Clients of sex workers by urbanization level in the United States

Sex workers and their clients are at high risk of acquiring and transmitting sexually transmitted infections (STIs). Although STI rates vary by urbanization level and sexual risk differs between clients and non-clients, few studies have examined differences in the prevalence of clients by urbanization level. This study compares demographics, behavioral risk factors, history of STI/HIV testing between ever clients and non-clients of sex workers and assesses whether the prevalence of clients differs by urbanization level among males (n=585) embedded in a probability sample of English speaking adults aged 18 to 45 years old residing in U.S. households in 1999-2000. The prevalence of clients increased with age: 2.3% [95% CI 0.6-9.1] among 18 to 25 years old, 12.0% [95% CI 8.2-16.9] among 26-35 year old and 17.1% [95% CI 12.6-22.7] among older adults. Clients had a significantly higher prevalence of both lifetime and past year sexual risk behaviors, and self-reported history of STIs than non-clients. The prevalence of clients was 11.1% (95% CI 7-16) in large central cities, 12.3% (95% CI 8-19) in fringe areas of large metropolitan areas, 10.4% (95% CI 7-16) in small-medium sized metropolitan areas, 11.1% (95% CI 4-25) in micropolitan and 16.2% (95% CI 7-33%) in non-core areas. Among men 26 to 45 years old, after controlling for age, sexual risk, prior STIs and region, only non-core men were marginally more prevalent than men in central cities to have been clients (PrR, 2.0 95% CI 0.9-4.4, p<0.10). Clients are an important group in STI/HIV prevention and are widespread by urbanization levels.