Objective Internet-based testing for Chlamydia trachomatis (CT) with self-sampling at home has gradually been implemented in Sweden since 2006 as a free-of-charge service within the public healthcare system. This study evaluated the national diagnostic outcome of this service.

Methods Requests for data on both self-sampling at home and clinic-based sampling for CT testing were sent to the laboratories in 18 of 21 counties. Four laboratories were also asked to provide data on testing patterns at the individual level for the years 2013–2017.

Results The proportion of self-sampling increased gradually from 2013, comprising 22.0% of all CT tests in Sweden in 2017. In an analysis of 14 counties (representing 83% of the population), self-sampling increased by 115% between 2013 and 2017 for women, compared with 71% for men, while test volumes for clinic-based sampling were fairly constant for both sexes (1.8% increase for women, 15% increase for men). In 2017 self-sampling accounted for 20.3% of all detected CT cases, and the detection rate was higher than, but similar to, clinic-based testing (5.5% vs 5.1%). The proportion of self-sampling men was also higher, but similar (33.7% vs 30.8%). Analysis of individual testing patterns in four counties over 5 years showed a higher proportion of men using self-sampling only (67%, n=10 533) compared with women (40%, n=8885).

Conclusions Self-sampling has increased substantially in recent years, especially among women. This service is at least as beneficial as clinic-based screening for detection of CT, and self-sampling reaches men more than clinic-based testing.