A comprehensive approach to risk assessment and surveillance guiding public health interventions

Tools are required to identify 'multi-endemic' population segments – in order to benefit the most vulnerable people and to make public health interventions cost-effective. The article suggests a comprehensive risk assessment and surveillance system approach based on a combination of epidemiological, environmental and social determinants. Such a cross-disciplinary approach will combine the advantages of forecasting upcoming disease 'hot spots' with provision of evidence for long-term planning under more stable conditions, and it may in principle apply to any combination of public health problems depending on the local context.     

Volunteer bias in nonrandomized evaluations of the efficacy of needle-exchange programs

Objective Nonrandomized comparisons of the incidence of HIV and hepatitis B and C between injection drug users (IDUs) who do and do not attend voluntary needle-exchange programs may be subject to bias. To explore possible sources of bias, we examined characteristics associated with voluntarily beginning or ceasing to participate in the Seattle needle exchange. Methods In a cohort of 2,879 IDUs, a standardized questionnaire measured characteristics present at enrollment. We examined the relation of these characteristics to the proportion of IDUs who began to use the program during the ensuing 12-month follow-up period and to the proportion of current exchangers who dropped out during that period of time. Results Of the 494 never-exchangers at baseline, 32% attended the exchange program during follow-up; those who reported sharing syringes or who were homeless at enrollment were more likely to become new exchange users (adjusted risk ratio [ARR] for becoming an exchange user = 1.8 for those who shared syringes, and ARR=2.2, for those who were homeless). Of 1,274 current exchangers, 16% stopped using the exchange during follow-up, with daily injectors (ARR=0.6) and those who reported backloading (ARR=0.6) being relatively less likely to drop out of the exchange. Conclusions The analysis suggests that IDUs participating in needle-exchange programs at a given point in time may include a particularly high proportion of those injectors whose pattern of drug use puts them at elevated risk of blood-borne viral infections.     

Epidemiology of periodontal diseases in the study of health in Pomerania

Aim: The aim of this study was to assess the prevalence and extent of periodontal diseases among adults in a province in Eastern Germany.
Material and Methods: The Study of Health in Pomerania is a population-based study conducted during 1997–2001. The net random sample comprised 4310 20–81-year-old subjects. Periodontal status was assessed at four surfaces using a half-mouth recording protocol.
Results: The prevalence of attachment loss 3 mm was 89.7%, with 62.8% of teeth being affected. Probing depths 4 mm were prevalent in 69.7% of subjects, and 29.6% of teeth were affected. 25.3% of all subjects had severe pockets (6 mm). Periodontitis was significantly more prevalent in males. For attachment loss, the prevalence and extent increased significantly with increasing age, whereas probing depth values levelled off after the age of 40. In older subjects, increased recession and attachment loss were found, while the probing depth remained constant. According to the recent CDC classification, 17.6% and 33.3% of persons had severe and moderate periodontitis, respectively. The prevalence of periodontitis increased significantly with age and remained constant after the age of 50–59.
Conclusions: Periodontitis is more prevalent in Pomerania than in the United States or Western Europe. In older subjects, attachment loss steadily increased, while the probing depth remained constant.     

Human mesenchymal stem cells promote human osteoclast differentiation from CD34+ bone marrow hematopoietic progenitors.

Interactions between osteoclast progenitors and stromal cells derived from mesenchymal stem cells (MSCs) within the bone marrow are important for osteoclast differentiation. In vitro models of osteoclastogenesis are well established in animal species; however, such assays do not necessarily reflect human osteoclastogenesis. We sought to establish a reproducible coculture model of human osteoclastogenesis using highly purified human marrow-derived MSCs (hMSCs) and CD34+ hematopoietic stem cells (HSCs). After 3 weeks, coculture of hMSCs and HSCs resulted in an increase in hematopoietic cell number with formation of multinucleated osteoclast-like cells (Ocls). Coculture of hMSCs with HSCs, transduced with a retroviral vector that expresses enhanced green fluorescent protein, produced enhanced green fluorescent protein+ Ocls, further demonstrating that Ocls arise from HSCs. These Ocls express calcitonin and vitronectin receptors and tartrate-resistant acid phosphatase and possess the ability to resorb bone. Ocl formation in this assay is cell contact dependent and is independent of added exogenous factors. Conditioned medium from the coculture contained high levels of interleukin (IL)-6, IL-11, leukemia inhibitory factor (LIF), and macrophage-colony stimulating factor. IL-6 and LIF were present at low levels in cultures of hMSCs but undetectable in cultures of HSCs alone. These data suggest that coculture with HSCs induce hMSCs to secrete cytokines involved in Ocl formation. Addition of neutralizing anti-IL-6, IL-11, LIF, or macrophage-colony stimulating factor antibodies to the coculture inhibited Ocl formation. hMSCs seem to support Ocl formation as undifferentiated progenitor cells, because treatment of hMSCs with dexamethasone, ascorbic acid, and beta-glycerophosphate (to induce osteogenic differentiation) actually inhibited osteoclastogenesis in this coculture model. In conclusion, we have developed a simple and reproducible assay using culture-expanded hMSCs and purified HSCs with which to study the mechanisms of human osteoclastogenesis.     

An Examination of the Medicaid Undercount in the Current Population Survey: Preliminary Results from Record Linking

Objective. To assess reasons why survey estimates of Medicaid enrollment are 43 percent lower than raw Medicaid program enrollment counts (i.e., "Medicaid undercount").
Data Sources. Linked 2000–2002 Medicaid Statistical Information System (MSIS) and the 2001–2002 Current Population Survey (CPS).
Data Collection Methods. Centers for Medicare and Medicaid Services provided the Census Bureau with its MSIS file. The Census Bureau linked the MSIS to the CPS data within its secure data analysis facilities.
Study Design. We analyzed how often Medicaid enrollees incorrectly answer the CPS health insurance item and imperfect concept alignment (e.g., inclusion in the MSIS of people who are not included in the CPS sample frame and people who were enrolled in Medicaid in more than one state during the year).
Principal Findings. The extent to which the Medicaid enrollee data were adjusted for imperfect concept alignment reduces the raw Medicaid undercount considerably (by 12 percentage points). However, survey response errors play an even larger role with 43 percent of Medicaid enrollees answering the CPS as though they were not enrolled and 17 percent reported being uninsured.
Conclusions. The CPS is widely used for health policy analysis but is a poor measure of Medicaid enrollment at any time during the year because many people who are enrolled in Medicaid fail to report it and may be incorrectly coded as being uninsured. This discrepancy should be considered when using the CPS for policy research.     

15. Manuelle Naht versus/sive Maschinennaht aus der Sicht Deutschlands

Zusammenfassung Die Verwendung von maschinellen Nähten im Gastrointestinaltrakt und in der Lunge ist eindeutig im Zunehmen. Dies beruht auf einem inzwischen hohen Perfektionsgrad der modernen Nahtgeräte, deren Vorläufermodelle eigentlich schon seit Anfang dieses Jahrhunderts entwickelt sind. Im Gastrointestinaltrakt wurde der echte Durchbruch durch die Einführung der zirkulären Stapler seit ca. 1978/79 erreicht. Gerade die zirkulären Stapler haben die Chirurgen zu besonderen Innovationen in den Rekonstruktionsprinzipien angeregt, so dass Ersatzmagenbildungen (Roux-Y und Pouch, Interposition und Pouch) in bisher nicht gekannter Weise standardisiert und mit neuen physiologischen Perspektiven geformt werden können. Im Rectumbereich hat sich der zirkuläre Stapler weitgehend durchgesetzt. Darüber darf jedoch eine neue Entwicklung der manuellen Naht mit mittelfristig absorbierbaren Nahtmaterialien nicht übersehen werden.