Needle exchange programs: an economic evaluation of a local experience.

OBJECTIVE: To determine whether providing a needle exchange program to prevent HIV transmission among injection drug users would cost less than the health care consequences of not having such a program. DESIGN: Incidence outcome model to estimate the number of cases of HIV infection that this program would prevent over 5 years, assuming that the HIV incidence rate would be 2% with the program and 4% without it, and that an estimated 275 injection drug users would use the service over this time. SETTING: Hamilton, Ont. OUTCOME MEASURES: Estimated number of cases of HIV infection expected to be prevented with and without the program over 5 years; estimated lifetime health care costs of treating an AIDS patient. The indirect costs of AIDS to society (e.g., lost productivity and informal caregiving) were not included. Projected costs were adjusted (discounted) to reflect their present value. In a sensitivity analysis, 3 parameters were varied: the estimate of the HIV transmission rate if no needle exchange program were provided, the number of injection drug users participating in the program, and the discount rate. RESULTS: With very conservative estimates, it was predicted that the Hamilton needle exchange program will prevent 24 cases of HIV infection over 5 years, thereby providing cost savings of $1.3 million after the program costs are taken into account. This translates into a ratio of cost savings to costs of 4:1. The sensitivity analysis confirmed that these findings are robust. CONCLUSION: Needle exchange programs are an efficient use of financial resources.

Understanding and enhancing compliance with the second dose of hepatitis B vaccine: a cohort analysis and a randomized controlled trial.

OBJECTIVE: To determine the predictors and extent of noncompliance with a second dose of hepatitis B vaccine and the effectiveness of a compliance enhancement strategy. DESIGN: Cohort analysis and randomized clinical trial. SUBJECTS: A total of 256 consecutive adults attending a sexually transmitted diseases clinic from October 1992 to July 1993 who were seronegative for hepatitis B virus and agreed to receive hepatitis B vaccination. SETTING: Hamilton, Ont. INTERVENTION: Subjects were followed up for 4 months. Those who did not return for the second dose of vaccine by 6 weeks after the first (2 weeks overdue) were randomly assigned to the enhanced intervention group (telephone and mail reminders) or the regular intervention group (mail reminder only). Subjects were considered noncompliant if they did not return for the second dose by 4 months after the first. RESULTS: The risk of not returning for the second dose of vaccine within 4 months after the first was strongly and linearly associated with level of education (p = 0.004). The noncompliance rate among those with less than a grade 10 education was 50%, grade 10-13 education 34%, some college education 15% and some university education 9%. In the randomized controlled trial the enhanced intervention group had twice the compliance rate of the regular intervention group (48% v. 25%; p = 0.008). Subjects with no postsecondary education were highly responsive to the enhanced intervention (relative risk 2.1; p = 0.02) compared with those with a higher level of education (relative risk 1.0; p = 1.0). CONCLUSION: Hepatitis B vaccine recipients with lower educational levels are at increased risk of noncompliance with the second dose of vaccine but are highly responsive to telephone reminders.