W Gaus

Universität Heidelberg, Heidelberg, Baden-Wuerttemberg, Germany

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Publications (66)147.94 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: To compare the efficacy of endoscopic paravariceal sclerotherapy and oral propranolol in the prevention of recurrent upper gastrointestinal bleeding, 78 cirrhotic patients were randomly assigned to either treatment after an endoscopically proven bleed from esophageal varices. After randomization, but before treatment had been started, a total of eight patients had to be withdrawn from the study due to early rebleeding (requiring emergency sclerotherapy) or violations of the protocol. Among the 70 patients analyzed (36 sclerotherapy, 34 propranolol), both treatment groups were comparable with respect to demographic, clinical and laboratory data. The groups also did not differ with respect to continued alcohol intake. Sclerotherapy was performed twice weekly using 1% polidocanol as the sclerosing agent until the varices were eradicated or well-covered by fibrous tissue. Propranolol was given twice daily at a dose reducing the resting heart rate by 25% (60 to 320 mg per day; mean ± SD = 161 ± 80 mg per day). Patients were followed for up to 2 years with visits at 3 monthly intervals (mean follow-up = sclerotherapy, 14 months; propranolol, 9.2 months). Life table analysis of patients without rebleeding from nonvariceal sites revealed a tendency in favor of propranolol; however, the difference did not reach statistical significance. No significant difference was observed between sclerotherapy and propranolol in the proportion of patients rebleeding from esophageal varices or from all sources of upper gastrointestinal bleeding. Furthermore, survival was similar in both treatment groups. A small esophageal perforation due to sclerotherapy was observed in one patient, and one propranolol patient had to discontinue the medication due to severe bradycardia. Other complications of sclerotherapy and side effects of propranolol were minor. Propranolol reduced variceal size significantly within 3 months of treatment. No such decrease was observed in a subgroup of patients who rebled under propranolol, and in the untreated control group of an ongoing trial of prophylactic sclerotherapy. We conclude that propranolol and sclerotherapy are of comparable value in preventing recurrent upper gastrointestinal bleeding in cirrhotics.
    Hepatology 12/2005; 7(2):355 - 361. · 12.00 Impact Factor
  • Steffen Witte, Dieter Loew, Wilhelm Gaus
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    ABSTRACT: The herbal medicinal product kava-kava, used for treating anxiety disorders, was assessed positively by the Cochrane Review. However, it was withdrawn from the market in Switzerland and Germany due to cases of liver failure and 'unproven' efficacy. A protocol for the meta-analysis based on patient source data was written, a literature search was done, and six placebo-controlled, randomized trials with the kava extract WS1490 were identified. The endpoints were the change in HAMA during treatment (continuous and binary). WS1490 has an effective success rate of OR=3.3 (95% confidence interval of 2.09-5.22) in patients with non-psychotic anxiety disorders. The continuous outcome supports this result: mean improvement with WS1490 by 5.94 (95% confidence interval -0.86 to 12.8) points on the HAMA scale better than placebo. Kava seems to be more effective in females and in younger patients. This meta-analysis has no publication bias, no remarkable heterogeneity and is based on trials with high methodological standards. It is concluded that WS1490, and possibly other kava extracts, are effective. Therefore they remain alternatives to benzodiazepines, selective serotonin re-uptake inhibitors (SSRIs) and other antidepressants in the treatment of non-psychotic anxiety disorders.
    Phytotherapy Research 04/2005; 19(3):183-8. · 2.07 Impact Factor
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    ABSTRACT: New therapies in rehabilitation medicine have to be evaluated with clinical trials. For drug approval the methodology of clinical trials is standardized world wide and the results of these studies are widely accepted. This standard should be achieved in clinical trials in rehabilitation research, too. One of the standards is the existence of a control group, comparing the effect of the new intervention against controls. In addition, the investigational and control groups must be equal in terms of the structure of possible confounders. Randomisation is the best possibility to distribute the patients to the therapy-groups, confounders will be equally distributed by chance. Other procedures for assignment to the study groups can result in confounding and lead into biased results. In spite of these advantages, randomisation is not generally accepted in rehabilitation research up to now. There are some reservations, mostly ethical, organisational and methodological ones. However, randomised clinical trials should be conducted in rehabilitation research in order to obtain more convincing results. Our intention is to bring some input in this debate and to present basics and practical aspects of randomisation.
    Die Rehabilitation 11/2002; 41(5):311-9. · 0.71 Impact Factor
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    ABSTRACT: Für eine effiziente Rehabilitation ist es elementar, Patienten möglichst früh erkennen zu können, denen aller Wahrscheinlichkeit nach eine spätere Erwerbsunfähigkeit droht, um unterstützende Maßnahmen bereits während der Rehabilitationsmaßnahme oder in einer entsprechenden Nachsorge durchführen zu können. Fragestellung: Wie gut kann ein statistisches Prognosemodell, welches auf routinemäßig, während einer stationären Rehabilitationsmaßnahme erhobenen Befunden beruht, die längerfristige Erwerbsfähigkeit prognostizieren? Welche Merkmale aus dem zur Verfügung stehenden Datenbestand tragen zur Prognose über einen Zeitraum von 1–2 Jahren nach der Rehabilitation bei? Für 841 Patienten wurde aus Befunden der stationären Reha-Maßnahme die Wahrscheinlichkeit der Erwerbsfähigkeit errechnet und diese Vorhersage mit den seither eingetretenen Berentungen aus dem Versichertenkonto des regionalen Rentenversicherungsträgers (LVA Württemberg) verglichen. Das entwickelte Vorhersagemodell hat für die Zielgröße „Erwerbsfähigkeit 1–2 Jahre nach der Rehabilitation“ eine Sensitivität von ca. 75% und eine Spezifität von ca. 80%. Der positive prädiktive Wert beträgt 34%, der negative prädiktive Wert 97%. Somit kann durch ein Modell, welches ausschließlich auf Routinedaten beruht, eine praktisch brauchbare Vorhersage der längerfristigen Erwerbsföhigkeit bzw. Erwerbsunfähigkeit getroffen werden. Durch Hinzunahme von weiteren, aufwändiger zu erhebenden, krankheitsspezifischen Zusatzinformationen lässt sich die Zuverlässigkeit der Prognose sicherlich noch verbessern. For an efficient rehabilitation it is essential to identify patients as early as possible, who will probably loose their working capacity. Using this information supporting measures could be undertaken during inpatient rehabilitation or intensified aftercare. The purpose of this study was to show, how well a statistical model predicts long-term return to work, using routinely documented data during inpatient rehabilitation. In addition it was important to find, which variables out of the available data-pool contribute to the prediction for a time-period of 1–2 years. For 841 patients the probability of return to work was estimated using data from inpatient rehabilitation. The probability was compared with information from the regional pension insurance institute of Wuerttemberg about the actually granting of pension due to loss of working capacity. For the prognosis “working capacity 1–2 years after rehabilitation” the model obtains a sensitivity of 75% and a specificity of 80%. The positive predictive value amounts to 34%, the negative predictive value to 97%. Therefore it is possible to predict long-term return to work with a statistical model using routinely registered data only. The model could be further improved in appending further disease specific information.
    Journal of Public Health 08/2002; 10(3):229-241. · 2.06 Impact Factor
  • Rehabilitation. 01/2002; 41(5):311-319.
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    ABSTRACT: Perioperative antibiotic prophylaxis surely reduces surgical infection rate. Pharmacokinetic data of oral ofloxacin in combination with its antibacterial spectrum suggest effective protection against perioperative infection. In addition, costs, adverse effects, and induction of microbial resistance are low. Therefore we performed a controlled randomized study comparing oral and intravenous single dose prophylaxis. A total of 61 patients undergoing colonic or pancreatic resection randomly received either a single dose standard intravenous prophylaxis or ofloxacin 400 mg and metronidazole 500 mg orally 2 h before surgery. Postoperative infections were recorded for 3 weeks. Groups were very well comparable regarding age, overweight, concomitant disease, type and duration of surgery, blood loss, and volume support. Infectious complications occurred in 14.8% after parenteral and 3.3% after enteral antibiotic prophylaxis. There was no difference in post-operative hospital stay. The data demonstrate that single-dose oral ofloxacin is at least as effective as a standard intravenous prophylaxis in patients with colonic or pancreatic resection. It offers significant advantages regarding costs and ease of administration.
    Langenbeck s Archives of Surgery 12/2001; 386(6):397-401. · 1.89 Impact Factor
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    ABSTRACT: For efficient rehabilitation it is important to identify, as early as possible, the patients likely to be successfully returned to work after rehabilitation. The aim of this pilot study was to develop a statistical model for predicting this return as reliably as possible. The model uses only information readily available at the beginning of rehabilitation. A multiple regression analysis with backward elimination was used from a routine data base and identified 8 variables of prognostic value. The model offers a comfortable possibility to predict the probability of return to work of a patient on the basis of routinely registered data. The prognosis was found correct in 68% of those returning to work after rehabilitation (sensitivity) and in 80% of those who did not (specificity). Further work to improve the model for prognosis in rehabilitation research is considered reasonable.
    Die Rehabilitation 11/2000; 39(5):262-7. · 0.71 Impact Factor
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    ABSTRACT: Methodology of clinical studies is highly sophisticated in drug research. But clinical trials are also necessary to demonstrate efficacy and safety of rehabilitation treatment. The call for evidence based medicine has also reached rehabilitation. However, in rehabilitation medicine it is much more difficult to design and conduct clinical trials with a high methodological standard. Among the reasons are: A comparable control group is necessary because spontaneous healing and unspecific measures contribute to therapeutic success, too. But what could "placebo rehabilitation" look like? The masking of therapies (blinded studies) will hardly ever be possible. Therefore, it is more difficult to achieve the same treatment and observation for the treatment and control group. Treatments in rehabilitation take longer to become effective than a drug and maybe the success will disappear after some time. Therefore, long-term trials and follow-ups are necessary. Such studies are expensive, need a strong organisation, and drop-outs are unavoidable. An appropriate outcome variable does not always exist. "Return to work" is an important, reliable and valid variable, but it delivers only one bit of information per patient. As a consequence, smaller progress in rehabilitation can only be demonstrated with large sample sizes. Outcome variables based on time enable studies with reasonable sample sizes. Sometimes it is more difficult to obtain acceptance of randomisation in rehabilitation patients than in acute patients. Some rehabilitation hospitals have only recently begun to take an interest in controlled clinical trials, hence are not so experienced. Nevertheless, controlled clinical trials delivering convincing results are possible in rehabilitation medicine as well. But biometrical consultation is necessary e.g. for study design, study conduction and evaluation. Most important points are the methodology of the study design and its practicability. Especially in these topics rehabilitation physicians and biometrician have to cooperate.
    Die Rehabilitation 09/2000; 39(4):200-4. · 0.71 Impact Factor
  • Rehabilitation. 01/2000; 39(4):200-204.
  • J Högel, W Gaus
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    ABSTRACT: K.R. Popper's philosophy of critical rationalism is concerned with the detection and removal of error. Fundamental contradictions exist between Popper's theory of knowledge and the present-day practice of the clinical investigation of new drugs. Currently, the public authorities concerned with the licensing of drugs pass judgment on trials, which are closely linked by the one-sponsor problem: the assertions made by the sponsor are not independently confirmed. This lack leads to excessive documentation and to costly monitoring and auditing, which are intended to ensure the credibility of results. In Popper's view, confirmatory trials, independent of the sponsor and supervised by the regulatory bodies, would be a better way to achieve reliable knowledge. The consequence would, among other things, be a reorganization of phase III of the clinical investigation of new drugs by dividing it into independent parts, one under the control of the sponsor and one under the control of the public authority. The implementation of this suggestion would lead to a more scientific manner of dealing with new drugs and to savings in terms of unproductive measures during the application process.
    Controlled Clinical Trials 01/2000; 20(6):511-8.
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    ABSTRACT: In adult patients with type 1 diabetes good metabolic control was associated with an undesired weight gain. In the present report the possible association of HbA1c and body mass index (BMI) in children and adolescents with type 1 diabetes (IDDM) was investigated in a long-term retrospective study from 1976 to 1995. Further, the relationship between BMI on one hand and age, gender, duration of IDDM, the number of units of insulin used and the number of injections per day on the other hand were considered. Statistical analysis was performed using repeated measurements analyses of variance. The 208 girls and 201 boys were 5-17 years old and had diabetes for beyond one year. For analysis 2512 data sets, in part measurements on the same patient in the course of the disease, were available. In various statistical models, the results show that age, gender, the daily amount of insulin, and the HbA1c level (p<0.001-0.005) were associated with the BMI. Extremely high HbA1c levels coincided with a remarkably low BMI. Hence, in children and adolescents with IDDM it may be difficult to achieve a constantly good metabolic control accompanied by a normal body weight.
    Experimental and Clinical Endocrinology & Diabetes 01/2000; 108(2):76-80. · 1.56 Impact Factor
  • Rehabilitation. 01/2000; 39(5):262-267.
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    ABSTRACT: The inhabitants of a rural community in southwestern Germany were examined for alveolar echinococcosis (AE). The study was prompted by the recent increase of the prevalence of the parasite in foxes and the increase of fox populations: in the study area, 75% of the foxes carried Echinococcus multilocularis. The human population was screened using hepatic ultrasound and serology. All participants were interviewed for demographic and potential risk factors. Of 2,560 participants, one was identified with active AE, while 3 others had suspicious liver lesions. Another 9 participants were seropositive for specific antibodies without detectable lesions. Demographic and behavioral factors were not correlated with active or suspected cases nor with seropositivity. If the prevalence of 40/100,000 (95% confidence interval = 15-295/100,000) for active cases would be representative for the rural population in high endemicity areas, the current number of AE cases in southwestern Germany is considerably higher than previously suspected.
    The American journal of tropical medicine and hygiene 11/1999; 61(4):566-73. · 2.53 Impact Factor
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    ABSTRACT: The comparison of the three instruments (QLQ-C30, SF-36, QWB-7) of HRQL research was made to investigate the question whether these instruments provide comparable results when tested in a population of patients with haematologic malignancies and solid tumours.For this purpose a comprehensive description of the three instruments considering general principles, construction of scales and items and scoring procedures was conducted. This can be taken as a prerequisite for comparing instruments which are used as health-outcome measures.The study showed that the comparability of the two questionnaires QLQ-C30 and SF-36 was generally better than these questionnaires with the QWB-7 interview. The interview does not identify poor health conditions. Although the QLQ-C30 and the SF-36 contribute comparable information, specifically for the Physical Functioning scale and Symptom scales Pain and Fatigue, important differences have to be considered. Only the QLQ-C30 contains the important question about ‘overall quality of life’. The results of the dimension ‘Role Functioning’ are not comparable because the SF-36 differentiates between Physical and Emotional Role Functioning whereas the QLQ-C30 constructs Role Functioning as a single dimension.All three instruments have a limited scope of applicability for a hospitalized population of patients with haematologic malignancies or solid tumours. Based on the study results further modification and refinement of these instruments are recommended for this population.
    Psycho-Oncology 12/1998; 5(2):103 - 117. · 3.51 Impact Factor
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    ABSTRACT: The total costs of the hospital treatment of patients with secondary peritonitis were investigated with a prospective, randomized, multicenter study. Moreover, the cost-effectiveness of an initial therapy with Imipenem/Cilastatin was compared to selected alternative antibiotic regimens. Altogether 154 patients (77 Imipenem/Cilastatin group, 77 alternative group) that displayed Mannheim Peritonitis Scores between 16 and 26 (average 20.8) were analyzed. The average total cost of treatment was DM 11,140 per patient (range DM 2794-45,526). Patients receiving an initial therapy with Imipenem/Cilastatin incurred average costs of DM 10,455, while patients with alternative regimens caused average costs of DM 11,826. The difference between the two treatment groups was statistically significant (P = 0.037).
    Der Chirurg 11/1998; 69(10):1093-100; discussion 1100. · 0.52 Impact Factor
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    ABSTRACT: Im Rahmen einer prospektiven, randomisierten, multizentrischen Studie wurden die Gesamtbehandlungskosten von Patienten mit sekundärer Peritonitis erhoben. Dabei wurde die Kosteneffektivität einer initialen Behandlung mit Imipenem/Cilastatin mit der anderer ausgewählter Therapieregimes verglichen. Es wurden insgesamt 154 Patienten (77 Imipenem/Cilastatingruppe, 77 Alternativtherapiegruppe), die Mannheimer Peritonitisindices zwischen 16 und 26 (Mittelwert: 20,8) aufwiesen, in die Auswertung einbezogen. Die ermittelten durchschnittlichen Gesamtkosten betrugen 11.140 DM pro Patient (Einzelwerte lagen zwischen 2.794–45.526 DM). Patienten mit einer initialen Imipenem/Cilastatintherapie verursachten im Mittel Kosten in Höhe von 10.455 DM, während für die Patienten mit einer Alternativtherapie durchschnittliche Kosten von 11.826 DM ermittelt wurden; der Unterschied zwischen den Gruppenergebnissen ist statistisch signifikant (p = 0,037). The total costs of the hospital treatment of patients with secondary peritonitis were investigated with a prospective, randomized, multicenter study. Moreover, the cost- effectiveness of an initial therapy with Imipenem/Cilastatin was compared to selected alternative antibiotic regimens. Altogether 154 patients (77 Imipenem/Cilastatin group, 77 alternative group) that displayed Mannheim Peritonitis Scores between 16 and 26 (average 20.8) were analyzed. The average total cost of treatment was DM 11 140 per patient (range DM 2794–45 526). Patients receiving an initial therapy with Imipenem/Cilastatin incurred average costs of DM 10 455, while patients with alternative regimens caused average costs of DM 11 826. The difference between the two treatment groups was statistically significant (P = 0.037).
    Der Chirurg 01/1998; 69(10):1093-1099. · 0.52 Impact Factor
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    ABSTRACT: Quantitative liver function tests such as the determination of galactose elimination capacity (GEC) or the aminopyrine breath test (ABT) may have the potential to serve as refined entry criteria and surrogate markers for end-points in controlled clinical trials. The magnitude of a statistically detectable difference in test results and the period of observation required to document such a difference must be known to properly design such trials. Therefore, we explored retrospectively the time course of changes in GEC and ABT and their reproducibility from a cohort of patients with alcoholic cirrhosis followed for 12 to 42 months, with a median of 34 months. In 15 patients who stopped drinking, GEC improved significantly by 0.64 mg/min/kg within 1 year (mean; 95% confidence interval [CI]: 0.42; 0.86). In contrast, it deteriorated by 0.53 mg/min/kg within 1 year (95% CI: 0.32; 0.74) in another 17 patients who continued to drink (P < .01). The residual standard deviation of the changes in GEC with respect to the patients' initial values was 0.43 mg/min/kg (95% CI: 0.32; 0.52). In addition, ABT improved significantly by 0.14% dose x kg/mmol CO2 (95% CI: 0.09; 0.18) in the abstinent group, and deteriorated by 0.09% dose x kg/mmol CO2 (95% CI: 0.06; 0.13) in the nonabstinent group (P < .01). The residual standard deviation in the above sense for ABT was 0.08% dose x kg/mmol CO2 (95% CI: 0.06; 0.10). These data indicate that clinical trials with a sample size of n = 20 in each group must achieve absolute differences (ADs) in GEC of 0.6 mg/min/kg and of 0.7 mg/min/kg to reach statistical significance at the 5% and 1% level, respectively. In the present study, a period of 11 and 12 months was necessary to observe such differences. The corresponding results for the ABT are 0.11% dose x kg/mmol CO2 (9 months of follow-up; 5% level) and 0.13% dose x kg/mmol CO2 (11 months of observation; 1% level), respectively. Provided that patients with liver diseases treated with drugs are similar to the abstinent and nonabstinent patients with alcoholic liver disease investigated in this study, such numbers could serve for the planning of controlled clinical trials, in which the control group is likely to deteriorate and the treated group is expected to improve. Trials based on GEC or ABT would require only 37 or 30 patient years of observation compared with a median of 444 patient years (range, 50-2,100 patient years) reported for various published controlled clinical trials using survival analysis.
    Hepatology 01/1998; 26(6):1426-33. · 12.00 Impact Factor
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    ABSTRACT: Economic studies in medicine are intended to investigate costs, associated with a particular problem dealing with the indication, diagnosis or therapy, for instance, whether the high costs involved in a highly intensive or innovative therapy could be balanced by the eventual savings made, due to the shorter periods of treatment. In such situations a randomized controlled trial is necessary to find out which therapy or which therapeutical strategy is least expensive in the long run. Economic studies do, however, present some specific problems. Making a list of all the cost-relevant treatment items can be very laborious, but the use of flat rates and lump sums alone cannot lead to a complete cost analysis. Often, costs between hospitals vary more than between treatment regimens. Early and sudden deaths incur low costs and may bias the results. Furthermore, costs are distributed with a long and heavy upper tail including extreme outliers. This does, in fact, complicate the estimation of the sample size. In this article, these problems are outlined and, with the help of the data obtained from two randomized economic trials in health care, solutions are proposed and discussed.
    Methods of Information in Medicine 01/1998; 37(1):53-8. · 1.08 Impact Factor
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    ABSTRACT: To confirm significant improvement of the skin score in systemic sclerosis by treatment with interferon gamma in a larger group of patients and to investigate on a molecular level the influence of interferon gamma on collagen type I messenger RNA expression. Open, noncontrolled multicenter study. Five outpatient clinics specializing in the care of systemic scleroderma. Thirty-two patients suffering from the diffuse or limited form of systemic sclerosis and progressive disease were recruited; 20 patients finished the study. Each patient received interferon gamma, 50 micrograms subcutaneously 3 times a week for 1 year. Skin score, collagen type I messenger RNA in skin biopsy specimens. The patients who completed the study showed an unchanged median skin score after 1 year of therapy. In addition, similar collagen type I messenger RNA levels were detected in skin biopsy specimens taken from involved skin before and after therapy in these patients. Treatment of systemic scleroderma with interferon gamma is associated with stabilization of the skin score and lack of worsening of visceral involvement.
    Archives of Dermatology 06/1997; 133(5):609-13. · 4.79 Impact Factor
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    ABSTRACT: We conducted a randomized, placebo-controlled, double-blind clinical trial in order to determine the efficacy of classical homeopathic therapy in patients with chronic headaches. After 6 weeks of baseline observation, patients received either the prescribed individualized homeopathic medication or an indistinguishable placebo for 12 weeks. Outcome parameters were headache frequency, duration, and intensity, measured daily by diary. Use of medication for acute headache was also monitored. Of the 98 patients in the sample, 37 were randomized to receive placebo, 61 received individualized homeopathic remedies. Groups were comparable at the beginning of the treatment. The median age was 48.5 years; 76% suffered from migraine, 51% from tension-type headaches, and 94% were previously treated for headache. The median headache frequency was 3 days a week. Headaches were present for 23 years (median). In both groups, patients showed an improvement of one headache day less per month. The use of medication for acute headache was reduced. The headache frequency of 21 patients was reduced by more than 40%. Thirty-nine patients either did not improve or experienced aggravations. There was no significant difference in any parameter between homeopathy and placebo.
    Cephalalgia 05/1997; 17(2):119-26; discussion 101. · 3.49 Impact Factor

Publication Stats

618 Citations
147.94 Total Impact Points

Institutions

  • 2005
    • Universität Heidelberg
      • Institute of Medical Biometry and Informatics
      Heidelberg, Baden-Wuerttemberg, Germany
  • 1977–2002
    • Universität Ulm
      • Department of Internal Medicine
      Ulm, Baden-Württemberg, Germany
  • 1996–1998
    • University of Leipzig
      • Institut für Medizinische Mikrobiologie und Infektionsepidemiologie
      Leipzig, Saxony, Germany
  • 1997
    • University of Freiburg
      Freiburg, Baden-Württemberg, Germany
    • Bernhard Nocht Institute for Tropical Medicine
      Hamburg, Hamburg, Germany
  • 1992
    • Institut für klinische Pharmakologie
      Stuttgart, Baden-Württemberg, Germany