Biomedical subjects

J Windeler

Publications and source records attributed to J Windeler.

At least 37 records · Page 2Linked to original sources

PubMed2000

The endogenous pathway is a major route for deep sternal wound infection.

OBJECTIVE: Deep wound infections pose an increasing problem in cardiac surgery patients. Prospective infection monitoring is thus a means of identifying possible risk factors. METHODS: Within a period of 5 months, a total of 376 adult patients, 260 men and 116 women, with a mean age of 62.6 years (range 18-88), underwent coronary bypass grafting (n=281) or other cardiac surgery procedures (n=95). Nasal cultures were taken preoperatively from every patient, as well as cultures of the wound during surgery and when dressings were changed thereafter. In addition, nasal cultures were taken from all the medical and nursing staff. To differentiate endogenous and exogenous infection pathways, DNA fingerprint analysis was performed. RESULTS: A total of 38 patients (10.1%) developed a wound infection, in 14 patients this happened to be a deep wound infection, in 24 patients a superficial one. Five sternal wound infections were associated with mediastinitis (1.3%). The occurrence of a wound infection overall resulted in prolonged hospitalization (29.4+/-24 vs. 11.9+/-6.9 days, P=0.001), but not in increased hospital mortality (4.4% vs. 3.9%). Obesity, diabetes mellitus and nasal carriage of Staphylococcus aureus proved to be independent risk factors with an odds ratio of 2.07, 2.26 and 2.28, respectively. In all but one of the sternal colonizations with S. aureus, DNA fingerprint analysis demonstrated an identical pattern of S. aureus from the patient's nose and sternum, indicating an endogenous infection pathway. CONCLUSIONS: The determination of the endogenous pathway for severe wound infection makes prevention possible by means of preoperative local S. aureus eradication.

Adult↗

PubMed2000

[Publications of dissertations on unconventional medical therapy and diagnosis procedures--a contribution to "publication bias"].

BACKGROUND: The problem of the so-called publication bias has received much attention during the last few years. It may be a major threat to the results of meta-analyses and systematic reviews. Its implications are not completely clear, and successful strategies to deal with this problem are far from being established. Some studies have begun to identify characteristic items which de- or increase the likelihood of publication of research results. AIM: It was to be investigated, whether or not a publication bias can be proved for results of medical theses on all kinds of complementary medical subjects and which modifying factors can be identified. METHODS: All 140 medical theses on aspects of complementary medicine of the years 1982-1992 were included. Data were extracted, and publications were searched for in MEDLINE and by personal communication with the authors and supervisors. Factors that may influence the likelihood of publication were identified by means of bivariate analysis and logistic regression analysis. RESULTS: Publications were found for 53 (37,9%) of medical theses included. The most dominant factors which were found to influence the likelihood of publication were 'positive result' (OR 2.337; 95% CI 0.733; 7.450), 'high-level statistical analysis' (1.483; 95% CI 0.710; 3.097), 'supervisers with a high publication output' (1.477; 95% CI 0.164; 13.267), and 'candidates of younger age' (0.691; 95% CI 0.388; 1.230). CONCLUSIONS: As it was found for other medical subjects, an apparent publication bias was shown in complementary medicine, with positive results having a greater chance of publication than negative ones.

Complementary Therapies↗

PubMed2000

[Testing, estimating, "significance"--concept and language of medical biometry].

The justification for the application of medical treatments and diagnostic methods has gained importance during the last decades. Together with scientific argumentations also the concepts of medical statistics have found a widespread use and are nowadays indispensible tools for clinical research. In publications of clinical trials, epidemiological investigations and animal experiments p-values, statistical tests and confidence intervals help the reader to evaluate the significance and relevance of the provided results. A prerequisite is a clear understanding of the concepts underlying these methodological terms. This paper presents the basic concepts of medical statistics and demonstrates the conclusions that can be drawn with the aid of these concepts.

Biometry↗

PubMed2000

[Statistical models and evaluation of observation studies].

Although randomized clinical trials can be regarded as the gold standard in many fields of clinical research, non-randomized (so called observational) studies are indispensable. Methodologic quality of such studies is at least as important as that of randomized trials but has been much less standardized. The analysis and interpretation of the results of observational studies is a very demanding job which needs a high level of knowledge and experience--medical as well as statistical. Basis for these analyses are complex statistical models the grounds and application of which are discussed in the following article.

Clinical Trials as Topic↗

PubMed2000

[How can "significance" and "relevance" be combined?].

Clinical trials are aimed at providing results which enable improvements in patient care. It is widely criticized, however, that the characterization of results as "significant" or "non-significant" does not allow any assessment of their clinical relevance. To counter this criticism 2 biostatistical concepts are available: the use of confidence intervals and the application of statistical tests with shifted null-hypotheses. Possibilities and limitations of these concepts are discussed in this contribution.

Clinical Trials as Topic↗

PubMed2000

[CONSORT--what a proper scientific publication should supply].

The publication of the CONSORT Statement was aimed at the improvement of the quality of research reports of randomized controlled clinical trials. It contains the most important standards of high quality research. Although originally meant for randomized studies only most aspects of this statement can be applied to other kinds of clinical studies. The following--and last--article of this series on medical biostatistics presents and comments the most important criteria.

Data Interpretation, Statistical↗

PubMed1999

[How can "significance" be combined with "relevance"?].

Clinical Trials as Topic↗

PubMed1999

[Statistical models and analysis of observational studies].

Humans↗

PubMed1999

[Testing, estimating, "significance"--concepts and terminology of medical biometry].

The justification for the application of medical treatments and diagnostic methods has gained importance during the last decades. Together with scientific argumentations also the concepts of medical statistics have found a wide-spread use and are nowadays indispensible tools for clinical research. In publications of clinical trials, epidemiological investigations and animal experiments p-values, statistical tests and confidence intervals help the reader to evaluate the significance and relevance of the provided results. A prerequisite is a clear understanding of the concepts underlying these methodological terms. This paper presents the basic concepts of medical statistics and demonstrates the conclusions that can be drawn with the aid of these concepts.

Animals↗

PubMed1999

[Methodological quality of controlled studies in the "Medizinische Klinik" journal. Analysis of contributions appearing between 1979 and 1996].

BACKGROUND: Standards concerning design, performance and analysis of controlled clinical trials have improved during the last decades. A number of recommendations has been published. Their impact is hardly known. METHODS: Using a standardized procedure controlled clinical trials published between 1979 and 1996 in the "Medizinische Klinik" were identified and reviewed for their quality of design, analysis and presentation of results. Results were subdivided by 6 three-year-periods. RESULTS: 132 trial reports were identified. Randomisation was reported in 107 papers (81%) with further details of the procedure in only 20. Adequate concealment is recognizable in 21 papers. Results of baseline comparisons were presented in 52 publications (39%). 57 reports did not mention any blinding although no arguments are given. Information about drop-outs can be found in 90 publications. In most papers, however, drop-outs were omitted from the analyses. An adequate intention-to-treat analysis is provided in 7 reports. Due to missing or incomplete data many results and statistical tests can not be recalculated by the reader. Only 6 papers presented some kind of power calculation. Methodological quality has improved over the complete time period with a certain weakening in the three years before 1996. CONCLUSION: Quality criteria for a meaningful controlled clinical trial are not sufficiently met in a number of cases. Percentages are in accordance with the international literature. Major problems comprise sample size calculation and the application of the intention-to-treat principle.

Data Interpretation, Statistical↗

PubMed1999

Thrombolysis with saruplase versus streptokinase in acute myocardial infarction: five-year results of the PRIMI trial.

BACKGROUND: Short-term safety and efficacy of thrombolysis with saruplase in acute myocardial infarction have been shown in several trials. To assess long-term outcome of patients treated with saruplase or streptokinase for myocardial infarction, a 5-year follow-up of patients included in the Pro-Urokinase in Myocardial Infarction Trial was performed. METHODS AND RESULTS: Follow-up data are available from 8 centers on 255 (92.4%) of 276 included patients. The 5-year mortality rate was comparable with 20.8% of patients in the saruplase group and 16.9% in the streptokinase group (odds ratio 1.29, 95% confidence interval 0.69 to 2.42). In both groups, a considerable number of fatal cardiovascular events occurred more than 1 year after study inclusion. Rates of percutaneous transluminal coronary angioplasty and coronary artery bypass grafting were comparable in both groups. Reinfarction within 5 years occurred in 19.0% of patients in the saruplase group and tended to be less frequent at 10.8% after streptokinase treatment (odds ratio 1.94, 95% confidence interval 0.98 to 3.84). In both groups, the majority of reinfarctions took place more than 3 months after study inclusion. The 5-year stroke rate was 3.6% and 7.2% in the saruplase and streptokinase groups, respectively (odds ratio 0.49, 95% confidence interval 0.16 to 1.47). Subjective symptoms of heart failure and angina pectoris were comparable in both groups. CONCLUSIONS: Our data are consistent with a similar long-term outcome for patients treated with saruplase or streptokinase. Despite the low-risk profile of the patient cohort, there were considerable adverse event rates over a 5-year period.

Aged↗

PubMed1999

Randomised clinical trial comparing the effects of acupuncture and a newly designed placebo needle in rotator cuff tendinitis.

Acupuncture has gained increasing attention in the treatment of chronic pain. The lack of a satisfying placebo method has made it impossible to show whether needling is an important part of the method or whether the improvement felt by the patient is due to the therapeutic setting and psychological phenomena. Also, the effectiveness of acupuncture has not been demonstrated sufficiently. We treated 52 sportsmen with rotator cuff tendinitis in a randomised single-blind clinical trial using a new placebo-needle as control. Patients were treated for 4 weeks. The primary endpoint of the trial was the change in the modified Constant-Murley-score from the baseline. Assessment of the treatment outcome was made by experienced orthopaedists not informed of the treatment allocation. Acupuncture with penetration of the skin was shown to be more effective than a similar therapeutic setting with placebo needling in the treatment of pain. The acupuncture-group improved 19.2 Constant-Murley-score points (SD 16.1, range from -13 to 50), the control-group improved 8.37 points (SD 14.56, range from -20 to 41), (P=0.014; C.I. 2.3;19.4). This study showed that needling is an important part of the acupuncture effect in the treatment of chronic shoulder pain in athletes. No conclusions can be derived from this study concerning the importance of choosing points and the rules of Traditional Chinese Medicine. Using the new placebo method as control for other ailments could improve the evidence of specific acupuncture effects beyond pain treatment.

Acupuncture Analgesia↗

PubMed1999

Saruplase is a safe and effective thrombolytic agent; observations in 1,698 patients: results of the PASS study. Practical Applications of Saruplase Study.

Saruplase (unglycosylated human-type high molecular weight single-chain urokinase-type plasminogen activator) was given to 1698 patients in the open-label Practical Applicability of Saruplase Study (PASS), which assessed the safety and efficacy of saruplase in the treatment of acute myocardial infarction. Thirty-seven hospitals in Europe participated in the study. All patients received 20 mg saruplase as a bolus followed by an infusion of 60 mg saruplase over 1 hour. Prior to the infusion of saruplase, 62% of the patients received a bolus of 5000 U of heparin, and after saruplase a 24-hour intravenous infusion of heparin was given to 95% of patients. The mean age of the patients was 59 years and 80.1% were male. The median delay from the onset of chest pain to the start of saruplase infusion was 145 minutes. Acute angiography was performed in 8 of the participating 37 centers in 350 patients (20.6%), on average 85 minutes (median) after the start of the saruplase infusion. TIMI 3 flow was obtained in 186 patients (53.1%) and TIMI 2 flow in 61 patients (17.4%). Patency rates were similar for patients with anterior and inferior infarction. ECG signs suggestive of reperfusion were seen in 63% of the patients. In-hospital mortality was low (92 patients; 5.4%), and nonfatal recurrent myocardial infarction was seen in 60 patients (3.5%). Severe bleeding complications occurred in 92 patients (5.4%), 21 of whom (1.2%) needed a blood transfusion. An intracerebral hemorrhage was observed in eight patients (0.5%), and seven patients (0.4%) suffered from a thromboembolic stroke. At discharge 85.9% of the patients were in NYHA functional class I. One-year mortality was low (142 patients; 8. 4%). Mortality was high in patients with TIMI 0 or 1 flow at the acute angiography who did not undergo rescue PTCA (9/39; 23.1%), lower in patients with TIMI 0 or 1 flow followed by successful rescue PTCA (7/64; 10.9%), and low in patients with TIMI 2 flow (1/61; 1.6%) or with TIMI 3 flow (2/186; 1.1%). Patency rates and (bleeding) complications did not differ between patients with a body weight greater than or less than 70 kilograms. No antibodies against saruplase were detected in samples from 455 patients. In conclusion, it can be stated that saruplase, given in combination with aspirin and intravenous heparin, can be given safely and effectively to patients with acute myocardial infarction.

Aged↗

PubMed1998

Randomized, double-blind study comparing saruplase with streptokinase therapy in acute myocardial infarction: the COMPASS Equivalence Trial. Comparison Trial of Saruplase and Streptokinase (COMASS) Investigators.

OBJECTIVES: This study sought to demonstrate the equivalence of saruplase and streptokinase in terms of 30-day mortality. BACKGROUND: The use of thrombolytic agents in the treatment of acute myocardial infarction is well established and has been shown to substantially reduce post-myocardial infarction mortality. METHODS: Three thousand eighty-nine patients with symptoms compatible with those of acute myocardial infarction for < 6 h entered the study at a total of 104 centers and were randomized to receive streptokinase (1.5-MU infusion over 60 min) or saruplase (20-mg bolus and 60-mg infusion over 60 min). In the saruplase group, a bolus of heparin (5,000 IU) was administered before saruplase, and a corresponding blinded double-dummy placebo bolus was administered before streptokinase. All patients received intravenous heparin infusions for > or = 24 h starting 30 min after the end of the thrombolytic infusions; the infusions were titrated to maintain an activated partial thromboplastin time at 1.5 to 2.5 times that of normal. RESULTS: Death of any cause up to 30 days after randomization occurred in 88 (5.7%) of 1,542 patients randomized to receive saruplase and 104 (6.7%) of 1,547 patients randomized to receive streptokinase (odds ratio 0.84, p < 0.01 for equivalence). Hemorrhagic strokes occurred more often in patients receiving saruplase (0.9% vs. 0.3%), whereas thromboembolic strokes were more prevalent in the streptokinase-treated patients (0.5% vs. 1.0%). The rate of bleeding was similar in the two treatment groups (10.4% vs. 10.9%). Hypotension and cardiogenic shock occurred less frequently in the saruplase group. Reinfarction rates were similar. CONCLUSIONS: Saruplase is a clinically safe and effective thrombolytic medication. This profile ranks saruplase favorably among the currently available thrombolytic agents.

Aged↗

PubMed1998

Prospective randomized study of stress and immune response after laparoscopic vs conventional colonic resection.

METHODS: In order to evaluate the stress and immunological response to laparoscopic and conventional colon resection we operated on male Wistar rats (350-380 g), performing either laparoscopic (n = 15) or open colon resection (n = 15). A third group (n = 10) underwent anesthesia only. Immediately before and after surgery as well as 1 and 7 days postoperatively a 1 ml sample of blood was taken from the retrobulbar veinous plexus. Stress (corticosterone) and immune parameters (neopterin and interleukin [IL] 1-beta) were measured. Furthermore, the body weight as a parameter of postoperative recovery was monitored. RESULTS: The analysis of variance showed significant differences between the three groups over a period of 1 week (p < 0.0001 for corticosterone, p = 0.0854 for IL 1-beta, p = 0. 0045 for neopterin). Additionally in a t-test significant differences were found between the laparoscopic and conventional group with regard to corticosterone (p = 0.08), to neopterin (p = 0. 045), and to IL 1-beta (p = 0.0043) at the end of the operation. One week after the operation the stress and immune parameters were back to normal levels in each group except IL 1-beta, but the recovery indicated by body weight was different according to the kind of the applied operative procedure: 7 days postoperatively the rats lost 5. 99% of their body weight after open surgery and only 2.4% after laparoscopic surgery. After anesthesia only the body weight increased by about 4.8%. CONCLUSION: Laparoscopic colon resection alters the stress and immune system of healthy rats less than open colon resection. This observation is confirmed by the quicker recovery in laparoscopically operated rats.

Animals↗

PubMed1998

An empirical investigation on matching in published case-control studies.

The methodological discussion about matching when recruiting controls in case-control studies has been controversial for a long time. To delineate the impact of this discussion on the practice of matching we reviewed 266 case-control studies published in nine yearly volumes of three major epidemiological journals within the period 1955-1994. Among studies published until 1980 71.7% of the control groups were recruited by individual matching compared to 46.4% in 1994. This decline is paralleled by an increase in the application of frequency matching (from 5.0% to 26.2%). As the issue of matching is closely connected with methodological questions of the statistical analysis we also examined the type of analysis applied to the data. We found that the use of logistic regression modeling has dramatically increased during this period (from 18.4% up to 87.2%), whereas application of the traditional Mantel-Haenszel technique for estimating summary odds ratios has nearly vanished. The correct approach for individually matched data in the logistic modeling framework, the conditional likelihood technique, has been unknown in the early part of the time window of our investigation, but is even nowadays applied by only three quarters of the corresponding studies. Our literature-based investigation provides thus compelling evidence that the type of control selection and statistical analysis used in case-control studies have changed substantially during recent years.

Case-Control Studies↗

PubMed1997

[The concept of therapeutic equivalence].

Usually, it is the purpose of a clinical trial to demonstrate the superiority of a (new) treatment in comparison to another treatment with regard to a well-defined criterion of efficacy. However, other aspects rather than improved efficacy might be regarded as advantages of a new therapy, i.e. less or less severe adverse events, a more simple applicability, or a lower price. In this case, it may be sufficient to show a "comparable" efficacy (therapeutic equivalence). Unfortunately, equivalence studies can lead to severe problems of interpretation in case of insufficient methodological planning. In general, more detailed information must be available in advance compared to the common (superiority) trials. Very carefully designed trials are necessary to evaluate the therapeutic equivalence of treatments.

Clinical Trials as Topic↗

PubMed1997

Comparison of saruplase and alteplase in acute myocardial infarction. SESAM Study Group. The Study in Europe with Saruplase and Alteplase in Myocardial Infarction.

Four hundred seventy-three patients with acute myocardial infarction (AMI) were treated with either saruplase (80 mg/hour, n = 236) or alteplase (100 mg every 3 hours, n = 237). Comedication included heparin and acetylsalicylic acid. Angiography was performed at 45 and 60 minutes after the start of thrombolytic therapy. When flow was insufficient, angiography was repeated at 90 minutes. Coronary angioplasty was then performed if Thrombolysis In Myocardial Infarction (TIMI) trial 0 to 1 flow was seen. Control angiography was at 24 to 40 hours. Baseline characteristics were similar. Angiography showed comparable and remarkably high early patency rates (TIMI 2 or 3 flow) in both treatment groups: at 45 minutes, 74.6% versus 68.9% (p = 0.22); and at 60 minutes 79.9% versus 75.3% (p = 0.26). Patency rates at 90 minutes before additional interventions were also comparable (79.9% and 81.4%). Angiographic reocclusion rates were not significantly different: 1.2% versus 2.4% (p = 0.68). After rescue angioplasty, angiographic reocclusion rates of 22.0% and 15.0% were observed. Safety data were similar for both groups. Thus, (1) early patency rates were high for saruplase and alteplase treatment, (2) reocclusion rates for both drugs were remarkably low, and (3) complication rates were similar. Thus, saruplase seems to be as safe and effective as alteplase.

Aged↗