Outcomes of contact investigations of infectious tuberculosis patients.

The objective of this study was to describe outcomes of tuberculosis (TB) contact investigations, factors correlated with those outcomes, and current successes and ways to improve TB contact investigations. We abstracted clinic records of a representative U.S. urban sample of 1,080 pulmonary, sputum-smear(+) TB patients reported to CDC July 1996 through June 1997 and the cohort of their 6,225 close contacts. We found a median of four close contacts per patient. Fewer contacts were identified for homeless patients. A visit to the patient's residence resulted in two additional (especially child) contacts identified. Eighty-eight percent of eligible contacts received tuberculin skin tests (TSTs). Recording the last exposure date to the infectious patient facilitated follow-up TST provision. Thirty-six percent of contacts were TST(+). Household contacts and contacts to highly smear(+) or cavitary TB patients were most likely to be TST(+). Seventy-four percent of TST(+) contacts started treatment for latent TB infection (LTBI), of whom 56% completed. Sites using public health nurses (PHNs) started more high-risk TST(-) contacts on presumptive treatment for LTBI. Using directly observed treatment (DOT) increased the likelihood of treatment completion. We documented outcomes of contact investigation efforts by urban TB programs. We identified several successful practices, as well as suggestions for improvements, that will help TB programs target policies and procedures to enhance contact investigation effectiveness.

Economic evaluation of HIV prevention programs.

Program managers and policy makers need to balance the costs and benefits of various interventions when planning and evaluating HIV prevention programs. Resources to fund these programs are limited and must be used judiciously to maximize the number of HIV infections averted. Economic evaluation studies of HIV prevention interventions, which we review and critique here, can provide some of the needed information. Special emphasis is given to studies dealing with interventions to reduce or avoid HIV-related risk behaviors. Ninety-three cost-benefit, cost-effectiveness and cost-utility analyses were identified overall. However, only 28 dealt with domestic, behavior change interventions; the remainder focused on screening and testing without prevention counseling, and on care and treatment services. There are compelling demonstrations that behavioral interventions can be cost-effective and even cost-saving. The threshold conditions under which these programs can be considered cost-effective or cost-saving are well defined. However, several important intervention types and multiple key populations have been unstudied. Research in these areas is urgently needed.

Threshold analysis and programs for prevention of HIV infection.

BACKGROUND: Measuring the economic effectiveness of HIV-infection prevention activities poses special challenges in terms of behavioral change and health outcomes assessment. METHODS: One way to address this difficulty is to employ threshold analysis to determine a level of cost per HIV infection averted above which society would seem unwilling to pay. The authors employ a cost-utility analytic framework to determine a monetary threshold for HIV prevention programs, subject base-case results to sensitivity analyses, and apply these results to the Centers for Disease Control and Prevention's fiscal year 1993 budget for extramural HIV prevention programs. RESULTS: The monetary threshold for cost per HIV infection averted was calculated to be $417,000 in 1993 dollars, and ranged from $185,000 to $648,000 depending upon the dollar amount society would be willing to pay per quality-adjusted life year gained. CONCLUSIONS: Economic evaluations of particular HIV-infection prevention activities at least can begin by determining whether their levels of effectiveness are above or below this derived monetary threshold, and refinements beyond this dichotomous evaluation can proceed as further data become available.

An overview of the effectiveness and efficiency of HIV prevention programs.

Because of the enormity of the HIV-AIDS epidemic and the urgency for preventing transmission, HIV prevention programs are a high priority for careful and timely evaluations. Information on program effectiveness and efficiency is needed for decision-making about future HIV prevention priorities. General characteristics of successful HIV prevention programs, programs empirically evaluated and found to change (or not change) high-risk behaviors or in need of further empirical study, and economic evaluations of certain programs are described and summarized with attention limited to programs that have a behavioral basis. HIV prevention programs have an impact on averting or reducing risk behaviors, particularly when they are delivered with sufficient resources, intensity, and cultural competency and are based on a firm foundation of behavioral and social science theory and past research. Economic evaluations have found that some of these behaviorally based programs yield net economic benefits to society, and others are likely cost-effective (even if not cost-saving) relative to other health programs. Still, specific improvements should be made in certain HIV prevention programs.