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At least 217 records · Page 12Linked to original sources
PubMed2003

Web services-based access to local clinical trial databases: a standards initiative of the Association of American Cancer Institutes.

Electronic discovery of the clinical trials being performed at a specific research center is a challenging task, which presently requires manual review of the center's locally maintained databases or web pages of protocol listings. Near real-time automated discovery of available trials would increase the efficiency and effectiveness of clinical trial searching, and would facilitate the development of new services for information providers and consumers. Automated discovery efforts to date have been hindered by issues such as disparate database schemas, vocabularies, and insufficient standards for easy intersystem exchange of high-level data, but adequate infrastructure now exists that make possible the development of applications for near real-time automated discovery of trials. This paper describes the current state (design and implementation) of the Web Services Specification for Publication and Discovery of Clinical Trials as developed by the Technology Task Force of the Association of American Cancer Institutes. The paper then briefly discusses a prototype web service-based application that implements the specification. Directions for evolution of this specification are also discussed.

Cancer Care Facilities↗
PubMed2003

Effect of Herbst treatment on temporomandibular joint morphology: a systematic literature review.

The purpose of this systematic review was to evaluate the effect of Herbst appliance therapy on temporomandibular joint (TMJ) morphology, with special reference to glenoid fossa remodeling, condylar remodeling, condylar position, and articular disc position. Publications of controlled trials of Herbst treatment of Class II patients using magnetic resonance imaging (MRI), computerized tomography scans, or tomography to assess TMJ morphology were identified with Medline (1966-2001), Best Evidence (1991-2001), Cochrane Database of Systematic Reviews (second quarter, 2001), and Embase (1998-2001). Case reports were excluded. Based on our search, only 5 studies met the selection criteria. All studies used internal controls with pretreatment and posttreatment imaging. Four studies used MRI, and 1 used tomograms. The 4 MRI studies used overlapping patient samples and were not considered as independent evidence. The MRI studies did not provide conclusive evidence of osseous remodeling or condyle position change. The tomography study demonstrated minor condyle position change. Methodological deficiencies prevented major conclusions regarding disc position. The reviewed studies highlight the importance of further research. Prospective controlled studies using serial MRI and tomography are required to establish the effect of Herbst treatment on TMJ morphology.

Bone Remodeling↗
PubMed2001

Symptom reduction and suicide risk among patients treated with placebo in antipsychotic clinical trials: an analysis of the food and drug administration database.

OBJECTIVE: The assumption that psychotic patients assigned to placebo in clinical trials of antipsychotics are exposed to substantial morbidity and mortality is not based on data about what actually happens to such patients. This study assesses symptoms and risks of suicide and suicide attempts in psychotic patients assigned to receive placebo in clinical trials. METHOD: The authors used the Food and Drug Administration database to assess suicides, suicide attempts, and psychotic symptom reduction in clinical trials of three new antipsychotics. RESULTS: Among 10,118 participating patients, 26 committed suicide and 51 attempted suicide. Rates of suicide and attempted suicide did not differ significantly between the placebo-treated and the drug-treated groups. Annual rates of suicide and attempted suicide based on patient exposure years were 1.8% and 3.3%, respectively, with placebo; 0.9% and 5.7% with an established antipsychotic; and 0.7% and 5.0% with a new antipsychotic. Symptom reduction was 16.6% with new antipsychotics (N=1,203), 17.3% with established antipsychotics (N=261), and 1.1% with placebo (N=462). CONCLUSIONS: These data may help inform discussions about the use of placebo in antipsychotic clinical trials.

Antipsychotic Agents↗
PubMed2005

Targeting pancreatic islets with phage display assisted by laser pressure catapult microdissection.

Heterogeneity of the microvasculature in different organs has been well documented by multiple methods including in vivo phage display. However, less is known about the diversity of blood vessels within functionally distinct regions of organs. Here, we combined in vivo phage display with laser pressure catapult microdissection to identify peptide ligands for vascular receptors in the islets of Langerhans in the murine pancreas. Protein database analyses of the peptides, CVSNPRWKC and CHVLWSTRC, showed sequence identity to two ephrin A-type ligand homologues, A2 and A4. Confocal microscopy confirmed that most immunoreactivity of CVSNPRWKC and CHVLWSTRC phage was associated with blood vessels in pancreatic islets. Antibodies recognizing EphA4, a receptor for ephrin-A ligands, were similarly associated with islet blood vessels. Importantly, binding of both islet-homing phage and anti-EphA4 antibody was strikingly increased in blood vessels of pancreatic islet tumors in RIP-Tag2 transgenic mice. These results indicate that endothelial cells of blood vessels in pancreatic islets preferentially express EphA4 receptors, and this expression is increased in tumors. Our findings show in vivo phage display and laser pressure catapult microdissection can be combined to reveal endothelial cell specialization within focal regions of the microvasculature.

Amino Acid Sequence↗
PubMed2000

Reengineering a database for clinical trials management: lessons for system architects.

This paper describes the process of enhancing Trial/DB, a database system for clinical studies management. The system's enhancements have been driven by the need to maximize the effectiveness of developer personnel in supporting numerous and diverse users, of study designers in setting up new studies, and of administrators in managing ongoing studies. Trial/DB was originally designed to work over a local area network within a single institution, and basic architectural changes were necessary to make it work over the Internet efficiently as well as securely. Further, as its use spread to diverse communities of users, changes were made to let the processes of study design and project management adapt to the working styles of the principal investigators and administrators for each study. The lessons learned in the process should prove instructive for system architects as well as managers of electronic patient record systems.

Clinical Trials as Topic↗
PubMedDate not supplied

Statistical outcome of random versus selected withdrawal of dental implants.

PURPOSE: When performing clinical trials, missing data from withdrawn patients should be evaluated differently, depending on the reason for the withdrawal of the patients. The question is, if a certain type of patient drops out, will that affect the result? Could a randomly selected sample of a study population be used for analyses instead of evaluating each and every patient? The purpose of this study was to answer these questions. MATERIALS AND METHODS: Detailed information on 1,738 implants in 487 patients was pooled together in a new database and used for statistical evaluations. Random or selected withdrawals were pulled from the database. Chi-squared tests were used for significance tests, and lifetables were used for survival analysis. RESULTS: There was a difference in the outcome depending on whether the withdrawals were randomly chosen or selected. Random withdrawals could represent, in this study, as much as 50% of the included patients without changing the statistical results. If selected withdrawals were based on which jaw was treated, the statistical outcome did change, but it did not change if withdrawals were based on gender or age. CONCLUSION: Evaluation of reasons for withdrawals and withdrawn patient characteristics are of utmost importance when evaluating clinical trials. A randomly selected sample of the entire population could, however, be expected to give the same statistical value as the entire group, if the original material were large enough. Therefore, the use of study samples may more easily enable clinicians to do follow-up investigations.

Age Factors↗
PubMed2002

Referral letters in oral medicine: standard versus non-standard letters.

Usually referral letters are the only means of communication between general practitioners and specialists in the health area. However, they are inadequate if important basic data are omitted. The aim of this study was to compare the content of standard and non-standard letters. A total of 1956 files from the Oral Medicine Service were consecutively evaluated (March 1996 to September 2000). Key items were considered for analysis and the results were stored in a database using the Epinfo 6.04 program. The chi2 test (alpha=0.05) was applied to the results. Of the 1956 files examined, 34% (662) had a referral letter, 31% of them being standard letters and 69% non-standard letters. Most standard letters (87%) were from professionals of public health institutions. Most percent discrepancies between standard and non-standard letters were observed for patient address (14.90 vs 1.32%), patient age (54.81 vs 9.47%), chief complaint (32.21 vs 8.37%), fundamental lesion (29.33 vs 13.66%), and symptoms (27.81 vs 15.42%). Statistically significant differences were observed for patient age, professional referring the patient, chief complaint, and site of the lesion. The quality and quantity of the information differed significantly between the two types of letters. The standard letters were more complete and contained information commonly absent in the non-standard letters. We suggest the use of standard letters for improving the quality of communication among professionals.

Chi-Square Distribution↗
PubMed2000

The science of systematic reviewing studies of diagnostic tests.

BACKGROUND: Systematic reviews have gradually replaced single studies as the highest level of documented effectiveness of health care interventions. Systematic reviewing is a new scientific method, concerned with the development and application of methods for identifying relevant literature, analysing the material while increasing validity and precision, and presenting and discussing the results in a way that does justice to the research question and to the available evidence. The objective of this study was to review the systematic reviews in laboratory medicine, to evaluate the methods applied in these reviews and the applicability of guidelines of the Cochrane Methods Working Group on Screening and Diagnostic Tests, and identify areas for future research. METHODS: All the systematic reviews in the field of clinical chemistry and laboratory haematology that could be identified in Medline, EMBASE and other literature databases up to December 1998, were evaluated. RESULTS: We studied 23 reviews of diagnostic trials. Although all reviews share the same basic methodology, there was a wide variation in the methods applied. There was no consensus on the quality criteria for inclusion of primary studies. The results of the primary studies were heterogeneous in most cases. This was partly due to design flaws in the primary studies, but was also inherent in the diverse study designs in diagnostic trials. We observed differences in the analysis of the factors that cause heterogeneity of the results, and in the summary statistics used to pool the data from the primary studies. The additional diagnostic value of a test, after other test results are taken into consideration, was only addressed in one study. CONCLUSION: This overview of 23 reviews of diagnostic trials identifies areas in the methods of systematic reviewing where consensus is lacking, such as quality rating of primary studies, analysis of heterogeneity between primary studies and pooling of data. Guidelines need to be improved on these points.

Clinical Chemistry Tests↗
PubMed2005

Trial Registration at ClinicalTrials.gov between May and October 2005.

BACKGROUND: Clinical trial registration allows interested parties to obtain information about ongoing and completed trials, but there are few data indicating the quality of the information provided during the registration process. We used information in the publicly available ClinicalTrials.gov database to describe patterns of trial registration before and after the implementation by journal editors of a new policy requiring registration as a prerequisite for publication. METHODS: We reviewed ClinicalTrials.gov records to determine patterns of completion of the "Intervention Name" and "Primary Outcome Measure" data fields for trials registered on May 20 and October 11, 2005, and for trials registered during the interval between these two dates, inclusively. RESULTS: During the interval studied, the number of registrations in ClinicalTrials.gov increased by 73 percent from 13,153 to 22,714. The percentage of interventional trials registered by industry with nonspecific Intervention Name entries (attributable to four drug companies) decreased from 10 percent to 2 percent; all other industry and nonindustry records contained specific entries in this field. Of the 2670 studies registered by industry between the two dates, 76 percent provided information in the Primary Outcome Measure field, although these entries varied markedly in their degree of specificity. In the remaining 24 percent of the records, this field was blank. CONCLUSIONS: During the summer of 2005, there were large increases in the number of clinical trial registrations. Overall, the data contained in records were more complete in October than they were in May, but there still is room for substantial improvement.

Clinical Trials as Topic↗
PubMed2005

Usefulness of the presence of peripheral vascular disease in predicting mortality in acute myocardial infarction patients treated with primary angioplasty (from the Primary Angioplasty in Myocardial Infarction Database).

Patients with acute myocardial infarction (AMI) often have multiple co-morbidities that influence outcome. We sought to evaluate the impact of peripheral vascular disease (PVD) on the outcome of patients with AMI treated with primary angioplasty. We evaluated 3,716 patients with AMI who underwent emergency catheterization with planned primary angioplasty in the Primary Angioplasty in Myocardial Infarction trials. Patients with a history of PVD (claudication, stroke, or transient ischemic attack) were compared with patients without PVD. Of the 3,716 patients, 394 (10.6%) had PVD and were older, more often women, and more frequently had a history of diabetes mellitus, hypertension, smoking, congestive heart failure, angina, myocardial infarction, and coronary revascularization. They presented more often with a heart rate >100 beats/min, Killip class >1, lower ejection fraction, and multivessel disease. No difference was found in stent use, final percentage of stenosis, or Thrombolysis In Myocardial Infarction 3 flow. Patients with PVD had a twofold increased in-hospital mortality (5.3% vs 2.6%, p = 0.0021). The difference remained significant at 1 month, 6 months, and 1 year (12.6% vs 6%, p < 0.0001). In multivariate logistic regression analysis, a history of PVD was an independent predictor of in-hospital mortality and death at 1 year (odds ratio 1.64, 95% confidence interval 1.04 to 2.57, p = 0.032). In conclusion, patients with AMI with PVD have increased co-morbidities and higher mortality despite treatment with primary angioplasty. The presence of PVD is an independent predictor of in-hospital mortality and death at 1 year.

Aged↗
PubMedDate not supplied

[Evaluation of the degree of compliance of Spanish scientific biomedical journals with international standards of presentation of periodicals].

BACKGROUND: Because standardization is important to ensure the successful transfer of scientific information, compliance with international standards for the presentation of periodicals in 205 Spanish biomedical journals, with the aim of improving their quality as instruments of information transfer, is evaluated. METHODS: Journals were identified by consulting five printed bibliographies and four electronic databases. A total of 136 parameters of evaluation for the presentation of periodicals derived from ISO (International Standardization Organization) standards (86%) and recommendations published by UNESCO, the International Committee of Medical Journal Editors, The Council of Biology Editors, and EJ Huth (14%) were evaluated. Three features (inclusion, presentation and location) were recorded for most data item, and the total number of items studied was 342. RESULTS: The rate of compliance with standards in Spanish biomedical journals was 33.5% +/- 8.5 (DE). Compliance was highest for items related with the identification of the journal in the text pages and the issue contents list. The lowest rates of compliance were found for items related the volume and the abstract sheet. The worst standardized journals were those published by private firms and public administration organizations. As a group, journals published annually were the best standardized. CONCLUSIONS: The low rate of compliance with standards did not reflect inadequate compliance with all items, but was rather the result of complete noncompliance with particular standards, especially those relating to the abstract sheet, volume front cover, volume contents list and volume index. To improve compliance a change in the policies governing the availability of standards, the preparation of guides and manuals for scientific periodical publishing, and the development of training programs aimed at authors, editors, publishers, librarians and information scientists, is suggested.

Bibliographies as Topic↗
PubMed2006

Evaluation of adverse events experienced by older patients participating in studies of molecularly targeted agents alone or in combination.

BACKGROUND: The tolerability of molecularly targeted agents in older patients has not been specifically examined. Adverse event data from clinical trials in the Princess Margaret Hospital Phase II Consortium database were analyzed to address this question. METHODS: The Consortium database collects trial information on all patients treated with either a molecularly targeted agent alone or in combination since 2001. The frequency of adverse events was determined and analyzed by two different age groups, <65 years and >/=65 years. Toxicity indices (TI) and frequencies of dose-limiting toxicities (DLT), based on adverse events of all causalities (TI(ALL) and DLT(ALL)), and on adverse events that were at least possibly related to the molecularly targeted agent (TI(MTA) and DLT(MTA)), were calculated for both age groups. RESULTS: Four hundred and one patients who received 1,252 treatment cycles were analyzed from 19 different studies. Baseline performance status was similar between both age groups, but fewer older patients have had multiple prior regimens of chemotherapy or prior radiation therapy. A comparison of the proportions of younger and older patients experiencing DLT(ALL) and DLT(MTA) showed similar results. The TI(MTA) values were comparable between the two age groups in both single agent (3.25 versus 3.00, for <65 versus >/=65 years) and multi-agent (3.65 versus 3.00, for <65 versus >/=65 years) trials. CONCLUSIONS: Older patients seem to tolerate molecularly targeted therapies either alone or in combination with chemotherapy as well as younger patients. Age alone should not be a barrier in the administration of targeted agents.

Adult↗
PubMed2003

[Teleteaching in otorhinolaryngology. Part 2: the European database "medicstream"].

Searching the medical literature is mainly characterized by the use of databases. The time for reviewing and printing a paper causes a delay between the first presentation of scientific results in a lecture and the appearance of the appropriate journal publication. Moreover, the possibilities for the integration of multimedia data are limited. Because of the development of new compression algorithms for audiovisual digitization software, the near simultaneous transmission of scientific presentations, both visually and aurally, has been possible since 1999. The section telemedicine of the interdisciplinary study group on image guided surgical navigation from the University of Leipzig has developed "medicstream" as a unique, audiovisual, scientific internetdatabase. It allows the documentation of presentations at congresses and courses, including the discussion,over a freely accessible, widely available homepage, using a home developed streaming technology. All presentations are examined by an authorized editorial committee consisting of representatives with different medical specializations for content before the admission to the data base. A total of 392 presentations from seven scientific meetings can be selected by an integrated search machine and viewed with Windows Media Player or Real Player using a conventional or faster internet connection to the homepage www.medicstream.de. The quality of the audiovisual transmission depends on the receiver-lateral data transmission rate,whereby the minimum variant of 56 kB/s is characterized by good detectability of the contents. In an analysis period of 242 days,we registered 44,199 accesses and 4,488 attendances. The telemedicine data base "medicstream" can optimize quality and extend medical education by live-streaming as well as by archiving scientific presentations as audiovisual data.

Congresses as Topic↗
PubMed2003

Effective PSA contamination in the Rotterdam section of the European Randomized Study of Screening for Prostate Cancer.

The extent of effective prostate-specific antigen (PSA) contamination in the Rotterdam section of the ongoing European Randomized Study of Screening for Prostate Cancer (ERSPC) trial was evaluated and defined as when opportunistic PSA testing of >/= 3.0 ng/ml was followed by biopsy, similar to the regular procedure within the trial. Records of participants aged 55-74 years at entry were linked to the regional database of the general practitioner (GP) laboratory to obtain PSA tests requested by GPs in the period 1 July 1997 to 31 May 2000 (2.9 years), and to the national pathology database to quantify the number of biopsies. All men randomized were included, only those with prostate cancer screen-detected or clinically diagnosed before July 1997 were omitted from the analyses. 2,895 out of the 14,349 men (20.2%) in the control arm and 1,981 out of the 14,052 men (14.1%) in the screening arm were PSA-tested, at an average annual rate of 73 and 52 per 1,000 person-years, respectively. These rates were higher than those recorded at the national and regional levels, 33 and 38 per 1,000 person-years, respectively. Opportunistic PSA testing in the control arm reached a peak within the first months of randomization, after which it decreased to around 70 per 1,000 person-years. An opposite pattern was observed in the screening arm, where participants already had received the scheduled screening within the trial. The proportion of men in the control arm with PSA >/= 3.0 ng/ml followed by biopsy and prostate cancer was 7-8% and 3%, respectively (3% and 0.4-0.6% in the screening arm), over the whole study period. Over a 4-year rescreening interval, the average PSA and effective contamination amount were approximately 28% and 10%, respectively. PSA testing in the control arm in the Rotterdam ERSPC section is high, but was not followed by a substantial increase in prostate biopsies. Although the reasons for ordering PSA test or indicating biopsy are unknown, effective PSA contamination in the Rotterdam ERSPC section is low and not likely to jeopardize the power of the trial.

Age Factors↗
PubMed1997

Safety of oral terbinafine: results of a postmarketing surveillance study in 25,884 patients.

OBJECTIVE: To broaden the safety database for oral terbinafine by determining the incidence of adverse events, particularly rare risks, that accompany its uncontrolled use in actual clinical practice. DESIGN: Four open, prospective, uncontrolled, postmarketing surveillance studies were conducted in unselected patients in 4 countries. No exclusion criteria were applied. The only treatment instructions participating physicians received were the manufacturer's product information. Physicians monitored patients for adverse events at baseline, during treatment, and at the end of treatment. Serious events were identified according to study protocol, which was consistent for all 4 studies, allowing data to be pooled and analyzed collectively. SETTING: Patients were recruited from dermatology, general, and family practices in the United Kingdom, the Netherlands, Germany, and Austria. PATIENTS: Of the 25884 patients who entered the study, 38.6% had concomitant diseases, 42.8% were taking other medications, and 22.7% were older than 60 years. The predominant indication for terbinafine treatment was onychomycosis (72.2%). INTERVENTIONS: Data on treatment duration was available for 25091 patients. Median duration of treatment was 12 weeks (mean, 13.2 weeks). Treatment extended beyond 6 weeks in 76.0% of patients and for at least 12 weeks in 59.3%. MAIN OUTCOME MEASURES: The incidence of adverse events as reported by physicians, with their opinions regarding relationship to terbinafine therapy. RESULTS: The incidence of adverse events was 10.5%; the majority involved the gastrointestinal system (4.9%) or skin (2.3%). These tended to be mild, transient, and reversible. Terbinafine was considered a possible or probable cause of 11 (0.04%) serious adverse events. No drug interactions were reported, even in patients taking oral antidiabetic agents, astemizole, terfenadine, or cimetidine hydrochloride. CONCLUSIONS: The positive safety profile established during controlled clinical trials of oral terbinafine extends to its uncontrolled use in clinical practice. No previously unrecognized risks were identified.

Adolescent↗