Evidence-based Facts Research Articles

Značaj ishrane u sekundarnoj prevenciji i rehabilitaciji koronarne bolesti

Long-term treatment of patients with acute coronary syndrome is necessary in order to prevent new cardiac events. It means lifestyle changes, modification of risk factors, proper nutrition, as well as pharmacotherapy. The aim of this review is to present current evidence-based facts about the diet in the secondary prevention and rehabilitation of coronary heart disease. The paper demonstrated and analyzed the published data about the role of different nutrients in control of some of the risk factors for development of cardiovascular disease, as well as Mediterranean diet. The results undoubtedly indicated that replacement of saturated fats with unsaturated fatty acids and carbohydrates should be an important part of all nutrition strategies for cardiovascular prevention. The dietary intake of trans-fatty acids and salt should be reduced. Education of patient should be directed to the total nutrition, not only to the individual food. Responsibility for proper diet in secondary prevention of coronary heart disease share the patients, health care services, family and society.

Nutrition and cognition: meeting the challenge to obtain credible and evidence-based facts

Nutrition provides a practical and appealing approach to cognitive enhancement, including the modulation of long-term cognitive processes such as neurodevelopment and neurodegeneration. An abundance of promising nutritional influences on cognition have been identified, but many long-term effects remain to be confirmed by data from randomized controlled trials (RCTs). The current article provides a general outline of various factors that hamper the demonstration of causal long-term nutritional effects on cognition by RCTs and advocates the development of methodological solutions to enable substantiation in future RCTs.

Evidenzbasierte Medizin in der Onkologie: spiegelt die Studienlage die klinische Realität wider?

Evidence-based medicine (ebm) is the answer to the postulate to grade the basis of scientific knowledge in medical care and to protect it against proceedings of unjustifiable arbitrariness. The ranking of controlled clinical trials, the evaluation of publications, meta-analyses, and references to "levels of evidence" in medical guidelines are well established. This is not inconsistent with the fact that many diagnostic and therapeutic measures are not evidence-based and that, even in reputable scientific journals, marketing intentions come into conflict with evidence-based facts. The demand for implementing ebm is furthermore an unsustainable ethical pretension as long as ebm itself is not evidence-based. In many cases better results from ebm are not supported by outcome studies. Health services research which, amongst others, evaluates implementation of study results under everyday conditions should be seen as an essential part of ebm. In oncology, cancer registries contribute to this type of transparency. Cancer registries show to what extent ebm is established as an encouraging future programme for the daily cancer health-care delivery and whether ebm exists as a barely realisable parallel world of promising controlled clinical trials.

Overview of clinical studies in hemodiafiltration: What do we need now ?

Despite several technical advances in dialysis treatment modalities and a better patient care management including correction of anemia, suppression of secondary hyperparathyroidism, lipid and oxidative stress profiles improvement, the morbidity and the mortality of dialysis patients still remain still elevated. Recent prospective interventional trials in hemodialysis (HEMO study and 4D study) were not very conclusive in showing any significant improvement in dialysis patient outcomes. High-efficiency convective therapies, such as online hemodiafiltration (HDF), are claimed to be superior to conventional diffusive hemodialysis (HD) in improving the dialysis efficacy and in reducing intradialytic morbidity and all-cause and cardiovascular mortality in dialysis patients. The aim of this report was, first, to review the evidence-based facts tending to prove the superiority of HDF vs. HD in terms of efficacy and tolerance, and, second, to analyze the needs to prove the clinical superiority of HDF in terms of reducing morbidity and all-cause mortality of dialysis patients. A systematic review of studies comparing HDF and HD has been performed in the microbiological safety of online production, the solute removal capacity of small and medium-size uremic toxins, and its implication in the reduction of the bioactive dialysis system vs. patient interaction. Major planned randomized international studies comparing HDF and HD in terms of morbidity and mortality have been reviewed. To conclude, it is thought that these long-term prospective randomized trials will clarify on a scientific evidence-based level the putative beneficial role of high-efficiency HDF modalities on dialysis patient outcomes.

Prophylactic or Therapeutic Adenoidectomy?: In Reply

In Reply.—We thank Dr Carron for his comments on our study.1 His main concern was the accuracy of the diagnosis of otitis media. Although it was not explicitly stated in our report, all the children had tympanostomy tubes, which made the diagnosis straightforward because it invariably involved discharge from the tympanostomy tube. Some children had lost their tympanostomy tubes during the follow-up period, but adenoidectomy did not prevent the need for reinsertion of tympanostomy tubes.Dr Carron suggested that children who have had adenoidectomy because of obstructive symptoms should have been included in our study. Such children, however, benefit from adenoidectomy irrespective of middle ear disease, because adenoidectomy will enable normal nasal breathing. Therefore, these children were excluded from our study. Comparisons of such children with our study children with recurrent otitis media would have been difficult, because they have different diseases.In some children, adenoids may be infected chronically and serve as a source of pathogenic bacteria, presumably predisposing to otitis media. This may explain why adenoidectomy was beneficial in earlier studies of children who were mainly older than 4 years and who had previously received tympanostomy tubes2 and in children who suffered from persistent middle ear disease.3,4 It may be presumed that these children had had infections starting from their infancy, which allowed a chronic infection to develop in their adenoids. However, this is entirely hypothetical, and it is quite vague to call adenoidectomy “therapeutic” without gross adenoid enlargement.Dr Carron also questioned what would happen to the child when the tympanostomy tubes fall out and the child is reliant on his or her own ventilation system again. The focus of such a study should involve only those children who have middle ear disease after the initial or even secondary insertion of tympanostomy tubes, as has been evaluated in an earlier study.2 He stated that “tympanostomy tubes are great for preventing ear infections.” This certainly is not an evidence-based fact at all, because the effect of tympanostomy tubes for preventing otitis media is at its best quite modest5 and is not “preventing most ear infections anyway.”Because children who are younger than 4 years and who do not suffer from gross adenoid enlargement comprise the vast majority of children with middle ear infections, it is especially important to evaluate the effect of adenoidectomy in this very population. As our study showed, adenoidectomy failed to produce any additional benefit in preventing otitis media.

Report on the 124th ENMC International Workshop. Treatment of Duchenne muscular dystrophy; defining the gold standards of management in the use of corticosteroids 2–4 April 2004, Naarden, The Netherlands

Thirty-two participants representing parents, funding agencies and clinicians involved in the care of children with Duchenne Muscular Dystrophy (DMD) from Belgium, Canada, Denmark, Finland, France, Germany, Italy, the Netherlands, Spain, Sweden, the UK and the USA met in Naarden on 2–4th April 2004. The meeting was held under the auspices of the ENMC Clinical Trials Network, and with the additional support of the United Parent Project. The aims of the workshop were to define the need for clinical trials in DMD and develop a protocol for such trials, relating primarily to the use of steroids (prednisolone, prednisone and deflazacort) in DMD. The first part of the meeting summarised the current state of practice on the use of steroids in DMD. Elizabeth Vroom (Netherlands) and Pat Furlong (USA) presented the views of parents surveyed by questionnaire by the United Parent Project. A major worry for parents was the lack of use of steroids at all in some countries, the multiplicity of steroid regimes used and the problems of getting firm information about which type of steroid or which regime for using steroids was best. This was reflected in the variation in practice amongst the participants at the Workshop, who between them used at least seven different regimes for giving steroids, and some did not use steroids at all. Adnan Manzur (UK), co-author of the Cochrane report on the use of glucocorticosteroids in DMD described the major findings of this systematic review [1]. Only five randomised controlled trials of the use of steroids in DMD were published in sufficient detail to be able to be included in the review. These trials did, however, present evidence that use of daily prednisolone (0.75 mg/kg per day) or deflazacort (0.9 mg/kg per day) increased strength in DMD. Robert Griggs, Richard Moxley (USA) and Doug Biggar (Canada) were able to confirm that long-term follow up of cohorts of patients treated under one or other of these regimes and who mostly continued using steroids beyond the loss of independent ambulation shows that this increase in strength is mirrored by improvement in function (with age at loss of ambulation in the mid teens, preservation of respiratory function, lack of need for scoliosis surgery and possibly preservation of cardiac function) [2–4]. With longterm use of steroids, the per kilogram dose of corticosteroid tended to reduce with time. In some cases, this was in response to side effects such as weight gain or behaviour changes, but in the majority represented a tendency not to keep up strictly with change in weight over time. Many different regimes for giving steroids in DMD have been suggested as a way to reduce the risk of the well-known side effects associated with the long-term use of daily steroids. The dose of 0.75 mg/kg per day was shown to be Neuromuscular Disorders 14 (2004) 526–534 www.elsevier.com/locate/nmd

On the three-dimensional physiological position of the temporomandibular joint.

Despite intensive research regarding the position of the temporomandibular joint, only few evidence-based facts are known about a three-dimensional physiological condyle-fossa relationship. The aim of this systematic literature review was therefore to summarize the existing literature regarding the condyle position and to draw conclusions about a standardized three-dimensional condyle position. An extended search profile based on the search strategy of the Cochrane Oral Health Group and applied to twelve medical databases was used to identify existing studies. Articles which were not electronically accessible (mainly those published before 1960) were identified from reference lists and bibliographies. These publications were assessed independently by two clinicians with reference to points based on specified criteria. The interexaminer agreement was assessed on the basis of the kappa coefficient.1903 articles published in the period 1899-2001 and relating to condyle position were identified. These studies showed a pronounced variability in their methodological approaches, with only 49 of them meeting the inclusion criteria. The interexaminer agreement yielded a kappa-value of 0.92. Although numerous studies used three-dimensional data, no physiological three-dimensional condyle position was determined. The most frequent analytic method was two-dimensional projection of the temporomandibular joint onto a subjectively selected sagittal plane. This evaluation method revealed a noticeable shift over time in condyle position from posterior to anterior, suggesting a clear-cut publication bias. Publications with the highest evidence level favored no specific position (p > 0.05). Simplification of the three-dimensional structure of the temporomandibular joint to a two-dimensional projection is questionable for therapeutic positioning of the condyle in relation to the fossa.

University of California, Los Angeles, David Geffen School of Medicine at UCLA.

University of California, Los Angeles, David Geffen School of Medicine at UCLA.

Implicit normativity in evidence-based medicine: a plea for integrated empirical ethics research.

This paper challenges the traditional assumption that descriptive and prescriptive sciences are essentially distinct by presenting a study on the implicit normativity of the production and presentation of biomedical scientific facts within evidence-based medicine. This interdisciplinary study serves as an illustration of the potential worth of the concept of implicit normativity for bioethics in general and for integrated empirical ethics research in particular. It demonstrates how both the production and presentation of scientific information in an evidence-based decision-support contain implicit presuppositions and values, which prestructure the moral environment of the clinical process of decision-making. As a consequence, the evidence-based decision support did not only support the clinical decision-making process; it also transformed it in a morally significant way. This phenomenon undermines the assumption within much of the literature on patient autonomy that information disclosure is a conditional requirement before patient autonomy even starts; patient autonomy is already influenced during the production and presentation of information. These results imply an increased responsibility of those who produce and present evidence-based facts (i.e. scientists in general and physicians in particular). The insights of this study not only involve a different focus on both theory and practice of patient autonomy and informed consent, but they also call for a broader scope of morality than does traditional empirical research in bioethics. The concept of implicit normativity within integrated empirical ethics research calls for strong cooperation between bioethicists and descriptive scientists, i.e., a cooperation that goes beyond the discipline-specific epistemic values and that takes place during all phases of the research process.

Drug Labeling and Risk Perceptions of Teratogenicity: A Survey of Pregnant Canadian Women and Their Health Professionals

There is a general perception that medicinal drugs are not safe in pregnancy despite the fact that fewer than 30 drugs have been shown to cause major malformations in humans. A large number of women need medications in pregnancy to treat pregnancy-induced conditions, acute illnesses, and chronic diseases. The objectives of this study were the following: (1) to characterize the perception of teratogenic risk by pregnant women and their partners and by health professionals and (2) to examine the most way to present data on a drug for nausea and vomiting of pregnancy that has been proven to be safe to the fetus. A convenience sample of pregnant Canadian women and their partners, pharmacists, nurses, physicians, and hospital workers were asked to choose the safest among four drugs by statements describing their safety. Although the text of all four was similar, the title and narrative were modified to be more or less reassuring by the use of more or less terms such as malformations and abnormalities. Health professionals rated the teratogenic risk significantly lower than the parents, but even they rated the drugs as not safe, despite a scientifically text. Sixty percent of the 240 participants, regardless of their perception of teratogenic risk, believed the four drugs were of similar risks. However, in the other 40%, the less reassuring text led to higher teratogenic perception, and the more options tended to decrease the false perception of teratogenic risk. It was concluded that in general, four different versions of text describing a scientifically proven safe drug in pregnancy did not lead expecting parents to believe they were safe. Among those who did not rank the four drugs as having equal safety/risk, the less reassuring text led to a higher perception of teratogenic risk. Even health professionals reading the labels describing safe drugs rated them as unsafe. Presently, the perception of teratogenic risk is strong even for safe drugs and is difficult to change even with evidence-based facts.

Drug Labeling and Risk Perceptions of Teratogenicity: A Survey of Pregnant Canadian Women and Their Health Professionals

There is a general perception that medicinal drugs are not safe in pregnancy despite the fact that fewer than 30 drugs have been shown to cause major malformations in humans. A large number of women need medications in pregnancy to treat pregnancy-induced conditions, acute illnesses, and chronic diseases. The objectives of this study were the following: (1) to characterize the perception of teratogenic risk by pregnant women and their partners and by health professionals and (2) to examine the most reassuring way to present data on a drug for nausea and vomiting of pregnancy that has been proven to be safe to the fetus. A convenience sample of pregnant Canadian women and their partners, pharmacists, nurses, physicians, and hospital workers were asked to choose the "safest" among four drugs by statements describing their safety. Although the text of all four was similar, the title and narrative were modified to be more or less "reassuring" by the use of more or less terms such as malformations and abnormalities. Health professionals rated the teratogenic risk significantly lower than the parents, but even they rated the drugs as not safe, despite a scientifically reassuring text. Sixty percent of the 240 participants, regardless of their perception of teratogenic risk, believed the four drugs were of similar risks. However, in the other 40%, the less "reassuring" text led to higher teratogenic perception, and the more reassuring options tended to decrease the false perception of teratogenic risk. It was concluded that in general, four different versions of reassuring text describing a scientifically proven safe drug in pregnancy did not lead expecting parents to believe they were safe. Among those who did not rank the four drugs as having equal safety/risk, the less "reassuring" text led to a higher perception of teratogenic risk. Even health professionals reading the labels describing safe drugs rated them as unsafe. Presently, the perception of teratogenic risk is strong even for safe drugs and is difficult to change even with evidence-based facts.