Biomedical subjects

Samuel A Bozzette

Publications and source records attributed to Samuel A Bozzette.

27 records · Page 2Linked to original sources

PubMed2002

A model for a smallpox-vaccination policy.

BACKGROUND: The new reality of biologic terrorism and warfare has ignited a debate about whether to reintroduce smallpox vaccination. METHODS: We developed scenarios of smallpox attacks and built a stochastic model of outcomes under various control policies. We conducted a systematic literature review and estimated model parameters on the basis of European and North American outbreaks since World War II. We assessed the trade-offs between vaccine-related harms and benefits. RESULTS: Nations or terrorists possessing a smallpox weapon could feasibly mount attacks that vary with respect to tactical complexity and target size, and patterns of spread can be expected to vary according to whether index patients are hospitalized early. For acceptable results, vaccination of contacts must be accompanied by effective isolation. Vaccination of contacts plus isolation is expected to result in 7 deaths (from vaccine or smallpox) in a scenario involving the release of variola virus from a laboratory, 19 deaths in a human-vector scenario, 300 deaths in a building-attack scenario, 2735 deaths in a scenario involving a low-impact airport attack, and 54,729 deaths in a scenario involving a high-impact airport attack. Immediate vaccination of the public in an attacked region would provide little additional benefit. Prior vaccination of health care workers, who would be disproportionately affected, would save lives in large local or national attacks but would cause 25 deaths nationally. Prior vaccination of health care workers and the public would save lives in a national attack but would cause 482 deaths nationally. The expected net benefits of vaccination depend on the assessed probability of an attack. Prior vaccination of health care workers would be expected to save lives if the probability of a building attack exceeded 0.22 or if the probability of a high-impact airport attack exceeded 0.002. The probability would have to be much higher to make vaccination of the public life-saving. CONCLUSIONS: The analysis favors prior vaccination of health care workers unless the likelihood of any attack is very low, but it favors vaccination of the public only if the likelihood of a national attack or of multiple attacks is high.

Bioterrorism↗

PubMed2002

Participation in research and access to experimental treatments by HIV-infected patients.

BACKGROUND: Although there is concern that minority groups and women are underrepresented in research involving patients with human immunodeficiency virus (HIV) infection, the available data are inconclusive. METHODS: We used nationally representative data from the HIV Cost and Services Utilization Study to determine the characteristics of the participants and nonparticipants in trials of medications for HIV infection and whether or not patients had access to experimental treatments. A probability sample of 2864 persons, representing all 231,400 adults with known HIV infection who are cared for in the contiguous United States, were interviewed on three occasions between 1996 and 1998. They were asked about participation in clinical research studies of medications and past receipt of experimental medications for HIV. RESULTS: We estimate that 14 percent of adults receiving care for HIV infection participated in a medication trial or study; 24 percent had received experimental medications; and 8 percent had tried and failed to obtain experimental treatments. According to multivariate models, non-Hispanic blacks and Hispanics were less likely to be participating in trials than non-Hispanic whites (odds ratio for participation among non-Hispanic blacks, 0.50 [95 percent confidence interval, 0.28 to 0.91]; odds ratio among Hispanics, 0.58 [95 percent confidence interval, 0.37 to 0.93]) and to have received experimental medications (odds ratios, 0.41 [95 percent confidence interval, 0.32 to 0.54] and 0.56 [95 percent confidence interval, 0.41 to 0.78], respectively). Patients who were cared for in private health maintenance organizations were less likely to participate in trials than those with fee-for-service insurance (odds ratio, 0.43 [95 percent confidence interval, 0.21 to 0.88]). Women were not underrepresented in research trials and had a similar likelihood of receiving experimental treatments. CONCLUSIONS: Among patients with HIV infection, participation in research trials and access to experimental treatment is influenced by race or ethnic group and type of health insurance.

Adult↗

PubMed2002

Efficacy of trimethoprim-sulfamethoxazole for the prevention of bacterial infections in a randomized prophylaxis trial of patients with advanced HIV infection.

We compared the occurrences of several types of infections in HIV-infected patients participating in a randomized clinical trial of three treatment strategies given for the primary prevention of Pneumocystis carinii pneumonia (PCP) and toxoplasmosis. In a phase III open label trial, 842 patients with HIV infection and fewer than 200 CD4+ cells/mm(3) received zidovudine (standard dose) plus one of three randomly assigned prophylactic agents: trimethoprim-sulfamethoxazole (TMP-SMZ), or dapsone (DAP), or aerosolized pentamidine (AP). Patients developing intolerance to treatment were crossed over to another predefined prophylactic therapy. Patients were monitored for infections every other week for 8 weeks and then monthly until the study was completed. Primary statistical models were proportional hazards models adapted to recurrent end points. In an intent-to-treat analysis, compared with AP and DAP, TMP-SMZ significantly reduced the risk of any bacterial infection (combining all distinct types) (p = 0.02 and p = 0.01, respectively). When considering distinct types separately, compared with AP, TMP-SMZ significantly reduced the risk of infectious diarrhea (p = 0.04); compared with DAP, AP and TMP-SMZ significantly reduced the risk of sinusitis/otitis media (p = 0.03 and p = 0.04, respectively); compared with AP and DAP, TMP-SMZ significantly reduced the risk of a second occurrence of pneumonia (p = 0.04 and 0.02, respectively). For any bacterial infection, infection rates per 100 patient-years of follow-up were 31, 39, and 38 for TMP-SMZ, DAP, and AP, respectively. In patients with advanced HIV infection not taking highly active antiretroviral therapy, the treatment strategy that initiates prophylaxis with TMP-SMZ is superior to those initiating with AP or DAP for preventing any bacterial infection, with most of the advantage manifested through infectious diarrhea, sinusitis/otitis media, and pneumonia.

AIDS-Related Opportunistic Infections↗

PubMed2002

Specialty training and specialization among physicians who treat HIV/AIDS in the United States.

OBJECTIVE: To assess the association of specialty training and experience in the care of HIV disease with HIV-specific knowledge, referral patterns, and HIV-related education activities. DESIGN: Cross-sectional survey. SETTING: The United States. PARTICIPANTS: Physicians caring for patients in the HIV Costs and Service Utilization Study, a study of a probability sample of HIV-infected individuals in the United States. MEASUREMENTS AND MAIN RESULTS: Measures included physicians' reports of specialty training and HIV caseload, scores on an HIV-specific knowledge test, referral patterns, and attendance rates at HIV-related educational activities. Approximately 72% (379) of the eligible physicians completed a survey. Of these, 152 (40%) had infectious disease (ID) training, and 213 (56%) were generalists; 4% of ID-trained physicians and 37% of generalist physicians did not consider themselves HIV experts. The median current caseloads were 150 and 200 patients for ID experts and generalist experts, respectively. In contrast, the median caseload for non-expert generalists was 5. Mean scores on the knowledge scale were similar for ID and generalist experts (9.0 items correct out of 11 vs 8.5; P=not significant), but lower for generalist non-experts (6.5 items correct; P <.01). Experts had attended more local and national HIV meetings than non-experts (9.3 vs 2.7; P <.01, and 2.3 vs.40; P <.01, respectively) in the past year. Fewer ID experts ever referred than generalist experts (13.0% vs 27.3%; P=.01). In multivariable models that included specialty training and caseload, physicians with caseloads of 20 to 49 and >50 were more likely to have a high knowledge score (defined as 80% or more correct, odds ratio [OR], 2.8; P=.04 and OR, 5.7; P <.001, respectively), and the effect of specialty was attenuated (OR, 2.7; P=.02 decreased from OR, 7.8; P <.001 in a model without caseload). In the models predicting referral practices, both experience (OR,.25; P <.01 and OR,.17; P <.01 for caseloads of 20 to 49 and >50, respectively) and specialty (OR,.19; P <.01 and OR,.09; P <.01 for generalist and ID experts, respectively) were significant. CONCLUSIONS: In a national sample of physicians, HIV-specific knowledge was more strongly associated with HIV caseload than with specialty training. In addition, although referral practices were related to both experience and specialty, generalist experts and ID physicians reported similar behaviors. This suggests that generalist physicians, through clinical experience and self-education, can develop specialized knowledge in HIV care.

Acquired Immunodeficiency Syndrome↗

PubMed2002

HIV patients' experiences with inpatient and outpatient care: results of a national survey.

CONTEXT: Little is known about HIV patients' care experiences. OBJECTIVE: To assess HIV patients' experiences with inpatient and outpatient care, and to assess the relationship and relative influence of patient characteristics and site of care on care experiences. DESIGN: Cohort study. SETTING: Patients with HIV receiving care outside of emergency rooms, prisons, or the military throughout the continental United States. One thousand seventy-four patients provided ratings of an inpatient stay and 2204 rated an outpatient visit; 818 patients provided evaluations of both inpatient and outpatient care. PATIENTS: A national probability sample of persons in care for HIV from the HIV Cost and Services Utilization Study. MEASUREMENTS: Outcome variables were rates of problems with, and global ratings of, inpatient and outpatient care. RESULTS: Mean problem rates were 20.9% and 8.4% (lower score means fewer problems) for inpatient and outpatient care, respectively. On 9 of 10 of the individual inpatient report items, 15% or more of respondents reported problems. Global ratings of inpatient and outpatient care were 65.3 and 75.0 (0-100 scale, higher scores indicate better ratings), respectively. In multivariable models that controlled for site effects, the only patient characteristic that was consistently associated with problem rates and global ratings of care was mental health (P <0.0001 for both inpatient and outpatient care). Models including site effects explained two to four times as much variance as models excluding site effects. CONCLUSIONS: Inpatients with HIV reported higher problem rates with inpatient than outpatient care. Better provider-patient communication during inpatient stays is needed. For both inpatient and outpatient care, quality improvement efforts may be most productively focused on providers and processes of care at sites rather than on specific patient subgroups.

Adult↗

PubMed2002

Measuring medication: do interviews agree with medical record and pharmacy data?

BACKGROUND: Medication measurement is crucial in assessing quality for chronic conditions yet agreement of alternate data sources remains uncertain. OBJECTIVES: To evaluate medication agreement between interviews, medical records, and pharmacy data; to assess data source contribution to attributing medication exposure; and to describe the impact of combining data sources on models that predict medication use. RESEARCH DESIGN: Prospective cohort study. SUBJECTS: Probability sample of HIV-infected participants in the HIV Cost and Services Utilization Study. MEASURES: Medications reported in 2267 interviews, 1936 medical records, and 457 pharmacy records were compared using crude agreement, kappa, and the proportion of average positive and negative agreement. The percent of medications reported in each source alone was used to assess their relative contribution to attributing exposure status. We performed weighted logistic regression in alternate data sources. RESULTS: Kappa varied from 0.38 for nucleoside reverse transcriptase inhibitors to 0.70 for protease inhibitors, when comparing drug classes in interview versus medical record, interview versus pharmacy data, and medical record versus pharmacy data. The percentage of medications reported in medical records was greater than that reported in interviews or pharmacy data. Pharmacy data contributed little to the attribution of medication exposure. Adding medication data to interview data did not appreciably change analytic models predicting medication use. CONCLUSIONS: For specific medications, agreement between alternative data sources is fair to substantial, but is lower for key drug classes. Relying on one data source may lead to misclassification of drug exposure status, but combining data sources does not change the results of analytic models predicting appropriate medication use.

Antiretroviral Therapy, Highly Active↗

PubMed2002

Where to seek care: an examination of people in rural areas with HIV/AIDS.

Though HIV/AIDS has spread to rural areas, little empirical evidence is available on where patients living in these areas receive care. This article presents estimates of rural residents in care for HIV/AIDS, their demographic and health-related characteristics, information about whether they receive care in a rural or urban setting, and data on the drug therapies prescribed. The estimates come from the HIV Cost and Services Utilization Study (HCSUS), a nationally representative probability sample of HIV-infected adults receiving care in the contiguous United States. Regardless of the definition used--enrollment site, usual source of HIV care, or site of most recent hospitalization--almost three quarters of rural residents with HIV/AIDS obtained their health care in urban areas. The authors find that differences in the demographic characteristics of those using urban vs. rural care do not drive the decision on where to obtain care, with the primary difference being that people with a rural provider tend to be older. Rural residents with an urban usual source of HIV care incurred significant inconvenience in obtaining care--the majority said their care was not conveniently located, they had substantially longer mean travel times, and over 25% had put off obtaining care in the past 6 months because they did not have a way to get to their provider. Given the considerable burden this places on a chronically ill population,further research is needed to explore how provider supply and provider experience affect the decision to travel for care and how quality of care is affected.

Acquired Immunodeficiency Syndrome↗

PubMed2002

Response to symptoms among a U.S. national probability sample of adults infected with human immunodeficiency virus.

Previous studies concerning disparities in Human Immunodeficiency Virus (HIV) services use among vulnerable groups did not control for specific clinical need for care such as symptom events. Using the Andersen Behavioral Model of Health Services Use, the authors determined whether minorities, women, and the less educated (vulnerable groups) were less likely to receive care for HIV symptoms. Persons enrolled in the HIV Cost and Services Utilization Study were asked whether they received care for their most bothersome symptom. Surprisingly, minorities and women were no more likely to go without care than other groups. Those with Medicaid, Medicare, private health maintenance organization (HMO) insurance, or no insurance were less likely to receive care for symptoms than those with private-non-HMO insurance. Vulnerable groups were no less likely to use services for HIV-related symptoms when need for care was considered. However, disparities may exist for symptom-specific care among HIV infected persons covered by public or HMO insurance.

Adolescent↗

PubMedDate not supplied

Creating a crosswalk to estimate AIDS Clinical Trials Group quality of life scores in a nationally representative sample of persons in care for HIV in the United States.

BACKGROUND: Optimizing health-related quality of life (HRQOL) is an increasingly important goal in the treatment of HIV/AIDS. Interpretation of HRQOL scores in clinical trials is enhanced by comparative data. PURPOSE: To estimate AIDS Clinical Trials Group (ACTG) QOL 601-602 questionnaire scale scores for a nationally representative sample of persons in care for HIV. METHOD: The study cohort was from the HIV Cost and Services Utilization Study (HCSUS), a multistage national probability sample. We derived HCSUS HRQOL scale scores from the items shared between the ACTG QOL 601-602 and HCSUS HRQOL questionnaires using regression equations. Cronbach's alpha coefficient was used to estimate the reliability of the multi-item scales in the ACTG QOL 601-602 and HCSUS HRQOL instruments. Correlation Coefficients and R2s of regression models were calculated to determine the concordance of the models. Multiple regression was used to determine if patient characteristics accounted for differences (residuals) between scores observed from the full HCSUS HRQOL instruments and scores predicted using the subset of shared items in ACTG QOL 601-2. RESULTS: Internal consistency reliability estimates were acceptable (>0.70) for all scales in the ACTG QOL 601-602 and HCSUS HRQOL instruments. Correlations between corresponding ACTG QOL 601-602 and HCSUS HRQOL scale scores were high (>0.9). The R2s for predicting HCSUS HRQOL scores from the ACTG QOL 601-602 scales were also high (>0.8). For physical functioning, emotional well-being, and general health perceptions, the predictors of differences (residuals) in observed and predicted HCSUS HRQOL scores were gender and CDC stage of HIV infection (P < .05). CONCLUSION: This study provides normative data from the US HIV/AIDS population for comparison to the ACTG QOL 601-602 questionnaire. Accuracy of estimation is enhanced if done separately by gender and HIV disease stage.

Adolescent↗