Recently, early investment in the human capital of children from socially disadvantaged environments has attracted a great deal of attention. Programs of such early intervention, aimed at children’s health and well-being, are spreading considerably in the US and are currently being tested in several European countries. In a discrete version of the Mirrlees model with a parents’ and a children’s generation, we model the intra-generational and the inter-generational redistributional consequences of such intervention programs. It turns out that the parents’ generation loses whenever such intervention programs are implemented. Furthermore, the rich part of the children’s generation always benefits. Despite the expectation that early intervention puts the poor descendants in a better position, our analysis reveals that the poor among the children’s generation may even be worse off, if the effect of early intervention on their productivity is not large enough. 相似文献
Cancer cluster studies in North Carolina identified several communities in which there existed an elevated risk of brain cancer. These findings prompted a series of case-control studies. The current article, which originated from the results of the 3rd of such studies, is focused on inclusion of the earth's own geomagnetic fields that interact with electromagnetic fields generated from distribution power lines. This article also contains an assessment of the contribution of confounding by residential (e.g., urban, rural) and case characteristics (e.g., age, race, gender). Newly diagnosed brain cancer cases were identified for a 4-county region of central North Carolina, which the authors chose on the basis of the results of earlier observations. A 3:1 matched series of cancer cases from the same hospitals in which the cases were diagnosed served as the comparison group. Extensive geographic information was collected and was based on an exact place of residence at the time of cancer diagnosis, thus providing several strategic geophysical elements for assessment. The model for this assessment was based on the effects of these two sources of electromagnetic fields for an ion cyclotron resonance mechanism of disease risk. The authors used logistic regression models that contained the predicted value for the parallel component of the earth's magnetic field; these models were somewhat erratic, and the elements were not merged productively into a single statistical model. Interpretation of these values was difficult; therefore, the modeled values for the model elements, at progressive distances from the nearest power-line segments, are provided. The results of this study demonstrate the merits of using large, population-based databases, as well as using rigorous Geographic Information System techniques, for the assessment of ecologic environmental risks. The results also suggest promise for exposure classification that is compatible with the theoretical biological mechanisms posited for electromagnetic fields. 相似文献
Objective. The purpose of this study was to describe an air transport service's protocol for direct transport of patients with abdominal aortic aneurysm leak (AAAL) into receiving hospital operating rooms (ORs). Methods. This retrospective consecutive-case analysis examined AAAL patients undergoing nurse-paramedic Boston MedFlight (BMF) transport during 1999–2004, who were taken directly into ORs at four academic centers. BMF uses a rotating roster system to assign receiving hospitals when referring physicians have no preidentified receiving facility, but this practice may prolong patient transport or be associated with less diagnostic certainty, andthus more delay, at receiving hospitals. Thus, the study compared “Roster” versus “Non-roster” patients' time andoutcome end points. Continuous nonparametric data (e.g., time intervals) were described with median andinterquartile range (IQR). Chi-square andKruskal-Wallis tests were used for univariate comparisons; regression analysis assessed dependent variables while adjusting for covariates (e.g., transport mileage). Results. There were 29 direct-to-OR transports, with median distance of 30 miles. All patients had AAAL diagnosis confirmed; 51.7% survived. System performance for end points was similar as assessed between Roster versus Non-roster patients. Conclusions. Interfacility direct-to-OR transport of AAAL patients is feasible. Use of a roster system allows for timely transport facilitation for patients needing specialized care; roster patients achieve similar end points as did patients who had already-identified receiving hospitals upon air medical transport request. 相似文献
OBJECTIVE: To prospectively evaluate the use of 18F-Fluorodeoxyglucose positron emission tomography (FDG-PET) in the initial staging of squamous cell head and neck carcinoma. SUMMARY BACKGROUND DATA: The status of cervical lymph nodes is an important prognostic factor and determinant of management approach in squamous cell head and neck cancer. METHODS: FDG-PET findings were compared with those of computed tomography (CT) before removal of the primary tumor and/or neck dissection. Histopathologic analysis was used as the gold standard for assessment of the sensitivity and specificity of these modalities. RESULTS: FDG-PET correctly identified the primary tumor in 35 of 40 patients in whom the site of the primary was known clinically and still present (sensitivity 88%). None of four unknown primaries were detected. Tumors not detected by FDG-PET were generally superficial, with depths of less than 4 mm. CT correctly identified 18 of the 35 primary tumors (sensitivity 51%). Eleven of 17 CT false-negative tumors were detected by FDG-PET. The sensitivity and specificity for the presence of metastatic neck disease on FDG-PET were 82% and 100%, respectively; those for CT were 81% and 81%, respectively. FDG-PET was true positive for metastatic neck disease in two of the three CT false-negative patients. CONCLUSIONS: FDG-PET shows promise in the initial staging of head and neck cancer and provides additional accuracy to a conventional staging process using CT. 相似文献
Background: Postoperative cognitive dysfunction (POCD) after noncardiac surgery is strongly associated with increasing age in elderly patients; middle-aged patients (aged 40-60 yr) may be expected to have a lower incidence, although subjective complaints are frequent.
Methods: The authors compared the changes in neuropsychological test results at 1 week and 3 months in patients aged 40-60 yr, using a battery of neuropsychological tests, with those of age-matched control subjects using Z-score analysis. They assessed risk factors and associations of POCD with measures of subjective cognitive function, depression, and activities of daily living.
Results: At 7 days, cognitive dysfunction as defined was present in 19.2% (confidence interval [CI], 15.7-23.1) of the patients and in 4.0% (CI, 1.6-8.0) of control subjects (P < 0.001). After 3 months, the incidence was 6.2% (CI, 4.1-8.9) in patients and 4.1% (CI, 1.7-8.4) in control subjects (not significant). POCD at 7 days was associated with supplementary epidural analgesia and reported avoidance of alcohol consumption. At 3 months, 29% of patients had subjective symptoms of POCD, and this finding was associated with depression. Early POCD was associated with reports of lower activity scores at 3 months. 相似文献
PURPOSE: We evaluated the cost-effectiveness of noncontact laser therapy compared with transurethral prostate resection and conservative treatment in men with symptoms associated with benign prostatic enlargement. MATERIALS AND METHODS: A total of 340 men with uncomplicated lower urinary tract symptoms participated in a large multicenter pragmatic randomized trial called the CLasP (Conservative management, Laser therapy, transurethral resection of the Prostate) study. Costs to the United Kingdom National Health Service and patients were determined from the time of randomization to the 7.5-month followup. Incremental cost-effectiveness ratios using conservative management as the base case were calculated for certain trial outcomes, including International Prostate Symptom Score (I-PSS), I-PSS quality of life score, maximum urinary flow, post-void residual urine volume, quality adjusted life-years and a composite measure of success based on I-PSS and maximum urinary flow. One-way sensitivity analysis of the basic costs and incremental cost-effectiveness ratios were done from the NHS viewpoint. RESULTS: Mean costs per patient were greatest for noncontact laser therapy and least for conservative management. The incremental cost-effectiveness ratios showed that transurethral prostate resection was more cost-effective than noncontact laser treatment for all primary trial outcomes. The incremental cost-effectiveness ratios of transurethral prostate resection compared with conservative management were pound 81 per unit decrease in the I-PSS score and pound 1,338 per additional successful case per 100 patients. Sensitivity analysis showed that the initial results were robust. CONCLUSIONS: Noncontact laser was the mostly costly treatment option. Transurethral prostate resection was more cost-effective than noncontact laser therapy in terms of symptomatic improvement. In men wishing to delay treatment conservative treatment appears to provide a cost-effective alternative in the short term. 相似文献
Depending upon initial treatment, between 2 and 30% of patients with a displaced intra-articular calcaneal fracture require
a secondary arthrodesis. The aim of this study was to investigate the effect of subtalar versus triple arthrodesis on functional
outcome. A total of 33 patients with 37 secondary arthrodeses (17 subtalar and 20 triple) with a median follow-up of 116 months
were asked to complete questionnaires regarding disease-specific functional outcome (Maryland Foot Score, MFS), quality of
life (SF-36) and overall satisfaction with the treatment (Visual Analogue Scale, VAS). Patient groups were comparable considering
median age at fracture, initial treatment (conservative or operative), time to arthrodesis, median follow-up, and post-arthrodesis
radiographic angles. The MFS score was similar after subtalar versus triple arthrodesis (59 vs. 56 points; P = 0.79). No statistically significant difference was found for the SF-36 (84 vs. 83 points; P = 0.67) and the VAS (5 vs. 6; P = 0.21). Smoking was statistically significantly associated with a non-union (χ2 = 6.60, P = 0.017). The current study suggests that there is no significant difference in functional outcome between an in situ subtalar
or triple arthrodesis as a salvage technique for symptomatic arthrosis after an intra-articular calcaneal fracture. Smoking
is a risk factor for non-union. 相似文献