Radiological implications of the use of uranium in vaseline glass.

Uranium oxides have been used as colourants in glassware since the 19th century and this type of glass is commonly referred to as vaseline glass. There are many collectors of vaseline glass in the UK who obtain pieces from the UK antiques market or from abroad. Dose rate measurements were made for a number of items of vaseline glass, and the uranium content of one item was measured. Potential doses to collectors were considered, along with implications for trade and transport due to the uranium content of the glassware. It was concluded that generally items of vaseline glass could give rise to low skin doses from beta radiation, though frequent wearing of necklaces made from vaseline glass may lead to doses in excess of the HPA (Health Protection Agency) dose criterion for consumer products that are not related to safety. Registration under the Radioactive Substances Act will not be required and almost all items of vaseline glass should be suitable for sending through the Royal Mail. For those items not accepted by Royal Mail, it is understood that the transport regulations for radioactive materials would not apply.

Review of trends in the UK population dose.

The Radiation Protection Division of the Health Protection Agency (HPA-RPD), formerly the National Radiological Protection Board, has periodically reported the doses to members of the public and workers in the UK from all sources of radiation. This paper is a review of the doses reported in these publications from the 1970s to 2000 or later. The paper aims to present how the estimated doses received by the UK population have changed over this time period, and where possible from earlier years as well, from all sources of radiation. It was not possible to directly compare the doses reported in the earlier reports. There have been changes in the type of doses estimated, the dosimetry (in particular the definition of effective dose) and improvements made in the measurement of natural background doses. In these cases the earlier reported doses have been recalculated using modern dosimetry so that the doses can be compared. The occupational doses reported in this paper are for those workers involved in the civil nuclear power production industry, industrial radiography or from the medical use of radiation sources. For workers it was found that the individual and collective dose has decreased significantly over this time through the introduction of legislation, the improvement in technology and better working practices. Members of the public are exposed to radiation following the atmospheric testing of nuclear weapons, discharges from UK civil nuclear sites and from diagnostic radiology as well as from natural sources. Exposure to anthropogenic sources has decreased over the period considered in this paper. However, the dose to the UK population as a whole, presented as a per caput dose to a population of 55 million, has not changed significantly as it is dominated by the constant level of exposure to natural sources of radiation.

Variations in radiation exposures of adults and children in the UK.

Members of the UK population receive radiation doses from a number of sources including cosmic radiation, from uranium, thorium and their decay products, particularly radon, and from medical sources. On average, members of the UK population receive an effective dose of about 200 mSv over their lifetime. This results in a risk of fatal cancer of about 1%. However, the radiation dose is not the same to all individuals. Some components give doses that vary systematically from one region to another. Doses may also vary greatly from one individual to another. The rate at which the dose is accumulated may vary as the individual ages. Different organs and tissues do not necessarily receive the same dose. This paper discusses these factors and attempts to quantify them. Cosmic rays deliver doses which vary little across the body or between individuals. Terrestrial gamma rays also deliver more or less uniform whole-body doses, but the difference between individuals can be greater. Radionuclides in food deliver doses which vary both across the body and between individuals. These variations are even more marked in the case of doses from radon and from medical exposures.

Review of the radiation exposure of the UK population.

Since 1974 the National Radiological Protection Board (now the Radiation Protection Division of the Health Protection Agency) has produced reviews of the levels of exposure to ionising radiation in the UK, from sources of natural and artificial origin. The latest review (Watson et al 2005 Ionising Radiation Exposure of the UK Population: 2005 Review HPA-RPD-001 (Chilton: HPA-RPD)) in the series gives estimates of annual doses based predominantly on data collected for the years 2001-2003. The overall average annual dose is rounded to 2.7 mSv, and the average annual dose from natural radiation is found to be 2.2 mSv. The overall average annual dose is slightly increased over that found in the previous, 1999, review. This increase is mainly due to a larger contribution from medical irradiation.

Displacement of microcalcifications during stereotactic 11-gauge directional vacuum-assisted biopsy with marking clip placement: case report.

A 53-year-old woman with right breast microcalcifications of intermediate concern underwent stereotactic directional vacuum-assisted biopsy with marking clip placement. Postbiopsy mammograms showed displacement of a few of the targeted microcalcifications adjacent to misplaced marker clips. Mammography following stereotactic breast biopsy is important to document the location and number of residual calcifications and to determine the adequacy and location of clip placement.

The prospective risk adjustment system.

The Episode Classification System is intended to perform two tasks. First, it will be a prospective capitation risk adjuster and predict future health care costs. It will do this by assigning each individual a single capitation risk adjustment category based on an analysis of the medical history and of health care services rendered during a specific period of time. Second, the Episode Classification System will create retrospective severity adjusted Episodes of illness or Episodes of Care. These latter Episodes will provide a framework for relating patient characteristics to the amount, type, and duration of services provided during the treatment of a specific disease. These Episodes will give users the ability to understand past costs and the risk of mortality. As such they will form the basis for provider profiling by allowing users to analyze a complete clinical episode.

A toxicity reduction evaluation for an oily waste treatment plant exhibiting episodic effluent toxicity.

A Toxicity Reduction Evaluation (TRE) was conducted on the oily wastewater treatment plant (Plant) at a Naval Fuel Depot. The Plant treats ship and ballast wastes, berm water from fuel storage areas and wastes generated in the fuel reclamation plant utilizing physical/chemical treatment processes. In the first period of the project (Period I), the TRE included chemical characterization of the plant wastewaters, monitoring the final effluent for acute toxicity and a thorough evaluation of each treatment process and Plant operating procedures. Toxicity Identification Evaluation (TIE) procedures were performed as part of the overall TRE to characterize and identify possible sources of toxicity. Several difficulties were encountered because the effluent was saline, test organisms were marine species and toxicity was sporadic and unpredictable. The treatability approach utilizing enhancements, improved housekeeping, and operational changes produced substantial reductions in the acute toxicity of the final effluent. In the second period (Period II), additional acute toxicity testing and chemical characterization were performed through the Plant to assess the long-term effects of major unit process improvements for the removal of toxicity. The TIE procedures were also modified for saline wastewaters to focus on suspected class of toxicants such as surfactants. The TRE was successful in reducing acute toxicity of the final effluent through process improvements and operational modifications. The results indicated that the cause of toxicity was most likely due to combination of pollutants (matrix effect) rather than a single pollutant.

Importance of functional measures in predicting mortality among older hospitalized patients.

CONTEXT: Measures of physical and cognitive function are strong prognostic predictors of hospital outcomes for older persons, but current risk adjustment and burden of illness assessment indices do not include these measures. OBJECTIVE: To evaluate and validate the contribution of functional measures to the ability of 5 standard burden of illness indices (Charlson, Acute Physiology and Chronic Health Evaluation [APACHE] II, Disease Staging, All Patient Refined Diagnosis Related Groups, and a clinician's subjective rating) in predicting 90-day and 2-year mortality among older hospitalized patients. DESIGN: Two prospective cohort studies. SETTING: General medicine service, university teaching hospital. PATIENTS: For the development cohort, 207 consecutive patients aged 70 years or older, and for the validation cohort, 318 comparable patients. MAIN OUTCOME MEASURE: Death within 90 days and 2 years from the index admission. RESULTS: In the development cohort, 29 patients (14%) and 81 patients (39%) died within 90 days and 2 years, respectively. A functional axis was developed using 3 independent risk factors: impairment in instrumental activities of daily living, Mini-Mental State Examination score of less than 20, and shortened Geriatric Depression Scale score of 7 or higher, creating low-, intermediate-, and high-risk groups with associated mortality rates of 20%, 32%, and 60%, respectively (P<.001); the C statistic for the final model was 0.69. The corresponding mortality rates in the validation cohort, in which 59 (19%) and 138 (43%) died within 90 days and 2 years, respectively, were 24%, 45%, and 60% (P<.001); the C statistic for the final model was 0.66. For each burden of illness index, the functional axis contributed significantly to the predictive ability of the model for both 90 days and 2 years. When the functional axis and each burden of illness measure were analyzed in cross-stratified format, mortality rates increased progressively from low-risk to high-risk functional groups within strata of burden of illness indices (double-gradient phenomenon). The contributions of functional and burden of illness measures were substantive and interrelated. CONCLUSIONS: Functional measures are strong predictors of 90-day and 2-year mortality after hospitalization. Furthermore, these measures contribute substantially to the prognostic ability of 5 burden of illness indices. Optimal risk adjustment for older hospitalized patients should incorporate functional status variables.

The clinical role of shoulder ultrasound.

BACKGROUND: Rotator cuff surgery is facilitated by accurate pre-operative information regarding the presence and size of cuff tears, and the extent of any cuff retraction or lamination. METHODS: A total of 117 consecutive patients who underwent shoulder ultrasound followed by surgical management were assessed, and the pre-operative ultrasound diagnoses were correlated with the operative findings. RESULTS: Ultrasound was found to be reliable for the detection of full-thickness cuff tears (positive predictive value 96%). In the assessment of partial thickness tears, ultrasound produced few false positives, but failed to diagnose a significant proportion of these lesions. Lamination and other interstitial cuff pathology were not reliably detected by ultrasound. In the diagnosis of subacromial impingement, ultrasound produced few false positives (positive predictive value 95%), but did produce a significant number of false negative results (negative predictive value 66%). CONCLUSIONS: Ultrasound is cheaper than MRI and arthrography, and is both non-invasive and 'dynamic'. It is reliable in the diagnosis of full-thickness cuff tears and is a useful adjunct in the diagnosis of cuff impingement and partial thickness tears, but is very much operator-dependent.

The interosseous membrane in radio-ulnar dissociation.

In severe forearm injuries, the diagnosis of disruption of the interosseous membrane is frequently delayed and sometimes missed, giving difficulties in the salvage of forearm stability. We studied the structure and function of the interosseous membrane in 11 cadaver preparations, using mechanical and histological analysis. Seven of the specimens tested in uniaxial tension sustained a mid-substance tear of the central band of the membrane at a mean peak load of 1038 +/- 308 N. The axial stiffness was 190 +/- 44 N/mm with elongation to failure of 10.34 +/- 2.46 mm. These results provide criteria for the evaluation of reconstructive methods. A preliminary clinical investigation of the use of ultrasound suggests that this may be of value in the screening of patients with complex fractures of the forearm, and for investigating the natural history of tears of the interosseous membrane.

Dry beans inhibit azoxymethane-induced colon carcinogenesis in F344 rats.

Epidemiological studies show a low incidence of colon cancer in many Latin American countries where the consumption of dry beans (e.g., pinto) is high. The purpose of this study was to use rats as an animal model to obtain experimental data on the inhibition of colon carcinogenesis by dry beans. Fifty-three 5-wk-old weanling male F344 rats were randomly assigned by weight to the following groups: control (11 rats), casein diet (21 rats), and bean diet (21 rats). Animals fed the casein and bean diets were treated with the carcinogen azoxymethane (AOM) once weekly for 2 wk. Rats in the control group also consumed the casein diet but were not exposed to AOM. All diets were isocaloric. The protein concentration of the diets was adjusted to 18 g/100 g with casein, and the fat concentration was adjusted to 5 g/100 g with corn oil. Rats fed the bean diet had significantly fewer colon adenocarcinomas (P < 0.05) than rats fed the casein diet (5 vs. 22 tumors), and significantly fewer rats fed the bean diet (P < 0.05) had colonic tumors than did casein-fed rats (24 vs. 50%). Tumor multiplicity was also significantly lower for the bean-fed rats, and significantly fewer (P < 0.05) tumors per tumor-bearing rat were observed in bean-fed rats than in casein-fed rats (1.0 +/- 0.0 vs. 2.5 +/- 0.6). This study demonstrates that dry beans contain anticarcinogenic compounds capable of inhibiting AOM-induced colon cancer in rats. However, the specific anticarcinogenic components within dry beans have not been identified, and it is unclear whether dietary fiber, phytochemicals or other components within dry beans are primarily responsible for the anticarcinogenic properties of beans.

Judging hospitals by severity-adjusted mortality rates: the influence of the severity-adjustment method.

OBJECTIVES: This research examined whether judgments about a hospital's risk-adjusted mortality performance are affected by the severity-adjustment method. METHODS: Data came from 100 acute care hospitals nationwide and 11880 adults admitted in 1991 for acute myocardial infarction. Ten severity measures were used in separate multivariable logistic models predicting in-hospital death. Observed-to-expected death rates and z scores were calculated with each severity measure for each hospital. RESULTS: Unadjusted mortality rates for the 100 hospitals ranged from 4.8% to 26.4%. For 32 hospitals, observed mortality rates differed significantly from expected rates for 1 or more, but not for all 10, severity measures. Agreement between pairs of severity measures on whether hospitals were flagged as statistical mortality outliers ranged from fair to good. Severity measures based on medical records frequently disagreed with measures based on discharge abstracts. CONCLUSIONS: Although the 10 severity measures agreed about relative hospital performance more often than would be expected by chance, assessments of individual hospital mortality rates varied by different severity-adjustment methods.

Severity measurement methods and judging hospital death rates for pneumonia.

Payers and policymakers are increasingly examining hospital mortality rates as indicators of hospital quality. To be meaningful, these death rates must be adjusted for patient severity. This research examined whether judgments about an individual hospital's risk-adjusted mortality is affected by the severity adjustment method. Data came from 105 acute care hospitals nationwide that use the Medis-Groups severity measure. The study population was 18,016 adults hospitalized in 1991 for pneumonia. Multivariable logistic models to predict in-hospital death were computed separately for 14 severity methods, controlling for patient age, sex, and diagnosis-related group (DRG). For each hospital, observed-to-expected death rates and z scores were calculated for each severity method. The overall in-hospital death rate was 9.6%. Unadjusted mortality rates for the 105 hospitals ranged from 1.4% to 19.6%. After adjusting for age, sex, DRG, and severity, 73 facilities had observed mortality rates that did not differ significantly from expected rates according to all 14 severity methods; two had rates significantly higher than expected for all 14 severity methods. For 30 hospitals, observed mortality rates differed significantly from expected rates when judged by one or more but not all 14 severity methods. Kappa analysis showed fair to excellent agreement between severity methods. The 14 severity methods agreed about relative hospital performance more often than expected by chance, but perceptions of individual hospitals' mortality rates varied using different severity adjustment methods for almost one third of facilities. Judgments about individual hospital performance using different severity adjustment approaches may reach different conclusions.

Judging hospitals by severity-adjusted mortality rates: the case of CABG surgery.

In many health care marketplaces, outcomes assessment is central to monitoring quality while controlling costs. Comparing outcomes across providers generally requires adjustment for patient severity. For mortality rates and other adverse outcomes comparisons, severity adjustment ideally aims to control for patient characteristics prior to the health care intervention. A variety of severity methodologies, specifically for hospitalized patients, are commercially available. Some have been adopted by state or regional initiatives for publicly comparing hospital outcomes. We applied 14 common severity measures to the same data set to determine whether judgments about risk-adjusted hospital death rates are sensitive to the specific severity method. We examined 7,765 patients undergoing coronary artery bypass graft (CABG) surgery at 38 hospitals. Unadjusted death rates ranged from 0% to 11.2% across hospitals. Comparisons of relative hospital performance were relatively insensitive to the severity adjustment method.

Predicting who dies depends on how severity is measured: implications for evaluating patient outcomes.

OBJECTIVE: To determine whether assessments of illness severity, defined as risk for in-hospital death, varied across four severity measures. DESIGN: Retrospective cohort study. SETTING: 100 hospitals using the MedisGroups severity measure. PATIENTS: 11 880 adults managed medically for acute myocardial infarction; 1574 in-hospital deaths (13.2%). MEASUREMENTS: For each patient, probability of death was predicted four times, each time by using patient age and sex and one of four common severity measures: 1) admission MedisGroups scores for probability of death scores; 2) scores based on values for 17 physiologic variables at time of admission; 3) Disease Staging's probability-of-mortality model; and 4) All Patient Refined Diagnosis Related Groups (APR-DRGs). Patients were ranked according to probability of death as predicted by each severity measure, and rankings were compared across measures. The presence or absence of each of six clinical findings considered to indicate poor prognosis in patients with myocardial infarction (congestive heart failure, pulmonary edema, coma, low systolic blood pressure, low left ventricular ejection fraction, and high blood urea nitrogen level) was determined for patients ranked differently by different severity measures. RESULTS: MedisGroups and the physiology score gave 94.7% of patients similar rankings. Disease Staging, MedisGroups, and the physiology score gave only 78% of patients similar rankings. MedisGroups and APR-DRGs gave 80% of patients similar rankings. Patients whose illnesses were more severe according to MedisGroups and the physiology score were more likely to have the six clinical findings than were patients whose illnesses were more severe according to Disease Staging and APR-DRGs. CONCLUSIONS: Some pairs of severity measures assigned very different severity levels to more than 20% of patients. Evaluations of patient outcomes need to be sensitive to the severity measures used for risk adjustment.

Diagnosis-related group refinement with diagnosis- and procedure-specific comorbidities and complications.

Diagnosis-related groups have been revised through more refined uses of secondary diagnoses. Under the refined diagnosis-related groups, patients are distinguished with respect to classes of secondary diagnoses that are disease- and procedure-specific. Each class represents a different level of utilization for a given principal diagnosis or surgical procedure. The refined system was evaluated with national data from the Medicare program. Estimates of hospital costs and utilization based on refined diagnosis-related groups were more precise than those based on unrefined diagnosis-related groups. This approach to diagnosis-related group refinement does not represent a radical departure from the current diagnosis-related group framework and does not require new data collection efforts. Moreover, a payment system based on the refined model is less affected by the ordering of the diagnoses than under the existing diagnosis-related group system. How the refined diagnosis-related group framework can accommodate future refinements at all levels of the classification scheme is also discussed.

Using severity-adjusted stroke mortality rates to judge hospitals.

Mortality rates are commonly used to judge hospital performance. In comparing death rates across hospitals, it is important to control for differences in patient severity. Various severity tools are now actively marketed in the United States. This study asked whether one would identify different hospitals as having higher- or lower-than-expected death rates using different severity measures. We applied 11 widely-used severity measures to the same database containing 9407 medically-treated stroke patients from 94 hospitals, with 916 (9.7%) in-hospital deaths. Unadjusted hospital mortality rates ranged from 0 to 24.4%. For 27 hospitals, observed mortality rates differed significantly from expected rates when judged by one or more, but not all 11, severity methods. The agreement between pairs of severity methods for identifying the worst 10% or best 50% of hospitals was fair to good. Efforts to evaluate hospital performance based on severity-adjusted, in-hospital death rates for stroke patients are likely to be sensitive to how severity is measured.

Distal clavicular excision: a detailed functional assessment.

Distal clavicular excision is commonly performed for a number of clinical conditions. The results of the procedure are not well described. Using the Constant, American Shoulder and Elbow Surgeons (ASES), University of California at Los Angeles (UCLA) and Neer scoring systems, the medium term results of distal clavicular excision were assessed. Over an 8 year period, 39 patients underwent distal clavicular excision for conditions other than acromioclavicular instability (subluxation or dislocation). A single technique was employed. A retrospective study was performed of all 18 patients who could be contacted. In those cases patient satisfaction was universal. Pre-operative pain was severe in 16 patients (89%) and moderate in two (11%). Following surgery, five (28%) were free from pain, 10 (55%) had only mild or occasional pain, and three (17%) reported moderate pain. The difference between pre-operative and postoperative levels of pain was highly significant (P < 0.001). However, continuing difficulties with work (59%), sleeping (55%) and activities of daily living (59%) were reported. Ten of 14 (71%) wishing to return to sporting activities were able to do so without restriction. Neither shoulder strength nor range of movement was fully restored following surgery, which relieved pain but did not restore normality. This series may facilitate subsequent assessment of arthroscopic distal clavicular excision.