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S Schewe

Publications and source records attributed to S Schewe.

At least 19 recordsLinked to original sources
PubMed1998

Learning at the computer: evaluation of an intelligent tutoring system.

The aim of the study was to test the efficacy of a new courseware. In a pre and post test frame, students were given the software to be used during one semester. A significant increase in the students' general study motivation was shown at the end of the semester. A change in the use and attitudes towards computers could not be observed. In a follow-up survey at the end of the semester, the students stated that the program was indeed helpful and useful but that they have had difficulties with the program's technical aspects and the general use. Furthermore, the results show that the majority of the participating students accepted the program's content, the general study motivation was high and the students showed a significant increase in learning gains, determined by the differences from pre and post test values. Especially students with low pre test values seemed to profit from the additional use of learning material, resp. the presented courseware. At the end of the semester the students with low and middle pre test results showed an increase in performance as well as an alignment in the performance for diagnosing rheumatological diseases to the students of the upper third pre test results.

Cardiology↗
PubMed1996

[Mortality and nursing home admission of severely disabled patients].

242 people had been interviewed 1-4 years (average 2 years) after first receiving benefits because of urgent need of nursing care. Meanwhile 57 persons had died at home. 17 persons had moved into a nursing home, and 8 of them had died there. For another two persons transfer to a nursing home was imminent. -Among those older than 60 years the probability of dying at home is more than three times greater than the risk of changeover to a nursing home. The highest transferrat to a nursing home (more than 18% within the observation period) was seen in women of 80 years of age and older.

Adolescent↗
PubMed1993

Stepwise development of a clinical expert system in rheumatology.

The evaluation of computer expert systems, a promising diagnostic tool for future application in clinical medicine, is of great importance. We present here the evaluation of our expert system, "RHEUMA". It is stressed, that repeated retrospective testing and updating of an expert system and its subsequent repeated assessment in clinical use and surroundings is mandatory. This increases the diagnostic accuracy of the system. For our system this is demonstrated under three separate conditions. In the first study the information available for the computer system (mainframe) came from medical histories only. Here an error rate of about 25%--similar to that of physicians themselves using the same information--was observed in 358 outpatients, compared to the final diagnoses of physicians also relying solely on information from medical histories. In a second step a completely new system on a personal computer was developed with all relevant diagnostic information. The error rate of this system (0.4%) was much too optimistic because the knowledge base was changed during the study, affecting about 30% of the 282 prospectively recruited outpatients. In a third step the efficacy of the expert system was tested in an additional hospital without the diagnostic involvement of the first testing clinic. The error rate of the system without changing the knowledge base reached 11% in 51 outpatients in this rheumatology clinic. This result reflects the diagnostic accuracy of the system today. Its ability to specify the same diagnoses which clinical experts reached approached 90%. Considerable time is needed for such prospective testing, with repeated updating of the knowledge base--in our case for both the two systems and field studies of 2 years each.(ABSTRACT TRUNCATED AT 250 WORDS)

Computers↗
PubMed1993

Graphical knowledge acquisition for medical diagnostic expert systems.

Like many textbook authors use text systems for writing their books, expert system authors should have easy to use knowledge acquisition systems for entering and testing their knowledge bases by themselves without much help from 'knowledge engineers'. In this paper, we report on a graphical knowledge acquisition tool (CLASSIKA) based on an expert system shell for heuristic classification (MED2) and designed for direct use by domain experts. We demonstrate how the system has been used for building a rather large expert system for diagnosing rheumatology diseases which is now being tested in clinical use.

Artificial Intelligence↗
PubMed1992

[Assessment of risk factors and their modification in rehabilitation applicants].

Compared with the general population male workers applying for medical rehabilitation show a higher risk-load, especially regarding smoking and alcohol consumption. However, at present it can't be decided, if the risk-load within this group of applicants is even higher than among the non-applying workmen. Such a selection would be intended. Overweight is the main risk-factor among applicants for medical rehabilitation. It is present far more often than generally within the general population and even within the working class. Male workers with repeated courses of medical rehabilitation exhibit a significant lower risk-load than applicants for a first rehabilitative procedure. A causal relation might be suggested, but at present other explanations regarding the observed relationship have to be considered. A long-term Follow-up study is necessary.

Adult↗
PubMed1992

[Duration of work incapacity before and after inpatient therapeutic procedures].

An analysis has been made of days off work prior to and following a course of treatment in clinics for rehabilitation. A comparison of pre-treatment and after-treatment three-year periods revealed a small decrease of 8 days (9.2%). The youngest age group had the most time off work and--measured in terms of days off work--also the greatest response to treatment. Also after post-hospital rehabilitative treatment clear, though not statistically significant, reductions in the number of days off work were observed. The most striking changes were seen when (only) total number of working days lost prior to the course of treatment was recorded: in the case of high pre-treatment figures for working days lost, a considerable decrease was subsequently observed, while in the case of low working days lost figures, a marked increase in days off occurred. With respect to some of the groups participating, the methodological approach we employed did not make it appear probable that (measured in terms of total working days lost) these groups were "more pathological". It must be pointed out that these results were obtained in relatively small groups; it was not possible to extend the investigation.

Absenteeism↗
PubMed1991

[Indications for sonography and follow-up studies. Initial results of a prospective study].

Ultrasonic examinations of the abdomen may result in expensive secondary imaging examinations. This prospective study was conducted in collaboration with the Zentralinstitut Köln. The first aim of our study was to compare the results of abdominal sonography in three different patient groups: The first group was comprised of patients referred for a medical check-up, the second group of patients referred because of upper abdominal pain and the third group of patients with generalized atherosclerosis. The second aim was to correlate sonographic findings (classified in three degrees of severity), with subsequently induced diagnostic procedures in the three groups. 2719 patients were enrolled, 2393 (88%) in group 1, 286 (11%) in group 2 and 40 (1%) in group 3. A total of 1792 abnormal findings were diagnosed. 65.6% of the findings in group 1, 65.7% in group 2 and 88% in group 3 were abnormal. Up to now, the findings led to a nearly equal number of subsequent diagnostic procedures in groups 1 and 2. The preliminary results show that abdominal sonography may be as effective in patients for a check-up as in patients referred because of a well-defined indication. Patients with defined abdominal symptoms show more abnormal sonographic findings than patients on a check-up. Higher costs resulting from subsequent examinations deserve critical assessment in the individual patient.

Abdomen↗
PubMed1991

Echocardiographic changes in patients with heterozygous and homozygous familial hypercholesterolemia: correlation with clinical findings.

59 heterozygous and 6 homozygous patients with familial hyperchole sterolemia were screened for atherosclerosis of the aortic root and cardiac valves by echocardiography. Pathological echocardiographic changes were found in 59% of heterozygotes and in all homozygotes. In heterozygotes, aortic root sclerosis usually appears after the age of 30 and its frequency increases progressively with age. Homozygotes showed severe changes before the age of 10. In heterozygotes, a pathological echocardiogram correlated strongly with the presence of overt coronary heart disease. Echocardiography proved to be a useful non-invasive method for better evaluation of the individual coronary risk in patients with familial hypercholesterolemia.

Adolescent↗
PubMed1990

Prospective application of an expert system for the medical history of joint pain.

An expert system with 60 questions about medical history was developed for 32 rheumatologic diseases: 358 outpatients with joint complaints have been examined. The final diagnosis (result of symptoms, signs, and findings) was compared with the computer diagnoses and with the independently assumed diagnoses of the physician. The only source of information available to the physician was the medical history. Misinterpretation of the computer diagnoses occurred in 25.6% of cases compared with 21.5% of the physician. The final clinical diagnosis remained uncertain in 32.6% of cases. The error frequency of the expert system was influenced by the underlying disease, the certainty of the assumed diagnosis by the physician, the user experience in rheumatology, the number of questions asked, and the time of application before or after the doctor-patient contact. Of the errors 44% were produced because of information deficits of the computer using standardized questions. The information of the physician in the diagnostic process is quite different to that of the computer.

Arthritis↗
PubMed1990

Genetic evidence from 7 families that the apolipoprotein B gene is not involved in familial combined hyperlipidemia.

Familial combined hyperlipidemia (FCHL) is the most common genetic form of hyperlipidemia in which affected individuals manifest multiple lipoprotein phenotypes. Although the molecular defect is still unknown, several kinetic studies have demonstrated increased turnover rates of apolipoprotein B (apo B) in patients with FCHL, irrespective of their lipoprotein phenotype. Using 3 restriction fragment length polymorphisms (RFLPs) of the apo B gene (XbaI, MspI and EcoRI) we have investigated 33 families which fulfill the diagnostic criteria of FCHL. No significant difference in allele frequency was found between 33 unrelated individuals with FCHL and 107 normolipidemic controls. 3-RFLP haplotypes were constructed in each pedigree. A co-segregation analysis was performed in 7 informative families. In no family was co-segregation observed between the haplotype of the apo B gene and the phenotype of FCHL. These data are not compatible with the hypothesis that FCHL is caused by mutations of the apo B gene acting as a simple mendelian trait.

Adult↗
PubMed1989

Double-blind study of metaclazepam versus diazepam treatment of outpatients with anxiety syndrome.

The therapeutic efficacy and tolerance of metaclazepam and diazepam were compared in a double-blind study of outpatients suffering from a generalized anxiety syndrome. The investigators were general practitioners. A total of 168 male and female patients aged between 18 and 60 years were included in the study and received either 15 mg metaclazepam or 15 mg diazepam per day. The analysis of tolerance was made for all 168 included patients, the evaluation of efficacy is based on the results of 131 patients (42 males and 89 females) with valid data over four weeks. During the four-week therapy period four examinations were made on days 0, 7, 14, and 28. A significant improvement of the severity of illness after administering the drugs was found for both drugs in the Clinical Global Impressions (CGI), in the Hamilton Anxiety Scale (HAMA), in the List of Complaints (B-L), and in the Adjective Checklist (EWL-K). Metaclazepam showed a statistically significant superiority over diazepam as far as the CGI items "severity of illness" and "global improvement" were concerned. Metaclazepam was slightly superior to diazepam in the two HAMA subscales "psychic anxiety" and "somatic anxiety". In the items of the selfrating scales (B-L and EWL-K) the therapeutic results of the metaclazepam group were, almost without exception, better than those of the diazepam group. A comparison of tolerance showed that metaclazepam was better tolerated. This can be seen in the greater frequency of side effects like tiredness and drowsiness under diazepam. Especially at the beginning of treatment, tiredness and drowsiness were recorded 2 1/2 times more frequently for the patients on diazepam than for those on metaclazepam.

Adolescent↗
PubMed1989

[Postoperative status of the duodenal ulcer patient. Review and personal studies].

Studies into the postoperative situation of duodenal ulcer patients have shown psychic factors to play a role in the context of both surgical achievement and the possibility of postoperative symptoms. These insights were supported by the authors' own investigations of vagotomised patients, primarily in the context of recordable factors of damage in early childhood. Postoperative results were worse in patients who had suffered severe trauma in early childhood. No answer has so far been found to the question for the relationship between hereditary factors and disorder of personality, primarily in the context of recurrence and development of new symptoms some time after surgery.

Adult↗
PubMed1989

[Life after urostomy. A retrospective study].

The study reported, which was based on a questionnaire and psychological tests, examined cystostomy patients with respect to the work-up and acceptance of their altered body. It was noted that 30% of the patients judged their situation as good, and 25% could accept the cystostomy, but a great many has to live with sexual disturbances, reduced social mobility, increased dependence, and psychic consequences; some had to give up their jobs. Sex, earlier psychosomatic diseases, developmental disorders in early childhood, which influence the personality, significantly affect the acceptance of the stoma. The problems are discussed. Suggestions are made, which include a plan for a holistic therapy.

Adaptation, Psychological↗
PubMed1988

Double-blind randomized trial of the benzodiazepine derivative metaclazepam as compared with placebo treatment of outpatients with anxiety syndromes.

In a double-blind randomized study the therapeutic anxiolytic efficacy and the tolerance of metaclazepam were tested in comparison with placebo. The study was performed according to the model of the "Study Group - Psychotropic Drugs in Medical Practice" (Laakmann and Hippius, 1981; Laakmann et al., 1982). A total of 121 male and female patients aged between 18 and 50 years were treated either with placebo, or with 15 mg or with 30 mg metaclazepam/day for two weeks, during which period they were examined on Day 0, Day 7 and Day 14. The patients suffered from a neurotic anxiety syndrome. In the physician's rating metaclazepam showed a therapeutic effect significantly superior to that of placebo, both in the Clinical Global Impressions (CGI) and in the Hamilton Anxiety Scale (HAMA). This effect was already noticeable at the end of the first week. Similarly, a significantly superior anxiolytic activity of metaclazepam as compared with placebo was observed in the patients' ratings in the course of treatment. This was true for the Erlangen Anxiety Scale (EKSA) as well as for the Scale of Well-being (Befindlichkeits-Skala [Bf-S]) and the List of Complaints (Beschwerden-Liste [B-L]) by von Zerssen. No difference in efficacy could be found between the doses of 15 mg and 30 mg metaclazepam/day, neither in the physicians' nor in the patient's ratings. Compared with placebo, twice as many undesirable side effects were recorded with 15 mg metaclazepam and three times as many with 30 mg metaclazepam. This was clearly demonstrated by the significantly higher frequency of daytime fatigue after 30 mg metaclazepam.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1985

[Pathogenesis and clinical significance of Mönckeberg medial calcinosis].

Medial calcinosis of Mönckeberg is frequently observed in peripheral arteries of diabetics with neuropathy. The cause of this vessel alteration is unknown and the clinical significance has been questioned. Six to eight years after uni- or bilateral lumbar sympathectomy 60 patients were investigated radiologically for medial calcinosis of foot arteries. Of 60 patients, 55 had Mönckeberg's sclerosis. In 93% of the patients who had undergone bilateral operation medial calcification was seen in both feet. After unilateral sympathectomy the incidence of medial calcinosis on the operated side was significantly higher than on the non-operated side (88% versus 18%, p less than 0.01). There was no significant difference between diabetics and non-diabetics. These findings suggest that medial calcification is related to autonomic neuropathy of peripheral vessels. Fifty-two of 160 patients (32.5%) with severe arterial occlusive disease of the lower limbs showed medial calcification of foot arteries. Mönckeberg's sclerosis was significantly associated with the peripheral type of vascular disease (p less than 0.025). Two groups of patients with the same stage of occlusive vascular disease but without (group A) and with (group B) medial calcification were examined by Doppler ultrasound. In group A the mean ankle pressure (pD) was 51 mm Hg lower than the Riva-Rocci pressure (pRR). In spite of the severe ischemia mean pD in group B exceeded pRR by 14 mm Hg. Of the patients of group B 63% had a pD-pRR value greater than or equal to 0 mm Hg. In group A no positive difference pD-pRR could be shown.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1979

[Sensitivity of the haemoccult test in colorectal tumours (author's transl)].

157 patients with histologically investigated colorectal tumours from 5 hospitals of the University of Munich were tested with the Haemoccult test. In 30 (35.7%) of 84 patients with malignancy of the colon and in 31 (58.5%) of 53 patients with adenomas or polyps the correctly performed test was negative. The test result showed no dependency on age or sex of the patient, nor on size, stage or localisation of the tumour. A problem-orientated history lowered the rate of false negative tests to 2.4%. The high rate of false negative results was not attributable to organisational or technical errors.

Adenoma↗