The U.S. Food and Drug Administration (FDA) is considering approval of an over-the-counter, rapid HIV test for home use. To date, testimony presented before the FDA has been overwhelmingly supportive. Advocates have argued enthusiastically that there is value in empowering individuals to manage their HIV risks and have suggested that the availability of a rapid home HIV test will dramatically increase rates of disease detection in communities that have proven difficult to reach and to link to appropriate care. The authors offer a more cautious perspective.

According to what is already known about the market demand for over-the-counter HIV testing kits, their costs, and the performance of rapid HIV tests in that market, the authors do not anticipate that the rapid home test will have a profound impact either on the HIV public health crisis or on the populations in greatest need. Home HIV testing will attract a predominantly affluent clientele, composed disproportionately of HIV-uninfected new couples and "worried well" persons, as well as very recently infected persons with undetectable disease. The authors illustrate how testing in these populations may have the perverse effect of increasing both false-positive and false-negative results. A poorly functioning home HIV test may thereby undermine confidence in the reliability of HIV testing more generally and weaken critical efforts to expand HIV detection and linkage to lifesaving care for the estimated 300 000 U.S. citizens with unidentified HIV infection.

Outcomes research often requires estimating the impact of a binary treatment on a binary outcome in a non-randomized setting, such as the effect of taking a drug on mortality. The data often come from self-selected samples, leading to a spurious correlation between the treatment and outcome when standard binary dependent variable techniques, like logit or probit, are used. Intuition suggests that a two-step procedure (analogous to two-stage least squares) might be sufficient to deal with this problem if variables are available that are correlated with the treatment choice but not the outcome.

This paper demonstrates the limitations of such a two-step procedure. We show that such estimators will not generally be consistent. We conduct a Monte Carlo exercise to compare the performance of the two-step probit estimator, the two-stage least squares linear probability model estimator, and the multivariate probit. The results from this exercise argue in favour of using the multivariate probit rather than the two-step or linear probability model estimators, especially when there is more than one treatment, when the average probability of the dependent variable is close to 0 or 1, or when the data generating process is not normal. We demonstrate how these different methods perform in an empirical example examining the effect of private and public insurance coverage on the mortality of HIV+ patients.

We sought to understand how diagnosis with HIV affects health-related quality of life. We assessed health-related quality of life using utility-based measures in a Department of Veterans Affairs (VA) clinic and a University-based clinic. Respondents assessed health-related quality of life regarding their current health, and retrospectively assessed their health 1 month prior to and 2 months after diagnosis with HIV infection. Sixty-six patients completed the study. The overall mean utilities for health 1 month before and 2 months after diagnosis were 0.87 (standard error 0.037), and 0.80 (0.043) (p0.005 by rank sign test), but the effect of diagnosis differed between the two clinics, with a substantial decrease in the university clinic and a small non-significant decrease in the VA clinic. The overall mean utility for current health was 0.85 (0.034), assessed on average 7.5 years after diagnosis. When asked directly whether diagnosis of HIV decreased health-related quality of life, 47% agreed, but 35% stated that HIV diagnosis positively affected health-related quality of life. Diagnosis with HIV decreased health-related quality of life at 2 months on average, but this effect diminished over time, and differed among patient populations. Years after diagnosis, although half of the patients believed that diagnosis reduced health-related quality of life, one-third reported improved health-related quality of life.

This issue of CHP/PCOR's quarterly newsletter, which covers news from the fall 2005 quarter, includes articles about:

• a study concluding that the implantable cardioverter defibrillator -- one of the most expensive medical devices on the market -- is worth its high cost, in appropriate patients, because it prevents sudden cardiac deaths;
• the evolution and broad application of the Quality Indicators, a set of practical tools developed by CHP/PCOR researchers that are used by hundreds of U.S. hospitals, medical groups, health insurers, state health agencies and business coalitions to screen for quality problems;
• a study finding that the Internet can be a valuable tool to help patients with stigmatized illnesses (such as mental illness) find information about and seek treatment for their illness;
• CHP/PCOR-hosted seminars on global health themes, given by Jack Chow of the World Health Organization -- who discussed combating malaria, TB and HIV/AIDS -- and Dean Jamison of the NIH's Fogarty International Center, who discussed evaluating countries' performance on health; and
• a prestigious national award won by two CHP/PCOR trainees at the annual meeting of the Society for Medical Decision Making.

To allocate HIV prevention resources effectively, it is important to have information about the effectiveness of alternative prevention programs as a function of expenditure. We refer to this relationship as the ldquoproduction functionrdquo for a prevention program. Few studies of HIV prevention programs have reported this relationship. This paper demonstrates the value of such information. We present a simple model for allocating HIV prevention resources, and apply the model to an illustrative HIV prevention resource allocation problem. We show that, without sufficient information about prevention program production functions, suboptimal decisions may be made. We show that epidemiologic data, such as estimates of HIV prevalence or incidence, may not provide enough information to support optimal allocation of HIV prevention resources. Our results suggest that good allocations can be obtained based on fairly basic information about prevention program production functions: an estimate of fixed cost plus a single estimate of cost and resulting risk reduction. We find that knowledge of production functions is most important when fixed cost is high and/or when the budget is a significantly constraining factor. We suggest that, at the minimum, future data collection on prevention program effectiveness should include fixed and variable cost estimates for the intervention when implemented at a ldquotypicalrdquo level, along with a detailed description of the intervention and detailed description of costs by category.

This issue of CHP/PCOR's quarterly newsletter, which covers news from the summer 2005 quarter, includes articles about:

• our new core faculty member Grant Miller, a Harvard-trained health economist with an interest in improving health in developing countries;
• a discussion with center director Alan Garber on key issues and challenges facing the Medicare program;
• the fourth meeting of the Patient Safety Consortium, a group of more than 100 U.S. hospitals taking part in CHP/PCOR research on patient safety culture;
• core faculty member Jay Bhattacharya's research on HIV patients' perceptions of their lifespan as examined through viatical settlement transactions; and
• a research project on technology coverage decisions in the U.S. vs. the U.K., undertaken by Stirling Bryan, a U.K.-based Harkness Fellow in Health Care Policy who is spending the next academic year at CHP/PCOR.

This issue of CHP/PCOR's quarterly newsletter covers developments from the spring 2005 quarter. It includes articles about:

• research on HIV/AIDS in Russia -- presented in May at an international conference -- which shows that in order to contain the country's rapidly expanding HIV/AIDS epidemic, Russia must aggressively treat HIV-positive injection drug users;
• a CHP/PCOR-hosted discussion session with Edward Sondik, director of the National Center for Health Statistics;
• an ongoing CHP/PCOR study that examines older adults' preferences about health states in which they would need help with basic tasks like bathing or eating;
• a panel discussion on "International Responses to Infectious Diseases," led by CHP/PCOR at the Stanford Institute for International Studies' first annual conference, featuring the World Health Organization's chief of infectious diseases;
• a widely publicized study by CHP/PCOR researchers which found that obese workers are paid less than non-obese workers in similar jobs, but only when they have employer-sponsored health insurance -- a finding suggesting that the wage gap is due to obese workers' higher medical costs, rather than outright prejudice; and
• an update on the Center on Advancing Decision Making for Aging, including two new seed projects and a lecture given by economics and psychology professor George Loewenstein.