Background:
Men who have sex with men (MSM) are at high risk of hepatitis A (HAV) and hepatitis B (HBV) infection; especially those men who actively seek multiple partners online. In addition, rates of vaccination among MSM are inadequate.

Objective:
To measure changes in knowledge about - and intentions to get - HAV and HBV vaccinations resulting from online educational materials.

Method:
MSM were recruited through banner ads on gay-related Web sites and invited to assess an educational site on hepatitis. Men were asked to choose one of three survey branches: HAV questions; HBV questions, or questions comparing two different informational treatments. Participants completed a pre-test, viewed the educational Web site, and answered post-test questions designed to assess vaccination intentions and knowledge.

Result:
Of the 358 who volunteered to participate, 137 were eligible for inclusion in the analysis. After viewing the online educational materials, knowledge levels (57% to 93% correct at pre-test) improved on all items (85% to 100% at post-test); 7 items of 16 were statistically significant. Intentions to get vaccinations increased significantly from 17.3% to 62.7% for HAV and from 37% to 74% for HBV.

Conclusion:
The online educational materials increased knowledge about and changed intentions to get HAV or HBV vaccinations among a small sample of high-risk MSM. Prior to the final launch of the online materials, improvements in nine of the sixteen knowledge items are warranted.

Implications:
This study provides useful information for public health professionals for designing and evaluating online educational materials for MSM. Using the Internet to reach this high-risk group is recommended. More studies are needed to assess the reach of online educational materials, and their long-term effectiveness as measured by actual vaccination rates. And finally, more research is needed to understand stratifications within the MSM community.