PubMed · 8563564
The source did not provide an abstract. Follow the original record for more information.
Explore connections, maps & timelines
O M Goodyear. 1996-01-20. Contract minimum dataset includes confidential data.. https://doi.org/10.1136/bmj.312.7024.185
Cite the original work for its findings. Save a collection to share your selection of sources.
KEEP EXPLORING
In most cohort studies of HIV infection and AIDS, seroprevalent cases provide a substantial amount of information. Inclusion of these people in natural history studies requires a fairly unbiased method to estimate their seroconversion distribution. When a cohort-based estimate is not feasible, an alternative is to estimate individual seroconversion distributions, based on marker values at entry. In this paper, a non-parametric marker-based estimation method is developed. The method is applied to data from the Amsterdam cohort study on homosexual men. For seroprevalent cases who entered the study between October 1984 and April 1985, individual seroconversion distributions are estimated based on their first measured CD4 count. In subsequent survival analyses, dates of seroconversion are estimated via conditional mean imputation. Inclusion of these seroprevalent cases greatly improves the quality of the data. Age at seroconversion is a significant cofactor for disease progression, a result not found when analysis is restricted to those who seroconvert. To incorporate the uncertainty in the imputed date of seroconversion, a bootstrap procedure is developed for the computation of p-values and confidence intervals. In our analyses, standard procedures, which ignore the uncertainty in the imputed date of seroconversion, perform almost as well.
Cytomegalovirus (CMV) replicates rapidly in its human host with a doubling time of approximately 1 day. Using simple mathematical models we show that the efficacy of the anti-CMV drug ganciclovir (GCV) against wild-type strains is 91.5% [95% confidence interval (CI) 89-94%] when given i.v. (5 mg/kg twice a day) but only 46.5% (95% CI 45-47.5%) when given orally (1 g three times a day) whereas the corresponding figures for a typical GCV-resistant virus are 62% (95% CI 57-66%) and 35% (95% CI 33-37%), respectively. During prolonged periods of GCV therapy we show that the apparent sudden appearance of GCV resistance is explained by the combination of two exponentially increasing populations (wild type and mutant) at doses of GCV that do not completely inhibit CMV replication. Cell culture methods to assess CMV drug resistance in vivo will underestimate its prevalence because of the fitness loss of resistant virus in the absence of therapy. The parameters determined from these models then were used to predict the likely viral load and resistance patterns in patients on prolonged therapy with GCV. The modeled and experimental data showed excellent agreement over extended time periods (up to 270 days of therapy) and provide a framework to predict the virologic course of patients at therapeutic initiation.
This paper compares health care use across subgroups of injection drug users (IDUs) with AIDS, as defined by current drug abuse status and participation in methadone maintenance treatment (MMT), using surveillance-identified IDU status and health care claims data. Merged Medicaid and AIDS surveillance data were analyzed using ordinary least squares regression, simple logistic regression and multinomial logistic regression. Consistent MMT was more likely among women, Whites and older subjects. Monthly total expenditures and inpatient expenditures were significantly lower for IDUs in MMT than for IDUs with claims indicative of current drug abuse. Consistent participation in MMT was associated with a higher probability of antiretroviral use and, among antiretroviral users, more consistent use of antiretrovirals. Merged administrative data sets can be an important data source that illuminate the relationships among drug abuse, drug treatment, and HIV-related health care. For AIDS-infected IDUs, consistent MMT may lower barriers to receipt of appropriate HIV-related health care and reinforce adherence to medical recommendations.