Chronic HBV infection raises the relative risk of death in women to 1.16 (1.04–1.34) when compared to noncarriers, which is consistent with prior study findings. As a result, life expectancy falls from 82.0 years in noncarriers to 80.1 years in carriers (Figure 3). In men, life expectancy falls from 79.3 years in noncarriers to 77.4 years in carriers. HBV infection also increases the risk of developing many types of cancer, including hepatocellular carcinoma and cholangiocarcinoma. Cancer is the second most common cause of death in people with chronic hepatitis B. An effective vaccine against HBV has been available for over 20 years. Despite this fact, there are still about 350 million people worldwide who have evidence of current or past infection with HBV. Unfortunately, despite its effectiveness as a vaccine, few people actually get vaccinated against HBV. The main reason cited by participants in a national survey conducted in 2004 was "fear of needles". People who do not know they are infected may suffer long-term consequences of HBV infection such as liver damage, cirrhosis, or cancer. It is also possible that they may pass on their infection to others through blood products or sexual contact. Although these outcomes require confirmation by scientific studies, they are considered major complications associated with HBV.