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At least 739 records · Page 41Linked to original sources
PubMed2006

[Analysis of the quality of papers dealing with clinical trails in "Chinese Journal of Burns" during 2000-2004 by the standard of evidence-based medicine].

OBJECTIVE: To investigate the quality of reports of clinical results concerning burn injury, in order to raise the standard of clinical study of burn care in accordance to the standard of evidence-based medicine (EBM), with the aim of improving clinical research in burn care of this country. METHODS: All the papers of clinical study published in Chinese Journal of Burns (CJB) from 2000 to 2004 were evaluated according to EBM standard. RESULTS: There were 89 papers about clinical trials published in the past 5 years, in which 43 (48.3%) of the studies were carried out with random control trials (RCT), and 46 (51.7%) were clinical control trials (CCT). RCT papers increased year by year, while the number of CCT papers fluctuated greatly. The disparity in the quality of research was found as follows. In all the RCT and CCT papers, blinded research was adopted only in 5 papers (5.6%). Strict diagnostic standard including inclusion and exclusion standards were reported in 53 articles (59.6%). The comparison with baselines was not provided in 64 articles (71.9%). P value was given in 10 papers but statistical method was not mentioned (11.2%). Follow-up visits and lost information were only recorded in 2 articles, but no detailed follow-up visiting data were provided. Side effects were reported in 10 articles (11.2%). There were analysis and explanation of mixed interfering factors only in 5 papers (5.6%). There was no explanation of the evaluation of sample size in any one paper. CONCLUSION: In summary, the literature concerning clinical studies published in CJB in the past five years has become more extensive. However, the present study indicates that many clinical trials are not designed and ethical consideration is often missing. Therefore, it is deemed imperative to improve the quality of the clinical studies by improving the planning of the protocols of the study and statistical analysis of the research results in future.

Burns↗
PubMed2006

[Analysis on results of endodontic treatment and influencing factors].

OBJECTIVE: To assess the clinical outcome of root canal therapy (RCT) and the various factors that may influence the outcome of RCT. METHODS: A total of 695 teeth from 357 patients were retrospectively studied three years after endodontic treatment. Pre- and intra-operative information was collected from the original patient records. The post-operative sign or symptom, periapical status and coronal restoration integrity were examined 3 years after obturation. Data were subjected to bivariate and multivariate analysis. RESULTS: The cure rate for 695 teeth was 75.1%, 96.0% of which was considered to be functional. The tooth group, pre-operative pulp and periapical status, quality of root filling and integrity of coronal restoration were revealed by means of bivariate analysis to exert a significant influence on treatment outcome. The logistic analysis indicated that the odds for cure in the teeth with pre-operative periapical radiolucency, underfilling and "open" coronal restoration were significantly lower by 2 folds, 3 folds and 1.6 folds than their counterparts, respectively. CONCLUSIONS: The pre-operative periapical status, quality of root filling and the integrity of coronal restoration are main predictors of outcome in RCT.

Adult↗
PubMed1989

Retinocortical time exhibits spatial selectivity.

We recorded simultaneous electroretinograms and visual evoked potentials to pattern-reversal stimulus in ten normal subjects employing check sizes subtending 7.5, 15, 30, 60, 120, 240 and 480 min of visual arc. The mean peak latency of the pattern electroretinogram (PERG) b wave decreased logarithmically with increasing check size. The mean peak latency of the pattern visual evoked potential (PVEP) P100 component was shortest for 30 min check size and was longer at both smaller and larger check sizes, a phenomenon termed spatial selectivity. Retinocortical time (RCT) was calculated as the latency difference between the PVEP P100 peak and the PERG b wave. The RCT also exhibited spatial selectivity similar to that of the PVEP P100 component; mean RCT was shortest for 30 min check size and was longer at both smaller and larger check sizes. Implications are discussed in light of our current knowledge of the origins of the PERG and PVEP and visual processing of pattern-reversal stimuli. Simultaneous recording of PERGs and PVEPs in patients with disease of the afferent visual pathways employing a large range of check sizes may increase the diagnostic sensitivity of visual electrophysiologic testing.

Adult↗
PubMed1988

Anticoagulant activity in cell homogenate of adult T cell leukemia.

The hemostatic abnormality in 18 patients with adult T cell leukemia (ATL) was studied. Activated partial thromboplastin time (APTT) was slightly prolonged and prekallikrein activity was markedly low in these patients. The leukemic cell homogenate from these patients prolonged the recalcification time (RCT) of normal plasma; homogenates containing more than 3 x 10(3) cells/microliter prolonged it, although a lower cell concentration shortened it. The crude anticoagulant fraction from the gel filtration, with a molecular weight of about 34,000, prolonged RCT. The crude anticoagulant did not affect prothrombin time (PT), thrombin activity or activated X activity at any concentration, but prolonged the contact activation test, inhibited the activation of prekallikrein and prolonged RCT of Fletcher trait, Fitzgerald trait and F XII deficient plasma. These effects of ATL cell homogenate were stronger on platelet poor plasma than on platelet rich plasma. Although ATL cells had low procoagulant activity, increase of leukemic cells made anticoagulant activity predominant, might be the cause of hemostatic abnormality or amplify the bleeding tendency in patients with ATL.

Adult↗
PubMed1985

Properties of poliovirus strains isolated from waste waters of nurseries in Prague in 1969-1982.

The rct marker and antigenic marker were studied in poliovirus strains of all the three types isolated from waste waters of selected communities of children in Prague in 1969-1982. Only three isolated strains (two of type 2 and one of type 3) i.e. 1.38% of strains from nursery waste waters and 0.99% of strains from the total Prague municipal sewerage system, differed in both markers from prototype vaccine strains. The rct marker was most frequently altered in strains of type 1; antigenic marker varied most often in strains of type 3, less conspicuously in strains of type 2 and minimum changes were found in type 1 strains. The dependence of changes in both studied markers of isolated strains on the interval between vaccination and isolation from waste waters was reflected in the dynamics of changes. The highest dynamics of changes in rct marker and antigenic marker was recorded in type 3 and type 2 strains, minimal dynamics being found in type 1 strains. Study of type 2 strains isolated for a long time in some years showed that the longer the interval between vaccination and isolation, the higher the similarity between the isolated strain and the prototype vaccine strain.

Animals↗
PubMed1979

Some ethical considerations in clinical trials.

The ethical norms established in various codes and regulations are inadequate to resolve some of the ethical problems presented by clinical trials. They are stated too vaguely to provide unequivocal answers to many specific questions. In order to remedy this situation, many commentators have proposed the development of more specific and complex regulations. We propose that a more fruitful approach would be to examine the ethical principles underlying the norms and to apply these principles to the specific problems. We apply this approach to two questions: (1) Is it ethical to select subjects for a randomized clinical trial (RCT) exclusively from Veterans Administration (VA) hospitals? (2) In the conduct of a RCT is it necessary to disclose the fact that therapy will be determined by chance? We conclude that problems of justice arise not only because of the vulnerability of patients in VA hospitals but also because of the loss of the physician-patient relationship in an RCT. However, the use of patients in a VA hospital is not always unjust; in most cases such use can be made more just through various modifications in design. We also conclude that the fact of randomization should be disclosed in any situation in which it might materially affect the prospective subject's decision, and that the values and preferences of the subjects should be taken into account in determining what information might be material. This work is only a preliminary step toward analyzing ethical issues in clinical trials. While some would challenge our conclusions, we hope that our methods will facilitate clarity about the locus of disagreement in current controversies and about the value questions that must be answered in order to set an ethical context for the conduct of clinical trials.

Clinical Trials as Topic↗
PubMed1983

[Echocardiographic recognition of ruptured chordae tendineae: patho-anatomical evaluation of the diagnostic criteria].

Various pathological changes of the mitral valve (MV) apparatus have been reported to be associated with ruptured chordae tendineae (RCT). We studied the clinical importance of echocardiographic examination to detect the etiology of RCT in 15 cases with patho-anatomical findings obtained. The commonly observed echocardiographic abnormalities were diastolic MV flutter (80%), systolic MV vibration (73%), flicky (or exaggerated) MV motion (73%), MV prolapse (47%), and abnormal systolic echoes in the left atrium (53%). Diastolic flicky motion of the MV was observed exclusively in the patients of bacterial endocarditis accompanied with MV vegetations. The main ruptured chordae of the MV were recognized as floating chordal echoes. MV prolapse was associated with myxomatous changes of the valve or multiple echoes chordae tendineae. These results show that M-mode and two-dimensional echocardiography may be predictive to evaluate the etiology of RCT.

Adult↗
PubMed1995

[Materials and technics in root canal treatments in Switzerland--a determination of their status].

No data is available on either the materials nor techniques used by Swiss clinicians when doing root canal therapy (RCT). Consequently, in January 1993 questionnaires were posted to all dentists registered with the Swiss Dental Association, excluding those known not to practice RCT. Sixteen questions were answered detailing the disinfecting and obturating materials used, which types of files, preparation and obturation techniques were used and which radiographs were taken during RCT. Demographic details were also answered. Of the 3353 questionnaires posted, 2091 (62.4%) were completed and returned. Major results showed that 50.6% of the responding clinicians used AH26 to obturate canals, 45% Endomethasone and 36.6% N2. Canals were disinfected using Ledermix (81.2%), Asphaline (67.6%), Ca(OH)2 (60.2%). Clinicians used H2O2 and NaOCl equally frequently (75%). Hedstroem files, reamers and flexofiles were used by 52%, 29% and 26% of the clinicians, respectively. Canals were obturated by single-cone technique (68%), lateral condensation (34%), or by using only a paste or sealer (23%). 86.4% take a diagnostic radiograph, 69.2% determine working length from radiographs, and 91.5% take a final radiograph as well. Too many Swiss clinicians still use formaldehyde-containing products in root canal therapy coupled with a "single cone" or a "no cone" obturation technique.

Humans↗
PubMed1995

Measuring effects without randomized trials? Options, problems, challenges.

The idea of using information routinely generated in the course of health care delivery for assessing the relative efficacy of alternative therapies has an undeniable attraction. If feasible, it would enable the difficulties of running a randomized controlled trial (RCT) to be bypassed. But grave obstacles, both practical and theoretical, beset the effort. If, nonetheless, the data base approach is chosen, certain suggestions may be helpful. First, make sure that necessity actually prevents using an RCT. Reconsider that question. Special attention is due to two variants of the usual RCT: the "firms" approach and the large simple trial. If, after reconsideration, a data base approach still is chosen, then let the undertaking be carefully planned, with participation from those who will produce the data and also from future users of the results. Let the planning result in a protocol, and in provisions for a quality assurance program. Finally, it is time to respond to a challenge left us by David Byar: arrange to record why the patient is being given the therapy selected. This information should be a powerful adjustment variable; arranging to collect it will call for imaginative thinking, experimentation, and patience, but it is an idea deserving much effort.

Data Collection↗
PubMed1994

[Caloric intake in parenteral nutrition of very low weight infants].

To evaluate the efficacy of a measure able to compare energy intake from parenteral and enteral nutrition we documented growth patterns in a group of VLBW infants treated with parenteral nutrition (PN). To analyze comparative energy intake from the two sources we expressed a percentage of both parenteral and enteral calories: the former (RCP%) related to an optimal value of 85 non protein calories and the latter (RCE%) to an optimal value of 150 total calories. Total energy intake was planned on the RCT% (RCP% + RCE%). We studied 75 VLBW infants with a mean BW of 1040 g and a mean GA of 29.5 weeks. The mean duration of PN was 25.8 +/- 10.4 days. The initial weight loss (10.2 +/- 5.3%), the time to regain BW (5.5 +/- 4 days) and the day of lowest weight (5.2 +/- 1.6 day of life) were in the normal range; the subsequent growth rate resulted 25.9 +/- 9.2 g/kg/die and did not change for different GA or BW. Growth pattern about head circumference and length were above the third percentile. The mean age of RCT% = 100% was 11.4 +/- 4.8 days of PN; this value was higher for the more premature infants. Severe metabolic abnormalities were not detected. Our observations show the efficacy of the RCT% as index of energy from both enteral and parenteral source during PN: the growth pattern seems to be quite satisfactory without any severe metabolic complication.

Energy Intake↗
PubMed1996

Randomized trials in single subjects: the N of 1 study.

Large-scale randomized trials are not available for all disorders, and conventional "trials of therapy" are susceptible to bias. Randomized controlled trials (RCTs) in individual patients (N of 1 RCTs) may provide a solution. In an N of 1 RCT, a patient receives treatments in pairs (one period of the experimental therapy and one period of either an alternative treatment or placebo, in random order), both patient and clinician are kept blind to allocation, and treatment targets are monitored. This type of RCT is useful in chronic, stable conditions in which the proposed treatment has a short half-life. Treatment targets usually include quantitative measurement of symptoms tracked through patient diaries. Pairs of treatment periods are continued until effectiveness is proved or refuted. The N of 1 RCT is potentially of great use in psychopharmacology and in drug development. The practical approach presented here will allow clinicians to conduct their own N of 1 RCTs.

Humans↗
PubMed1997

A systematic review of randomized controlled trials of pharmacological therapy in osteoarthritis of the hip.

OBJECTIVE: To systematically review all randomized controlled trials (RCT) of pharmacological therapy in osteoarthritis (OA) of the hip. To determine which nonsteroidal antiinflammatory drug (NSAID) is the most effective, and which NSAID is the most toxic. METHODS: A MEDLINE search was used to identify RCT of pharmacological therapy in patients with OA of the hip published between 1966 and August 1994. Qualitative assessments were performed using a quality scoring system designed for NSAID trials in rheumatoid arthritis. Both the design and analysis aspects of the trials were evaluated, each aspect rated on a scale of 0 to 8. A quantitative method, which calculates the ratio of improvement produced by one NSAID to that produced by another, was used to rate the relative efficacy of different NSAID with respect to pain relief. Toxicity comparisons were made according to the authors' findings. RESULTS: 43 RCT were identified, and of these, 39 evaluated NSAID while 4 evaluated only analgesics. The median design and analysis scores were 2 and 4, respectively, 6 NSAID were included in at least 5 trials; of these, indomethacin was rated more effective in 5 of its 7 comparisons, but more toxic in 7 of 12 comparisons. Only 5 of the 29 (17%) NSAID comparisons found statistically significant differences in efficacy. CONCLUSION: NSAID trials in patients with OA of the hip appear to be weakened by the lack of standardization of case definition of OA, and also by the lack of standardization of outcome assessments. No recommendations for the choice of specific NSAID therapy in hip OA can be offered based on this analysis.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed1998

Is sonography performed by the rheumatologist as useful as arthrography executed by the radiologist for the assessment of full thickness rotator cuff tears?

OBJECTIVE: Sonography and arthrography are techniques used to detect rotator cuff tears (RCT). The diagnostic value of sonography executed by a rheumatologist versus that of arthrography performed by a radiologist for assessment of RCT was investigated among patients with unilateral chronic shoulder complaints without an underlying inflammatory rheumatic disease. METHODS: Forty-eight patients underwent sonography, arthrography, and surgical inspection, the results of surgical inspection being the gold standard. RESULTS: Sensitivity for assessment of a full thickness RCT was 0.86 for sonography and 0.77 for arthrography, specificity was 0.88 for sonography and 0.92 for arthrography. CONCLUSION: Compared to arthrography performed by the radiologist, sonography executed by the rheumatologist is as useful for assessment of full thickness rotator cuff tears. Sonography performed by the rheumatologist in combination with history taking and the physical examination during a single visit might change the routine daily practice of rheumatologists.

Adult↗
PubMed1998

Multimodal therapy in rectal cancer.

The possibilities and results of multimodal treatment in rectal cancer were reviewed with respect to the results of surgical treatment only. Based on the results of 4 studies, reducing local relapse rates and increasing long-term survival rates significantly, postoperative radiochemotherapy (RCT) + chemotherapy (CT) should remain the recommended standard for R0 resected UICC II and III rectal cancers. Preoperative neoadjuvant radiotherapy (RT) reduced local relapse rates in 8 studies, and extended survival in one study that evaluated all eligible patients. Preoperative RT may evolve as standard, if the patient selection is improved and postoperative morbidity and long-term toxicity are reduced. Postoperative adjuvant RT reduced local relapses significantly in a single trial, and no impact on survival time is reported. Since postoperative RT is inferior to preoperative RT, this treatment cannot be recommended, if RT is chosen as a single treatment modality as an adjunct to surgery. Preoperative RCT + CT downstages resectable and nonresectable tumors and induces a higher sphincter preservation rate. This treatment may be routinely applied in nonresectable primary tumors or local relapses. Intraoperative RT could be added to this concept or be used together with preoperative/postoperative RT with the same indications. The results of local tumor excisions may be improved with pre- or postoperative RCT + CT.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1998

Discussion sections in reports of controlled trials published in general medical journals: islands in search of continents?

CONTEXT: Several journals have adopted the Consolidated Standards of Reporting Trials (CONSORT) recommendations to make assessment of the quality of randomized controlled trials (RCTs) easier. One of these recommendations is that the trial's results be discussed in light of the totality of the available evidence. OBJECTIVE: To assess the extent to which reports of RCTs published in 5 general medical journals have discussed new results in light of all available evidence. DESIGN: Assessment of the discussion sections in all 26 reports of RCTs published during May 1997 in Annals of Internal Medicine, BMJ, JAMA, The Lancet, and The New England Journal of Medicine. MAIN OUTCOME MEASURE: The inclusion or mention of a systematic review in the discussion section of each article. RESULTS: In only 2 articles were the RCT's results discussed in the context of an updated systematic review of earlier trials. In a further 4 articles, references were made to relevant systematic reviews, but no attempts were made to integrate the results of the new trials in updated versions of these reviews. One article was probably the first published trial to address the question studied. The remaining 19 articles included no evidence that any systematic attempt had been made to set the reported trial's results in the context of previous trials. CONCLUSION: There is little evidence that journals have adequately implemented the CONSORT recommendation that results of an RCT be discussed in light of the totality of the available evidence.

Periodicals as Topic↗
PubMedDate not supplied

Preoperative radiotherapy for resectable rectal cancer: A meta-analysis.

CONTEXT: The benefit of adjuvant radiotherapy for resectable rectal cancer has been extensively studied, but data on survival are still equivocal despite a reduction in the rate of local recurrence. OBJECTIVE: To assess the effectiveness of preoperative radiotherapy followed by surgery in the reduction of overall and cancer-related mortality and in the prevention of local recurrence and distant metastases. DATA SOURCES: Computerized bibliographic searches of MEDLINE and CANCERLIT (1970 to December 1999), including non-English sources, were supplemented with hand searches of reference lists. The medical subject headings used were rectal cancer, radiotherapy, surgery, RCT, randomized, and clinical trial. STUDY SELECTION: Studies were included if they were randomized controlled trials (RCTs) comparing preoperative radiotherapy plus surgery with surgery alone and if they included patients with resectable histologically proven rectal adenocarcinoma, without metastatic disease. Fourteen RCTs were analyzed. DATA EXTRACTION: Data on population, intervention, and outcomes were extracted from each RCT according to the intention-to-treat method by 3 independent observers and combined using the DerSimonian and Laird method. DATA SYNTHESIS: Radiotherapy plus surgery compared with surgery alone significantly reduced the 5-year overall mortality rate (odds ratio [OR] 0.84; 95% confidence interval [CI], 0.72-0.98; P =.03), cancer-related mortality rate (OR, 0.71; 95% CI, 0.61-0.82; P<.001), and local recurrence rate (OR, 0.49; 95% CI, 0.38-0.62; P<.001). No reduction was observed in the occurrence of distant metastases (OR, 0.93; 95% CI, 0.73-1.18; P =.54). CONCLUSIONS: In patients with resectable rectal cancer, preoperative radiotherapy significantly improved overall and cancer-specific survival compared with surgery alone. The magnitude of the benefit is relatively small and criteria are needed to identify patients most likely to benefit from adjuvant radiotherapy. JAMA. 2000;284:1008-1015

Humans↗
PubMed2001

Physician interpretations and textbook definitions of blinding terminology in randomized controlled trials.

CONTEXT: When clinicians assess the validity of randomized controlled trials (RCTs), they commonly evaluate the blinding status of individuals in the RCT. The terminology authors often use to convey blinding status (single, double, and triple blinding) may be open to various interpretations. OBJECTIVE: To determine physician interpretations and textbook definitions of RCT blinding terms. DESIGN AND SETTING: Observational study undertaken at 3 Canadian university tertiary care centers between February and May 1999. PARTICIPANTS: Ninety-one internal medicine physicians who responded to a survey. MAIN OUTCOME MEASURES: Respondents identified which of the following groups they thought were blinded in single-, double-, and triple-blinded RCTs: participants, health care providers, data collectors, judicial assessors of outcomes, data analysts, and personnel who write the article. Definitions from 25 systematically identified textbooks published since 1990 providing definitions for single, double, or triple blinding. RESULTS: Physician respondents identified 10, 17, and 15 unique interpretations of single, double, and triple blinding, respectively, and textbooks provided 5, 9, and 7 different definitions of each. The frequencies of the most common physician interpretation and textbook definition were 75% (95% confidence interval [CI], 65%-83%) and 74% (95% CI, 52%-90%) for single blinding, 38% (95% CI, 28%-49%) and 43% (95% CI, 24%-63%) for double blinding, and 18% (95% CI, 10%-28%) and 14% (95% CI, 0%-58%) for triple blinding, respectively. CONCLUSIONS: Our study suggests that both physicians and textbooks vary greatly in their interpretations and definitions of single, double, and triple blinding. Explicit statements about the blinding status of specific groups involved in RCTs should replace the current ambiguous terminology.

Double-Blind Method↗
PubMed2003

Effect of awareness of a randomized controlled trial on use of experimental therapy.

CONTEXT: Use of experimental therapies during but outside of randomized controlled trials (RCTs) has not been studied. OBJECTIVE: To determine whether initiation of an RCT leads to increased use of the experimental therapy outside the trial. DESIGN AND SETTING: Data on national apheresis use during 3 Canadian RCTs for multiple sclerosis (1986-1988), thrombotic thrombocytopenic purpura (1982-1988), and myeloma cast nephropathy (1998-2000) were obtained from 19 major medical centers in Canada. The multiple sclerosis and myeloma cast nephropathy trials had data on apheresis use for 3 years prior to and during the trials, which permitted a time-series analysis to determine the impact of the RCTs on the use of apheresis. The ongoing myeloma cast nephropathy trial provided data on the number of patients inside and outside of the RCTs in trial and nontrial centers. Initial and follow-up questionnaires were sent to 24 Canadian physicians in trial and nontrial centers to determine if they had noted an increase in apheresis activity during the trials and, if so, their explanation for it. MAIN OUTCOME MEASURE: Change in number of patients undergoing apheresis for thrombotic thrombocytopenic purpura, multiple sclerosis, and myeloma cast nephropathy prior to and during the respective RCTs compared with all patients undergoing apheresis during the same periods. RESULTS: During all 3 RCTs, there were large increases in use of apheresis. The majority of the increased use of apheresis was outside of the trials: for multiple sclerosis, 30 of 49 patients per year (61% of increase); thrombotic thrombocytopenic purpura, 49 of 56 patients per year (72% of increase); and myeloma cast nephropathy, 60 of 72 patients per year (57% of increase). The myeloma cast nephropathy study noted that this increase occurred in both nontrial and trial centers. Among questionnaire respondents (n = 22; 92% response rate), most physicians noted an increase in apheresis activity during the trials and attributed it to a "jumping-the-gun" phenomenon. CONCLUSIONS: During 3 Canadian RCTs, apheresis increased, but most of the increase occurred outside the trials. This behavior during an RCT, in the absence of clear efficacy, can be termed jumping the gun.

Blood Component Removal↗