3.1. Prevalence estimates and trends of NMAS
The estimated lifetime prevalence rate of NMAS was approximately 1.0% and held steady in the four survey years between 1993 and 2001 (). Based on multiple pair-wise comparisons, there were no significant differences in the rates, with the exception of the increase in past-year NMAS between 1993 and 2001. A significant linear trend for 12-month NMAS was found, with a 1-year increase resulting in an expected 10% increase in the odds of past-year NMAS (OR = 1.10; 95% CI = 1.03, 1.17) during this time period. This trend appears to be driven by an increase among males (OR = 1.11, 95% CI = 1.04, 1.20).
Prevalence and trends in non-medical use of anabolic steroids among U.S. college students (weighted estimates)
3.2. Student- and college-level characteristics associated with NMAS
Lifetime NMAS was more prevalent among U.S. college students who were male, married, older than 23 years of age, and/or participants in intercollegiate athletics in at least two survey years when adjusting for the other predictors in the models (). College men had significantly higher odds than college women of reporting lifetime NMAS in each survey year (AORs ranged from 5.34 to 8.52). College students who played or participated in intercollegiate athletics had increased odds as compared to non-athletes of reporting lifetime NMAS in all four survey years (AORs ranged from 1.63 to 2.43). Married students had higher odds of reporting lifetime NMAS as compared to students who were never married in 1999 and 2001. Finally, students older than 23 years of age had greater odds of lifetime NMAS as compared to students under 21 years of age in 1993 and 1997.
Multivariate HGLM analyses of lifetime non-medical use of anabolic steroids (weighted estimates)
Many of the same associations were present for past-year NMAS. For example, college men had greater odds than college women of reporting past-year NMAS in each survey year (AORs ranged from 4.17 to 12.23, p < 0.01). College students who played or participated in intercollegiate athletics had increased odds as compared to non-athletes to report past-year NMAS in 1993 (AOR = 2.25, 95% CI = 1.13, 4.50, p < 0.05) and 1997 (AOR = 2.23, 95% CI = 1.13, 4.40, p < 0.05). Married students had greater odds of past-year NMAS as compared to non-married individuals in 1993 (AOR = 3.22, 95% CI = 1.02, 10.24, p < 0.05) and 2001 (AOR = 4.18, 95% CI = 1.07, 16.39, p < 0.05). Age was not associated with past-year NMAS.
Lifetime NMAS was significantly more prevalent at commuter colleges (1999 and 2001), but urbanicity, geographical region, size of student enrollment, NCAA athletic division, admission criteria and type of college (public versus private) were not associated with either lifetime or past-year NMAS in at least two years. The variance of the random college effects in 1999 and 2001 was found to be significantly greater than zero (p < 0.05), suggesting that additional college-level factors which were not measured in the CAS may explain additional between-college variation in the rates of NMAS. Finally, we found no consistent associations of college-level factors in the models predicting past-year NMAS.
3.3. Relationship between NMAS and other substance use behaviors
Lifetime NMAS was significantly associated with cigarette smoking, binge drinking, marijuana use, other illicit drug use, DSM-IV alcohol use disorders and other risky health behaviors (). For example, anabolic steroid users were nearly 12 times more likely than non-users to report using cocaine in the past-month, when controlling for other related factors (AOR = 11.59, 95% CI = 5.34, 25.15). Furthermore, an estimated 21% of lifetime non-medical users of anabolic steroids met the criteria for past-year DSM-IV alcohol dependence as compared to about 6% of non-steroid users (AOR = 3.08, 95% CI = 1.66, 5.70). Further, lifetime non-medical users of anabolic steroids were over six times more likely than non-users to have driven after binge drinking in the past 30 days (AOR = 6.20, 95% CI = 3.32, 11.58). An estimated 77% of non-medical users of anabolic steroids reported using at least one illicit drug (including use of prescription drugs non-medically) in the past-year, as compared to 32% of non-steroid users (AOR = 7.93, 95% CI = 4.54, 13.86).
Associations between lifetime non-medical use of anabolic steroids and other risky behaviors, 2001 (weighted estimates)
These same associations held true for past-year NMAS. For example, an estimated 33% of past-year anabolic steroid users met criteria for past-year DSM-IV alcohol dependence as compared to 6% of non-users (AOR = 7.42, 95% CI = 3.34, 16.48). Notably, poor mental health/depressive symptoms based on the SF-36 was not significantly associated with lifetime or past-year NMAS. Finally, the results presented in are primarily from the 2001 survey only, but similar associations were observed in previous survey years (1993, 1997, and 1999).