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This study employs several large Health Care Financing Administration data sets for 1983 and 1985 to examine the recent growth in Medicare physician services. The study concludes that the recent growth (approximately 15% in real terms between 1983 and 1985) has been more rapid in areas with higher incomes per capita and suggests that this may be related to faster adoption and diffusion of new medical technologies in these areas. The volume of physician services had grown considerably faster for those specialists who utilize newer procedures and technologies than for those who do not. The study also provides evidence that the sharp increase in assignment rates in recent years because of the introduction of the physician participation program also contributed to the growth in physician services during this period. Medicare's prospective payment system, which controlled hospital payments and encouraged hospitals to become more efficient, had at most a small positive impact on the growth in Part B spending. Finally, the freeze on physician's fees did not seem to have had a major impact on the volume of physician services. 相似文献
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A total of 1786 blood donors were screened for the presence of anti-hepatitis A antibody (anti HAV). 64.5% of the donors were found to be positive. The prevalence of the antibody was found to be age-related, 55% at 18 years and 75% at 65 years. No relationship was noted between the presence of antibody, foreign travel or a specific destination. Assay of antibody levels in selected seropositive individuals gave a mean level of 5.0 IU/ml. The prevalence of infection in this selected population is important in the context of passive immunization with normal human immunoglobulin and for defining a policy of immunization with hepatitis A vaccines, which are currently undergoing clinical trials. 相似文献
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Computed tomography as a screening exam in patients with suspected blunt aortic injury. 总被引:1,自引:1,他引:0 下载免费PDF全文
R M Durham D Zuckerman M Wolverson E Heiberg W B Luchtefeld D J Herr M J Shapiro J E Mazuski Z Salimi M Sundaram 《Annals of surgery》1994,220(5):699-704
BACKGROUND: Chest computed tomography (CT) screening of patients with blunt trauma for thoracic aortic injury is controversial. This study was undertaken to determine whether CT could exclude aortic injury and be used to select patients for aortography. METHODS: Computed tomography and aortography were used to evaluate 155 patients with blunt trauma. Computed tomography scans were reviewed separately by four attending radiologists who were unaware of the patients' clinical course and angiographic findings. RESULTS: Eight of 155 patients had aortic injuries requiring operation. Computed tomography scans in five patients were read as positive by all reviewers. One scan was read as positive by three reviewers and as negative by one. Two scans were read as positive by two radiologists and as negative by two. After poor scans were excluded, the combined sensitivity of CT for detecting aortic injury was 88%, specificity was 54%, positive predictive value was 9%, and negative predictive value 99%. CONCLUSIONS: The sensitivity of CT scan for indicating the need for aortography is observer dependent. As CT manifestations of aortic injury are often subtle, CT does not reliably exclude aortic injury. 相似文献
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This article summarizes what is known about the effects of cocaine, opiates, marijuana, and alcohol on neonatal and postnatal growth and development. The development of a child affected by prenatal exposure to drugs and alcohol is best understood through a multifactorial model consisting of interrelated prenatal and postnatal factors. The article also describes the prenatal effects of drugs and alcohol on the newborn, especially on central nervous system functioning, which is seen as creating a biologic vulnerability that renders a child more vulnerable to the effects of poor caretaking. 相似文献
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