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H J Trampisch

Publications and source records attributed to H J Trampisch.

At least 19 recordsLinked to original sources
PubMed1998

Practical experience with the design and analysis of a three-armed equivalence study.

OBJECTIVE: While there is a lot of experience with the design, conduct and interpretation of bioequivalence studies, the methodology of trials concerning therapeutic equivalence is still at an early stage of development. Two-armed equivalence studies involve special problems of interpretation, which can be partly solved by the introduction of a third (placebo) arm. We describe a trial in which the therapeutic equivalence of horse chestnut seed extract (HCSE) and compression treatment was to be demonstrated in patients with chronic venous insufficiency (CVI). Compression is regarded as the standard therapy in this field. However, the efficacy of compression in terms of the variable of primary interest, namely oedema reduction, has never been demonstrated according to current methodological rules. Thus, the 'standard' had to be established in the trial itself. This can be achieved by demonstration of relevant superiority in comparison with placebo. METHODS: Two hypotheses had to be tested: (1) the relevant superiority of compression compared with placebo as a precondition for (2) the at most irrelevant inferiority of HCSE in comparison with compression ('equivalence'). For both corresponding statistical tests, the irrelevance criterion -- formulated as standardized difference -- was set to 0.5. RESULTS: Therapeutic equivalence could not be demonstrated following this design, because compression failed to be relevantly superior compared with placebo, even though HCSE was shown to be at most irrelevantly inferior compared with compression. Explorative analyses show that it is not possible to reject simultaneously both null hypotheses with the obtained data when using equal irrelevance limits for both tests. CONCLUSION: Although the primary objective of the trial could not be achieved, the results were encouraging. Thus, a new study was planned and started based on the observed data. The concept of a shifted null hypothesis may be applied to 'routine' clinical trials too; using 'no difference' as the null hypothesis in a trial does not seem to be meaningful when in fact an at least relevant difference is required.

Clinical Trials as Topic↗
PubMed1996

Comparison of leg compression stocking and oral horse-chestnut seed extract therapy in patients with chronic venous insufficiency.

BACKGROUND: Diseases of the venous system are widespread disorders sometimes associated with modern civilisation and are among the major concerns of social and occupational medicine. This study was carried out to compare the efficacy (oedema reduction) and safety of compression stockings class II and dried horse chestnut seed extract (HCSE, 50 mg aescin, twice daily). METHODS: Equivalence of both therapies was examined in a novel hierarchical statistical design in 240 patients with chronic venous insufficiency. Patients were treated over a period of 12 weeks in a randomised, partially blinded, placebo-controlled, parallel study design. FINDINGS: Lower leg volume of the more severely affected limb decreased on average by 43.8 mL (n = 95) with HCSE and 46.7 mL (n = 99) with compression therapy, while it increased by 9.8 mL with placebo (n = 46) after 12 weeks therapy for the intention-to-treat group (95% CI: HCSE: 21.1-66.4; compression: 30.4-63.0; placebo: 40.0-20.4). Significant oedema reductions were achieved by HCSE (p = 0.005) and compression (p = 0.002) compared to placebo, and the two therapies were shown to be equivalent (p = 0.001); in this design, however, compression could not be proven as standard with regard to oedema reduction in the statistical test procedure. Both HCSE and compression therapy were well tolerated and no serious treatment-related events were reported. INTERPRETATION: These results indicate that compression stocking therapy and HCSE therapy are alternative therapies for the effective treatment of patients with oedema resulting from chronic venous insufficiency.

Bandages↗
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

How to evaluate measuring methods in the case of non-defined external validity.

In the clinical routine of chronic diseases, a new measurement has to be compared to an established criterion to see whether there is agreement on assessing disease progress. Because of the nonexistence of established criteria for rheumatoid arthritis the evaluation of grading systems for radiological assessment needs an alternative approach. Using the measurement error as a measure for repeatability and rater agreement in comparison to the progress of the grading score might be a solution to this dilemma.

Arthritis, Rheumatoid↗
PubMed1994

[General requirements for study designs].

It is the purpose of this review to outline the principles of biometric methods in clinical research. Several study designs such as cohort studies, case-control studies or randomized controlled trials are explained in detail, and their problems and their interpretation are discussed. It is demonstrated that observational studies may yield valuable information about associations between exposure and outcome variables but that only properly designed randomized clinical trials of adequate sample size make it possible to answer research questions about causal relationships. It is emphasized that good clinical research depends on properly designed studies more than on complicated statistical procedures.

Clinical Trials as Topic↗
PubMed1993

Evaluation of a structured treatment and teaching programme on hypertension in general practice.

OBJECTIVE: Evaluation of a structured hypertension treatment and teaching programme in general practice. DESIGN: Prospective controlled trial; follow-up period 18 months. SETTING: 10 primary health care practices. PRACTICES AND PATIENTS: From each practice 20 patients (30 to 60 years old, mean of the last two blood pressure measurements at or above 160 and/or 95 mmHg) were randomly selected; in 5 practices these patients were to participate in the treatment and teaching programme; in the remaining 5 practices hypertension care was continued without the availability of such a programme (controls). INTERVENTION: Structured treatment and teaching programme based upon four group sessions for patients mainly conducted by paramedical personnel. MAIN OUTCOME MEASURES: Blood pressure, body weight, prescription of antihypertensive drugs - as documented in the patient's records. MAIN RESULTS: Of the 100 control patients 26 and of the 100 intervention patients 14 were lost to observation; 46 patients had agreed to participate in the programme. The mean number of prescribed antihypertensive agents per patient decreased in the intervention group (1.8 +/- 1.3 at baseline, vs 1.2 +/- 1.2 at follow-up) compared to the control group (1.6 +/- 1.3 vs 1.8 +/- 1.6); difference 0.8 (95% CI 0.4 to 1.1), p < 0.0001. In the control group 9% and in the intervention group 33% of patients had documented reductions of body weight (p < 0.0001). Blood pressure decreased in the intervention group (162 +/- 14/100 +/- 7 mmHg at baseline, vs 154 +/- 16/95 +/- 9 mmHg at follow-up) compared to the control group (161 +/- 13/98 +/- 7 mmHg vs 158 +/- 18/96 +/- 11 mmHg); differences for systolic blood pressure 5 (95% CI 0 to 10) mmHg, p = 0.071; for diastolic blood pressure 4 (1 to 7) mmHg, p = 0.018. CONCLUSIONS: The introduction of a structured hypertension treatment and teaching programme in general practice may lead to significant improvements of hypertension care.

Adult↗
PubMed1992

No evidence for the existence of preformed antibodies against hydroxyethyl starch in man.

Using the highly sensitive ELISA technique for detecting anti-hydroxyethyl starch (HES) antibodies in man sera from 1,056 patients were analyzed. Patients of both sex, who had never had any prior contact with HES, were included in the study. In none of the cases could any titer of HES-reactive antibodies be detected. These data suggest that in man preformed HES-reactive antibodies do not exist or are extremely rare. In any case, unlike dextran-reactive antibodies, they should not have a high clinical importance. The mechanism behind the very rarely observed anaphylactoid reactions after HES application is still unknown.

Adult↗
PubMed1991

Right ventricular function assessed by thermodilution technique during apnea and mechanical ventilation.

OBJECTIVES: To evaluate strategies for thermodilution-based measurement of cardiac output and right ventricular (RV) ejection fraction and to assess the effects of controlled mechanical ventilation in patients. Furthermore, to compare strategy-associated reproducibility with reference values obtained during long-term apnea. DESIGN: Crossover trial in patients; reference values from apneic animals. SETTING: University ICU and physiology laboratory. PATIENTS: Six consecutive male ICU patients (48 to 70 yrs) after major abdominal vascular surgery. ANIMALS: two adult female sheep. INTERVENTIONS: Three ventilatory rates (8, 16, and 24 cycles/min) and 15-sec periods of apnea were selected for measurements in patients. In animals, continuous apnea was achieved with extracorporeal CO2 removal and apneic oxygenation. MEASUREMENTS: Measurements were performed using an appropriate pulmonary artery catheter and an ejection fraction/cardiac output computer prototype. The thermal indicator was injected automatically at four defined points of the ventilatory cycle, but triggered manually during apnea. MAIN RESULTS: At 8 cycles/min, there was a wide mean range of cyclic variable modulation, with a coefficient of variation of 11.6% and 23.2% for cardiac output and RV ejection fraction, respectively. Allowing for ventilatory phase or changing from 8 to 16 cycles/min reduced errors by half. Combining both procedures resulted in a coefficient of variation of 4.7% and 6.6% for cardiac output and RV ejection fraction, respectively. The best coefficient of variation values obtained during 15 secs of apnea in patients approached those variations in experimental apnea (coefficient of variation of 2.1% and 4.5% for cardiac output and RV ejection fraction, respectively). CONCLUSIONS: At low ventilatory rates, best results are achieved by averaging four phase-selected measurements. One-point measurements were less accurate and random point measurements less reproducible.

Aged↗
PubMed1990

Birth weight of children with congenital heart disease.

Birth weights of 843 children with congenital heart disease (CHD) were compared to the respective data of a normal West German population. On average, the CHD group had significantly lower birth weights, but the weight deficit was far less pronounced than in previous studies. The decrease in birth weight was distinct only in children with tetralogy of Fallot and atrial septal defect. Compared to normal newborns, patients with CHD were more often small for gestational age (15.0%) or had a low (less than 2500 g) birth weight (8.6%). The prevalence of prematurity was not increased. Extracardiac malformations were not significantly more common in CHD patients, who were small for gestational age, than in CHD patients with normal birth weight.

Birth Weight↗
PubMed1990

Diagnostic value of electrocardiographic variables to predict the presence of ventricular late potentials.

To test the hypothesis that the presence of ventricular late potentials in the highly amplified, averaged and filtered surface electrocardiogram (ECG) can be predicted from the conventional surface ECG, 211 patients with and without previously documented sustained ventricular tachycardia outside the acute phase of myocardial infarction were studied. The presence of left ventricular akinesia or aneurysm was significantly correlated with the ECG score (based on Q wave duration, R wave duration and amplitude ratio). The mean ECG score in patients without ventricular tachycardia was 3.4 +/- 3.5 points compared with 5.5 +/- 3.9 points (p less than 0.001) in patients with ventricular tachycardia. The presence of late potentials was positively correlated with the ECG score in the whole cohort of patients. This was also the case in the subgroup of patients without a history of sustained ventricular tachycardia. In contrast, in patients with ventricular tachycardia, the presence of late potentials was independent of their ECG score. Using linear discriminant function analyses to predict the presence of late potentials, a history of ventricular tachycardia alone and the ECG score alone had a high predictive power (high standardized coefficients). If combinations of variables were analyzed including estimates of left ventricular function (presence of aneurysm or akinesia; ejection fraction), the ECG score and a history of ventricular tachycardia still ranked highest. The influence of ejection fraction if used in combination with other variables for the prediction of late potentials was relatively small (standardized coefficient of 0.4). In conclusion, the surface ECG can be used in patients previously free of sustained ventricular tachycardia to predict the presence of ventricular late potentials.(ABSTRACT TRUNCATED AT 250 WORDS)

Electrocardiography↗
PubMed1989

Endobronchial versus intravenous application of the vasopressin derivative glypressin during diagnostic bronchoscopy.

Glypressin is a vasopressin derivative which is used in the present study to stop pulmonary bleeding. The effects of endobronchially versus intravenously applied glypressin were examined during diagnostic fibreoptic bronchoscopy in 27 patients. Transcutaneously measured blood gases and haemodynamics were analysed after 1 mg glypressin was given. The glypressin plasma level was 251 fold higher after the intravenous than after the endobronchial administration. After endobronchial application no significant changes were observed for blood pressure, heart rate or blood gases. Following the intravenous glypressin application there was a significant increase in diastolic blood pressure. The bronchial mucosa pallor appeared earlier after topical than after systemic glypressin application. The haemostyptic effect was similar for both routes of application.

Adult↗