Self-reported antiretroviral therapy in injection drug users.

CONTEXT: The US Public Health Service and the International AIDS Society-USA recently published recommendations for antiretroviral therapy (ART) for persons infected with human immunodeficiency virus (HIV); however, anecdotal evidence suggests that HIV-infected injection drug users (IDUs) may not be receiving optimal care as defined by the recommendations. OBJECTIVE: To assess ART use in HIV-infected IDUs. DESIGN: A cross-sectional survey of self-reported ART use between July 1996 and June 1997 in IDUs. SETTING: A community-based clinic affiliated with Johns Hopkins University, Baltimore, Md. PARTICIPANTS: A total of 404 HIV-infected IDUs with CD4+ cell counts less than 0.50 x 10(9)/L recruited into a longitudinal study in 1988 and 1989. MAIN OUTCOME MEASURE: Self-reported ART use was assessed: no current therapy, monotherapy, or combination therapy with or without a protease inhibitor. RESULTS: One half (199/404 [49%]) of patients reported no recent ART. A total of 14% (58/404) had monotherapy, 23% (90/404) were receiving combination therapy without a protease inhibitor, and 14% (57/404) had triple-combination therapy with a protease inhibitor. A multivariate analysis of factors associated with ART showed that care continuity and recent HIV-related outpatient visit (odds ratio [OR], 4.30; 95% confidence interval [CI], 2.36-7.81 and OR, 2.84; 95% CI, 1.66-4.88, respectively), CD4+ cell count of less than 0.20 x 10(9) (OR, 2.41; 95% CI, 1.51-3.84), no current drug use and being in drug treatment (OR, 2.16; 95% CI, 1.34-3.47; OR, 2.12; 95% CI, 1.23-3.66, respectively), and unemployment (OR, 2.31; 95% CI, 1.21-4.40) were associated with reporting ART use. In other analysis, less likely to receive protease inhibitors were current drug injectors (OR, 0.5; 95% CI, 0.3-1.0) and those recently incarcerated (OR, 0.2; 95% CI, 0.03-0.9), but patients with acquired immunodeficiency syndrome were more likely to receive protease inhibitors (OR, 2.0; 95% CI, 0.9-4.6). Protease inhibitor use doubled (P<.01) from July and December 1996 to January and June 1997 (7.7% and 14.8%, respectively). CONCLUSIONS: Those IDUs infected with HIV who were not receiving ART tended to be active drug users without clinical disease who have less contact with health care providers. Although we do not have information on clinical judgment regarding treatment decisions or whether persons were prescribed therapy not taken, the proportion of subjects reporting receiving ART suggests that strategies for improving treatment in this population are indicated. Expanding simultaneous treatment services for HIV infection and substance abuse would enhance the response to these related epidemics.

Bayesian inference for model-based segmentation of computed radiographs of the hand.

We present a method for medical image understanding by computer that uses model-based, hierarchical Bayesian inference to accurately segment imaged anatomy. A first application is a prototype system that automatically segments and measures symptoms of arthridities in hand radiographs. This is potentially useful in radiological diagnosis and tracking of arthridities. Key steps of the model-based, Bayesian inference approach are: (1) prediction of imagery features from 3D models of anatomy, parameterized by population statistics, (2) local image feature extraction in predicted sub-regions, and (3) the use of a probabilistic calculus to accrue results of image processing and image feature matching procedures in support or denial of hypotheses about the imaged anatomy. The prototype system for hand radiograph analysis accurately segments normal and somewhat degenerated hand anatomy. Results are shown of the ability of the automated system to 'fail soft', recognizing when segmentation is inadequate for accurate measurement. This self evaluation capability improves reliability of measurements for potential clinical use.