adolescent↗
PubMed1989

Review of Papyrus bibliographic database software.

Papyrus is an inexpensive bibliographic database which provides some features not found in other similar packages. Its flexibility in handling references of many types and formats, its capacity for integration with manuscripts prepared with word processors, its capacity for importing references from national databases and its ability to perform microcosmic literature searches are attractive features. Because Papyrus has tackled a complex task, mastery of the intricacies of the program may present a substantial challenge to novice computer users. Although the manipulation of an existing customized bibliographic database would seem to be attractive for any researcher or author who prepares manuscripts for publication, the optimal use of the program also requires an extensive commitment of time and labor for the initial entry of all pertinent references into the database. While this could be accomplished gradually in conjunction with the preparation of individual manuscripts, the creation of a complete file of references could require hundreds of hours of labor. Individual authors, as well as larger research groups, should be prepared for this type of commitment before acquiring the Papyrus system.

Bibliographies as Topic↗
PubMed2000

Using UMLS semantics for classification purposes.

The Unified Medical Language System (UMLS) contains semantic information about terms from various sources; each concept can be understood and located by its relationships to other concepts. We describe a method in which the semantic relationships between UMLS concepts are exploited for the purpose of classification. This method combines three existing components: 1) Mapping terms to UMLS concepts; 2) Restricting UMLS concepts to MeSH; and 3) Mapping MeSH terms to disease categories. When applied to the automatic classification of condition terms into broad disease categories in the Clinical Trials database, this method assigned relevant categories to 92% of the 1823 condition terms encountered. 135 (7%) failed to be classified and 14 (.77%) were misclassified. The limits of this method are discussed, as well as the reuse of existing components, and the tuning required to achieve automatic classification.

Algorithms↗
PubMedDate not supplied

Bibliography database managers. A comparative review.

Bibliography database managers (BDMs) are used to manage information resources: specifically, to maintain a database of references and create bibliographies and reference lists for written works. This comparative review provides an overview of BDMs and capsule reviews of five programs: EndNote Plus 2.0; Library Master 3.0; Papyrus 7.0.11; Pro-Cite 2.2.1; and Reference Manager 6.02.

Bibliographies as Topic↗
PubMedDate not supplied

Data extraction and ad hoc query of an entity-attribute-value database.

Entity--attribute--value (EAV) tables form the major component of several mainstream electronic patient record systems (EPRSs). Such systems have been optimized for real-time retrieval of individual patient data. Data warehousing, on the other hand, involves cross-patient data retrieval based on values of patient attributes, with a focus on ad hoc query. Attribute-centric query is inherently more difficult when data are stored in EAV form than when they are stored conventionally. The authors illustrate their approach to the attribute-centric query problem with ACT/DB, a database for managing clinical trials data. This approach is based on metadata supporting a query front end that essentially hides the EAV/non-EAV nature of individual attributes from the user. The authors' work does not close the query problem, and they identify several complex subproblems that are still to be solved.

Clinical Trials as Topic↗
PubMed1999

[Systematic reviews on infectious diseases. The Cochrane Collaboration].

BACKGROUND: Theoretically, doctors update their knowledge from the scientific literature, and bibliographic databases have made it possible to overcome many of the limitations with this information, but not all of them. When faced with a therapeutic issue, the practice of evidence based medicine requires the efficient access to information derived from controlled clinical trials (CCT). Reviews of the scientific literature are of increasing importance. The Cochrane Collaboration is dedicated to preparing, maintaining and disseminating updated, systematic reviews of CCTs of health care interventions, which are published in the Cochrane Library. OBJECTIVE: To describe the Cochrane Collaboration and to locate, with the greatest exhaustiveness possible, CCTs published in the journals "Enfermedades Infecciosas y Microbiología Clínica", describe their characteristics and include them in a global database of clinical trials maintained by the Cochrane Collaboration. METHODS: The CCTs were identified by systematic manual searches of all issues of the journal. A descriptive analysis of the CCTs located was made. RESULTS: A total of 24 CCTs were published in 15 years (1.6 per year), 10 were original articles and 14 were communications at congresses. All were done in Spain and the majority were done in hospitals. The most frequently researched question was antibiotic prophylaxis and all evaluated pharmaceutical interventions. The majority of the CCTs published had important information missing (phase of study, randomization, blinding, etc.). CONCLUSIONS: The identification of CCTs is a prerequisite for the development of systematic reviews. There were few clinical trials published in the 15 years of publication of this journal, and the most common characteristic is, clearly, the absence of basic data. The most common is a lack of on the phase of the clinical trial, the follow-up period, and funding sources. The idea of what experimental clinical investigation in infectious diseases is in our country needs to include the identification of CCTs published in other Spanish and international journals.

Bibliometrics↗
PubMedDate not supplied

The exclusion of women from clinical trials of thrombolytic therapy: implications for developing the thrombolytic predictive instrument database.

The thrombolytic predictive instrument (TPI) was developed to identify those patients most likely to benefit from thrombolytic therapy for acute myocardial infarction as well as to facilitate the earliest possible administration of this treatment. The TPI consists of predictive models derived from clinical data obtained from both clinical trials and data registries. These models are subject to potential bias due to combinations of primary data from different sources. The purpose of this investigation was to assess the influence of gender in developing the TPI database. In this database, there were 1,096 (22%) women and 3,826 (78%) men; only 38% of the women were enrolled in clinical trials, whereas 46% of the men were (p < 0.0001). Within clinical trials, there were few significant eligibility differences between women and men, as the vast majority of patients met eligibility standards for entry in these trials. However, within clinical registries, the women were older (p < 0.0001) and more often had elevated blood pressure on admission (p = 0.002). Multivariate logistic regression indicated that after adjustment for significant predictors of trial inclusion, women were 25% less likely to be included in clinical trials (odds ratio = 0.76, 95% confidence interval = 0.60, 0.96). In order to counter bias introduced by the exclusion of women from clinical trials, the TPI database included patients from non-trial settings. Carefully including patients from clinical registries or non-trial settings may be an important strategy in constructing generally applicable predictive instruments.

Aged↗
PubMedDate not supplied

Lower respiratory tract infection therapy--the role of ciprofloxacin.

Lower respiratory tract infections account for a large proportion of prescribed antibiotics and, with emerging resistance to standard agents, the introduction of the fluoroquinolones, in particular ciprofloxacin, has provided a further component in the armamentarium. This review encompasses 37 published clinical trials which featured ciprofloxacin; 3274 patients with lower respiratory tract infections were treated with this agent; in 94.1% of patients treatment was clinically successful and 90.9% of cases showed eradication of the causative pathogen. When these data were supplemented with previously unpublished information from the clinical trial database, specific organism eradication rates of 86.1%, 96.2% and 94.6% for Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis, respectively, were observed. These findings suggest that the high respiratory tissue penetration of ciprofloxacin and the achievable minimum inhibitory concentrations lead to acceptable clinical outcomes in lower respiratory tract infections.

Adult↗