Diagnosis of Chagasic Encephalitis by Sequencing of 28S rRNA Gene.

We report a case of chagasic encephalitis diagnosed by 28S rRNA sequencing. The diagnosis of chagasic encephalitis is challenging, given the broad differential diagnosis for central nervous system lesions in immunocompromised patients and low sensitivity of traditional diagnostics. Sequencing should be part of the diagnostic armamentarium for potential chagasic encephalitis.

Exposure to ionizing radiation and estimate of secondary cancers in the era of high-speed CT scanning: projections from the Medicare population.

PURPOSE: The aims of this study were to analyze the distribution and amount of ionizing radiation delivered by CT scans in the modern era of high-speed CT and to estimate cancer risk in the elderly, the patient group most frequently imaged using CT scanning. METHODS: A retrospective cohort study was conducted using Medicare claims spanning 8 years (1998-2005) to assess CT use. The data were analyzed in two 4-year cohorts, 1998 to 2001 (n = 5,267,230) and 2002 to 2005 (n = 5,555,345). The number and types of CT scans each patient received over the 4-year periods were analyzed to determine the percentage of patients exposed to threshold radiation of 50 to 100 mSv (defined as low) and >100 mSv (defined as high). The National Research Council's Biological Effects of Ionizing Radiation VII models were used to estimate the number of radiation-induced cancers. RESULTS: CT scans of the head were the most common examinations in both Medicare cohorts, but abdominal imaging delivered the greatest proportion (43% in the first cohort and 40% in the second cohort) of radiation. In the 1998 to 2001 cohort, 42% of Medicare patients underwent CT scans, with 2.2% and 0.5% receiving radiation doses in the low and high ranges, respectively. In the 2002 to 2005 cohort, 50% of Medicare patients received CT scans, with 4.2% and 1.2% receiving doses in the low and high ranges. In the two populations, 1,659 (0.03%) and 2,185 (0.04%) cancers related to ionizing radiation were estimated, respectively. CONCLUSIONS: Although radiation doses have been increasing along with the increasing reliance on CT scans for diagnosis and therapy, using conservative estimates with worst-case scenario methodology, the authors found that the risk for secondary cancers is low in older adults, the group subjected to the most frequent CT scanning. Trends showing increasing use, however, underscore the importance of monitoring CT utilization and its consequences.

Meaningful variation in performance: a systematic literature review.

BACKGROUND: Recommendations for directing quality improvement initiatives at particular levels (eg, patients, physicians, provider groups) have been made on the basis of empirical components of variance analyses of performance. OBJECTIVE: To review the literature on use of multilevel analyses of variability in quality. RESEARCH DESIGN: Systematic literature review of English-language articles (n = 39) examining variability and reliability of performance measures in Medline using PubMed (1949-November 2008). RESULTS: Variation was most commonly assessed at facility (eg, hospital, medical center) (n = 19) and physician (n = 18) levels; most articles reported variability as the proportion of total variation attributable to given levels (n = 22). Proportions of variability explained by aggregated levels were generally low (eg, <19% for physicians), and numerous authors concluded that the proportion of variability at a specific level did not justify targeting quality interventions to that level. Few articles based their recommendations on absolute differences among physicians, hospitals, or other levels. Seven of 12 articles that assessed reliability found that reliability was poor at the physician or hospital level due to low proportional variability and small sample sizes per unit, and cautioned that public reporting or incentives based on these measures may be inappropriate. CONCLUSIONS: The proportion of variability at levels higher than patients is often found to be "low." Although low proportional variability may lead to poor measurement reliability, a number of authors further suggested that it also indicates a lack of potential for quality improvement. Few studies provided additional information to help determine whether variation was, nevertheless, clinically meaningful.