Study examines link in college women's use of substances, condoms

Young people between the ages of 15 and 24 account for 50 percent of all new HIV infections and are also at an elevated risk for other sexually transmitted infections (STIs). Condom use is an excellent method for reducing the risk of STIs as well as unplanned pregnancy, so it is important to understand the factors predicting use.

Jennifer Walsh, PhD, of the Centers for Behavioral and Preventive Medicine at The Miriam Hospital is the lead author of a study funded by a grant from the National Institutes of on Alcohol Abuse and Alcoholism. Walsh and fellow researchers set out to determine whether college women were less likely to use condoms if they consumed alcohol or smoked marijuana before engaging in sexual intercourse. To do so, they looked at data from 1,856 sexual events reported by 297 first-year college women.

Two study hypotheses were confirmed. First, the researchers found a negative association between the number of drinks and condom use -- women who consumed more alcohol before sex were less likely to use condoms than women who had fewer drinks. Second, they found that when a woman has been dating a romantic partner for three months or more, marijuana use may increase the risk of unprotected sex.

Walsh explains why this study was unique. "Our study provides new information about condom use and substance use with specific subtypes of sexual partners," she says. Past studies have often characterized sexual partners as only romantic/steady or casual.

Walsh says for this study, the researchers collected data on a wider range of sexual partners. She notes, "We found that both substance use and condom use varied based on specific partner type. Not only were alcohol use and condom use both less likely with romantic than with casual partners, but specific subtypes of romantic partners (new versus established) and casual partners (ex-boyfriends, friends, acquaintances, and strangers) differed from one another."

The method for this study involved a large sample, multiple sexual events per person and detailed assessments. Walsh believes this methodology helped her and her colleagues to improve upon most previous research, allowing stronger inferences regarding the alcohol-condom use and marijuana-condom use associations.

Walsh concludes, "The results of our study suggest possible areas for intervention with young women. Efforts to reduce alcohol-involved sexual risk behavior might emphasize the dose-response relationship of drinks to condom use once one decides to drink or aim to reduce alcohol-sexual risk expectancies. Differences between types of sexual partners suggest the value of detailed assessments of partner types, and future research should consider categorizing sexual partners in a similar manner."