Estimating the Empirical Lorenz Curve and Gini Coefficient in the Presence of Error

The Lorenz curve is a graphical tool that is widely used to characterize the concentration of a measure in a population, such as wealth. It is frequently the case that the measure of interest used to rank experimental units when estimating the empirical Lorenz curve, and the corresponding Gini coefficient, is subject to random error. This error can result in an incorrect ranking of experimental units which inevitably leads to a curve that exaggerates the degree of concentration (variation) in the population. We explore this bias and discuss several widely available statistical methods that have the potential to reduce or remove the bias in the empirical Lorenz curve. The properties of these methods are examined and compared in a simulation study. This work is motivated by a health outcomes application which seeks to assess the concentration of black patient visits among primary care physicians. The methods are illustrated on data from this study

The Use of Acellular Dermal Matrices in Two-Stage Expander/Implant Reconstruction: A Multicenter, Blinded, Randomized Controlled Trial

Current efficacy data supporting the routine use of acellular dermal matrices (ADM) in postmastectomy tissue expander/implant reconstruction is limited. A multi-center, blinded, randomized controlled study was designed to evaluate the effectiveness of ADM in the setting of TE/I reconstruction. The primary objective of the study was to determine whether the use of ADM would decrease patient-reported, post-operative pain. The secondary objective was to determine whether the use of ADM accelerated the rate of post-operative expansion. Tertiary objectives included an evaluation of long-term aesthetic results, capsular contracture rates and patient satisfaction

Osteonecrosis of the Maxilla and Mandible in Patients with Advanced Cancer Treated with Bisphosphonate Therapy

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/139939/1/onco0911.pd

Additional file 1: of Clinical and radiographic differentiation of lung nodules caused by mycobacteria and lung cancer: a case–control study

Receiver operating characteristic curve for maximum standardized uptake values on differentiating between mycobacterial lung disease and lung cancer. (PDF 67 kb

Long-term effects of high-dose chemotherapy and radiation for relapsed and refractory Hodgkin's lymphoma

To evaluate the risk of late morbidity and mortality, and to assess long-term health-related quality of life (QOL) among patients with relapsed/refractory Hodgkin's lymphoma (HL) after high-dose chemoradiotherapy (HDT) and autologous stem-cell rescue (ASCR). From 1985 to 1998, 218 patients with HL were treated on HDT with ASCR salvage protocols. Of these 218, 153 (70%) who survived > or = 2 years after ASCR were evaluated for late morbidity and mortality from causes other than HL. QOL information was obtained through self-administered questionnaires. Risk ratios (RR) were calculated to compare observed second malignancy (SM) rates in this cohort with expected SM rates from the Surveillance Epidemiology and End Results (SEER) registry. Median follow-up after ASCR was 11.5 years. Among 153 patients, there were 53 deaths; 33 from HL and 20 from other causes. Thirteen deaths were caused by SM, with median time from ASCR to SM diagnosis of 9 years (range, 3 to 18 years). The RR of SM was 6.5 (95% CI, 3.6 to 10.7) when compared with the general population, but 2.4 (95% CI, 1.4 to 4.05) when compared with patients with HL. Global QOL of ASCR survivors was comparable with the general population, but for specific domains, respondents' scores indicated reduced functioning and worse symptoms. HL accounts for most deaths among patients surviving HDT and ASCR. Survivors of ASCR had an elevated risk of SM compared with the cancer risk in the general population, but when compared with patients with HL in SEER, the risk was less pronounced

p27 expression in post-treatment rectal cancer: a potential novel approach for predicting residual nodal disease

Expression profiles of p21, p27, p53, Ki-67, and thymidylate synthase may be associated with response to neoadjuvant chemoradiation. The relationship between post-treatment protein expression and regional lymph node involvement has not been fully explored. Tumor cores from 126 rectal cancer patients underwent immunohistochemical analysis for the aforementioned proteins. Staining indices (SIs) using percentage of stained cells and staining intensity were calculated for 10 tumor cores per patient. SI for each marker was compared between node negative and node positive patients. Twenty-six (20.6%) cancer patients had a pathologic complete response and 37 had inadequate tissue or cancer cells, leaving 63 for analysis. Thirty-seven (58.7%) cancer patients were node negative and 26 (41.3%) were node positive. There was an association between increased p27 SI and nodal positivity (P = .04). Increased p27 expression in post-treatment rectal cancer is associated with nodal positivity and may determine which patients are suitable for local excision