Injection experience and practices
Respondents began injecting drugs an average of 5.4 years prior to the survey interview (median = 5.0 years) at a mean age of 21.3 years (Table 1). Based upon self-reported injecting practices during the month prior to the survey, 70% of IDUs were considered regular injectors (at least one injection per day) and 30% were intermittent injectors.