Sexual Orientation, Drugs, Alcohol and Disease in the Denver Metro Health Clinic (DMHC): Use of An Electronic Medical Record to Identify Predictors of Chlamydia Trachomatis (CT) and Neisseria Gonorrhoeae (GC) Infections

Background: Alcohol or drug abuse may drive increased sexual risk taking and thus rates of common sexually transmitted infections (STI) such as CT and GC.  Sexual orientation (SO) may also affect rates. 

Objectives: 1.  To determine whether SO, alcohol use, and drug use are predictors of CT or GC infection in the DMHC.  2.  To demonstrate the utility of an electronic medical record (EMR) in large-scale chart review.

Methods: The DMHC uses a computerized encounter form.  Data collected include sexual behavior, alcohol use, illicit drug use, and laboratory results.  For new visits between 9/20/10 and 10/13/11, we calculated % with CT or GC, and % with binge drinking (>4/occasion), illicit drug use (marijuana, cocaine, heroin or methamphetamine), or both, according to behavioral SO during the preceding 12 months, defined as male contact with men only (MSM), women only (MSW) or both (MSWM), and female contact with men only (WSM), women only (WSW) or both (WSMW).  Rates of infection, and rates of substance abuse according to SO were compared by Chi-square.

Results: CT and GC testing were done in 4199 women and 6390 men during this time.  CT was found in 523 women (12.5%) and 971 men (15.2%).  GC was found in 95 women (2.3%) and 320 men (6.3%).  Alcohol abuse in women but not men predicted CT infection (p <0.0001 vs. p=0.3), while alcohol plus drugs in men but not women predicted it (p<0.0001 vs. p=0.1).  WSMW vs. WSM and MSM vs. MSW had higher GC rates (p<0.01 for both).

Conclusions: Substance abuse and SO predict CT and GC rates in our clinic, but effects vary between men and women.

Implications for Programs, Policy, and Research: An EMR can permit an STI clinic to determine predictors of STI in its own population, allowing more informed decisions about addressing rates in sub-groups.