Numerical model for intraosseous infusion of the human calvarium for hydrocephalus shunting.

Hydrocephaly is the defective absorption of cerebrospinal fluid (CSF) into the blood stream. This work is an experimental and computational fluid dynamic modelling study to determine the permeability of the diploë as a potential receptor for CSF. Human calvariae were studied by micro-CT to measure their porosity, the area of flow and develop model geometry. Pressure-flow measurements were conducted on specimens to determine their permeability in the physiological and transverse flow directions to compare with numerical results. The overall porosity and permeability of the calvaria were spatially variable. Results suggest an order of magnitude increase in permeability for a 14% increase in overall porosity based on a small number of samples. Numerical results fell within the experimental infusion tests results. Due to the difficulty and ethical considerations in obtaining adolescent skull samples to perform large-scale testing, the developed model will be invaluable.

Elemental imaging of MRI contrast agents: benchmarking of LA-ICP-MS to MRI.

Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) has been used to map the spatial distribution of magnetic resonance imaging (MRI) contrast agents (Gd-based) in histological sections in order to explore synergies with in vivo MRI. Images from respective techniques are presented for two separate studies namely (1) convection enhanced delivery of a Gd nanocomplex (developmental therapeutic) into rat brain and (2) convection enhanced delivery, with co-infusion of Magnevist (commercial Gd contrast agent) and Carboplatin (chemotherapy drug), into pig brain. The LA technique was shown to be a powerful compliment to MRI not only in offering improved sensitivity, spatial resolution and signal quantitation but also in giving added value regarding the fate of administered agents (Gd and Pt agents). Furthermore simultaneous measurement of Fe enabled assignment of an anomalous contrast enhancement region in rat brain to haemorrhage at the infusion site.

Impact of statins and angiotensin-converting enzyme inhibitors on mortality of subjects hospitalised with pneumonia.

Recent studies suggest that statins and angiotensin-converting enzyme (ACE) inhibitors may have beneficial effects for some types of infections. The present study aimed to examine the association of outpatient use of these medications on 30-day mortality for subjects aged >65 yrs and hospitalised with community-acquired pneumonia. A retrospective national cohort study was conducted using the Department of Veterans Affairs administrative data including subjects aged >/=65 yrs hospitalised with community-acquired pneumonia, and having >/=1 yr of prior Veterans Affairs outpatient care. In total, 8,652 subjects were identified with a mean age of 75 yrs, 98.6% were male, and 9.9% of subjects died within 30 days of presentation. In this cohort, 18.1% of subjects were using statins and 33.9% were using ACE inhibitors. After adjusting for potential confounders, current statin use (odds ratio (OR) 0.54, 95% confidence interval (CI) 0.42-0.70) and ACE inhibitor use (OR 0.80, 95% CI 0.68-0.89) were significantly associated with decreased 30-day mortality. Use of statins and angiotensin-converting enzyme inhibitors prior to admission is associated with decreased mortality in subjects hospitalised with community-acquired pneumonia. Randomised controlled trials are needed to examine whether the use of these medications in patients hospitalised with community-acquired pneumonia may be beneficial.

COPD is associated with increased mortality in patients with community-acquired pneumonia.

Patients with chronic obstructive pulmonary disease (COPD) who develop community-acquired pneumonia (CAP) may experience worse clinical outcomes. However, COPD is not included as a distinct diagnosis in validated instruments that predict mortality in patients with CAP. The aim of the present study was to evaluate the impact of COPD as a comorbid condition on 30- and 90-day mortality in CAP patients. A retrospective observational study was conducted at two hospitals. Eligible patients had a discharge diagnosis and radiological confirmation of CAP. Among 744 patients with CAP, 215 had a comorbid diagnosis of COPD and 529 did not have COPD. The COPD group had a higher mean pneumonia severity index score (105+/-32 versus 87+/-34) and were admitted to the intensive care unit more frequently (25 versus 18%). After adjusting for severity of disease and processes of care, CAP patients with COPD showed significantly higher 30- and 90-day mortality than non-COPD patients. Chronic obstructive pulmonary disease patients hospitalised with community-acquired pneumonia exhibited higher 30- and 90-day mortality than patients without chronic obstructive pulmonary disease. Chronic obstructive pulmonary disease should be evaluated for inclusion in community-acquired pneumonia prediction instruments.

Evidence-based guidelines meet the real world: the case of diabetes care.

OBJECTIVE: Improving diabetes care in the U.S. is critical because diabetes rates are increasing dramatically, particularly among minority and low-income populations. Although evidence-based practice guidelines for diabetes have been widely disseminated, many physicians fail to implement them. The objective of this study was to explore what happens to diabetes practice guidelines in real-world clinical settings. RESEARCH DESIGN AND METHODS: A qualitative research design was used. Open-ended semistructured interviews lasting 1-2 h were conducted with 32 key informants (physicians, certified diabetes educators, researchers, and agency personnel) selected for their knowledge of diabetes care in South Texas, an area with a high diabetes prevalence and a large proportion of minority and low-income patients. RESULTS: Health professionals stress that contextual factors are more important barriers to optimal diabetes care than physician knowledge and attitudes. Barriers exist at multiple levels and are interrelated in a complex manner. Examples include the following: time constraints and practice economics in the private practice setting; the need to maintain referral relationships and maldistribution of professionals in the practice community; low awareness and low socioeconomic status among patients; and lack of access for low-income patients, low reimbursement, and insufficient focus on prevention in the U.S. health care system. CONCLUSIONS: Contextual barriers must be addressed in order for diabetes practice guidelines to be implemented in real-world clinical practice. Suggested changes include an increased focus on prevention, improvements in health care delivery for chronic diseases, and increased attention to the special needs of minority and low-income populations.

Evidence-based practice and perioperative nursing.

The implementation of evidence-based practice in perioperative nursing holds promise of improving quality of care and client outcomes. Several factors within health care have precipitated an emphasis on evidence-based practice. The use of research results in clinical decisions is recommended as the basis of nursing practice of the future. To assist with development of evidence-based practice in nursing, basic steps of the process are presented. In addition, strategies for locating existing evidence-based practice guidelines and resources are described. Perioperative nurse researchers and practice leaders should move this issue into a top priority for the specialty.

Diabetes-related lower-extremity amputations disproportionately affect Blacks and Mexican Americans.

BACKGROUND: We sought to identify the age-adjusted incidence of lower-extremity amputation (LEA) in Mexican Americans, blacks, and non-Hispanic whites with diabetes in south Texas. METHODS: We summarized medical records for hospitalizations for LEAs for 1993 in six metropolitan statistical areas in south Texas. RESULTS: Age-adjusted incidence per 10,000 patients with diabetes was 146.59 in blacks, 60.68 in non-Hispanic whites, and 94.08 in Mexican Americans. Of the patients, 47% of amputees had a history of amputation, and 17.7% were hospitalized more than once during 1993. Mexican Americans had more diabetes-related amputations (85.9%) than blacks (74.7%) or non-Hispanic whites (56.3%). CONCLUSIONS: This study is the first to identify the incidence of diabetes-related lower-extremity amputations in minorities using primary data. Minorities had both a higher incidence and proportion of diabetes-related, LEAs compared with non-Hispanic whites. Public health initiatives and national strategies, such as Healthy People 2000 and 2010, need to specifically focus on high-risk populations and high-risk geographic areas to decrease the frequency of amputation and reamputation.

Attitudes of primary care providers toward diabetes: barriers to guideline implementation.

OBJECTIVE: Primary care providers have been slow to adopt standards of care for diabetes, and continuing medical education (CME) programs have been minimally effective in changing provider behavior. The objective of this study was to explore the previously reported finding that attitudes, rather than knowledge, may impede primary care provider adherence to standards of care. RESEARCH DESIGN AND METHODS: Study participants included 31 primary care providers attending an eight-session CME program on diabetes. Providers rated on a 10-point scale how the treatment of diabetes compared with that of five other chronic conditions (hypertension, hyperlipidemia, angina, arthritis, and heart failure; 1 = easier to 10 = harder; midpoint 5.5). In a subsequent open-ended qualitative interview, providers explained their scale ratings. RESULTS: Diabetes was rated as significantly harder to treat than hypertension (24 of 30 >5.5; P < 0.001) and angina (20 of 30 >5.5; P = 0.03). A majority also rated hyperlipidemia (18 of 30) and arthritis (18 of 30) as easier to treat than diabetes. Explanatory themes underlying provider frustrations with diabetes include characteristics of the disease itself and the complexity of its management, and a perceived lack of support from society and the health care system for their efforts to control diabetes. CONCLUSIONS: CME that addresses provider attitudes toward diabetes in addition to updating knowledge may be more effective than traditional CME in promoting adherence to standards of care. Additional changes are needed in our health care system to shift from an acute to a chronic disease model to effectively support diabetes care efforts.

Patient choice in diabetes education curriculum. Nutritional versus standard content for type 2 diabetes.

OBJECTIVE: To examine the effects of patient choice between two education curriculums that emphasized either the standard or nutritional management of type 2 diabetes on class attendance and other outcomes among a mostly Hispanic patient population. RESEARCH DESIGN AND METHODS: A total of 596 patients with type 2 diabetes were randomly assigned to either a choice or no choice condition. Patients in the choice condition were allowed to choose their curriculum, while patients in the no choice condition were randomly assigned to one of the two curriculums. Outcomes were assessed at baseline and at a 6-month follow-up. RESULTS: When given a choice, patients chose the nutrition curriculum almost four times more frequently than the standard curriculum. Contrary to our hypothesis, however, patients who had a choice did not significantly increase their attendance rates or demonstrate improvements in other diabetes outcomes compared with patients who were randomly assigned to the two curriculums. Patients in the nutrition curriculum had significantly lower serum cholesterol at a 6-month follow-up, whereas patients in the standard curriculum had significant improvements in glycemic control. Of the randomized patients, 30% never attended any classes; the most frequently cited reasons for nonattendance were socioeconomic. Hispanic patients, however, were just as likely as non-Hispanic patients to attend classes and participate at the follow-up. Patients who attended all five classes of either curriculum significantly increased their diabetes knowledge, gained less weight, and reported improved physical functioning compared with patients who did not attend any classes. CONCLUSIONS: Although providing patients with a choice in curriculums at the introductory level did not improve outcomes, differential improvements were noted between patients who attended curriculums with different content emphasis. We suggest that diabetes education programs should provide the opportunity for long-term, repetitive contacts to expand on the modest gains achieved at the introductory level, as well as provide more options to match individual needs and interests and to address socioeconomic barriers to participation.

Bienestar: a diabetes risk-factor prevention program.

The Bienester Health Program, a diabetes risk-factor prevention pilot program, targeted fourth grade Mexican American children. The primary goals are to decrease the two established risk factors for diabetes--overweight and dietary fats. Since the health program is based on Social Cognitive Theory, on social systems structure, and on culturally relevant material, it considers the child's social systems on both its health program and process evaluation. Learning activities were developed for four social systems that potentially influence children's health behaviors (parent, classroom, school cafeteria, and after-school care). Preliminary results show that the Bienestar Health Program significantly decreased dietary fat, increased fruit and vegetable servings, and increased diabetes health knowledge.

Porque me tocó a mi? Mexican American diabetes patients' causal stories and their relationship to treatment behaviors.

This paper reports findings from an ethnographic study of self-care behaviors and illness concepts among Mexican-American non-insulin dependent diabetes mellitus (NIDDM) patients. Open-ended interviews were conducted with 49 NIDDM patients from two public hospital outpatient clinics in South Texas. They are self-identified Mexican-Americans who have had NIDDM for at least 1 yr, and have no major impairment due to NIDDM. Interviews focused on their concepts and experiences in managing their illness and their self-care behaviors. Clinical assessment of their glucose control was also extracted from their medical records. The texts of patient interviews were content analyzed through building and refining thematic matrixes focusing on their causal explanations and treatment behaviors. We found patients' causal explanations of their illness often are driven by an effort to connect the illness in a direct and specific way to their personal history and their past experience with treatments. While most cite biomedically accepted causes such as heredity and diet, they elaborate these concepts into personally relevant constructs by citing Provoking Factors, such as behaviors or events. Their causal models are thus both specific to their personal history and consistent with their experiences with treatment success or failure. Based on these findings, we raise a critique of the Locus of Control Model of treatment behavior prevalent in the diabetes education literature. Our analysis suggests that a sense that one's own behavior is important to the disease onset may reflect patients' evaluation of their experience with treatment outcomes, rather than determining their level of activity in treatment.

NIDDM patients' fears and hopes about insulin therapy. The basis of patient reluctance.

OBJECTIVE: This study examines NIDDM patients' attitudes toward insulin injections, the basis of these attitudes, and how they may affect patients' willingness to take insulin. RESEARCH DESIGN AND METHODS: Forty-four low-income Mexican American NIDDM patients were interviewed using open-ended in-depth interviewing techniques. Transcripts were analyzed using techniques of content analysis. Data classification was cross-checked in analysis conferences and through a second researcher coding 50% of the cases, comparing the results, then resolving any discrepancies. RESULTS: Patients' positive attitudes toward insulin focus on its efficacy and efficiency, the avoidance of complications, and feeling better and more energetic. Negative attitudes were much more frequently discussed and include "technical concerns": anxiety about the pain, proper techniques, and general hassles of taking injections; about hypoglycemic symptoms; and about insulin causing serious health problems; and "experimental concerns": sensing that the disease has progressed into a serious phase, that past treatment efforts have failed, and that the patient has not taken proper care. Attitudes were based on personal experience, observation, what others say, and interactions with health care professionals. CONCLUSIONS: Results from the few published reports on NIDDM patients' attitudes about insulin from various cultural settings were consistent with our findings, indicating that these themes may be generally applicable to a wider population. It is recommended that health care providers take care to avoid unwitting promotion of negative attitudes toward insulin and actively elicit and respond to patient attitudes to reduce reluctance to take the medication.

Predictors of the rate of renal function decline in non-insulin-dependent diabetes mellitus.

A multivariate analysis of 263 Mexican-American, African-American, and Non-Hispanic white non-insulin-dependent diabetes mellitus patients with end-stage renal disease revealed that in subjects following a linear course of decline of renal function, Mexican-American ethnicity (p = 0.0503) and female sex (p = 0.0036) hasten the rate of decline of renal function, while age (p = 0.0004), hypertension duration (p = 0.0058), and diabetes duration (p = 0.0587) slow the rate of decline of renal function. Blood pressure and glycemic control do not predict the rate of decline. These data suggest that ethnicity and sex-related factors may be as important as blood pressure and glycemic control during the course of non-insulin-dependent diabetic nephropathy.

Costs of diabetes in Texas, 1992.

OBJECTIVE: To estimate direct and indirect costs of diabetes in Texas in 1992. RESEARCH DESIGN AND METHODS: For most direct medical costs, we relied on third party and provider billing databases, including Medicare, Medicaid, VA facilities, public hospitals, and others. The researchers identified people with diabetes in the respective databases, located all records of their care, and sorted records as clearly, probably, or probably not attributable to diabetes on the basis of principal diagnoses. In most cases, costs were valued as allowable or paid charges. Some medical costs, such as private insurance, were estimated from national data and state surveys. Indirect costs included current short- and long-term disability costs and the discounted present value of future costs of mortality. Disability estimates relied on National Health Interview Survey (NHIS) data and U.S. Department of Labor wage data applied to Texas. Mortality estimates were based on death certificates. RESULTS: Total costs clearly or probably attributable to diabetes among Texans in 1992 were estimated at $4.0 billion. Direct medical costs were approximately $1.6 billion. Indirect costs were estimated at $2.4 billion. the largest direct costs were paid by Medicare. Most indirect costs were from long-term disability. CONCLUSIONS: This study demonstrates methods for conducting cost of illness studies at the state level. In a state like Texas, with a large and growing Mexican-American population, estimation of current and future economic costs of diabetes is vital for development of strategies to minimize social and economic consequences of diabetes.

Relationship of dose of hemodialysis and cause-specific mortality.

A number of studies have found a relationship of lower all-cause mortality risk for ESRD patients treated with increasing dose of dialysis. The objective of this study was to determine the relationship of delivered dose of dialysis with cause-specific mortality. Data from the USRDS Case Mix Adequacy Study, which includes a national random sample of hemodialysis patients, were utilized. To minimize the contribution of unmeasured residual renal function, the sample used in this analysis (N = 2479) included only patients on dialysis for one year or more. Cox proportional hazards models, stratified for diabetes, were used to analyze the effect of delivered dose of dialysis (measured and reported by both Kt/V and URR) on major causes of death and withdrawal from dialysis, adjusting for other covariates including demographics, comorbid diseases present at start of study, functional status, laboratory values and other dialysis parameters. Patient follow-up for mortality was censored at the earliest of time of transplantation, 60 days after a switch to peritoneal dialysis or at the time of data abstraction. For each 0.1 higher Kt/V, the adjusted relative risk of death due to coronary artery disease was 9% lower (RR = 0.91, P < 0.05), due to other cardiac causes was 12% lower (RR = 0.88, P < 0.01), due to cerebrovascular disease (CVD) was 14% lower (RR = 0.86, P < 0.05), due to infection was 9% lower (RR = 0.91, P = 0.05), and due to other known causes was 6% lower (RR = 0.94, P < 0.05). There was no statistically significant relationship of Kt/V and risk of death among patients who died of malignancy (RR = 0.84, P = 0.10) or among patients whose death cause was missing (RR = 0.95, P = 0.41). The risk of withdrawal from dialysis prior to death due to any cause was 9% lower (RR = 0.91, P < 0.05) for each 0.1 higher Kt/V. The relationships of delivered dose of dialysis, as measured by URR, and cause-specific mortality were essentially similar in relative magnitude and statistical significance as the relationships observed using Kt/V as the measurement of dialysis dose, with the exception that the relationship was less significant for cerebrovascular disease and withdrawal from dialysis. The relationship of dialysis dose with risk of death due to each cause of death category except other cardiac causes and "other" causes appeared to be of greater magnitude and of greater statistical significance among diabetics than non-diabetics. These results indicate that low dose of dialysis is not associated with mortality due to just one isolated cause of death, but rather is due to a number of the major causes of death in this population. This study is consistent with hypotheses that low doses of dialysis may promote atherogenesis, infection, malnutrition and failure to thrive through a variety of pathophysiologic mechanisms. Further study is necessary to confirm these results and to test hypotheses that are developed.

Minority advantage in diabetic end-stage renal disease survival on hemodialysis: due to different proportions of diabetic type?

The objectives of this study were to identify predictors of survival on hemodialysis in patients with diabetic end-stage renal disease (ESRD) and to explain ethnic differences in survival among non-Hispanic whites, African-Americans, and Mexican-Americans. The study design was a survival analysis of an inception cohort and was conducted in dialysis centers in two urban counties in Texas. A population-based, tri-ethnic cohort of 638 adult patients with diabetic ESRD were studied. Follow-up was completed in 96% of the cohort, with a median length of follow-up of 3.8 years. Survival length on center hemodialysis was the main outcome measure. In a combined model of types I and II diabetes, Mexican-Americans (relative hazard [RH], 0.666; 95% confidence interval [CI], 0.457 to 0.944) and African-Americans (RH, 0.598; 95% CI, 0.414 to 0.864) showed a better survival than non-Hispanic whites. Other predictors independently associated with survival were age (RH, 1.015 per 10 years of age; 95% CI, 1.001 to 1.028), high self-reported physical disability (RH, 1.770; 95% CI, 1.213 to 2.583), coronary artery disease (RH, 1.445; 95% CI, 1.044 to 2.012), lower extremity amputations (RH, 2.049; 95% CI, 1.438 to 2.920), and average blood glucose levels prior to ESRD (RH, 1.002 per 1 mg/dL increment; 95% CI, 1.003 to 1.004). Non-Hispanic whites had a significantly higher rate of type I diabetes, but did not have a greater burden of any of the other predictors. In separate type I and II models, ethnicity was still a significant predictor of survival among type I but not among type II. In conclusion, we have reconfirmed the survival advantage on dialysis of African-Americans and Mexican-Americans over non-Hispanic whites with diabetic ESRD. However, among type II patients, this minority survival advantage disappears. Self-reported physical disability is an important predictor of survival among both diabetes types. Functional status at baseline is an important predictor of survival and should be assessed as an adjunct to measurement of co-morbidities. Macrovascular disease is important for type II, while educational status is important for type I. While amputation may be a marker for the severity of systemic illness, it could be a marker for quality of primary care provided to diabetic patients, since a majority of diabetic lower extremity amputations are thought to be preventable.

Non-insulin-dependent diabetes mellitus in minorities in the United States.

PURPOSE: To review the available information on prevalence, complications, and mortality of non-insulin-dependent diabetes mellitus and primary and secondary prevention activities in black persons, Hispanic persons, Native Americans, and Asians and Pacific Islanders in the United States. DATA SOURCE: MEDLINE search from 1976 to 1994 through the PlusNet search system. STUDY SELECTION: Use of the key words non-insulin-dependent diabetes mellitus, the names of each specific minority group, socioeconomic status, acculturation, genetics, diet, complications, mortality, treatment, and intervention (lifestyle or medication) produced 290 unduplicated articles. Additional articles cited in the original articles were also included. DATA EXTRACTION: Risk factors, incidence, prevalence, complications, and mortality of non-insulin-dependent diabetes mellitus. DATA SYNTHESIS: All minorities, except natives of Alaska, have a prevalence of non-insulin-dependent diabetes mellitus that is two to six times greater than that of white persons. Most studies show an increased prevalence of nephropathy that can be as much as six times higher than that of white persons. Retinopathy has variably higher rates in black persons, Hispanic persons, and Native Americans. Amputations are done more frequently among black persons than among white persons (9.0 per 1000 compared with 6.3 per 1000), and Pima Indians have 3.7 times more amputations than do white persons. Diabetes-related mortality is higher for minorities than for white persons, and the rate is increasing. The relative importance of genetic heritage, diet, exercise, socioeconomic status, culture, language, and access to health care in the prevalence, incidence, and mortality of diabetes is not clear. Studies of interventions in minority populations are in progress. CONCLUSION: Diabetes should be treated as a public health problem for minority populations.

Diabetic nephropathy and end-stage renal disease in Mexican Americans.

Hispanics are the second largest minority group in the United States. Mexican Americans (MAs) are the largest subgroup at 14 million in 1990. MAs have a two- to threefold increased prevalence of non-insulin-dependent diabetes mellitus. Population-based studies of MAs with non-insulin-dependent diabetes have shown that these patients may be more likely than non-Hispanic whites to develop proteinuria and are more likely to develop end-stage renal disease. The reasons for this excess risk are yet to be completely elucidated, but may be due to worse glycemic control, worse blood pressure control when hypertension does occur, worse access to medical care, and/or genetics. When MAs are treated for diabetic end-stage renal disease, they have better survival. Much less data are available for other Hispanic subgroups. From a public health perspective, higher incidence and longer survival as well as relatively young and rapidly growing population predict an increasing burden for MAs if prevention measures are not instituted soon.