Risk factors for acute kidney injury associated with the treatment of bacterial endocarditis at a tertiary academic medical center

BACKGROUND

Acute kidney injury (AKI) is a common complication of endocarditis.

OBJECTIVE

To determine risk factors for the development of AKI in patients treated for endocarditis.

METHODS

This single centre, retrospective univariate and multivariate analysis to determine risk factors for the development of AKI included patients diagnosed with endocarditis between January 2009 and October 2013.

RESULTS

Of 211 included patients, a total of 84 (39.8%) patients developed AKI. We identified multiple independent variables associated with the development of AKI, including: age ≥ 65 years, presence of hardware, chronic kidney disease, AKI on admission, infection with Staphylococcus spp, receipt of nafcillin or oxacillin or aminoglycoside and nafcillin or oxacillin or aminoglycoside and vancomycin, vancomycin trough level ≥ 20.0 mcg/ml, aminoglycoside total daily dose reduction, duration of vancomycin exceeding three days, receipt of loop diuretic or more than three concomitant nephrotoxins and duration of loop diuretic or non-steroidal anti-inflammatory drug therapy exceeding seven days.

CONCLUSIONS

In patients treated for endocarditis, multiple risk factors for AKI were identified. Prospective studies are needed to evaluate these variables for causation of AKI in patients treated for endocarditis.

Incidence and outcomes of bloodstream infections among hematopoietic cell transplant recipients from species commonly reported to be in over-the-counter probiotic formulations

BACKGROUND

Probiotic supplementation has been promoted for numerous health conditions; however, safety in immunosuppressed patients is unknown. We evaluated bloodstream infections (BSIs) caused by common probiotic organisms in hematopoietic cell transplant recipients.

METHODS

All blood culture (BC) results from a cohort of hematopoietic cell transplant recipients transplanted at Fred Hutchinson Cancer Research Center in Seattle, Washington, between 2002 and 2011 were reviewed. Patients with at least 1 positive BC for common probiotic organisms (Lactobacillus species, Bifidobacterium species, Streptococcus thermophilus, and Saccharomyces species) within 1 year post hematopoietic cell transplantation (HCT) were considered cases. Data were collected from center databases, which contain archived laboratory data, patient demographics, and clinical summaries.

RESULTS

A total of 19/3796 (0.5%) patients developed a BSI from one of these organisms within 1 year post HCT; no Bifidobacterium species or S. thermophilus were identified. Cases had a median age of 49 years (interquartile range [IQR]: 39-53), and the majority were allogeneic hematopoietic cell transplant recipients (14/19, 74%). Most positive BCs were Lactobacillus species (18/19) and occurred at a median of 84 days (IQR: 34-127) post transplant. The incidence rate of Lactobacillus bacteremia was 1.62 cases per 100,000 patient-days; the highest rate occurred within 100 days post transplant (3.3 per 100,000 patient-days). Eight patients (44%) were diagnosed with acute graft-versus-host disease of the gut prior to the development of bacteremia. No mortality was attributable to any of these infections.

CONCLUSION

Organisms frequently incorporated in available over-the-counter probiotics are infrequent causes of bacteremia after HCT. Studies evaluating the use of probiotics among high-risk patients are needed.

A Closer Look at Rural-Urban Health Disparities: Associations Between Obesity and Rurality Vary by Geospatial and Sociodemographic Factors

BACKGROUND

Obesity affects over one-third of older adults in the United States. Both aging and obesity contribute to an increased risk for chronic disease, early mortality, and additional health care utilization. Obesity rates are higher in rural areas than in urban areas, although findings are mixed. The objectives of this study are to assess potential nonlinearity in the association between rurality and obesity, and to evaluate the potential for socioeconomic status and geographic area to moderate the associations between rurality and obesity.

METHODS

Using a representative sample of adults aged 65 and above from the Behavioral Risk Factor Surveillance System, obesity (BMI ≥ 30 kg/m² ) was modeled against the primary exposure of rural-urban status, as measured by the Index of Relative Rurality. Binary logistic regression models were used to estimate the odds of obesity by rurality both as a continuous variable and by decile of rurality. Models were then stratified by per-capita income and state to assess potential moderation by these factors.

RESULTS

The prevalence of obesity in older adults was highest in intermediate rurality areas (OR in rurality decile #5 1.134, 95% CI: 1.086-1.184) and lowest in the most rural and most urban areas. Obesity was highest in low- and middle-income areas, regardless of rural-urban status. In high-income areas, obesity among older adults was highest in areas of intermediate rurality and lowest in the most rural areas (OR 0.726, 95% CI: 0.606-0.870) and more urban areas, showing a J-shaped association. There were substantial differences in the associations between rurality and obesity in older adults among states.

CONCLUSION

Associations between rurality and obesity varied by degree of rurality, socioeconomic status, and geography. Therefore, traditional "one-size-fits-all" approaches to reducing rural-urban health disparities in older adults may be more effective if tailored to the area-specific rural-urban gradients in health.

Challenges and barriers to health care and overall health in older residents of Alaska: evidence from a national survey

Background

From 1970 to 2010, the Alaskan population increased from 302,583 to 698,473. During that time, the growth rate of Alaskan seniors (65+) was 4 times higher than their national counterparts. Ageing in Alaska requires confronting unique environmental, sociodemographic and infrastructural challenges, including an extreme climate, geographical isolation and less developed health care infrastructure compared to the continental US.

Objective

The objective of this analysis is to compare the health needs of Alaskan seniors to those in the continental US.

Design

We abstracted 315,161 records of individuals age 65+ from the 2013 and 2014 Behavioral Risk Factor Surveillance System, of which 1,852 were residents of Alaska. To compare residents of Alaska to residents of the 48 contiguous states we used generalized linear models which allowed us to adjust for demographic differences and survey weighting procedures. We examined 3 primary outcomes – general health status, health care coverage status and length of time since last routine check-up.

Results

Alaskan seniors were 59% less likely to have had a routine check-up in the past year and 12% less likely to report excellent health status than comparable seniors in the contiguous US.

Conclusions

Given the growth rate of Alaskan seniors and inherent health care challenges this vulnerable population faces, future research should examine the specific pathways through which these disparities occur and inform policies to ensure that all US seniors, regardless of geographical location, have access to high-quality health services.

Spatiotemporal Discordance in Five Common Measures of Rurality for US Counties and Applications for Health Disparities Research in Older Adults

Introduction

Rural populations face numerous barriers to health, including poorer health care infrastructure, access to care, and other sociodemographic factors largely associated with rurality. Multiple measures of rurality used in the biomedical and public health literature can help assess rural–urban health disparities and may impact the observed associations between rurality and health. Furthermore, understanding what makes a place truly “rural” versus “urban” may vary from region to region in the US.

Purpose

The objectives of this study are to compare and contrast five common measures of rurality and determine how well-correlated these measures are at the national, regional, and divisional level, as well as to assess patterns in the correlations between the prevalence of obesity in the population aged 60+ and each of the five measures of rurality at the regional and divisional level.

Methods

Five measures of rurality were abstracted from the US Census and US Department of Agriculture (USDA) to characterize US counties. Obesity data in the population aged 60+ were abstracted from the Behavioral Risk Factor Surveillance System (BRFSS). Spearman’s rank correlations were used to quantify the associations among the five rurality measurements at the national, regional, and divisional level, as defined by the US Census Bureau. Geographic information systems were used to visually illustrate temporal, spatial, and regional variability.

Results

Overall, Spearman’s rank correlations among the five measures ranged from 0.521 (percent urban–urban influence code) to 0.917 (rural–urban continuum code–urban influence code). Notable discrepancies existed in these associations by Census region and by division. The associations between measures of rurality and obesity in the 60+ population varied by rurality measure used and by region.

Conclusion

This study is among the first to systematically assess the spatial, temporal, and regional differences and similarities among five commonly used measures of rurality in the US. There are important, quantifiable distinctions in defining what it means to be a rural county depending on both the geographic region and the measurement used. These findings highlight the importance of developing and selecting an appropriate rurality metric in health research.

Psychosocial factors of caregiver burden in child caregivers: results from the new national study of caregiving

BACKGROUND

Over 50 million informal caregivers in the United States provide care to an aging adult, saving the economy hundreds of billions of dollars annually from costly hospitalization or institutionalization. Despite the benefits associated with caregiving, caregiver stress can lead to negative physical and mental health consequences, or "caregiver burden". Given these potential negative consequences of caregiver burden, it is important not only to understand the multidimensional components of burden but to also understand the experience from the perspective of the caregiver themselves. Therefore, the objectives of our study are to use exploratory factor analysis to obtain a set of latent factors among a subset of caregiver burden questions identified in previous studies and assess their reliability.

METHODS

All data was obtained from the 2011 National Study of Caregiving (NSOC). Exploratory factor analysis (EFA) was performed to identify a set of latent factors assessing four domains of caregiver burden in "child caregivers": those informal caregivers who provide care to a parent or stepparent. Sensitivity analysis was also conducted by repeating the EFA on demographic subsets of caregivers.

RESULTS

After multiple factor analyses, four consistent caregiver burden factors emerged from the 23 questions analyzed: Negative emotional, positive emotional, social, and financial. Reliability of each factor varied, and was strongest for the positive emotional domain for caregiver burden. These domains were generally consistent across demographic subsets of informal caregivers.

CONCLUSION

These results provide researchers a more comprehensive understanding of caregiver burden to target interventions to protect caregiver health and maintain this vital component of the US health care system.

Sex and sexual orientation disparities in adverse childhood experiences and early age at sexual debut in the United States: results from a nationally representative sample

Adverse childhood experiences (ACEs) have been linked to early sexual debut, which has been found to be associated with multiple adverse health outcomes. Sexual minorities and men tend to have earlier sexual debut compared to heterosexual populations and women, respectively. However, studies examining the association between ACEs and early sexual debut among men and sexual minorities are lacking. The aim of this study was to examine the sex and sexual orientation disparities in the association between ACEs and age at sexual debut. Data were obtained from Wave 2 of the National Epidemiologic Survey on Alcohol and Related Conditions. Logistic and linear regression models were used to obtain crude and adjusted estimates and 95% confidence intervals adjusting for age, race/ethnicity, income, education, insurance and marital status for the association between ACEs (neglect, physical/psychological abuse, sexual abuse, parental violence, and parental incarceration and psychopathology) and early sexual debut. Analyses were stratified by sex and sexual orientation. Larger effect estimates depicting the association between ACEs and sexual debut were seen for women compared to men, and among sexual minorities, particularly among men who have sex with men (MSM) and women who have sex with women (WSW), compared to heterosexuals. Sexual health education programs with a focus on delaying sexual debut among children and adolescents should also consider addressing ACEs, such as neglect, physical, psychological and sexual abuse, witnessing parental violence, and parental incarceration and psychopathology. Public health practitioners, researchers and sexual health education curriculum coordinators should consider these differences by sex and sexual orientation when designing these programs.

Meeting sex partners through the Internet, risky sexual behavior, and HIV testing among sexually transmitted infections clinic patients

The Internet has now become a popular venue to meet sex partners. People who use the Internet to meet sex partners may be at a higher risk for contracting HIV and STIs. This study examined the association between meeting sex partners from the Internet, and HIV testing, STI history, and risky sexual behavior. Data were obtained from the Virginia Department of Health STD Surveillance Network. Logistic regression models were used to obtain crude and adjusted odds ratios, and 95 % confidence intervals for the associations between meeting sex partners through the Internet and ever tested for HIV, HIV testing in the past 12 months, STI history, and risky sexual behavior. Logistic regression was also used to determine if gender and men who have sex with men interaction terms significantly improved the model. Women who met a sex partner from the Internet were more likely to have had an HIV test in the past 12 months than women who did not meet a partner in this way. On the other hand, men who met a sex partner through the Internet were more likely to have ever had an HIV test than other men, but this was only seen for heterosexual men. All populations who met a sex partner from the Internet were more likely to take part in risky sexual behavior. HIV prevention strategies should emphasize annual testing for all populations.

Duration of U.S. residence and suicidality among racial/ethnic minority immigrants

PURPOSE

The immigration experience embodies a range of factors including different cultural norms and expectations, which may be particularly important for groups who become racial/ethnic minorities when they migrate to the U.S. However, little is known about the correlates of mental health indicators among these groups. The primary and secondary aims were to determine the association between duration of U.S. residence and suicidality, and 12-month mood, anxiety, and substance use disorders, respectively, among racial/ethnic minority immigrants.

METHODS

Data were obtained from the National Survey of American Life and the National Latino and Asian American Survey. Multivariable logistic regression was used to determine the association between duration of US residence, and suicidality and 12-month psychopathology.

RESULTS

Among Afro-Caribbeans, there was a modest positive association between duration of U.S. residence and 12-month psychopathology (P linear trend = 0.016). Among Asians there was a modest positive association between duration of US residence and suicidal ideation and attempts (P linear trend = 0.018, 0.063, respectively). Among Latinos, there was a positive association between duration of US residence, and suicidal ideation, attempts and 12-month psychopathology (P linear trend = 0.001, 0.012, 0.002, respectively). Latinos who had been in the U.S. for >20 years had 2.6 times greater likelihood of suicidal ideation relative to those who had been in the U.S. for <5 years (95% CI 1.01-6.78).

CONCLUSIONS

The association between duration of US residence and suicidality and psychopathology varies across racial/ethnic minority groups. The results for Latino immigrants are broadly consistent with the goal-striving or acculturation stress hypothesis.

Examining trends in the treatment of ureterocele yields no definitive solution

INTRODUCTION

The surgical management of ureteroceles is extremely variable. Some have hypothesized that if these patients were treated with 'definitive' staged surgical intervention, the need for further revision surgery would be eliminated.

OBJECTIVE

The present study sought to determine if the rate of revision surgery differed among patients who have undergone different surgical approaches for the ureterocele complex.

STUDY DESIGN

A large retrospective chart review was conducted, identifying all patients having undergone ureterocele surgery at a single institution over the past 41 years. The cohort was divided into four groups based on surgical approach: upper tract approach (UTA), lower tract reconstruction (LTR), simultaneous upper and lower tract approach (ULTA), and staged lower tract reconstruction (SLTR). Demographics, the presence of preoperative/postoperative VUR, postoperative morbidity and the need for revision surgery were compared using the Chi- squared test, Fisher's exact test, Kruskal-Wallis test, Mann-Whitney U test (Bonferroni correction), logistic regression modeling and survival analyses (Kaplan-Meier and Cox proportional Hazards regression with unplanned revision operation as the outcome event).

RESULTS

Between 1969 and 2010, 180 patients were identified as having undergone surgical management of ureteroceles, of which 120 had complete demographic data available for analysis. The median age at the time of initial surgical intervention was 5.8 months and the majority of patients (83.3%) were female. The median follow-up was 33.1 months. Surgical management was as follows: 18 (15.0%) patients underwent UTA, 47 (39.2%) underwent LTR, 23 (19.2%) underwent ULTA, and 32 (26.6%) underwent SLTR. Among these groups, the only difference in median age was between the LTR and SLTR groups (6.3 months vs 3.7 months, P=0.012). Additional revision surgery was required in: nine (50.0%) of UTA, ten (21.3%) of LTR, four (17.4%) of ULTA, and three (9.4%) of SLTR. The only statistically significant difference in unplanned revision surgery was noted in the UTA group versus each of the other groups with VUR as the predominant indication (88.9%). The likelihood of requiring revision surgery in comparison to the SLTR group was significantly increased in the UTA group (OR 9.67, CI 2.15-43.56), but not in the LTR (OR 2.61, CI 0.66-10.37) or the ULTA group (OR 2.04, CI 0.41-10.13). Obstruction, recurring UTIs and VUR were the main indications for revision surgery overall.

DISCUSSION

There is a large body of literature examining the surgical management of ureteroceles. It most recently primarily focuses on an endoscopic approach to the lower tract. The present retrospective review examined the need for re-operative intervention by comparing four different surgical approaches, and found that there is no panacea. Although heminephrectomy (UTA) was a definitive procedure in some patients without reflux at presentation, many who underwent heminephrectomy, went on to require later bladder surgery for either recurrent UTI or persistent reflux. The present study has multiple limitations. Although VUR was an indication for revision surgery in the early part of the series, the current treatment of VUR is not necessarily as stringent. In addition, no distinction was made between an orthotopic or ectopic ureterocele, although some authors have reported differing outcomes in these two groups. However, it is felt that given the large data set of a relatively uncommon condition, the lack of superiority of one approach is apparent.

CONCLUSION

There is no definitive surgical repair for the ureterocele complex. All groups except UTA had statistically similar rates of revision surgery. The widespread variability in current management echoes the lack of one superior approach found in this comprehensive series.

Nonrandom return: lessons from women returning for follow-up results of cervical cancer screening in rural haiti

PURPOSE

Few studies have evaluated approaches to improve patient follow-up in screening programs within resource-limited areas. This study investigated the patterns of return among women presenting for results from a cervical cancer screening program implemented in a resource-poor region to highlight areas for future research and potential interventions.

METHODS

In the development of a cervical cancer screening program in rural Haiti, women aged 18-45 years were recruited from local churches to undergo cervical cancer screening and follow-up for results. A dot plot was used to analyze the distribution of women returning during the results phase compared to the random return rates based on the screening phase.

RESULTS

Of the 250 women tested, 121 (48%) returned for follow-up. On the 2 result days with the most returnees, 46 and 63% of the women had been tested during only 3 of the 11 testing days which themselves accounted for 41% of the total number of women who returned. The highest volume return days, a Monday and a Friday, gave results to women tested on Monday, Wednesday and Friday, and on Monday, Tuesday and Thursday, respectively. The 2 result days with the lowest return numbers had 80% (8/10) of those who returned coming as the only returnee from their day of testing.

CONCLUSION

Result days corresponding with the highest return rates had increased clustering of women from the screening phase, and the result days with fewer women returning had less clustering. These findings are among the first to implicate the importance of defining these patterns of return and the potential for recruitment techniques that exploit such groupings, potentially described by social connections, in limited-resource settings to improve follow-up for screening programs.

Socioeconomic and demographic factors modify the association between informal caregiving and health in the Sandwich Generation

Background

Nearly 50 million Americans provide informal care to an older relative or friend. Many are members of the “sandwich generation”, providing care for elderly parents and children simultaneously. Although evidence suggests that the negative health consequences of caregiving are more severe for sandwiched caregivers, little is known about how these associations vary by sociodemographic factors.

Methods

We abstracted data from the Behavioral Risk Factor Surveillance System to determine how the association between caregiving and health varies by sociodemographic factors, using ordinal logistic regression with interaction terms and stratification by number of children, income, and race/ethnicity.

Results

The association between informal caregiving and health varied by membership in the “sandwich generation,” income, and race/ethnicity. This association was significant among subjects with one (OR = 1.13, 95% CI [1.04, 1.24]) and two or more children (OR = 1.17, 95% CI = 1.09, 1.26]), but not in those without children (OR = 1.01, 95% CI [0.97, 1.05]). Associations were strongest in those earning $50,000-$75,000 annually, but these income-dependent associations varied by race/ethnicity. In Whites with two or more children, the strongest associations between caregiving and health occurred in lower income individuals. These trends were not observed for Whites without children.

Conclusions

Our findings suggest that the added burden of caregiving for both children and elderly relatives may be impacted by income and race/ethnicity. These differences should be considered when developing culturally appropriate interventions to improve caregiver health and maintain this vital component of the US health care system.

Dietary intake and severe early childhood caries in low-income, young children

Evidence suggests that risk for early childhood caries (ECCs), the most common chronic infectious disease in childhood, is increased by specific eating behaviors. To identify whether consumption of added sugars, sugar-sweetened beverages (SSBs), and 100% fruit juice, as well as eating frequency, are associated with severe ECCs, cross-sectional data collected from a sample of low-income, racially diverse children aged 2 to 6 years were used. Four hundred fifty-four children with severe ECCs and 429 caries-free children were recruited in 2004-2008 from three pediatric dental clinics in Columbus, OH; Cincinnati, OH; and Washington, DC. Dietary data were obtained from one parent-completed 24-hour recall and an interviewer-administered food frequency questionnaire (FFQ). Multivariate logistic regression analyses were conducted to assess associations between severe ECCs and dietary variables. On average, children with severe ECCs consumed 3.2-4.8 fl oz more SSBs (24-hour recall=1.80 vs 1.17; P< 0.001; FFQ=0.82 vs 0.39; P<0.001) and reported significantly more daily eating occasions (5.26 vs 4.72; P<0.0001) than caries-free children. After controlling for age, sex, race/ethnicity, maternal education, recruitment site, and family size, children with the highest SSB intake were 2.0 to 4.6 times more likely to have severe ECCs compared with those with the lowest intake, depending on dietary assessment method (24-hour recall odds ratio 2.02, 95% CI 1.33 to 3.06; FFQ odds ratio 4.63, 95% CI 2.86 to 7.49). The relationship between eating frequency and severe ECC status was no longer significant in multivariate analyses. Specific dietary guidance for parents of young children, particularly regarding SSB consumption, could help reduce severe ECC prevalence.

Evaluation of recombinant activated protein C for severe sepsis at a tertiary academic medical center

Purpose

Early clinical trials of recombinant human activated protein C (rhAPC) for severe sepsis excluded patients at high risk of bleeding. Recent literature suggests bleeding rates are higher in clinical practice and may be associated with worsened outcomes. Our objective was to evaluate baseline demographics; incidence, and risk factors for major bleeding; and mortality of patients receiving rhAPC for severe sepsis at our institution.

Methods

A retrospective study was performed for all patients receiving rhAPC for treatment of severe sepsis at a tertiary academic medical center from January 2002 to June 2009. Demographic information, clinical variables, intensive care unit, and hospital outcomes were recorded.

Results

Of the 156 patients that received rhAPC, 54 (34.6%) did not meet institutional criteria for safe use at baseline due to bleeding precaution or contraindication. Twenty-three (14.7%) patients experienced a major bleeding event. Multivariate analysis demonstrated baseline International Normalized Ratio ≥2.5 (odds ratio [OR] 3.68, 95% confidence interval [CI]: 1.28–10.56; P = 0.03) and platelet count ≤100 × 10³/mm³ (OR 2.86, 95% CI: 1.07–7.67; P = 0.01) as significant predictors of a major bleed. Overall hospital mortality was 57.7%. Multivariate analysis demonstrated the presence of ≥3 organ dysfunctions (OR 2.46, 95% CI: 1.19–5.09; P < 0.05) and medical intensive care unit admission (OR 1.99, 95% CI: 1.00–3.98; P = 0.05) were independent variables associated with hospital mortality.

Conclusion

Patients receiving rhAPC at our institution had higher APACHE II scores, mortality, and major bleeding events than published postmarketing studies. Risk factors for major bleeding other than package-labeling contraindications and bleeding precautions were identified in our patient population.

Development of a pediatric cariogenicity index

OBJECTIVES

This study was designed to develop food and liquid cariogenicity indices and to preliminarily test their utility using dietary data from a study of children with and without severe early childhood caries (S-ECC), defined as 3 + smooth surface carious lesions, including at least one pulpally involved tooth.

METHODS

Data were collected in a diverse cohort of low-income preschool-aged children made up of 454 children with S-ECC and 429 caries-free children who presented for care at pediatric dental clinics in Washington, DC, Columbus, OH, and Cincinnati, OH. The cariogenicity indices were used to score dietary data from a Food Frequency Questionnaire (FFQ) and a 24-hour recall (24HR).

RESULTS

There were no statistically significant differences in mean food cariogenicity scores between groups. The liquid cariogenicity score was higher in the S-ECC group as compared with caries-free children (24HR: 5.28 versus 4.66, respectively, P < 0.001; FFQ: 5.03 versus 4.38, P < 0.001). The food cariogenicity score did not discriminate between those with and without S-ECC, while the liquid cariogenicity score did differentiate between the two groups (24HR: OR: 1.2; 95 percent CI: 1.1, 1.3; FFQ: 1.7; 95 percent CI 1.4, 2.0). The liquid cariogenicity score was also associated with number of carious lesions.

CONCLUSIONS

The liquid cariogenicity index has potential in research and clinical settings to provide a liquid cariogenicity score and help quickly identify modifiable risk factors within a child's diet. Further research is needed to test its utility in clinical and public health settings.

Snowbirds and infection--new phenomena in pneumonia and influenza hospitalizations from winter migration of older adults: a spatiotemporal analysis

BACKGROUND

Despite advances in surveillance and prevention, pneumonia and influenza (P&I) remain among the leading causes of mortality in the United States. Elderly adults experience the most severe morbidity from influenza-associated diseases, and have the highest rates of seasonal migration within the U.S. compared to other subpopulations. The objective of this study is to assess spatiotemporal patterns in influenza-associated hospitalizations in the elderly, by time, geography, and intensity of P&I. Given the high seasonal migration of individuals to Florida, this state was examined more closely using harmonic regression to assess spatial and temporal patterns of P&I hospitalizations by state of residence.

METHODS

Data containing all Medicare-eligible hospitalizations in the United States for 1991-2006 with P&I (ICD-9-CM codes 480-487) were abstracted for the 65+ population. Hospitalizations were classified by state of residence, provider state, and date of admissions, specifically comparing those admitted between October and March to those admitted between April and September. We then compared the hospitalization profile data of Florida residents with that of out-of-state residents by state of primary residence and time of year (in-season or out-of-season).

RESULTS

We observed distinct seasonal patterns of nonresident P&I hospitalizations, especially comparing typical winter destination states, such as California, Arizona, Texas, and Florida, to other states. Although most other states generally experienced a higher proportion of non-resident P&I during the summer months (April-September), these states had higher nonresident P&I during the traditional peak influenza season (October-March).

CONCLUSIONS

This study is among the first to quantify spatiotemporal P&I hospitalization patterns in the elderly, focusing on the change of patterns that are possibly due to seasonal population migration. Understanding migration and influenza-associated disease patterns in this vulnerable population is critical to prepare for and potentially prevent influenza outbreaks in this vulnerable population.

Pursuing cost-effectiveness in mental health service delivery for youth with complex needs

BACKGROUND

Mental health advocates seek to expand children's services, noting widespread failure to meet the needs of public sector youth suffering from serious emotional disturbance (SED). However, state and national budgets face deepening cuts, with rising health care costs taking the blame. As the gap between needs and finances widens, identification of cost-effective treatments that will benefit children with SED and their families is of increasing importance. Community-based interventions for this population, such as the wraparound approach and systems-of-care, are being disseminated but literature is scant regarding effects on expense. The Mental Health Services Program for Youth (MHSPY) model is aligned philosophically with wraparound and systems-of-care but unique in blending public agency dollars to deliver integrated medical, mental health and social services. MHSPY's linked clinical and expense data is useful to study community-based treatment cost-effectiveness.

AIMS OF STUDY

To examine the cost-effectiveness of an intensively integrated, family and community-based clinical intervention for youth with mental health needs in comparison to "usual care.''

METHODS

Study and reference populations were matched on age, gender, community, psychiatric diagnosis, morbidity and insurance type. Claims analyses included patterns of service utilization and medical expense for both groups. Using propensity score matching, results for study youth are compared with results for the population receiving "usual care.'' Clinical functioning was measured for the intervention group at baseline and 12 months.

RESULTS

The intervention group used lower intensity services and had substantially lower claims expense (e.g. 32% lower for emergency room, 74% lower for inpatient psychiatry) than their matched counterparts in the "usual care'' group. Intervention youth were consistently maintained in least restrictive settings, with over 88% of days spent at home and showed improved clinical functioning on standard measures.

DISCUSSION

The intensive MHSPY model of service delivery offers potential as a cost-effective intervention for complex youth. Its integrated approach, recognizing needs across multiple life domains, appears to enhance engagement and the effectiveness of mental health treatment, resulting in statistically significant clinical improvements. Functional measures are not collected in "usual care,'' limiting comparisons. However, claims expense for intervention youth was substantially lower than claims expense for Medicaid comparison youth, suggesting clinical needs for intervention youth post-enrollment were lower than for those receiving "usual care.''

IMPLICATIONS FOR HEALTH CARE PROVISION AND USE

The MHSPY model, which intentionally engages families in "clustered'' traditional and non-traditional services, represents a replicable strategy for enhancing the impact of clinical interventions, thereby reducing medical expense.

IMPLICATIONS FOR HEALTH POLICIES

Blending categorical state agency dollars and insurance funds creates flexibility to support community-based care, including individualized services for high-risk youth. Resulting expenses total no more, and are often less, than "treatment as usual'' but yield greater clinical benefits.

IMPLICATIONS FOR FURTHER RESEARCH

Further research is needed regarding which intervention elements contribute the most towards improved clinical functioning, as well as which patients are most likely to benefit. A randomized trial of MHSPY vs. "usual care,'' including examination of the sustainability of effects post-disenrollment, would provide a chance to further test this innovative model.

Visual analytics for epidemiologists: understanding the interactions between age, time, and disease with multi-panel graphs

BACKGROUND

Visual analytics, a technique aiding data analysis and decision making, is a novel tool that allows for a better understanding of the context of complex systems. Public health professionals can greatly benefit from this technique since context is integral in disease monitoring and biosurveillance. We propose a graphical tool that can reveal the distribution of an outcome by time and age simultaneously.

METHODOLOGY/PRINCIPAL FINDINGS

We introduce and demonstrate multi-panel (MP) graphs applied in four different settings: U.S. national influenza-associated and salmonellosis-associated hospitalizations among the older adult population (≥65 years old), 1991-2004; confirmed salmonellosis cases reported to the Massachusetts Department of Public Health for the general population, 2004-2005; and asthma-associated hospital visits for children aged 0-18 at Milwaukee Children's Hospital of Wisconsin, 1997-2006. We illustrate trends and anomalies that otherwise would be obscured by traditional visualization techniques such as case pyramids and time-series plots.

CONCLUSION/SIGNIFICANCE

MP graphs can weave together two vital dynamics--temporality and demographics--that play important roles in the distribution and spread of diseases, making these graphs a powerful tool for public health and disease biosurveillance efforts.

Measuring disease burden in the older population using the slope-intercept method for population log-linear estimation (SIMPLE)

Estimating disease burden in the older population can be problematic, due to a dearth of measurements that take into account population dynamics, small population sizes, and age-related disease distribution issues. Age itself explains a substantial amount of the variability in population disease rates. However, in many common techniques to account for age, such as age standardization and age categorization, age is treated as a nuisance parameter. In this paper, we present a method, the slope-intercept method for population log-linear estimation (SIMPLE), to assess disease burden in the Medicare population of the US. We demonstrate the utility and potential limitations of this straightforward and crude method in assessing age-related morbidity, mortality, and case-fatality on multiple geographic levels. We highlight several examples of when this measure is most applicable using examples abstracted from a comprehensive administrative database of hospitalizations in older adults. Traditional measurements of disease burden are compared with the measurements extracted from this modeling method for comparison purposes. We also present spatial and temporal associations between the two measurements the SIMPLE method produces.

Influenza vaccination in young children reduces influenza-associated hospitalizations in older adults, 2002-2006

OBJECTIVES

To assess how influenza vaccination coverage in children is related to pneumonia and influenza (P&I) in older adults and whether sociodemographic factors modify these associations.

DESIGN

Approximately 5 million hospitalization records from the Centers for Medicare and Medicaid Services for four influenza years (2002-2006) were abstracted. A single-year age distribution of rates of P&I hospitalization was estimated according to state for each influenza season; an exponential acceleration in the P&I rates with age was observed for each influenza season. State- and season-specific P&I rate accelerations were regressed against the percentage of vaccinated children, older adults, or both using mixed effects models.

SETTING

U.S. population, 2002 to 2006.

PARTICIPANTS

U.S. population aged 65 and older.

MEASUREMENTS

State-level influenza annual vaccination coverage data in children and older adults were obtained from the National Immunization Survey and the Behavioral Risk Factor Surveillance System, respectively.

RESULTS

Child influenza vaccination coverage was negatively associated with age acceleration in P&I, whereas influenza vaccination in the older adults themselves was not significantly associated with P&I in older adults.

CONCLUSION

Vaccination of children against influenza may induce herd immunity against influenza for older adults and has the potential to be more beneficial to older adults than the existing policy of preventing influenza by vaccinating older adults themselves.

Formation of field-reversed-configuration plasma with punctuated-betatron-orbit electrons

We describe ab initio, self-consistent, 3D, fully electromagnetic numerical simulations of current drive and field-reversed-configuration plasma formation by odd-parity rotating magnetic fields (RMF{o}). Magnetic-separatrix formation and field reversal are attained from an initial mirror configuration. A population of punctuated-betatron-orbit electrons, generated by the RMF{o}, carries the majority of the field-normal azimuthal electrical current responsible for field reversal. Appreciable current and plasma pressure exist outside the magnetic separatrix whose shape is modulated by the RMF{o} phase. The predicted plasma density and electron energy distribution compare favorably with RMF{o} experiments.