Faculty Bibliography

BACKGROUND: Male veterans represent a large population at risk for acquiring or transmitting human immunodeficiency virus (HIV) infection. We sought to determine the prevalence of risky sexual behavior among veterans with and without HIV infection and to assess the relationship of intoxication before intercourse and other measures of drug and alcohol use to risky sexual behavior in this population. METHODS: We analyzed baseline data on 1009 HIV-positive (mean age 49 years) and 710 HIV-negative male veterans (mean age 55 years) who were participating in the Veterans Aging Cohort 5-Site Study (VACS 5). Participants completed a written questionnaire that included measures of alcohol and drug use and risky sexual behavior. RESULTS: Compared with HIV-negative veterans, HIV-positive veterans were more likely to report 5 or more sexual partners in the past year (14% vs. 4%, P < 0.01), less likely to report not using a condom at last intercourse (25% vs. 75%, P < 0.01), and similarly likely to report having 2 or more partners and inconsistent condom use (10% vs. 10%). Among sexually active HIV-positive veterans, intoxication before intercourse was significantly associated with having 5 or more sexual partners in the past year (odds ratio [OR] 1.8, 95% confidence interval [CI] 1.1-2.8), inconsistent condom use (OR 1.8, 95% CI 1.2-2.7), and the combined measure of 2 or more partners and inconsistent condom use (OR 1.8, 95% CI 1.1-3.0). Intoxication before intercourse was not significantly associated with these behaviors in HIV-negative veterans, although similar trends were noted. CONCLUSION: Risky sexual behavior was common among male veterans attending outpatient clinics and is more common among HIV-positive veterans who use alcohol and drugs in sexual situations. Asking HIV-positive men a single question about intoxication before intercourse could help to identify men at increased risk of engaging in risky sexual behavior, and specific advice to avoid intoxication in sexual situations could help to reduce risky sexual behavior

The authors discuss techniques for Monte Carlo (MC) cohort simulations that reduce the number of simulation replications required to achieve a given degree of precision for various output measures. Known as variance reduction techniques, they are often used in industrial engineering and operations research models, but they are seldom used in medical models. However, most MC cohort simulations are well suited to the implementation of these techniques. The authors discuss the cost of implementation versus the benefit of reduced replications

BACKGROUND: Intentional exposures to aerosolized Bacillus anthracis spores have caused fatalities. OBJECTIVE: To evaluate the cost-effectiveness of strategies to reduce mortality from future inhalational anthrax exposures. METHODS: Computer cohort simulation of a 100,000-person single-site exposure (worst-case scenario) and a 100-person multiple-site exposure (resembling the recent US attack). For each scenario, universal vaccination and an emergency surveillance and response (ESR) system were compared with a default strategy that assumed eventual discovery of the exposure. RESULTS: If an exposure was unlikely to occur or was small in scale, neither vaccination nor an ESR system was cost-effective. If an exposure was certain and large in scale, an ESR system was more cost-effective than vaccination ($73 v. $29,600 per life-year saved), and a rapid response saved more lives than improved surveillance. CONCLUSIONS: Strategies to reduce deaths from anthrax attacks are cost-effective only if large exposures are certain. A faster response is more beneficial than enhanced surveillance

PURPOSE: Effective antiretroviral therapies have improved the prognosis for patients infected with the human immunodeficiency virus (HIV). We aimed to estimate the likelihood that HIV-infected patients would die of comorbid disease. METHODS: A probabilistic simulation of antiretroviral-naive HIV-infected patients in the United States was calibrated with data from an observational cohort (N = 3545) and validated with data from a separate patient cohort (N = 12574). The simulation explicitly represents the 2 main determinants of treatment failure and subsequent death from HIV-related causes: nonadherence to combination therapy and accumulation of phenotypic resistance to combination therapy. The likelihood of deaths not directly attributable to HIV was estimated from the Collaborations in HIV Outcomes Research-US (CHORUS) cohort. RESULTS: For patients with newly diagnosed HIV infections, CD4 counts of 500 cells/mm3, and viral loads of 10000 copies/mL, the median estimated survival was 26.8 years for 30-year-olds, 24.4 years for 40-year-olds and 14.6 years for 50-year-olds. The proportion of deaths not directly attributable to HIV was 36% for 30-year-olds, 53% for 40-year-olds, and 72% for 50-year-olds. For patients with characteristics similar to CHORUS participants, the median estimated survival approached 20.4 years, the mean age at death approached 60.4 years, and 41% died of illnesses not directly attributable to HIV. These estimates of non-HIV mortality were likely conservative. CONCLUSION: As HIV-infected patients live longer, our results suggest they will experience increasing mortality from causes not directly attributable to HIV. The projected risk from comorbid disease has clinical and policy implications for future delivery of care to HIV-infected patients

BACKGROUND: Previous studies have shown that alcohol consumption is associated with decreased medication adherence, but this association may be confounded by characteristics common among those who drink heavily and those who fail to adhere (e.g., illicit drug use). Our objective was to determine whether there are temporal and dose-response relationships between alcohol consumption and poor adherence. METHODS: We administered telephone interview surveys to participants in the Veterans Aging Cohort Study, an eight-site observational study of HIV+ and matched HIV- veterans in care, to determine whether alcohol consumption on a particular day was associated with nonadherence to prescribed medications on that same day. We used the Time Line Follow Back to measure alcohol consumption and the Time Line Follow Back Modified for Adherence to measure adherence. Individuals were categorized as abstainers (no alcohol in past 30 days), nonbinge drinkers (alcohol in past 30 days but < or =four standard drinks on each day), or binge drinkers (> or =five standard drinks on at least one day). RESULTS: Among 2702 respondents, 1582 (56.6%) were abstainers, 931 (34.5%) were nonbinge drinkers, and 239 (8.9%) were binge drinkers. Abstainers missed medication doses on 2.4% of surveyed days. Nonbinge drinkers missed doses on 3.5% of drinking days, 3.1% of postdrinking days, and 2.1% of nondrinking days (p < 0.001 for trend), and this trend was more pronounced among HIV+ individuals than HIV- individuals. Binge drinkers missed doses on 11.0% of drinking days, 7.0% of postdrinking days, and 4.1% of nondrinking days (p < 0.001 for trend), and this trend was comparably strong for HIV+ and HIV- individuals. CONCLUSIONS: Among veterans in care, self-reported alcohol consumption demonstrates a temporal and dose-response relationship to poor adherence. HIV+ individuals may be particularly sensitive to alcohol consumption

BACKGROUND: Testing of urine samples is noninvasive and could overcome several barriers to screening for chlamydial and gonococcal infections, but most test samples are obtained directly from the cervix or urethra. PURPOSE: To systematically review studies that assessed the sensitivity and specificity of nucleic acid amplification tests for Chlamydia trachomatis and Neisseria gonorrhoeae in urine specimens and to compare test characteristics according to type of assay, site of sample collection, presence of symptoms, disease prevalence, and characteristics of the reference standard. DATA SOURCES: Relevant studies in all languages were identified by searching the MEDLINE database (January 1991 to December 2004) and by hand-searching the references of identified articles and relevant journals. STUDY SELECTION: Studies were selected that evaluated 1 of 3 commercially available nucleic acid amplification tests, included data from tests of both a urine sample and a traditional sample (obtained from the cervix or urethra), and used an appropriate reference standard. DATA EXTRACTION: From 29 eligible studies, 2 investigators independently abstracted data on sample characteristics, reference standard, sensitivity, and specificity. DATA SYNTHESIS: Articles were assessed qualitatively and quantitatively. Summary estimates for men and women were calculated separately for chlamydial and gonococcal infections and were stratified by assay and presence of symptoms. The pooled study specificities of each of the 3 assays exceeded 97% when urine samples were tested, for both chlamydial infection and gonorrhea and in both men and women. The pooled study sensitivities for the polymerase chain reaction, transcription-mediated amplification, and strand displacement amplification assays, respectively, were 83.3%, 92.5%, and 79.9% for chlamydial infections in women; 84.0%, 87.7%, and 93.1% for chlamydial infections in men; and 55.6%, 91.3%, and 84.9% for gonococcal infections in women. The pooled specificity of polymerase chain reaction to gonococcal infections in men was 90.4%. In subgroup analyses, the sensitivity did not vary according to the prevalence of infection or the presence of symptoms but did vary according to the reference standard used. LIMITATIONS: Few published studies present data on the transcription-mediated amplification or strand displacement amplification assays, and few studies report data from asymptomatic patients or low-prevalence groups. CONCLUSIONS: Results of nucleic acid amplification tests for C. trachomatis on urine samples are nearly identical to those obtained on samples collected directly from the cervix or urethra. Although all 3 assays can also be used to test for N. gonorrhoeae, the sensitivity of the polymerase chain reaction assay in women is too low to recommend its routine use to test for gonorrhea in urine specimens

An exposure assessment and risk characterization was conducted to better understand the potential human health significance of trace levels of perfluorooctanoate (PFO) detected in certain consumer articles. PFO is the anion of perfluorooctanoic acid (PFOA). Concentrations of PFO in the consumer articles were determined from extraction tests and product formulation information. Potential exposures during consumer use of the articles were quantified based on an assessment of behavior patterns and regulatory guidance. Health benchmarks were developed and then compared to the exposure estimates to yield margins of exposure (MOEs). A simple one-compartment model was also developed to estimate contributions of potential consumer exposures to PFO concentrations in serum. While there are considerable uncertainties in this assessment, it indicates that exposures to PFO during consumer use of the articles evaluated in this study are not expected to cause adverse human health effects in infants, children, adolescents, adult residents, or professionals nor result in quantifiable levels of PFO in human serum

BACKGROUND: Delays in the care of hospitalized patients may lead to increased length of stay, iatrogenic complications, and costs. No study has characterized delays among general medicine inpatients in the current prospective payment era of care. OBJECTIVE: To quantify and characterize delays in care which prolong hospitalizations for general medicine inpatients. DESIGN: Prospective survey of senior residents. SETTING: Urban tertiary care university-affiliated teaching hospital. PARTICIPANTS: Sixteen senior residents were surveyed regarding 2,831 patient-days. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Data were collected on 97.6% (2,762) of patient-days eligible for evaluation. Three hundred seventy-three patient-days (13.5% of all hospital days) were judged unnecessary for acute inpatient care, and occurred because of delays in needed services. Sixty-three percent of these unnecessary days were due to nonmedical service delays and 37% were due to medical service delays. The vast majority of nonmedical service delays (84%) were due to difficulty finding a bed in a skilled nursing facility. Medical service delays were most often due to postponement of procedures (54%) and diagnostic test performance (21%) or interpretation (10%), and were significantly more common on weekend days (relative risk [RR], 1.49; P=.02). Indeed, nearly one fourth of unnecessary patient-days (24% overall, 88 patient-days) involved an inability to access medical services on a weekend day (Saturday or Sunday). CONCLUSIONS: At our institution, a substantial number of hospital days were judged unnecessary for acute inpatient care and were attributable to delays in medical and nonmedical services. Future work is needed to develop and investigate measures to decrease delays

BACKGROUND: No previous studies have investigated whether medical emergency team (MET) responses can be used to detect medical errors. OBJECTIVES: To determine whether review of MET responses can be used as a surveillance method for detecting medical errors. METHODS: Charts of all patients receiving MET responses during an 8 month period were reviewed by a hospital based Quality Improvement Committee to establish if the clinical deterioration that prompted the MET response was associated with a medical error (defined as an adverse event that was preventable with the current state of medical knowledge). Medical errors were categorized as diagnostic, treatment, or preventive errors using a descriptive typology based on previous published reports. RESULTS: Three hundred and sixty four consecutive MET responses underwent chart review and 114 (31.3%) were associated with medical errors: 77 (67.5%) were categorized as diagnostic errors, 68 (59.6%) as treatment errors, and 30 (26.3%) as prevention errors. Eighteen separate hospital care processes were identified and modified as a result of this review, 10 of which involved standardization. CONCLUSIONS: MET review may be used for surveillance to detect medical errors and to identify and modify processes of care that underlie those errors