Background Chlamydia trachomatis (CT) testing in Sweden is free of charge and now exceeds 600,000 annual tests in a population of 10 million. These tests include internet-based self-sampling tests, a service that gradually has been implemented as a part of routine diagnostics in all 21 counties. To our knowledge Sweden is the country with the highest coverage of internet based self-sampling for CT. This study evaluates the diagnostic outcome for self-sampling.

Methods Requests for both self-sampling at home and clinic based sampling for CT-testing were sent to the laboratories in 18 of 21 counties. All 18 counties provided data on self-sampling in 2017 and 12 counties (representing 80% of the population) provided data on both self-collected samples at home and clinic based testing for the years 2013 to 2017.

Results The proportion of self-sampling increased from 12.9% in 2013 to 17.8% in 2016 when compared to national chlamydia test figures. Between 23% and 26% of delivered test kits were never sent back for analysis during 2013–2017. In analysis of 12 counties self-sampling increased by 110% between 2013 (n=32,993) and 2017 (n=69,181) for women, compared to 67% for men (2013: n=21,008; 2017: n=35,091). Test volumes for clinic based sampling was fairly constant for both sexes (women 2013 n=245,274; 2017 n=243,338; men 2013 n=97,519; 2017 n=110,617). The proportion of men was 36% for self-sampling compared to 30% (p<0,00001) for clinic based sampling, and the positivity rate decreased for both groups from 2013 to 2017 (7,8% to 7,1% (p<0,01)) vs 9.1% to 7.0% (p<0,0001)). Corresponding figures for women went from 5.3% to 4.6% (p<0,0001)and from 4.9% to 4.1% (p<0,0001).

Conclusion Self-sampling has increased significantly in recent years, especially among women.

The positivity rate is similar in self-collected and clinic collected samples.

Self-sampling reaches men more than clinic based testing, but not as much as expected.

Disclosure No significant relationships.