The accuracy of tests for chlamydia depends, among other things, upon the quality of the clinical specimen. Most chlamydia tests do not allow comment on specimen quality. It has been shown that examination of Papanicolaou stains or Diff-Quik stains of endocervical secretions can be used to assess the quality of endocervical sampling. This study has found that by analysing surrogate markers, such as the rates of inadequate cervical cytology and chlamydia detection rates in patients not identified as chlamydia contacts, it is possible to identify doctors performing less well in cervical sampling without the need for extra tests.