The present study analyzed tests collected from 4475 young people via postal testing kits at a local sexual health clinic and further education colleges in Lothian, Scotland.

84.8% of the testers were female, and 15.2% were male. Eighty-four men and 403 women tested positive. The odds of a positive result were nearly doubled for postal and clinic testers, relative to college testers, and increased by 70% for 16–19-year-olds, compared with 13–15-year-olds. Postal testing was the primary source for men, while 46.1% of women used postal, and 48.1% used clinic testing. Postal testing was significantly associated with age, sex, and NHS board area, with odds increasing with age, lower odds among females than males, and Lothian residents than those out with this NHS board area.

The study concluded that substantial chlamydial infection was apparent among the young people in this study. Positivity rates were highest among postal and clinic testers and those in the 16–19-year age group. While postal kits were the primary source for men and should be used to target them, combining this approach with continuing screening programs in clinical settings would be most effective at targeting those most at risk.