TY - JOUR T1 - Describing a complex and changing landscape: metrics for understanding and planning chlamydia control JF - Sexually Transmitted Infections JO - Sex Transm Infect SP - 170 LP - 170 DO - 10.1136/sextrans-2015-052277 VL - 92 IS - 3 AU - Woodhall, Sarah C AU - Saunders, John Y1 - 2016/05/01 UR - http://sti.bmj.com/content/92/3/170.abstract N2 - In this edition, den Heijer et al1 describe the complex landscape of chlamydia testing practices among people aged 16–29 years in the South Limburg region of the Netherlands, between 2006 and 2010.1 The study combined data from sexually transmitted infection (STI) clinics and laboratories with that from the Chlamydia Screening Implementation project, which used a population registry to invite residents to order a chlamydia test via the internet.2 The authors report on a number of key metrics: the proportion of tests that resulted in a positive diagnosis (‘positivity’), the percentage of all tests contributed by different testing service providers and the percentage of all diagnoses contributed by service type and patient demographic characteristics. They show that general practice (GP) and internet screening each accounted for just less than one-third of all tests, whereas STI clinics and gynaecology each accounted for around one-fifth of all tests. The majority of diagnoses were made in GP and STI clinics. They also highlight differences in positivity between settings, with &gt;10% of urogenital tests in GP and STI clinics resulting in a … ER -