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Biomedical subjects

E Vittinghoff

Publications and source records attributed to E Vittinghoff.

At least 19 recordsLinked to original sources
PubMed2006

Communication of HIV viral load to guide sexual risk decisions with serodiscordant partners among San Francisco men who have sex with men.

The objective of this study was to estimate frequency and correlates of discussing HIV viral load (VL) with serodiscordant sex partners to guide decisions about sexual activities among men who have sex with men (MSM). We conducted a cross-sectional survey of 573 San Francisco MSM. Among 507 who knew their HIV status, 397 (78%) were familiar with the term 'viral load', and half (n=199) had a serodiscordant partner in the prior year. These 199 respondents (n=130 [65%] HIV-positive; n=69 [35%] HIV-negative) were the focus of this analysis. A majority (n=111, 56%) discussed VL in the prior year with serodiscordant partners specifically to guide decisions about sexual risk behaviour. Discussion was more common among HIV-positive than HIV-negative participants (adjusted odds ratio [AOR], 3.5; 95% confidence interval [CI], 1.6-7.6), and African Americans compared to whites (AOR, 3.7; 95% CI, 1.5-9.5). HIV-negative men who discussed VL were more concerned about becoming infected, but also more willing to engage in risky behaviour with a partner whose VL is undetectable, than men not discussing VL. Some HIV-negative men may be discussing VL to engage in higher risk behaviour upon learning of an HIV-positive partner's undetectable VL. Interventions targeting MSM should explain that while risk of transmission is likely reduced with a low blood plasma VL, it is not necessarily eliminated.

Adult↗
PubMed2006

Case-only analysis of treatment-covariate interactions in clinical trials.

Differential effectiveness of treatments across subgroups defined by pretreatment variables are of increasing interest, particularly in the expanding research field of pharmacogenomics. When the pretreatment variable is difficult to obtain or expensive to measure, but can be assessed at the end of the study using stored samples, nested case-control and case-cohort methods can be used to reduce costs in large efficacy trials with rare outcomes. Case-only methods are even more efficient, and reliable under a range of circumstances.

Alendronate↗
PubMed2005

Longitudinal analysis of B cell repertoire and antibody gene rearrangements during early HIV infection.

In chronically HIV infected individuals, a number of functional B cell abnormalities have been described. However, the immediate changes that occur in the B cell compartment following viral exposure and how they affect the long-term course of infection are not well understood. We report the longitudinal analysis of B cell repertoires during early infection in untreated and treated individuals receiving highly active antiretroviral therapy (HAART). Analysis was based on IgG heavy chain gene utilization and CDR3 length measurement and relationship with CD4/CD8 counts, viral load, and total serum IgG, and anti-HIV antibodies levels. Repertoires were assessed at baseline and at weeks 2, 4, 12, 24, and 72 after initiation of therapy. The findings indicate a stable peripheral B cell repertoire during the first 72 weeks following infection, particularly in the HAART treated patients. A modest association between B cell repertoire integrity and viremia levels as well as treatment was detected.

Adult↗
PubMed2004

Urinary incontinence in elderly women: findings from the Health, Aging, and Body Composition Study.

OBJECTIVE: To estimate the prevalence of and risk factors for stress and urge incontinence in a biracial sample of well-functioning older women. METHODS: We performed a cross-sectional analysis of 1,584 white and black women, aged 70-79 years, enrolled in a longitudinal cohort study. Participants were asked about incontinence, medical problems, and demographic and reproductive characteristics and underwent physical measurements. Using multivariable logistic regression, we compared women reporting at least weekly incontinence with those without incontinence. RESULTS: Overall, 21% reported incontinence at least weekly. Of these, 42% reported predominantly urge incontinence, and 40% reported stress. Nearly twice as many white women as black women reported weekly incontinence (27% versus 14%, P <.001). Factors associated with urge incontinence included white race (odds ratio [OR] 3.1, 95% confidence interval [CI] 2.0-4.8), diabetes treated with insulin (OR 3.5, 95% CI 1.6-7.9), depressive symptoms (OR 2.7, 95% CI 1.4-5.3), current oral estrogen use (OR 1.7, 95% CI 1.1-2.6), arthritis (OR 1.7, 95% CI 1.1-2.6), and decreased physical performance (OR 1.6 per point on 0-4 scale, 95% CI 1.1-2.3). Factors associated with stress incontinence were chronic obstructive pulmonary disease (OR 5.6, 95% CI 1.3-23.2), white race (OR 4.1, 95% CI 2.5-6.7), current oral estrogen use (OR 2.0, 95% CI 1.3-3.1), arthritis (OR 1.6, 95% CI 1.0-2.4), and high body mass index (OR 1.3 per 5 kg/m2, 95% CI 1.1-1.6). CONCLUSION: Urinary incontinence is highly prevalent, even in well-functioning older women, whites in particular. Many risk factors differ for stress and urge incontinence, suggesting differing etiologies and prevention strategies.

Age Factors↗
PubMed2003

HLA-DR2 dose effect on susceptibility to multiple sclerosis and influence on disease course.

Models of disease susceptibility in multiple sclerosis (MS) often assume a dominant action for the HLA-DRB1*1501 allele and its associated haplotype (DRB1*1501-DQB1*0602 or DR2). A robust and phenotypically well-characterized MS data set was used to explore this model in more detail. A dose effect of HLA-DR2 haplotypes on MS susceptibility was revealed. This observation suggests that, in addition to the role of HLA-DR2 in MS, two copies of a susceptibility haplotype further increase disease risk. Second, we report that DR2 haplotypes modify disease expression. There is a paucity of benign MS and an increase of severe MS in individuals homozygous for DR2. Concepts of the molecular mechanisms that underlie linkage and association of the human leukocyte antigen (HLA) region to MS need to be revised to accommodate these data.

Disease Progression↗
PubMed2002

What happened to home HIV test collection kits? Intent to use kits, actual use, and barriers to use among persons at risk for HIV infection.

Through sequential cross-sectional surveys, we examined intent to use home HIV test collection kits, actual use and barriers to use among persons at high risk for HIV infection. Interest in kits was assessed in the 1995-96 HIV Testing Survey (HITS, n=1683). Kit use, knowledge of kits and barriers to use were assessed in the 1998-99 HITS (n=1788), after kits had become widely available. When asked to choose among future testing options, 19% of 1995-96 participants intended to use kits. Untested participants were more likely than previously tested HIV-negative participants to choose kits for their next HIV test (p < 0.001). Among 1998-99 participants, only 24 (1%) had used kits; 46% had never heard of kits. Predictors of not knowing about kits included never having been HIV tested and black or Latino race. Common reasons for not using kits among participants aware of home test kits were concerns about accuracy, lack of in-person counselling and cost. Despite high rates of anticipated use, kits have had minimal impact on the testing behaviour of persons at high risk for HIV infection. Increasing awareness of kits, reducing price and addressing concerns about kit testing procedures may increase kit use, leading to more HIV testing by at-risk individuals.

Cross-Sectional Studies↗
PubMed2001

Predictors of use of highly active antiretroviral therapy (HAART) among persons with AIDS in San Francisco, 1996-1999.

Highly active antiretroviral therapy (HAART) has contributed to a decrease in AIDS-related morbidity and mortality. This study used population-based AIDS surveillance data to evaluate the prevalence and predictors of HAART use among persons with AIDS in San Francisco. Use of HAART among persons living with AIDS increased from 41% in 1996 to 72% in 1999. Fourteen percent of persons diagnosed with AIDS between 1996 and 1999 initiated HAART before their AIDS diagnosis. Use of HAART before an AIDS diagnosis increased from 5% in 1996 to 26% in 1999. In the multivariable analysis, African Americans, injection drug users, and those without insurance at the time of AIDS diagnosis were less likely to use HAART before AIDS diagnosis. Delayed initiation of HAART after AIDS was more likely to occur among African Americans, injection drug users, homeless persons, those with public insurance, and those with higher CD4 counts. Although the overall prevalence of HAART use was high, disparity in use of HAART existed by race and risk group, patient's insurance status, and facility of diagnosis. Barriers in use of treatment should be identified so all persons with AIDS can benefit from improved therapies.

Acquired Immunodeficiency Syndrome↗
PubMed2001

Drug use and sexual risk behavior among gay and bisexual men who attend circuit parties: a venue-based comparison.

CONTEXT: HIV risk behavior among urban gay/bisexual men has recently increased. High-risk sexual activity and drug use may be particularly high during circuit party (CP) weekends, during which gay/bisexual men congregate for social activities and dancing. OBJECTIVES: To compare prevalence of risk behaviors during CP weekends with those during non-CP weekends. DESIGN: Cross-sectional study. PARTICIPANTS: 295 gay/bisexual men from the San Francisco Bay Area. MAIN OUTCOME MEASURES: Drug use and sexual risk behavior during a San Francisco CP weekend, a CP weekend held in another geographic area (distant weekends), and two non-CP weekends. RESULTS: During their most recent distant CP weekend, 80% of participants used methylenedioxymethamphetamine (ecstasy), 66% ketamine, 43% crystal methamphetamines, 29% gamma-hydroxybutyrate or gamma-butyrolactone (GHB/GBL), 14% sildenafil (Viagra), and 12% amyl nitrites (poppers); 53% used four or more drugs. Drug use prevalence was greater during CP than non-CP weekends ( p <.001). Unprotected anal sex with partners of unknown or opposite HIV serostatus was most prevalent during distant CP weekends, reported by 21% of HIV-positive and 9% of HIV-negative participants. In multivariate analysis, predictors of unprotected anal sex with opposite or unknown HIV serostatus partners included being HIV-positive (odds ratio [OR], 3.2; 95% confidence interval [CI], 1.4-7.5), and weekend use of crystal methamphetamines (OR 2.4; 95% CI, 1.1-4.9), sildenafil (OR, 3.8; 95% CI, 2.0-7.3), and amyl nitrites (OR, 2.2; 95% CI, 1.3-4.0). CONCLUSIONS: Prevalence of high-risk activity during these weekends suggests significant potential for HIV transmission in this population. Public health programs in communities hosting CPs should aim to reduce rates of drug use and sexual risk behavior among CP participants, especially HIV-positive men.

Adult↗
PubMed2001

Cofactors for HIV disease progression in a cohort of homosexual and bisexual men.

To evaluate cofactors for progression of HIV infection, the authors identified 370 men with well-defined seroconversion dates and cofactor data among participants in the San Francisco City Clinic Cohort (SFCCC). Postseroconversion substance use, sexual behavior, and sexually transmitted diseases were assessed using multivariate proportional hazards models. Weekly use of hallucinogens strongly and independently predicted death (relative hazard [RH], 2.59; 95% confidence interval [CI], 1.56-4.28), as well as diagnosis of AIDS; weekly cocaine use also predicted mortality. Receptive anal intercourse with ejaculation was independently associated with mortality risk (RH, 1.45; 95% CI, 1.02-2.04) and AIDS. The associations of accelerated progression with weekly use of recreational drugs and unprotected receptive anal intercourse need to be confirmed in other prospective cohorts.

Adult↗
PubMed2001

Risk factors for skin and soft-tissue abscesses among injection drug users: a case-control study.

Skin and soft-tissue abscesses, a common problem among injection drug users (IDUs), result in serious morbidity for the patient and costly hospitalizations for incision and drainage; however, there has been little etiologic or preventive epidemiologic research on this problem. We performed a case-control study that enrolled 151 IDUs who had been given a new diagnosis of abscess requiring incision and drainage (cases) and 267 IDUs who did not have abscess or other bacterial infection during the previous year and who were stratum-matched to cases according to age, sex, and race (controls). Subcutaneous or intramuscular, instead of intravenous, injection is a major risk factor for abscess among IDUs. The injection of a cocaine and heroin mixture, or "speedball," may predispose patients to develop abscess by inducing soft-tissue ischemia. Cleaning the skin with alcohol before injection was found to have a protective effect. Neither human immunodeficiency virus nor human T-lymphotropic virus type II seropositivity was significantly associated with abscess.

Abscess↗
PubMed2001

Control of HIV-1 viremia and protection from AIDS are associated with HLA-Bw4 homozygosity.

Certain HLA-B antigens have been associated with lack of progression to AIDS. HLA-B alleles can be divided into two mutually exclusive groups based on the expression of the molecular epitopes HLA-Bw4 and HLA-Bw6. Notably, in addition to its role in presenting viral peptides for immune recognition, the HLA-Bw4, but not HLA-Bw6, motif functions as a ligand for a natural killer cell inhibitory receptor (KIR). Here, we show that profound suppression of HIV-1 viremia is significantly associated with homozygosity for HLA-B alleles that share the HLA-Bw4 epitope. Furthermore, homozygosity for HLA-Bw4 alleles was also significantly associated with the ability to remain AIDS free and to maintain a normal CD4 T cell count in a second cohort of HIV-1-infected individuals with well defined dates of seroconversion. This association was independent of the presence of a mutation in CC chemokine receptor 5 (CCR5) associated with resistance to HIV-1 infection, and it was independent of the presence of HLA alleles that could potentially confound the results. We conclude that homozygosity for HLA-Bw4-bearing B alleles is associated with a significant advantage and that the HLA-Bw4 motif is important in AIDS pathogenesis.

Acquired Immunodeficiency Syndrome↗
PubMed2001

Factors associated with the health care utilization of homeless persons.

CONTEXT: Homeless persons face numerous barriers to receiving health care and have high rates of illness and disability. Factors associated with health care utilization by homeless persons have not been explored from a national perspective. OBJECTIVE: To describe factors associated with use of and perceived barriers to receipt of health care among homeless persons. DESIGN AND SETTING: Secondary data analysis of the National Survey of Homeless Assistance Providers and Clients. SUBJECTS: A total of 2974 currently homeless persons interviewed through homeless assistance programs throughout the United States in October and November 1996. MAIN OUTCOME MEASURES: Self-reported use of ambulatory care services, emergency departments, and inpatient hospital services; inability to receive necessary care; and inability to comply with prescription medication in the prior year. RESULTS: Overall, 62.8% of subjects had 1 or more ambulatory care visits during the preceding year, 32.2% visited an emergency department, and 23.3% had been hospitalized. However, 24.6% reported having been unable to receive necessary medical care. Of the 1201 respondents who reported having been prescribed medication, 32.1% reported being unable to comply. After adjustment for age, sex, race/ethnicity, medical illness, mental health problems, substance abuse, and other covariates, having health insurance was associated with greater use of ambulatory care (odds ratio [OR], 2.54; 95% confidence interval [CI], 1.19-5.42), inpatient hospitalization (OR, 2.60; 95% CI, 1.16-5.81), and lower reporting of barriers to needed care (OR, 0.37; 95% CI, 0.15-0.90) and prescription medication compliance (OR, 0.35; 95% CI, 0.14-0.85). Insurance was not associated with emergency department visits (OR, 0.90; 95% CI, 0.47-1.75). CONCLUSIONS: In this nationally representative survey, homeless persons reported high levels of barriers to needed care and used acute hospital-based care at high rates. Insurance was associated with a greater use of ambulatory care and fewer reported barriers. Provision of insurance may improve the substantial morbidity experienced by homeless persons and decrease their reliance on acute hospital-based care.

Adult↗
PubMed2001

Longitudinal analysis of T-cell receptor gene use by CD8(+) T cells in early human immunodeficiency virus infection in patients receiving highly active antiretroviral therapy.

The effects of early antiretroviral therapy on the peripheral CD8(+) T-cell population were assessed by sequentially determining the T-cell receptor (TCR) repertoire complexity in a cohort of 15 individuals recently diagnosed with human immunodeficiency virus infection. Analysis was based on quantitative TCR variable B gene (TCRBV) usage and complementary-determining region 3 length assessment. Repertories were assessed at baseline and at weeks 2, 4, 12, 24, and 72 after initiation of therapy. Early administration of highly active antiretroviral therapy has a positive effect on the preservation and homeostasis of the CD8(+) cell repertoire. Nevertheless, differences from average baseline and control TCR profiles and initial development of repertoire perturbations were observed. The findings suggest that additional therapeutic protocols will be required during primary infection to significantly prevent long-term erosion of the T-cell-mediated immune response.

Adult↗
PubMed2001

Postmenopausal hormones and incontinence: the Heart and Estrogen/Progestin Replacement Study.

OBJECTIVE: To determine whether postmenopausal hormone therapy improves the severity of urinary incontinence. METHODS: We included measures of incontinence and voiding frequency in the Heart and Estrogen/Progestin Replacement Study, a randomized, blinded trial of the effect of hormone therapy among 2763 postmenopausal women younger than 80 years with coronary disease and intact uteri. This report includes 1525 participants who reported at least one episode of incontinence per week at baseline. Participants were randomly assigned to 0.625 mg of conjugated estrogens plus 2.5 mg of medroxyprogesterone acetate in one tablet daily (n = 768) or placebo (n = 757) and were followed for a mean of 4.1 years. Severity of incontinence was classified as improved (decrease of at least two episodes per week), unchanged (change of at most one episode per week), or worsened (increase of at least two episodes per week). RESULTS: Incontinence improved in 26% of the women assigned to placebo compared with 21% assigned to hormones, while 27% of the placebo group worsened compared with 39% of the hormone group (P =.001). This difference was evident by 4 months of treatment and was observed for both urge and stress incontinence. The number of incontinent episodes per week increased an average of 0.7 in the hormone group and decreased by 0.1 in the placebo group (P <.001). CONCLUSION: Daily oral estrogen plus progestin therapy was associated with worsening urinary incontinence in older postmenopausal women with weekly incontinence. We do not recommend this therapy for the treatment of incontinence.

Drug Combinations↗
PubMed2001

Cost of pelvic organ prolapse surgery in the United States.

OBJECTIVE: To estimate the annual direct cost to society of pelvic organ prolapse operations in the United States. METHODS: We multiplied the number of pelvic organ prolapse operations identified in the 1997 National Hospital Discharge Survey by national average Medicare reimbursement for physician services and hospitalizations. Although this reimbursement does not estimate the actual cost, it is a proxy for cost, which estimates what society pays for the procedures. RESULTS: In 1997, direct costs of pelvic organ prolapse surgery were 1012 million dollars (95% confidence interval [CI] 775 dollars, 1251 million), including 494 dollars million (49%) for vaginal hysterectomy, 279 million dollars (28%) for cystocele and rectocele repair, and 135 million dollars (13%) for abdominal hysterectomy. Physician services accounted for 29% (298 million dollars) of total costs, and hospitalization accounted for 71% (714 million dollars). Twenty-one percent of pelvic organ prolapse operations included urinary incontinence procedures (218 million dollars). If all operations were reimbursed by non-Medicare sources, the annual estimated cost would increase by 52% to 1543 million dollars. CONCLUSION: The annual direct costs of operations for pelvic organ prolapse are substantial.

Direct Service Costs↗
PubMed2001

Urinary tract infections in postmenopausal women: effect of hormone therapy and risk factors.

OBJECTIVE: To assess the effects of hormone therapy on urinary tract infection frequency and to examine potential risk factors. METHODS: We used data from the Heart and Estrogen/Progestin Replacement Study, a randomized, blinded trial of the effects of hormone therapy on coronary heart disease events among 2763 postmenopausal women aged 44-79 with established coronary heart disease. Participants were randomly assigned to 0.625 mg of conjugated estrogens plus 2.5 mg of medroxyprogesterone acetate or placebo and followed for a mean of 4.1 years. History of physician-diagnosed urinary tract infections and risk factors were assessed by self-report at baseline and each annual visit. RESULTS: Urinary tract infection frequency was higher in the group randomized to hormone treatment, although the difference was not statistically significant (odds ratio [OR] 1.16, 95% confidence interval [CI] 0.99, 1.37). Statistically significant risk factors for urinary tract infections in multivariable analysis included: women with diabetes on treatment (insulin OR 1.81, 95% CI 1.40, 2.34), oral medications OR 1.44, 95% CI 1.09, 1.90), poor health (OR 1.34, 95% CI 1.14, 1.57), childbirth (OR 1.38, 95% CI 1.00, 1.90), vaginal itching (OR 1.63, 95% CI 1.07, 2.50), vaginal dryness (OR 1.30, 95% CI 1.04, 1.67), and urge incontinence (OR 1.51, 95% CI 1.30, 1.75). Urinary tract infections in the previous year were strongly associated with a single urinary tract infection (OR 7.00, 95% CI 5.91, 8.29) as well as multiple urinary tract infections (OR 18.51, 95% CI 14.27, 24.02). CONCLUSIONS: Oral hormone therapy did not reduce frequency of urinary tract infections. Potentially modifiable risk factors in postmenopausal women are different from those in younger women, and include diabetes, vaginal symptoms, and urge incontinence.

Adult↗
PubMed2001

PTPRC (CD45) is not associated with the development of multiple sclerosis in U.S. patients.

A C-->G nucleotide transition in exon 4 of PTPRC (encoding protein-tyrosine phosphatase receptor-type C, also known as CD45) was recently reported to be genetically associated with the development of multiple sclerosis (MS). We performed an extensive evaluation of this polymorphism using large family-based and case-control comparisons. Overall, we observed no evidence of genetic association between the PTPRC polymorphism and MS susceptibility or disease course.

Adult↗