Addressing geographic disparities in liver transplantation through redistricting.

Severe geographic disparities exist in liver transplantation; for patients with comparable disease severity, 90-day transplant rates range from 18% to 86% and death rates range from 14% to 82% across donation service areas (DSAs). Broader sharing has been proposed to resolve geographic inequity; however, we hypothesized that the efficacy of broader sharing depends on the geographic partitions used. To determine the potential impact of redistricting on geographic disparity in disease severity at transplantation, we combined existing DSAs into novel regions using mathematical redistricting optimization. Optimized maps and current maps were evaluated using the Liver Simulated Allocation Model. Primary analysis was based on 6700 deceased donors, 28 063 liver transplant candidates, and 242 727 Model of End-Stage Liver Disease (MELD) changes in 2010. Fully regional sharing within the current regional map would paradoxically worsen geographic disparity (variance in MELD at transplantation increases from 11.2 to 13.5, p = 0.021), although it would decrease waitlist deaths (from 1368 to 1329, p = 0.002). In contrast, regional sharing within an optimized map would significantly reduce geographic disparity (to 7.0, p = 0.002) while achieving a larger decrease in waitlist deaths (to 1307, p = 0.002). Redistricting optimization, but not broader sharing alone, would reduce geographic disparity in allocation of livers for transplant across the United States.

Epilogue. Establishment of the Center for Chronic Disease Prevention and Health Promotion.

The establishment of the Center for Chronic Disease Prevention and Health Promotion (CCDPHP) at the Centers for Disease Control (CDC) following the Conferences on the State of the Art in Quality Control Measures for Diagnostic Cytology Laboratories is briefly discussed. The CCDPHP is expected to play a major role in the CDC's cancer control program, including participation in establishing effective screening programs and assuring the quality of such methodologies as the Papanicolaou test and mammography.

Measuring screening skills in gynecologic cytology. Results of voluntary self-assessment.

When the Clinical Laboratory Improvement Act (CLIA) was passed in 1967, the Centers for Disease Control (CDC) became interested in evaluating screening performance in cytodiagnosis. Finding no validated performance measurement methods that could be used on a national scale, the CDC initiated a program of sequential investigations to develop information that would describe the state of the art in microscopic performance in gynecologic cytopathology. The first of these experiments developed a method, the Self-Assessment Workshop, to measure performance at the microscope by using sets of glass slides. This paper describes the method, its validation process and participant performance over a 15-year period. Study results indicated that cytotechnologists and pathologists tended to correctly identify specimens (slides) in the negative and benign reaction categories in up to 95% of responses, but on slides of dysplasia they made 12% of their calls too low. Carcinomas in situ and invasive squamous cancers were undercalled in only about 5% of responses, but endometrial adenocarcinomas and other rare malignancies were undercalled in as much as 20%. The self-assessment technique is a practical, useful tool for identifying cytology personnel with serious deficiencies in cell location/identification skills and is well accepted by cytotechnologists and pathologists. However its limitations should be kept in mind: screening results from this simulated test should not be extrapolated to routine work performance; the screening time limit of five minutes per slide may adversely affect performance; and, finally, these results may reflect state-of-the-art performance only in voluntary, not mandatory, settings.