Publications

BACKGROUND

Efforts to curb healthcare spending have included interventions that target frequently hospitalized individuals. It is unclear the extent to which the most frequently hospitalized individuals also represent the costliest individuals.

OBJECTIVE

To examine the relationship between 2 types of "high users" commonly targeted in cost-containment interventions-those incurring the highest hospital costs ("high cost") and those incurring the highest number of hospitalizations ("high admit").

DESIGN, SETTING, AND PATIENTS

Cross-sectional study of 2566 individuals with a primary care physician and at least 1 hospitalization within an academic health system from 2010 to 2011.

MEASUREMENTS

Overlap between the population constituting the top decile of hospital costs and the population constituting the top decile of hospitalizations; characteristics of the 3 resulting high user subgroups.

RESULTS

Only 48% of individuals who were high cost (>$65,000) were also high admit (≥ 3 hospitalizations). Compared to hospitalizations incurred by high cost-high admit individuals (n = 605), hospitalizations incurred by high cost-low admit individuals (n = 206) were more likely to be for surgical procedures (58 vs 22%, P < 0.001), had a higher cost ($68,000 vs $28,000, P < 0.001), longer length of stay (10 vs 5 days, P < 0.001), and were less likely to be a 30-day readmission (17 vs 47%, P < 0.001).

CONCLUSIONS

Stratifying high admit individuals by costs and high cost individuals by hospitalizations yields 3 distinct high user subgroups with important differences in clinical characteristics and utilization patterns. Consideration of these distinct subgroups may lead to better-tailored interventions and achieve greater cost savings.

BACKGROUND

Current knowledge of racial disparities in healthcare utilization and disease outcomes for ulcerative colitis (UC) is limited. We sought to investigate these differences among Caucasian, African American, Asian, and Hispanic patients with ulcerative colitis in Kaiser Permanente, a large integrated health-care system in Northern California.

METHODS

This retrospective cohort study used computerized clinical data from 5,196 Caucasians, 387 African-Americans, 550 Asians, and 801 Hispanics with prevalent UC identified between 1996 and 2007. Healthcare utilization and outcomes were compared at one and five-year follow-up by use of multivariate logistic regression analysis.

RESULTS

Compared with whites, the male-to-female ratio differed for African-Americans (0.68 vs. 0.91, p < 0.01) and Asians (1.3 vs. 0.91, p < 0.01). Asians had fewer co-morbid conditions (p < 0.01) than whites, whereas more African-Americans had hypertension and asthma (p < 0.01). Use of immunomodulators did not differ significantly among race and/or ethnic groups. Among Asians, 5-ASA use was highest (p < 0.05) and the incidence of surgery was lowest (p < 0.01). Prolonged steroid exposure was more common among Hispanics (p < 0.05 at 1-year) who also had more UC-related surgery (p < 0.01 at 5-year) and hospitalization (<0.05 at 5-year), although these differences were not significant in multivariate analysis.

CONCLUSIONS

In this population of UC patients with good access to care, overall health-care utilization patterns and clinical outcomes were similar across races and ethnicity. Asians may have milder disease than other races whereas Hispanics had a trend toward more aggressive disease, although the differences we observed were modest. These differences may be related to biological factors or different treatment preferences.

The SecA2 proteins are a special class of transport-associated ATPases that are related to the SecA component of the general Sec system, and are found in an increasingly large number of Gram-positive bacterial species. The SecA2 substrates are typically linked to the cell wall, but may be lipid-linked, peptidoglycan-linked, or non-covalently associated S-layer proteins. These substrates can have a significant impact on virulence of pathogenic organisms, but may also aid colonization by commensals. The SecA2 orthologues range from being highly similar to their SecA paralogues, to being distinctly different in apparent structure and function. Two broad classes of SecA2 are evident. One transports multiple substrates, and may interact with the general Sec system, or with an as yet unidentified transmembrane channel. The second type transports a single substrate, and is a component of the accessory Sec system, which includes the SecY paralogue SecY2 along with the accessory Sec proteins Asp1-3. Recent studies indicate that the latter three proteins may have a unique role in coordinating post-translational modification of the substrate with transport by SecA2. Comparative functional and phylogenetic analyses suggest that each SecA2 may be uniquely adapted for a specific type of substrate. This article is part of a Special Issue entitled: Protein trafficking and secretion in bacteria. Guest Editors: Anastassios Economou and Ross Dalbey.

Acute exacerbations of idiopathic pulmonary fibrosis are associated with high mortality and are of unknown cause. The effect of air pollution on exacerbations of interstitial lung disease is unknown. This study aims to define the association of air pollution exposure with acute exacerbation of idiopathic pulmonary fibrosis. Patients with idiopathic pulmonary fibrosis and corresponding air pollution data were identified from a longitudinal cohort. Air pollution exposures were assigned to each patient for ozone, nitrogen dioxide, particulate matter, sulfur dioxide and carbon monoxide based on geo-coded residential addresses. Cox proportional hazards models were used to estimate the association of air pollution exposures and acute exacerbations. Acute exacerbation was significantly associated with antecedent 6-week increases in mean level, maximum level and number of exceedances above accepted standards of ozone (hazard ratio (HR) 1.57, 95% CI 1.09-2.24; HR 1.42, 95% CI 1.11-1.82; and HR 1.51, 95% CI 1.17-1.94, respectively) and nitrogen dioxide (HR 1.41, 95% CI 1.04-1.91; HR 1.27, 95% CI 1.01-1.59; and HR 1.20, 95% CI 1.10-1.31, respectively). Increased ozone and nitrogen dioxide exposure over the preceding 6 weeks was associated with an increased risk of acute exacerbation of idiopathic pulmonary fibrosis, suggesting that air pollution may contribute to the development of this clinically meaningful event.

Multiple studies have reported that Latina women in the United States are diagnosed with breast cancer at more advanced stages and have poorer survival than non-Latina White women. However, Latinas are a heterogeneous group with individuals having different proportions of European, Indigenous American, and African genetic ancestry. In this study, we evaluated the association between genetic ancestry and survival after breast cancer diagnosis among 899 Latina women from the San Francisco Bay area. Genetic ancestry was estimated from single-nucleotide polymorphisms from an Affymetrix 6.0 array and we used Cox proportional hazards models to evaluate the association between genetic ancestry and breast cancer-specific mortality (tests were two-sided). Women were followed for an average of 9 years during which 75 died from breast cancer. Our results showed that Individuals with higher Indigenous American ancestry had increased risk of breast cancer-specific mortality [HR: 1.57 per 25% increase in Indigenous American ancestry; 95% confidence interval (CI): 1.08-2.29]. Adjustment for demographic factors, tumor characteristics, and some treatment information did not explain the observed association (HR: 1.75; 95%CI, 1.12-2.74). In an analysis in which ancestry was dichotomized, the hazard of mortality showed a two-fold increase when comparing women with less than 50% Indigenous American ancestry to women with 50% or more [HR, 1.89, 95%CI, 1.10-3.24]. This was also reflected by Kaplan-Meier survival estimates (P for log-rank test of 0.003). Overall, results suggest that genetic factors and/or unmeasured differences in treatment or access to care should be further explored to understand and reduce ethnic disparities in breast cancer outcomes.