Publications

OBJECTIVE

To determine the relationship of HIV infection, demographic, and cardiovascular disease (CVD) risk factors with mortality in the recent highly active antiretroviral therapy era.

METHODS

Vital status was ascertained from 2004 to 2007 in 922 HIV infected and 280 controls in the Study of Fat Redistribution and Metabolic Change in HIV infection; 469 HIV infected were included in analysis comparing HIV with similar age controls. Multivariable exponential survival regression (adjusting for demographic and CVD factors) estimated hazard ratios (HRs) for death.

RESULTS

After 5 years of follow-up, the overall adjusted mortality HR was 3.4 [95% confidence interval (CI): 1.35-8.5]; HR was 6.3 among HIV infected with CD4 < 200 (95% CI: 2.2-18.2), 4.3 with CD4 200-350 (95% CI: 1.14-16.0), and 2.3 with CD4 > 350 (95% CI: 0.78-6.9). Among HIV infected, current smoking (HR = 2.73 vs. never smokers, 95% CI: 1.64-4.5) and older age (HR = 1.61 per decade, 95% CI: 1.27-2.1) were independent risk factors for death; higher baseline CD4 count was associated with lower risk (HR = 0.65 per CD4 doubling, 95% CI: 0.58-0.73).

CONCLUSIONS

HIV infection was associated with a 3-fold mortality risk compared with controls after adjustment for demographic and CVD risk factors. In addition to low baseline CD4 count, older age and current smoking were strong and independent predictors of mortality in a US cohort of HIV-infected participants in clinical care.

The incidence of hepatitis A infection in the United States has decreased dramatically in recent years because of childhood immunization programs. A decision analysis of the cost-effectiveness of hepatitis A vaccination for adults with hepatitis C was conducted. No vaccination strategy is cost-effective for adults with hepatitis C using the recent lower anticipated hepatitis A incidence, private sector costs, and a cost-effectiveness criterion of $100,000/QALY. Vaccination is cost-effective only for individuals who have cleared the hepatitis C virus when Department of Veterans Affairs costs are used. The recommendation to vaccinate adults with hepatitis C against hepatitis A should be reconsidered.

CONTEXT

Medical devices are common in clinical practice and have important effects on morbidity and mortality, yet there has not been a systematic examination of evidence used by the US Food and Drug Administration (FDA) for device approval.

OBJECTIVES

To study premarket approval (PMA)--the most stringent FDA review process--of cardiovascular devices and to characterize the type and strength of evidence on which it is based.

DATA SOURCES AND STUDY SELECTION

Systematic review of 78 summaries of safety and effectiveness data for 78 PMAs for high risk cardiovascular devices that received PMA between January 2000 and December 2007 [corrected].

DATA EXTRACTION

Examination of the methodological characteristics considered essential to minimize confounding and bias, as well as the primary end points of the 123 studies supporting the PMAs.

RESULTS

Thirty-three of 123 studies (27%) used to support recent FDA approval of cardiovascular devices were randomized and 17 of 123 (14%) were blinded. Fifty-one of 78 PMAs (65%) were based on a single study. One hundred eleven of 213 primary end points (52%) were compared with controls and 34 of 111 controls (31%) were retrospective. One hundred eighty-seven of 213 primary end points (88%) were surrogate measures and 122 of 157 (78%) had a discrepancy between the number of patients enrolled in the study and the number analyzed.

CONCLUSION

Premarket approval of cardiovascular devices by the FDA is often based on studies that lack adequate strength and may be prone to bias.

Pulmonary alveolar type I cells (TI cell) are very large (approximately 5400 microm(2) in surface area) squamous cells that cover more than 98% of the internal surface area of rodent lungs. In the past, TI cells were believed to serve only passive barrier functions, with no active functional properties in the lung. The fairly recent development of methods to isolate TI cells has permitted investigation of functions of this cell type for the first time. Resolvable by electron microscopy, TI cells contain microvilli and organelles typically associated with metabolic functions, such as mitochondria, abundant smooth and rough endoplasmic reticulum and Golgi apparatus. TI cells contain the molecular machinery necessary for ion transport and take up Na(+), K(+), and Cl(-), from which one can infer that it is likely that they play a role in ion and fluid transport in vivo. Because the abundance/microm(2) of highly selective Na(+) channels (HSC channels, consisting of all three ENaC subunits) is the same in TI and TII cells and because TI cells cover the majority of the lung internal surface, TI cells may play the major role in bulk transport of Na(+). In vitro, TI cells can proliferate and exhibit phenotypic plasticity, raising the question of whether this cell type may play a role in development and lung repair after injury. From gene expression analysis of TI cells, one can infer a variety of other possible functions for TI cells. The development of techniques to administer transgenes specifically to TI cells will permit direct study of this cell type in vivo.