Publications
Department of Medicine faculty members published more than 3,600 peer-reviewed articles in 2024.
2014
BACKGROUND
Social determinants directly contribute to poorer health, and coordination between healthcare and community-based resources is pivotal to addressing these needs. However, our healthcare system remains poorly equipped to address social determinants of health. The potential of health information technology to bridge this gap across the delivery of healthcare and social services remains unrealized.
OBJECTIVE, DESIGN, AND PARTICIPANTS
We conducted in-depth, in-person interviews with 50 healthcare and social service providers to determine the feasibility of a social-health information exchange (S-HIE) in an urban safety-net setting in Dallas County, Texas. After completion of interviews, we conducted a town hall meeting to identify desired functionalities for a S-HIE.
APPROACH
We conducted thematic analysis of interview responses using the constant comparative method to explore perceptions about current communication and coordination across sectors, and barriers and enablers to S-HIE implementation. We sought participant confirmation of findings and conducted a forced-rank vote during the town hall to prioritize potential S-HIE functionalities.
KEY RESULTS
We found that healthcare and social service providers perceived a need for improved information sharing, communication, and care coordination across sectors and were enthusiastic about the potential of a S-HIE, but shared many technical, legal, and ethical concerns around cross-sector information sharing. Desired technical S-HIE functionalities encompassed fairly simple transactional operations such as the ability to view basic demographic information, visit and referral data, and medical history from both healthcare and social service settings.
CONCLUSIONS
A S-HIE is an innovative and feasible approach to enabling better linkages between healthcare and social service providers. However, to develop S-HIEs in communities across the country, policy interventions are needed to standardize regulatory requirements, to foster increased IT capability and uptake among social service agencies, and to align healthcare and social service priorities to enable dissemination and broader adoption of this and similar IT initiatives.
View on PubMed2014
BACKGROUND
Chemoprevention offers a promising strategy for prevention of malaria in African children. However, the optimal chemoprevention drug and dosing strategy is unclear in areas of year-round transmission and resistance to many antimalarial drugs. To compare three available regimens, we conducted an open-label randomized controlled trial of chemoprevention in Ugandan children.
METHODS AND FINDINGS
This study was conducted between June 28, 2010, and September 25, 2013. 400 infants were enrolled and 393 randomized at 6 mo of age to no chemoprevention, monthly sulfadoxine-pyrimethamine (SP), daily trimethoprim-sulfamethoxazole (TS), or monthly dihydroartemisinin-piperaquine (DP). Study drugs were administered at home without supervision. Piperaquine (PQ) levels were used as a measure of compliance in the DP arm. Participants were given insecticide-treated bednets, and caregivers were encouraged to bring their child to a study clinic whenever they were ill. Chemoprevention was stopped at 24 mo of age, and participants followed-up an additional year. Primary outcome was the incidence of malaria during the intervention period. During the intervention, the incidence of malaria in the no chemoprevention arm was 6.95 episodes per person-year at risk. Protective efficacy was 58% (95% CI, 45%-67%, p<0.001) for DP, 28% (95% CI, 7%-44%, p = 0.01) for TS, and 7% for SP (95% CI, -19% to 28%, p = 0.57). PQ levels were below the detection limit 52% of the time when malaria was diagnosed in the DP arm, suggesting non-adherence. There were no differences between the study arms in the incidence of serious adverse events during the intervention and the incidence of malaria during the 1-y period after the intervention was stopped.
CONCLUSIONS
For preventing malaria in children living in an area of high transmission intensity, monthly DP was the most efficacious and safe, although adherence may pose a problem. Monthly SP and daily TS may not be appropriate in areas with high transmission intensity and frequent resistance to antifolates.
TRIAL REGISTRATION
www.ClinicalTrials.gov NCT00948896 Please see later in the article for the Editors' Summary.
View on PubMed2014
The level (or frequency) of circulating monocyte subpopulations such as classical (CD14(hi)CD16(-)) and non-classical (CD14(dim)CD16(+)) monocytes varies during the course of HIV disease progression and antiretroviral therapy (ART). We hypothesized that such variation and/or differences in the degree to which these cells expressed the immunoregulatory enzyme, heme oxygenase-1 (HO-1), would be associated with CD4(+) T cell recovery after the initiation of ART. This hypothesis was tested in a cross-sectional study of four groups of HIV-infected subjects, including those who were seronegative, untreated virologic controllers [detectable viral load (VL) of <1000 copies/mL], untreated virologic non-controllers [VL > 10,000 copies/mL], and ART-mediated virologic controllers [VL < 75 copies/mL]. A longitudinal analysis of ART-treated subjects was also performed along with regression analysis to determine which biomarkers were associated with and/or predictive of CD4(+) T cell recovery. Suppressive ART was associated with increased levels of classical monocyte subpopulations (CD14(hi)CD16(-)) and decreased levels of non-classical monocyte populations (CD14(dim)CD16(+)). Among peripheral blood mononuclear cells (PBMCs), HO-1 was found to be most highly up-regulated in CD14(+) monocytes after ex vivo stimulation. Neither the levels of monocyte subpopulations nor of HO-1 expression in CD14(+) monocytes were significantly associated with the degree of CD4(+) T cell recovery. Monocyte subpopulations and HO-1 gene expression were, however, restored to normal levels by suppressive ART. These results suggest that the level of circulating monocyte subpopulations and their expression of HO-1 have no evident relationship to CD4(+) T cell recovery after the initiation of ART.
View on PubMed2014
OBJECTIVE
To determine the prevalence of gestational diabetes (GDM) and hypertensive disorders of pregnancy (HDP) among women Veterans using Department of Veterans Affairs (VA) maternity benefits previously deployed in service of Operation Enduring Freedom/Operation Iraqi Freedom/Operation New Dawn (OEF/OIF/OND), and whether pregnancy complications were associated with VA use following delivery.
METHODS
We identified the study population through linkage with the Department of Defense roster and VA administrative and clinical data. GDM and HDP were identified by International Classification of Diseases, Ninth Revision codes in VA inpatient or outpatient files. Similarly, we constructed a nationally representative sample of deliveries from the Nationwide Inpatient Sample. We calculated standardized incidence ratios (SIR) adjusted for age and year of delivery to compare rates of GDM and HDP. Proportional hazards regression was used to determine whether pregnancy complications were associated with use of VA following delivery.
RESULTS
Between 2001 and 2010, 2,288 women OEF/OIF/OND Veterans used VA maternity benefits; 5.2% had GDM and 9.6% had HDP. Compared with women delivering in the United States, women OEF/OIF/OND Veterans using VA maternity benefits had higher risk of developing GDM (SIR: 1.40; 95% confidence interval [CI] 1.16, 1.68) and HDP (SIR: 1.32; 95% CI 1.15, 1.51). Among women OEF/OIF/OND Veterans using VA maternity benefits, GDM (HR 1.01, 95% CI 0.83, 1.24) and HDP (HR 1.07, 95% CI 0.92, 1.25) were not associated with use of VA following delivery.
CONCLUSIONS
Non-VA providers should be aware of their patients' Veteran status and the associated elevated risk for pregnancy complications. Within VA, focused efforts to optimize Veterans' preconception and postpartum health are needed.
View on PubMed2014
2014
BACKGROUND
Placing inpatients with presumed active pulmonary tuberculosis in respiratory isolation pending results of serial sputum acid-fast bacilli (AFB) smear microscopy is standard practice in high-income countries. However, this diagnostic strategy is slow and yields few tuberculosis diagnoses. We sought to determine if replacing microscopy with the GeneXpert MTB/RIF (Xpert) nucleic acid amplification assay could reduce testing time and usage of isolation rooms.
METHODS
We prospectively followed inpatients at San Francisco General Hospital undergoing tuberculosis evaluation. We performed smear microscopy and Xpert testing on concentrated sputum, and calculated diagnostic accuracy for both strategies in reference to serial sputum mycobacterial culture. We measured turnaround time for microscopy and estimated hypothetical turnaround times for Xpert on concentrated and unconcentrated sputum. We compared median and total isolation times for microscopy to those estimated for the 2 Xpert strategies.
RESULTS
Among 139 patients with 142 admissions, median age was 54 years (interquartile range [IQR], 43-60 years); 32 (23%) patients were female, and 42 (30%) were HIV seropositive. Serial sputum smear microscopy and a single concentrated sputum Xpert had identical sensitivity (89%; 95% confidence interval [CI], 52%-100%) and similar specificity (99% [95% CI, 96%-100%] vs 100% [95% CI, 97%-100%]). A single concentrated sputum Xpert could have saved a median of 35 hours (IQR, 24-36 hours) in unnecessary isolation compared with microscopy, and a single unconcentrated sputum Xpert, 45 hours (IQR, 35-46 hours).
CONCLUSIONS
Replacing serial sputum smear microscopy with a single sputum Xpert could eliminate most unnecessary isolation for inpatients with presumed tuberculosis, greatly benefiting patients and hospitals.
View on PubMed2014
2014
BACKGROUND
Allergic rhinitis is a common disease whose genetic basis is incompletely explained. We report an integrated genomic analysis of allergic rhinitis.
METHODS
We performed genome wide association studies (GWAS) of allergic rhinitis in 5633 ethnically diverse North American subjects. Next, we profiled gene expression in disease-relevant tissue (peripheral blood CD4+ lymphocytes) collected from subjects who had been genotyped. We then integrated the GWAS and gene expression data using expression single nucleotide (eSNP), coexpression network, and pathway approaches to identify the biologic relevance of our GWAS.
RESULTS
GWAS revealed ethnicity-specific findings, with 4 genome-wide significant loci among Latinos and 1 genome-wide significant locus in the GWAS meta-analysis across ethnic groups. To identify biologic context for these results, we constructed a coexpression network to define modules of genes with similar patterns of CD4+ gene expression (coexpression modules) that could serve as constructs of broader gene expression. 6 of the 22 GWAS loci with P-value ≤ 1x10-6 tagged one particular coexpression module (4.0-fold enrichment, P-value 0.0029), and this module also had the greatest enrichment (3.4-fold enrichment, P-value 2.6 × 10-24) for allergic rhinitis-associated eSNPs (genetic variants associated with both gene expression and allergic rhinitis). The integrated GWAS, coexpression network, and eSNP results therefore supported this coexpression module as an allergic rhinitis module. Pathway analysis revealed that the module was enriched for mitochondrial pathways (8.6-fold enrichment, P-value 4.5 × 10-72).
CONCLUSIONS
Our results highlight mitochondrial pathways as a target for further investigation of allergic rhinitis mechanism and treatment. Our integrated approach can be applied to provide biologic context for GWAS of other diseases.
View on PubMed2014
To determine Latino parents' beliefs on the health effects of beverages on infants and toddlers, their sources of information on beverages and perceived barriers to following guidelines for healthy beverage consumption by children. We conducted 29 interviews with parents of Latino children ages 6-36 months. Parents were recruited in three community health centers in Northern California. The interviews were recorded, transcribed and analyzed using standard qualitative methods. The following dominant themes emerged. Parents believed that water and milk were healthy beverages for children and that sugar-sweetened beverages (SSBs) were unhealthy. Views on 100% fruit juice were mixed. Parents distinguished between homemade beverages such as "agua fresca" which they considered healthy, despite containing added sugar, and beverages from stores which were viewed as unhealthy. Participants' main source of information on beverages was the federal nutrition program for Women, Infants, and Children (WIC). Parents were confused, however, as to why WIC provides juice yet counseled parents to avoid giving their children juice. Parents preferred to receive information on beverages from experts. Differing practices among family members regarding which beverages they provide to children was the most important barrier to following beverage guidelines. Our study suggests that Latino parents are receptive to counseling on beverages from expert sources. Such counseling should address both store-bought and homemade beverages. The WIC program is a key source of information on beverages for Latino parents; thus counseling offered by WIC should be evidence-based and avoid mixed messages.
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