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J Windeler

Publications and source records attributed to J Windeler.

At least 19 recordsLinked to original sources
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↗
PubMed1997

Is there a gain from "chance-corrected" measures of diagnostic validity?

Several authors have proposed alternatives to sensitivity and specificity which they recommend as so-called "chance-corrected" versions of these parameters of diagnostic validity. We argue that these new measures have some undesirable properties in comparison with the established measures and no substantial advantages. In particular, the extension of this concept to chance-corrected ROC curves is shown to be less useful than classical ROC analysis.

Diagnosis↗
PubMed1996

Hemostatic changes after thrombolytic therapy with saruplase (unglycosylated single-chain urokinase-type plasminogen activator) and urokinase (two-chain urokinase-type plasminogen activator).

Urokinase, or two-chain urokinase-type plasminogen activator (tcu-PA), is an effective thrombolytic agent. Its single-chain precursor (scu-PA), unlike tcu-PA, is able to selectively activate fibrin-bound plasminogen. The induced clot lysis is amplified by plasmin-triggered conversion of scu-PA to tcu-PA. The aim of our study was to compare the hemostatic effects of recombinant unglycosylated scu-PA, INN saruplase, and urokinase, at doses considered optimal (80 mg saruplase and 3 million units urokinase) in patients with acute myocardial infarction, within 6 h of onset of pain. Complete sample sets from more than 230 patients in each treatment group have been analyzed. The median hemostatic changes caused by saruplase and urokinase were virtually identical indicating that saruplase is converted early in vivo to its active tcu-PA derivative with the dose regimen used. Fibrinogen degradation products were higher for saruplase with a maximum at 2h. They rose markedly after saruplase from 0.43 mg/l at 0 h to a maximum of 160 mg/l at 2 h, whereas the increase after urokinase (from 0.45 mg/l to 89.0 mg/l) was significantly smaller (P < 0.001).

Double-Blind Method↗
PubMed1996

Evaluation of a new version of the EnviroAmp Legionella kit for the detection of legionellae in water samples by the polymerase chain reaction.

The detection of Legionella sp. in various types of environmental water samples was evaluated using a revised version of the EnviroAmp Legionella kit (Perkin-Elmer), which is based on the polymerase chain reaction (PCR). The new kit employs a modified protocol for the pretreatment of water samples, which is designed to further reduce the inhibitory action of some samples to the PCR. The results of the new kit were compared with those of culture. Seventy-four water samples were examined. Of these samples, 51 were taken from hospital water systems, 16 were household water samples, 5 were from surface water, and 2 were rain water. These samples were examined both by PCR and by culture on MWY Legionella selective agar. Of the 74 samples, 46 (62%) were positive by both test systems. Twenty-five samples (34%) were positive by PCR, but negative by culture. While 3 samples (4%) were negative by both test methods, no sample was negative by PCR and positive by culture. Statistical analysis revealed high positive predictive values of PCR, when L. pneumophila was detected or when the genus Legionella was detected at high intensity. Negative predictive values were high, when the PCR was negative or only weakly positive for the genus Legionella.

Bacteriological Techniques↗
PubMed1995

Randomised, placebo-controlled, double-blind clinical trial of beta-sitosterol in patients with benign prostatic hyperplasia. Beta-sitosterol Study Group.

Medical treatments have become available for benign hypertrophy of the prostate, including alpha-receptor blocking agents and 5-alpha-reductase inhibitors. Drugs derived from plants, for which no precise mechanism of action has been described, are widely used for this purpose in Europe. In a randomised, double-blind, placebo-controlled multicentre study, 200 patients (recruited between April and October 1993) with symptomatic benign prostatic hyperplasia were treated with either 20 mg beta-sitosterol (which contains a mixture of phytosterols) three times per day or placebo. Primary end-point was a difference of modified Boyarsky score between treatment groups after 6 months; secondary end-points were changes in International Prostate Symptom Score (IPSS), urine flow, and prostate volume. Modified Boyarsky score decreased significantly with a mean of -6.7 (SD 4.0) points in the beta-sitosterol-treated group versus -2.1 (3.2) points in the placebo group p < 0.01. There was a decrease in IPSS (-7.4 [3.8] points in the beta-sitosterol-treated group vs -2.1 [3.8] points in the placebo group) and changes in urine flow parameters: beta-sitosterol treatment resulted in increasing peak flow (15.2 [5.7] mL/s from 9.9 [2.5] mL/s), and decrease of mean residual urinary volume (30.4 [39.9] mL from 65.8 [20.8] mL). These parameters did not change in the placebo group (p < 0.01). No relevant reduction of prostatic volume was observed in either group. Significant improvement in symptoms and urinary flow parameters show the effectiveness of beta-sitosterol in the treatment of benign prostatic hyperplasia.

Aged↗
PubMed1995

Events per person year--a dubious concept.

In 1982 a new measure was introduced in research into osteoporosis and is now used everywhere in the literature. The so called "fracture rate" relates the number of fractures (single in some patients, multiple in others) to the cumulative time of observation of all patients. This concept, however, has no sound basis. Counting events instead of patients usually violates basic statistical assumptions and invalidates the use of common statistical tests and estimators. Its clinical interpretation is rather dubious. The use of such a measure impedes the search for valid and clinically meaningful outcome criteria and should be abandoned.

Estrogens↗
PubMed1995

Thrombolysis with recombinant unglycosylated single-chain urokinase-type plasminogen activator (saruplase) in acute myocardial infarction: influence of heparin on early patency rate (LIMITS study). Liquemin in Myocardial Infarction During Thrombolysis With Saruplase.

OBJECTIVES: The Liquemin in Myocardial Infarction During Thrombolysis With Saruplase (LIMITS) study was instituted to evaluate and characterize the effect of a prethrombolytic heparin bolus (5,000 IU) on the efficacy and safety of saruplase in patients with acute myocardial infarction. BACKGROUND: Heparin has been used after thrombolytic therapy for acute myocardial infarction to prevent reocclusion of the infarct-related artery. METHODS: The study was designed as a randomized, parallel-group, double-blind, multicenter trial. Patients were treated within 6 h of onset of symptoms with either a bolus of 5,000 IU of heparin (Liquemin) (n = 56, HSH group) or placebo (n = 62, PSH group) before thrombolytic treatment with saruplase given as a 20-mg bolus followed by an infusion of 60 mg over 60 min. Thirty minutes after completion of thrombolysis, an intravenous heparin infusion was administered for 5 days. Before coronary angiography was performed at 6 to 12 h after start of lysis, an additional bolus of 5,000 IU heparin was given to all patients. End points studied were patency of the infarct-related artery, changes in the hemostatic system and bleeding complications. RESULTS: In the HSH group (heparin-saruplase-heparin), 78.6% of patients had an open infarct-related vessel (Thrombolysis in Myocardial Infarction [TIMI] flow grade 2 or 3) compared with 56.5% in the PSH group (placebo-saruplase-heparin) (intention-to-treat analysis, p = 0.01). No significant difference was observed between the two groups with regard to changes in fibrinogen and fibrin/fibrinogen degradation products. A total of eight bleeding complications (14.3%) were observed in the HSH group and five (8.1%) in the PSH group; no cerebrovascular event occurred, and no allergic reaction was reported. A total of 12 patients died during the hospital stay, 3 in the HSH group (5.4%) and 9 in the PSH group (14.5%). CONCLUSIONS: In acute myocardial infarction, the administration of a heparin bolus before thrombolytic therapy with saruplase is associated with a significantly higher patency at angiography 6 to 12 h after the start of thrombolysis without any appreciable increase in risk of bleeding.

Adult↗