Heparin-induced thrombocytopenia

Seen from a societal perspective, the health gains that might result from prostate screening are too uncertain to justify the substantial associated costs and adverse health effects. Clinicians who rely on observational screening studies to justify current screening practices should be aware of the potential biases that render conclusions suspect. Medical history documents numerous cases of medical interventions that appeared reasonable at the time, but ultimately proved worthless and even harmful. Before embarking on an ambitious screening program for prostate cancer, clinicians should demand that five basic criteria are satisfied: (1) that prostate cancer is a significant health burden, (2) that screening can identify localized disease, (3) that tests used in screening programs have acceptable performance among the population being tested, (4) that the potential for cure is greater among patients with screen-detected disease, and (5) that screen-detected patients have improved health outcomes compared with those who are not screened. Randomized trials provide the best methodology for determining the efficacy of screening and treatment. Clinicians are often too quick to credit medical intervention for successful outcomes and blame tumor biology for disease progression. Furthermore, when faced with a decision of administering or withholding therapy, physicians generally wish to err on the side of having done everything possible. Data modeling can provide critical insights concerning these issues using currently available information. Three recently published models suggest that the overall benefit to a population of men screened for prostate cancer can be measured in days of additional time of life gained, not months or years. Furthermore, models suggest that a substantial number of men need to undergo treatment in order to avert a single cancer death. The costs of implementing a screening program are enormous and deflect resources away from alternative uses, such as increased basic science funding to identify a cure for this disease. Therefore, based on the evidence presented, I believe that without more substantial data supporting the efficacy of screening programs, screening for prostate cancer is neither appropriate nor cost-effective.     

Guidelines for the design and conduct of clinical trials on dentine hypersensitivity

Clinical trials on dentine hypersensitivity have been numerous and protocols varied. To date there is little consensus as to the conduct of studies on this poorly-understood yet common and painful dental condition. A committee of interested persons from academia and industry was convened to discuss the subject of clinical trials on dentine hypersensitivity and a consensus report is presented. A double-blind randomized parallel groups design is recommended, although cross-over designs may be used for the preliminary screening of agents. Subjects may have multiple sites scored. Sample size will be determined by estimating the variability in the study population, the effect to be detected and the power of the statistical test to be used. Subject selection is based on a clinical diagnosis of dentine hypersensitivity, excluding those with conflicting characteristics such as currently-active medical or dental therapy. The vestibular surfaces of incisors, cuspids and bicuspids are preferred as sites to be tested. A range of sensitivity levels should be included. Tactile, cold and evaporative air stimuli should be applied. Negative and benchmark controls should be incorporated. Most trials should last 8 weeks. Sensitivity may be assessed either in terms of the stimulus intensity required to evoke pain or the subjective evaluation of pain produced by a stimulus using a visual analog or other appropriate scale. The subject's overall assessment may be determined by questionnaire. Outcomes should be expressed in terms of clinically significant changes in symptoms. Follow-up evaluation is required to determine the persistence of changes. At least 2 independent trials should be conducted before a product receives approval.     

Guidelines for the diagnosis and treatment of chronic obstructive lung disease--effective and necessary

The independent practice of the art of medicine which doctors took for granted in the past has ended. With almost revolutionary speed, insurers, administrators and politicians have distributed the unique relationship between doctors and their patients. Treatment and diagnostic guidelines in different clinical entities have been based on the pillars of medicine - controlled studies and/or a common consensus among specialists and practitioners. These dynamic activities have enriched our knowledge and practice of medicine. However, only the continuing direct collaboration of physicians at all levels and constant adjustment to changing conditions make these guidelines applicable to the ever changing world of medicine. Chronic obstructive lung disease is one such clinical entity that requires uniform guidelines. Issues that have to be addressed are not only who belongs in this category but also what interventions, such as lateral chest radiographs, CT scans and sleep lab investigations, should be performed as well as the indications for costly therapies such as long-term home oxygen, alpha-1-protease inhibitor augmentation therapy and lung transplantations. Instead of looking at guidelines at straitjackets that limit excellence in the practice of medicine, medical associations should treat them as an opportunity to define their own quality standards. By doing so, the medical community would eliminate the influence of administrative directions or gatekeeper decisions, while patients and the whole population would greatly benefit.     

Potential contribution of screening to cancer mortality reduction

The objective of screening for cancer is to reduce mortality or to improve quality of life. Screening is practiced for several anatomical sites and by several tests. Only cervical cancer screening based on cytological smears has been shown to be effective as a public health policy. Screening for breast cancer based on mammography was shown to reduce mortality in several randomized trials and nonexperimental studies. However, no data are available on its effectiveness at population levels in terms of a public health policy. There are several other valid tests. Application of these tests has failed to demonstrate a reduction in mortality or such an application was never tried and tested. This emphasizes that the prerequisite for effective screening is that the total program is valid and not only the test. At present, knowledge on screening is not fully applied in most European countries. Regular screening for cervical cancer will result in a 90% reduction in the risk of invasive disease. It is likely that the protective effect for breast cancer is about 30%. At the population level, smaller protections are to be expected, and well-organized screening programs are likely to reduce the total cancer death rate by 6 to 10% among females.     

Virtual and three-dimensional bronchoscopy with spiral and electron beam computed tomography

PURPOSE: To compare spiral computed tomography (CT) and electron-beam CT (EBT) for 3D and virtual CT-bronchoscopy. MATERIALS AND METHODS: 17 patients with various disorders of the tracheobronchial system were examined using fiberoptic bronchoscopy, spiral CT and EBT. 3D images were reconstructed from CT data sets using automated segmentation based on volume-growing methods. Surface-rendered, volume-rendered, and hybrid reconstructions were visualized in real time using a data helmet. RESULTS: All data sets could be processed to high-quality three-dimensional (3D) and virtual reconstructions. The reduction of motion artifacts due to shorter scan times made EBT data sets better suited for automated segmentation and less susceptible to motion artifacts. 3D and virtual reconstructions did not increase the diagnostic sensitivity of CT compared to axial reconstructions alone. CONCLUSIONS: Shorter scan times of CT imaging yield higher-quality 3D and virtual reconstructions. Modern reconstruction techniques are valuable visualization tools for select indications and are the prerequisite for future developments in computer-aided medicine.     

Electron-beam CT scanning for detection of coronary calcification and prediction of coronary heart disease

Electron-beam or ultrafast computerized tomographic (CT) scanning provides a convenient and sensitive means of detecting coronary calcification, which is an early index of atherosclerosis. The procedure has strong negative predictive power for the presence of coronary artery disease, but a limited ability to predict disease severity. However, preliminary indications are that it is as good or better than conventional risk factors in this respect. Although further validation is needed before electron-beam CT can be regarded as an established method of detecting presymptomatic coronary atherosclerosis, the procedure has potential in this context.     

Impact of policy and practice on the effectiveness of contact screening for tuberculosis

BACKGROUND: Screening for tuberculosis is conducted because TB is a disease of public health importance that can be prevented if screening is followed by isoniazid prophylaxis for infected individuals. Screening alone is not effective unless that screening is rational and systematic and is followed by prevention where appropriate. Our aim was to consider whether the TB contact screening guidelines are evidence-based and appropriate, how well these guidelines are implemented, and how policy and practice impact on prevention. METHODS: A cohort of 1,142 recent contacts screened in 1991 in Victoria, Australia, was studied. We evaluated the appropriateness of the screening guidelines and how well they were implemented and how the combination of these two factors impacted on the efficacy of the screening program. RESULTS: The screening guidelines required updating and were not evidence-based. Chest radiograph (CXR) was overused and was the sole screening tool for nearly 40% (449/1,142) of contacts. Eighty percent of repeat CXRs were done following a normal initial study. Skin testing was underused. In nearly 60% (658/1,142) of all contacts, the presence or absence of infection could not be determined because a skin test was not done and the CXR, if done, was clear. Only 22% (38/175) of identified, eligible contacts received isoniazid preventive therapy. CONCLUSIONS: Lack of evidence-based guidelines, as well as poor adherence to guidelines, resulted in an inefficient program. This problem may not be unique to the study setting, but cannot be identified without systematic program evaluation, for which we have provided a model.     

Pyomyositis and AIDS

After more than a decade of special treatment, HIV medicine is ready to enter the mainstream of medical practice in developed countries. Access to a conveniently located, well informed, primary care doctor who works well with an appropriate specialist is the cornerstone of best medical care for chronic illness, including HIV disease. Managing HIV is part of the second phase of a national educational program aimed at equipping more doctors with the skills to care for people with HIV.     

Viability and recovery of peripheral blood mononuclear cells cryopreserved for up to 12 years in a multicenter study

Polish physicians-philosophers tried to find a compromise between medicine as a science and medicine as a healing art. They stated that clinical practice should be transformed into science, bearing in mind that there would be no medicine without the existence of the sick. A perfect physician is a good and wise person and not exclusively a proficient expert. Polish physicians exercised a science that they called philosophy of medicine. It included logic, psychology, and medical ethics. The Polish school claimed that the history of medicine and philosophy of medicine are necessary for future doctors. The historical and philosophical approach makes it possible to recognize the subject of medicine (health, disease, and the sick) and its aim (treatment, restoration of health or just alleviation of suffering). The ethics teaches what values are pursued by medicine, what moral duties a doctor has, and what role model to follow to become a good physician. Placing the sick in the focus of medical interest, the Polish school taught future physicians to see in them suffering fellow men who should be embraced with care, compassion, and Christian charity. Such an approach to the ethical aspect of medical philosophy became incorporated into an education towards humane values, responsibility for ones' life and health in the spirit of the ethics of care.     

Coronary arteries: retrospective cardiac gating technique to reduce cardiac motion artifact at spiral CT

Coronary artery calcification is a marker of atherosclerosis. Detection and quantification has previously been accomplished with electron-beam computed tomography (CT). Use of spiral CT for this application has been limited by cardiac motion. The authors evaluated a retrospective cardiac-gated postprocessing technique that necessitates no modification of scanner hardware or software. At spiral CT in 26 patients, motion artifact was reduced, coronary arteries were consistently visualized, and quantification of calcification could be performed in those patients with prominent deposits. Coronary artery calcification screening can therefore be offered in sites that have access to only spiral CT.     

Providing dental treatment for patients with cardiovascular disease

The appropriate management of dental patients with cardiovascular disease is contingent on appropriate assessment and evaluation. Baseline vital signs, a good medical history and medical evaluation are all essential for the safe delivery of care. All patients with cardiovascular disease can be managed using the following guidelines: 1. Properly assess the patient. This should include an assessment by the dentist and also a medical consultation if required. 2. Establish what medications the patient is taking along with the dose and timing and note any potential drug interactions and side effects. 3. Use short appointments (less than one hour), preferably in the morning. 4. Premedication should be considered to alleviate anxiety. The intraoperative use of nitrous oxide and oxygen is also a reasonable strategy for patients with cardiovascular disease, particularly those with ischemic heart disease. 5. Effective local anesthesia is important in order to avoid undue stress during the appointment as long as the guidelines for the administration of epinephrine are followed. The use of epinephrine impregnated gingival displacement cord should be strictly avoided in patients with cardiovascular disease. 6. For patients with angina pectoris, a fresh supply of nitroglycerin should be available at the time of the appointment. Prophylactic nitroglycerin has been shown to be effective in the prevention of both hypertension and angina pectoris during dental treatment. The appointment should be terminated early if the patient becomes overly anxious. In the event of cardiovascular symptoms during dental treatment, all work should be stopped. Emergency measures should be instituted if necessary. Preparations for emergencies should be undertaken by all dentists. The treatment of patients with cardiovascular disease is relatively simple if the proper steps are taken. The use of blood pressure measurements on all patients will help to screen for undiagnosed hypertension and all patients who are potentially hypertensive should be referred for medical evaluation. A preventive approach to the treatment of these patients will serve to prevent untoward outcomes and provide safe and simple delivery of dental care for cardiovascular patients.     

A blueprint for academic obstetrics and gynecology

A consensus conference sponsored by the Council of University Chairs of Obstetrics and Gynecology in February 1997 formulated the organization's response to the many external issues affecting academic medicine and obstetrics and gynecology including 1) a new practice model based on "wellness," 2) reimbursement changes that have jeopardized traditional revenue sources, 3) an emphasis on quality assurance based on outcomes research and evidence-based medicine, 4) the concept of lifelong learning dictated by an expanding knowledge base and new technology, 5) insufficient resources for basic and clinical investigation in obstetrics and gynecology, 6) workforce statistics indicating stabilization in the number of subspecialists, 7) the increasing diversity of the United States population. Recommendations were developed that are intended to foster change and contribute to the design of academic programs. These include appropriate training for residents as providers of primary care, with an emphasis on continuity clinics, an interdisciplinary curriculum in women's health for medical students; promotion of gender, racial, and ethnic diversity at all levels of medical education and academic leadership; creation of clinical trials research units; and the development of expanded opportunities for research in obstetrics and gynecology supported by the National Institutes of Health.     

Evaluation of various screening and surveillance methods in colorectal carcinoma

Colorectal cancer is a common disease which is almost wholly preventable by early removal of adenomatous polyps. Screening should be offered to all persons without risk factors from the age of 50. Selection of the appropriate screening programme should take into account personal preference, local expertise and insurance coverage. Endoscopic screening and surveillance investigations should be strongly encouraged in all persons wit risk factors such as (1) previous treatment of colorectal adenomatous polyps or cancers, (2) ulcerative colitis, (3) patients with hereditary colorectal cancer syndromes and (4) first degree relatives of patients with colorectal cancer. The following four strategies are available for candidates > 50 years without risk factors: (1) faecal occult blood testing (annually), (2) flexible sigmoidoscopy (every 5 years), (3) a combination of both (1 + 2) strategies and (4) coloscopy (every 10 years). Coloscopy should be performed after a positive test result in strategy programs 1-3. Results from prospective randomized trials are available only for faecal occult blood testing, showing an approximately 15% reduction of mortality in the screening group. The potential for reduction of colorectal cancer mortality has been estimated at 30-70% and 60-90% for flexible sigmoidoscopy and coloscopy respectively. However, no results from prospective randomized trials are presently available. Cost-effectiveness analysis has not shown relevant differences between the four different screening strategies.     

Value of electron-beam computed tomography for the noninvasive detection of high-grade coronary-artery stenoses and occlusions

BACKGROUND: Reliable noninvasive assessment of coronary-artery stenoses and occlusions would constitute an advantage in the care of patients with known or suspected coronary artery disease. We investigated the accuracy of contrast-enhanced electron-beam computed tomography (CT) for the detection of high-grade coronary-artery stenoses and occlusions. METHODS: Electron-beam CT was performed in 125 patients. After intravenous injection of a contrast agent, 40 cross-sectional images of the heart were acquired during inspiration, triggered by the electrocardiogram in diastole. Three-dimensional reconstructions of the heart and coronary arteries were rendered to facilitate evaluation of the images. The proximal and middle segments of the major coronary arteries were evaluated for the presence or absence of high-grade stenoses and occlusions. The results were compared with those of invasive coronary angiography in a blinded fashion. RESULTS: Because of technical problems that impaired the quality of the images, 124 (25 percent) of the 500 coronary arteries studied (left main, left anterior descending, left circumflex, and right coronary) in a total of 125 patients were excluded from evaluation. No vessels could be evaluated in 19 patients (15 percent), and another 28 patients (22 percent) had one, two, or three vessels that could not be evaluated. In the remaining coronary arteries with adequate image quality, electron-beam CT permitted visualization of 69 of 75 high-grade stenoses and occlusions (sensitivity, 92 percent), whereas in 282 of 301 arteries, the absence of high-grade stenoses and occlusions was correctly detected (specificity, 94 percent). CONCLUSIONS: When image quality is adequate, electron-beam CT may be useful to detect or rule out high-grade coronary-artery stenoses and occlusions.     

Mass screening for prostate cancer--how to eliminate clinically insignificant cancer

The ultimate aim of the mass screening program for prostate cancer is to decrease prostate cancer mortality, which can be demonstrated only in a well-designed and well-controlled trial comparing screened and unscreened populations. However, no trials have been performed to demonstrate the effect of this program. Some reports claimed that such a program includes the high possibility of detecting clinically insignificant cancer, for example, latent cancer. In this paper, early cancer detection and treatment in mass screening program are discussed.     

Prenatal screening for cystic fibrosis carriers: an economic evaluation

The cloning of the CFTR gene has made it technically possible to avert the unwanted birth of a child with cystic fibrosis (CF). Several large trials offering prenatal CF carrier screening suggest that such screening is practical and that identified carriers generally use the information obtained. Therefore, a critical question is whether the cost of such screening is justified. Decision analysis was performed that used information about choices that pregnant women were observed to make at each stage in the Rochester prenatal carrier-screening trial. The cost of screening per CF birth voluntarily averted was estimated to be $1,320,000-$1,400,000. However, the lifetime medical cost of the care of a CF child in today's dollars was estimated to be slightly>$1,000,000. Therefore, despite both the high cost of carrier testing and the relative infrequency of CF conceptions in the general population, the averted medical-care cost resulting from choices freely made are estimated to offset approximately 74%-78% of the costs of a screening program. At present, if it is assumed that a pregnancy terminated because of CF is replaced, the marginal cost for prenatal CF carrier screening is estimated to be $8,290 per quality-adjusted life-year. This value compares favorably with that of many accepted medical services. The cost of prenatal CF carrier screening could fall to equal the averted costs of CF patient care if the cost of carrier testing were to fall to $100.     

Potential contribution of therapy to cancer mortality reduction

Reductions in cancer mortality may come about for a number of reasons, including improvements in treatment. The impact will vary from cancer to cancer. For some, expert curative surgery is crucial, whereas for others, the use of appropriate chemotherapy is a key factor. Examples of the latter, in which there are already discernible reductions in national cancer mortality data resulting from chemotherapy, include testicular cancer and Hodgkin's disease. For more common diseases, such as ovarian cancer, reductions also are being seen. For others, such as breast and colorectal cancer, the current more widespread use of adjuvant chemotherapy may lead to overall mortality reduction in the future. It should be recognized that chemotherapy should be given only by those experienced in its use, and that this facility should form part of a larger provision for health care in relation to cancer, ranging from public education to population screening and from better oncology training for clinicians to greater encouragement to participation in clinical trials. New drug development is clearly a priority, but further advances can be made in many countries already using available forms of chemotherapy if treatment facilities are organized appropriately.     

Localized in vivo 1H nuclear MR spectroscopy for evaluation of human uterine cervical carcinoma

Spontaneous abortion occurs in 15% to 20% of all human pregnancies. Since the late 1800s, the management of incomplete spontaneous abortion has focused on using curettage to empty the uterus as quickly as possible. This practice began to reduce blood loss and infection and has been unquestioned for 4 decades. In today's medical climate, few spontaneous abortions are the resuslt of illegal manipulation, given the availability of legal pregnancy termination. Antibiotics and transfusions are available, should complications arise in conservatively managed cases. Two prospective randomized trials suggest that conservative management may be advantageous for women who have stable vital signs without evidence of infection. They will have fewer perforations and, possibly, fewer infections and uterine synechiae with expectant or medical management. Larger trials should be undertaken to critically assess surgical evacuation compared to medical management, factoring in the psychologic impact of treatment. We believe that medical management will prove to be the most appropriate treatment for uncomplicated spontaneous incomplete abortion in the 21st century.     

Snake oil for the 21st century

Evidence-based medicine is the use of the best current evidence in making decisions about the care of individual patients. Practicing EBM requires recognition that in most encounters with patients, questions arise that should be answered to provide the patient with the best available medical care. Asking well-built clinical questions that contain 4 elements--a patient or problem, an intervention, a comparison intervention (if necessary), and an outcome--is an important step in practicing EMB. Once appropriate questions have been formulated, the best source for finding most types of best evidence is by searching the MEDLINE database by computer. MEDLINE searches have inherent software and operator limitations that make their reliability quite variable. One should be aware of these limitations and improve one's skills in searching. The Cochrane Collaboration Controlled Clinical Trials Registry contains more than 190,000 controlled clinical trials and is the best source of evidence about treatment. The quality (strength) of evidence is based on a hierarchy of evidence: results of systematic reviews of well-designed clinical studies, results of 1 or more well-designed clinical studies, results of large case series, expert opinion, and personal experience. Once the best evidence has been found, the EBM approach involves critically appraising the quality of the evidence, determining its magnitude and precision, and applying it to the specific patient. Guidelines to critically appraise and apply evidence are available. The clinical question, best evidence, and its critical appraisal should be saved in a format that can be easily retrieved for future use.     

Behavioural medicine: A process for managing performance problems.

Suggests that behavioral medicine as a treatment program provides an excellent model for effective management of complex medical cases. The present authors describe a process for integrating, coordinating, and effectively applying medical and psychological principles to complex cases of work-performance deficiency in which there is some degree of medical involvement. This process is designed to yield many benefits to employees and employers: It optimizes medical and behavioral treatment, minimizes risks, reduces absenteeism, lowers disability costs, prevents arbitrations, increases productivity, provides both employer and employee with objective data on which vocational decisions can be based, and, above all, helps the patient. The process involves the coordination of a company's medical staff, specialists in behavioral medicine, the company's human resource management personnel, and the line managers in the company, who deal with those employees referred for assessment and/or treatment. General outcome data are presented from a behavioral medicine unit over 5 yrs, which illustrate the successful application of this process. (French abstract) (15 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)