Progress toward the elimination of hepatitis B virus transmission among health care workers in the United States

BACKGROUND: Hepatitis B virus (HBV) infection is a well-recognized occupational risk for health care workers (HCWs). Vaccination coverage, disease trends, and the need for booster doses after hepatitis B vaccination of adults have been the subject of intense study during the 15 years of the vaccine's availability. METHODS: Vaccination coverage of HCWs was determined from a review of medical records on a sample of employees from 113 randomly selected hospitals. The number of HBV infections among HCWs and the general US population for 1983 through 1995 was estimated from national surveillance data. Studies on long-term protection after hepatitis B vaccination of adults were reviewed. RESULTS: A total of 2837 employee medical records were reviewed; 2532 employees (90%) were eligible to receive hepatitis B vaccine, and 66.5% of them (95% confidence interval, 61.9%-70.9%) had received 3 doses of hepatitis B vaccine. Vaccination coverage was highest (75%) for personnel with frequent exposure to infectious body fluids (phlebotomists, laboratory personnel, and nursing staff) and lowest (45%) for employees at low risk for exposure (dietary and clerical staff). The number of HBV infections among HCWs declined from 17,000 in 1983 to 400 in 1995. The 95% decline in incidence observed among HCWs is 1.5-fold greater than the reduction in incidence in the general US population. Studies on long-term protection demonstrate that vaccine-induced protection persists at least 11 years even when titers of antibody to hepatitis B surface antigen decline below detectable levels. CONCLUSIONS: Although a high percentage of HCWs have been fully vaccinated with hepatitis B vaccine, efforts need to be made to improve this coverage. There has been a dramatic decrease in the number of HBV infections among HCWs who are now at lower risk of HBV infection than the general US population. Vaccine-induced protection persists at least 11 years and booster doses are not needed at this time for adults who have responded to vaccination.     

Reconstruction of deformities resulting from penile enlargement surgery

PURPOSE: More than 30 patients presented for reconstruction of penile deformities secondary to penile enlargement surgery performed by other physicians. Lengthening was performed by releasing the suspensory ligament of the penis and advancing pubic skin with a V-Y advancement flap. Girth was increased by injecting autologous fat. Specific complaints relating to the lengthening procedure involve hypertrophic and/or wide scars, a proximal penile hump from a thick, hair-bearing V-Y flap, and a low hanging penis. Complications relating to autologous fat injections include disappearance of fat, penile lumps and nodules, and shaft deformities. The repair of these deformities is described. MATERIALS AND METHODS: From 1994 through October 1996, 19 men underwent 24 various combinations of reconstructive operations, such as scar revisions, V-Y advancement flap reversal, and removal of fat nodules and asymmetrical fat deposits. RESULTS: Penile appearance and function were improved. Complications include 1 hematoma requiring drainage, minor wound complications and 1 inadequately reversed V-Y flap. CONCLUSIONS: The methods of various repairs are discussed, including reconstructive limitations, timing and staging. Significant improvement can be achieved with proper reconstruction of penile deformities.     

A survey of provider experiences and perceptions of preferential access to cardiovascular care in Ontario, Canada

BACKGROUND: The public health insurance system in Canada is predicated on equal access to care for persons in need. OBJECTIVE: To determine the views and experiences of Ontario physicians and hospital administrators in providing patients with preferential access to specialized cardiovascular care on the basis of nonclinical factors. DESIGN: Survey with self-administered questionnaire. SETTING: Ontario, Canada. PARTICIPANTS: All Ontario cardiologists (n = 268), cardiac surgeons (n = 68), and hospital chief executives (n = 218) and random samples of internists (n = 300) and family physicians (n = 300). MEASUREMENTS: Elicited responses (yes or no) to questions on whether and why preferential access occurred and whether the respondents had been personally involved in such a situation. RESULTS: After undeliverable surveys and respondents no longer involved with acute care were excluded, the eligible response rate was 71.3% (788 of 1105 respondents). More than 80% of physicians and 53% of hospital chief executives had been personally involved in managing a patient who had received preferential access on the basis of factors other than medical need. Patients deemed most likely to receive such treatment were those with personal ties to the treating physicians (93% [95% CI, 91% to 95%]), high-profile public figures (85% [CI, 82% to 87%]), and politicians (83% [CI, 80% to 86%]). Physicians were significantly more likely than chief executives to indicate that hospital board members (81% and 68%; P < 0.001) and donors to hospital foundations (63% and 42%; P < 0.001) would receive preferential access. Most respondents indicated that preferential access was more likely to be provided if patients or families were well informed, aggressive, or potentially litigious. The survey did not permit estimation of the frequency of episodes of preferential access. CONCLUSIONS: Although equality of access is a cornerstone principle of Canada's universal health care system, some access to specialized cardiovascular services occurs preferentially on the basis of factors other than clinical need. The actual magnitude and consequences of this phenomenon remain unknown.     

Uncertainty Propagation in Model-Based Recognition

Robust recognition systems require a careful understanding of the effects of error in sensed features. In model-based recognition, matches between model features and sensed image features typically are used to compute a model pose and then project the unmatched model features into the image. The error in the image features results in uncertainty in the projected model features. We first show how error propagates when poses are based on three pairs of 3D model and 2D image points. In particular, we show how to simply and efficiently compute the distributed region in the image where an unmatched model point might appear, for both Gaussian and bounded error in the detection of image points, and for both scaled-orthographic and perspective projection models. Next, we provide geometric and experimental analyses to indicate when this linear approximation will succeed and when it will fail. Then, based on the linear approximation, we show how we can utilize Linear Programming to compute bounded propagated error regions for any number of initial matches. Finally, we use these results to extend, from two-dimensional to three-dimensional objects, robust implementations of alignment, interpretation-tree search, and transformation clustering.     

Use of lithium niobate detector for measuring X-ray intensity in mammographic range

A detector system that can measure X-ray intensity in the mammographic range of 22 to 36 kVp (equivalent photon energies of the beam between 11 and 15 keV) is presented. It consists of a lithium niobate detector and a high-sensitivity current-to-voltage converter.     

Possibilities for cross-fertilization between interpretive approaches and other methods for analyzing information systems

This paper explores possibilities for cross-fertilization between interpretive approaches and other approaches for performing the initial analysis of an information system as part of an effort to redesign and improve it. The paper presents a hypothetical situation concerning the analysis of a loan approval system in a large bank. It assumes that ethnographers observed three systems analysis projects that applied different approaches in three identical banks. It uses hypothetical accounts of the three analysis efforts to propose likely differences in the process and in the results. These differences illustrate possible opportunities for cross-fertilization that might make each approach more powerful and reliable. The paper concludes that the most likely direction for cross-fertilization is from interpretive approaches to the other approaches. An earlier version of this paper was presented at the First International Workshop on Interpretive Approaches to Information Systems and Computing Research, SIG-IAM, Brunel University, July 25–27, 2002, to motivate discussion about the applications, strengths, and limitations of interpretive approaches and to help in the further development of systems analysis methods.