Explicit temporal models for decision-theoretic planning of clinical management

The management of patients over a prolonged period of time is a complicated task involving both diagnostic and prognostic reasoning with incomplete and often uncertain knowledge. Various formalisations of this type of task exist, but these often conceal one or more essential ingredients of the problem. This article explores the suitability of partially observable Markov decision processes to formalising the planning of clinical management. These processes allow for explicit representation of clinical states of the patient, the management strategy employed, the objectives of treatment, and the role of time and change in reasoning. However, practical application is hampered by their coarse representational granularity and complex formulation. It is discussed how probabilistic network representations can be used to alleviate these obstacles. The resulting method is illustrated with a real-world example from the domain of paediatric cardiology.     

Organization of extracorporeal membrane oxygenation for acute respiratory distress syndrome in the United Kingdom

This article reviews the evolution of extracorporeal membrane oxygenation (ECMO) in the United Kingdom to treat patients with refractory acute respiratory distress. The UK centralized commissioning of public health care has delivered a coherent high-quality national adult ECMO service and defined the key factors in the designation as adult ECMO centre. This strategy seems adequate to provide for the needs of the population and avoid the danger of occasional practice by teams who do not undertake ECMO regularly.     

Development of a Conceptual Framework for Understanding Shared Decision making Among African-American LGBT Patients and their Clinicians

BACKGROUND

Enhancing patient-centered care and shared decision making (SDM) has become a national priority as a means of engaging patients in their care, improving treatment adherence, and enhancing health outcomes. Relatively little is known about the healthcare experiences or shared decision making among racial/ethnic minorities who also identify as being LGBT. The purpose of this paper is to understand how race, sexual orientation and gender identity can simultaneously influence SDM among African-American LGBT persons, and to propose a model of SDM between such patients and their healthcare providers.

METHODS

We reviewed key constructs necessary for understanding SDM among African-American LGBT persons, which guided our systematic literature review. Eligible studies for the review included English-language studies of adults (≥ 19 y/o) in North America, with a focus on LGBT persons who were African-American/black (i.e., > 50 % of the study population) or included sub-analyses by sexual orientation/gender identity and race. We searched PubMed, CINAHL, ProQuest Dissertations & Theses, PsycINFO, and Scopus databases using MESH terms and keywords related to shared decision making, communication quality (e.g., trust, bias), African-Americans, and LGBT persons. Additional references were identified by manual reviews of peer-reviewed journals’ tables of contents and key papers’ references.

RESULTS

We identified 2298 abstracts, three of which met the inclusion criteria. Of the included studies, one was cross-sectional and two were qualitative; one study involved transgender women (91 % minorities, 65 % of whom were African-Americans), and two involved African-American men who have sex with men (MSM). All of the studies focused on HIV infection. Sexual orientation and gender identity were patient-reported factors that negatively impacted patient/provider relationships and SDM. Engaging in SDM helped some patients overcome normative beliefs about clinical encounters. In this paper, we present a conceptual model for understanding SDM in African-American LGBT persons, wherein multiple systems of social stratification (e.g., race, gender, sexual orientation) influence patient and provider perceptions, behaviors, and shared decision making.

DISCUSSION

Few studies exist that explore SDM among African-American LGBT persons, and no interventions were identified in our systematic review. Thus, we are unable to draw conclusions about the effect size of SDM among this population on health outcomes. Qualitative work suggests that race, sexual orientation and gender work collectively to enhance perceptions of discrimination and decrease SDM among African-American LGBT persons. More research is needed to obtain a comprehensive understanding of shared decision making and subsequent health outcomes among African-Americans along the entire spectrum of gender and sexual orientation.

     

Host and microbial constituents influence Helicobacter pylori-induced cancer in a murine model of hypergastrinemia

BACKGROUND & AIMS: Helicobacter pylori cag(+) strains and high-expression host interleukin 1beta (IL-1beta) polymorphisms augment the risk for intestinal-type gastric adenocarcinoma, a malignancy that predominates in males. We examined the effects of an H. pylori cancer-associated determinant (cagE), IL-1beta, and host gender in a transgenic hypergastrinemic (INS-GAS) murine model of gastric carcinogenesis. METHODS: Male and female INS-GAS mice infected with wild-type H. pylori, an H. pylori cagE(-) mutant, or H. felis were killed 2-24 weeks postchallenge. Gastric injury was scored from 0 to 4, and mucosal IL-1beta levels were quantified by ELISA. RESULTS: Male INS-GAS mice infected with H. pylori uniformly developed atrophy, intestinal metaplasia, and dysplasia by 6 weeks and carcinoma by 24 weeks. Mucosal IL-1beta concentrations increased 12 weeks following Helicobacter challenge, but levels then decreased by 24 weeks. Inactivation of cagE delayed the progression to carcinoma, but neoplasia ultimately developed in all males infected with the H. pylori mutant. In contrast, none of the H. pylori-infected female mice developed cancer, and injury scores, but not IL-1beta levels, were significantly higher in males compared with females. CONCLUSIONS: H. pylori infection induces gastric adenocarcinoma in an experimental mouse model of disease. Cancer is restricted to males and loss of cagE temporally retards but does not abrogate pathologic progression. Mucosal levels of IL-1beta increase prior to the development of gastric cancer but are not related to gender. The INS-GAS model is effective for investigating discrete host-microbial interactions that culminate in gastric cancer within the context of biologic conditions induced by H. pylori.     

Simultaneous double-isotope autoradiographic measurement of local cerebral glucose metabolic rate and acid-base status in rat brain

We developed a double-isotope autoradiographic method for the simultaneous measurement of the local cerebral metabolic rate for glucose (1CMRG) and index of regional acid-base status (rABI) in single brain slices using [2-¹⁴C]deoxy-D-glucose (DG) and 5,5-dimethyl-[2-¹⁴C]oxazolidine-2,4, dione (DMO). After iv isotope administration, paper chromatography separates plasma DMO from DG activity using a methanol-methylene chloride solvent system. Initial tissue autoradiograms depict regional DMO plus DG and DG metabolite distribution. After 14 days in a well-ventilated hood, 97.5 ±0.5% of all DMO is lost from tissue sections by sublimation, and a second autoradiogram depicts DG plus DG metabolite distribution. Retention of brain lipids does not alter beta-particle self-absorption, avoiding problems associated with isotope extraction with solvents. Autoradiograms are digitized and converted to isotope-content images. The second autoradiogram is used for lCMRG computation. After subtracting the second regional isotope-content value from the first, the DMO content is obtained and used to compute rABI. Application of this method to normal animals yields expected values for lCMRG and rABI. This method is amenable to whole-slice digitization and creation of functional images of lCMRG and ABI followed by pixel-by-pixel correlations of the two variables, making this a potentially valuable tool for the investigation of the relationships between glucose metabolism and brain acid-base balance.     

National Prevalence of Lifestyle Counseling or Referral Among African-Americans and Whites with Diabetes

Background  Modifiable risk factors such as diet and physical activity contribute to racial disparities among patients with diabetes. Despite this, little is known about how frequently physicians provide counseling or referral to address these risk factors, or whether such rates differ by patient race. Methods  We analyzed cross-sectional data from the 2002–2004 National Ambulatory Medical Care Survey and the National Hospital Ambulatory Medical Care Survey. We used logistic regression to investigate the relationship between counseling/referral for nutrition or exercise and patient factors, provider factors, and geographic location, with a focus on whether counseling rates were independently associated with patient race. Results  Overall, counseling/referral for nutrition occurred in 36% of patient visits and counseling/referral for exercise occurred in 18% of patient visits. After adjusting for patient, physician, and practice characteristics, there was no statistically significant association between race and counseling/referral for nutrition (odds ratio for African-Americans compared to whites [OR] 1.00, 95% confidence intervals [CI] 0.71–1.41) or for exercise (OR 0.74, CI 0.49–1.11). Significant predictors of counseling/referral for both lifestyle interventions included younger patient age, private insurance, and treatment by a primary care provider. Conclusions  Rates of lifestyle modification counseling/referral were similarly low among African-Americans and whites in this national study. Our results highlight a need for interventions to enhance physician counseling for patients with diabetes, particularly those at high-risk for diabetes-associated morbidity and mortality, such as racial/ethnic minorities.