High-resolution vascular imaging of the rat spine using liposomal blood pool MR agent.

BACKGROUND AND PURPOSE: High-resolution, vascular MR imaging of the spine region in small animals poses several challenges. The small anatomic features, extravascular diffusion, and low signal-to-noise ratio limit the use of conventional contrast agents. We hypothesize that a long-circulating, intravascular liposomal-encapsulated MR contrast agent (liposomal-Gd) would facilitate visualization of small anatomic features of the perispinal vasculature not visible with conventional contrast agent (gadolinium-diethylene-triaminepentaacetic acid [Gd-DTPA]). METHODS: In this study, high-resolution MR angiography of the spine region was performed in a rat model using a liposomal-Gd, which is known to remain within the blood pool for an extended period. The imaging characteristics of this agent were compared with those of a conventional contrast agent, Gd-DTPA. RESULTS: The liposomal-Gd enabled acquisition of high quality angiograms with high signal-to-noise ratio. Several important vascular features, such as radicular arteries, posterior spinal vein, and epidural venous plexus were visualized in the angiograms obtained with the liposomal agent. The MR angiograms obtained with conventional Gd-DTPA did not demonstrate these vessels clearly because of marked extravascular soft-tissue enhancement that obscured the vasculature. CONCLUSIONS: This study demonstrates the potential benefit of long-circulating liposomal-Gd as a MR contrast agent for high-resolution vascular imaging applications.

Quality assurance plan for a vaccine preventable diseases surveillance program

Public health surveillance programs for vaccine preventable diseases (VPD) need functional quality assurance (QA) in order to operate with high quality activities to prevent preventable communicable diseases from spreading in the community. Having a functional QA plan can assure the performance and quality of a program without putting excessive stress on the resources. A functional QA plan acts as a check on the quality of day-to-day activities performed by the VPD surveillance program while also providing data that would be useful for evaluating the program. This study developed a QA plan that involves collection, collation, analysis and reporting of information based on standardized (predetermined) formats and indicators as an integral part of routine work for the vaccine preventable disease surveillance program at the City of Houston Department of Health and Human Services. The QA plan also provides sampling and analysis plans for assessing various QA indicators, as well as recommendations to the Houston Department of Health and Humans Services for implementation of the QA plan. The QA plan developed for VPD surveillance in the City of Houston is intended to be a low cost system that could serve as a template for QA plans as part of other public health programs not only in the city or the nation, but could be adapted for use anywhere across the globe. Having a QA plan for VPD surveillance in the City of Houston would serve well for the funding agencies like the CDC by assuring that the resources are being expended efficiently, while achieving the real goal of positively impacting the health and lives of the recipient/target population. ^

Quality in healthcare organizations: Its meaning and measurement

This dissertation explores two important aspects of quality in healthcare: its meaning and its measurement. For a better understanding of what quality means, the history of quality in the manufacturing and service industries is reviewed. Concepts that are similar are pointed out as are concepts that are different. The definition introduced by the Institute of Medicine (IOM) for quality in healthcare and the six IOM aims of safety, timeliness, patient-centeredness, effectiveness, efficiency, and equitableness for a high quality healthcare system are adopted. The current activities by various organizations that proclaim improvement in quality or measurement of quality as their goal are reviewed. This is followed by examining what is offered by these organizations in terms of how many of IOM aims they address.^ This dissertation ends by offering a quality measurement framework that satisfies all IOM aims. Operational aspects of the measurement framework are discussed. Future areas of research are also discussed.^

Is depression associated with insulin resistance? A systematic review

Studies suggest that depression affects glucose metabolism, and therefore is a risk factor for insulin resistance. The association between depression and insulin resistance has been investigated in a number of studies, but there is no agreement on the results. The objective of this study is to survey the epidemiological studies, identify the ones that measured the association of depression (as exposure) with insulin resistance (as outcome), and perform a systematic review to assess the reliability and strength of the association. For high quality reporting, and assessment, this systematic review used the outlined procedures, guidelines and recommendations for reviews in health care, suggested by the Centre for Reviews and Dissemination, along with recommendations from the STROBE group (Strengthening the Reporting of Observational Studies in Epidemiology). Ovid MEDLINE 1996 to April Week 1 2010, was used to identify the relevant epidemiological studies. To identify the most relevant set of articles for this systematic review, a set of inclusion and exclusion criteria were applied. Six studies that met the specific criteria were selected. Key information from identified studies was tabulated, and the methodological quality, internal and external validity, and the strength of the evidence of the selected studies were assessed. The result from the tabulated data of the reviewed studies indicates that the studies either did not apply a case definition for insulin resistance in their investigation, or did not state a specific value for the index used to define insulin resistance. The quality assessment of the reviewed studies indicates that to assess the association between insulin resistance and depression, specifying a case definition for insulin resistance is important. The case definition for insulin resistance is defined by the World Health Organization and the European Group for the Study of Insulin Resistance as the insulin sensitivity index of the lowest quartile or lowest decile of a general population, respectively. Three studies defined the percentile cut-off point for insulin resistance, but did not give the insulin sensitivity index value. In these cases, it is not possible to compare the results. Three other studies did not define the cut-off point for insulin resistance. In these cases, it is hard to confirm the existence of insulin resistance. In conclusion, to convincingly answer our question, future studies need to adopt a clear case definition, define a percentile cut-off point and reference population, and give value of the insulin resistance measure at the specified percentile.^

A review of economic analysis in the vaccination program; decision making and governance: Adivisory Committee on Immunization Practices (ACIP)

The Advisory Committee on Immunization Practices (ACIP) develops written recommendations for the routine administration of vaccines to children and adults in the U.S. civilian population. The ACIP is the only entity in the federal government that makes such recommendations. ACIP elaborates on selection of its members and rules out concerns regarding its integrity, but fails to provide information about the importance of economic analysis in vaccine selection. ACIP recommendations can have large health and economic consequences. Emphasis on economic evaluation in health is a likely response to severe pressures of the federal and state health budget. This study describes the economic aspects considered by the ACIP while sanctioning a vaccine, and reviews the economic evaluations (our economic data) provided for vaccine deliberations. A five year study period from 2004 to 2009 is adopted. Publicly available data from ACIP web database is used. Drummond et al. (2005) checklist serves as a guide to assess the quality of economic evaluations presented. Drummond et al.'s checklist is a comprehensive hence it is unrealistic to expect every ACIP deliberation to meet all of their criteria. For practical purposes we have selected seven criteria that we judge to be significant criteria provided by Drummond et al. Twenty-four data points were obtained in a five year period. Our results show that out of the total twenty-four data point‘s (economic evaluations) only five data points received a score of six; that is six items on the list of seven were met. None of the data points received a perfect score of seven. Seven of the twenty-four data points received a score of five. A minimum of a two score was received by only one of the economic analyses. The type of economic evaluation along with the model criteria and ICER/QALY criteria met at 0.875 (87.5%). These three criteria were met at the highest rate among the seven criteria studied. Our study findings demonstrate that the perspective criteria met at 0.583 (58.3%) followed by source and sensitivity analysis criteria both tied at 0.541 (54.1%). The discount factor was met at 0.250 (25.0%).^ Economic analysis is not a novel concept to the ACIP. It has been practiced and presented at these meetings on a regular basis for more than five years. ACIP‘s stated goal is to utilize good quality epidemiologic, clinical and economic analyses to help policy makers choose among alternatives presented and thus achieve a better informed decision. As seen in our study the economic analyses over the years are inconsistent. The large variability coupled with lack of a standardized format may compromise the utility of the economic information for decision-making. While making recommendations, the ACIP takes into account all available information about a vaccine. Thus it is vital that standardized high quality economic information is provided at the ACIP meetings. Our study may provide a call for the ACIP to further investigate deficiencies within the system and thereby to improve economic evaluation data presented. ^

Importance of antibiotic class to the development of Clostridium difficile infection (CDI) in adults: A systematic review

C. difficile causes gastrointestinal infections in humans, including severe diarrhea. It is implicated in 20%-30% of cases of antibiotic-associated diarrhea, in 50%-70% of cases of antibiotic-associated colitis, and in >90% of cases of antibiotic-associated pseudomembranous colitis. Exposure to antimicrobial agent, hospitalization and age are some of the risk factors that predispose to CDI. Virtually all hospitalized patients with nosocomially-acquired CDI have a history of treatment with antimicrobials or neoplastic agent within the previous 2 months. The development of CDI usually occurs during treatment with antibiotics or some weeks after completing the course of the antibiotics. ^ After exposure to the organism (often in a hospital), the median incubation period is less than 1 week, with a median time of onset of 2days. The difference in the time between the use of antibiotic and the development of the disease relate to the timing of exogenous acquisition of C. difficile. ^ This paper reviewed the literature for studies on different classes of antibiotics in association with the rates of primary CDI and RCDI from the year 1984 to 2012. The databases searched in this systematic review were: PubMed (National Library of Medicine) and Medline (R) (Ovid). RefWorks was used to store bibliographic data. ^ The search strategy yielded 733 studies, 692 articles from Ovid Medline (R) and 41 articles from PubMed after removing all duplicates. Only 11 studies were included as high quality studies. Out of the 11 studies reviewed, 6 studies described the development of CDI in non-CDI patients taking antibiotics for other purposes and 5 studies identified the risk factors associated with the development of recurrent CDI after exposure to antibiotics. ^ The risk of developing CDI in non-CDI patients receiving beta lactam antibiotics was 2.35%, while fluoroquinolones, clindamycin/macrolides and other antibiotics were associated with 2.64%, 2.54% and 2.35% respectively. Of those who received beta lactam antibiotic, 26.7% developed RCDI, while 36.8% of those who received any fluoroquinolone developed RCDI, 26.5% of those who received either clindamycin or macrolides developed RCDI and 29.1% of those who received other antibiotics developed RCDI. Continued use of non-C. difficile antibiotics especially fluoroquinolones was identified as an important risk factor for primary CDI and recurrent CDI. ^