An analysis of US drug use data shows that the Baby Boom generation (born 1946 to 1964) has the highest rate of injection drug use ever. That bubble in injection drug use continues to this day, with the authors of the study noting that "the mean age of injection drug users has increased substantially."

Study author Gregory Armstrong of the Centers for Disease Control analyzed data from the National Household Survey on Drug Abuse from 1979 through 2002. He found that 1.5% of people surveyed in 2000-2002, or some 3.4 million people, reported ever injecting drugs. Nearly 0.2%, or some 440,000 people, reported shooting up in the previous year. The highest injection drug use rate by age came among 35-to-49-year-olds, with 3.1% reporting having put the needle in the vein.

The findings "may challenge conventional stereotypes of injection drug users," Armstrong said. "Injection drug users are a heterogenous group and, on average, they are no longer young." Nor are they black. The analysis found that injection drug use rates "are now lower among young blacks than among young whites."

That contrasts with the pattern for people born before 1955. While whites are now twice as likely to have shot up than blacks (1.7% vs. 0.8%), it was the other way around for people over 50. Among that cohort, blacks were more likely to have injected drugs.

The figures should be heeded by physicians, said Armstrong. "Anyone who has ever used injection drugs, no matter how infrequently or how remotely in the past, should be appropriately counseled and offered testing for HIV, hepatitis B, and hepatitis C," he warned.

The full report, "Injection Drug Users in the United States, 1979-2002, An Aging Population," was published in the Archives of Internal Medicine (2007;167:166-173). It is not available online without paying a fee. An abstract of the report can viewed here.