Cervical screening has been shown to reduce the incidence of cervical cancer, but only in the setting of well organised, high quality programmes. In the United Kingdom the NHS cervical screening programme has been estimated to prevent around 80% of deaths from cervical cancer.1

Liquid based cytology represents the first major change in preparation method for cervical screening samples for over 50 years. Instead of cells being smeared onto a glass slide, they are washed into a vial of liquid and filtered, and a random sample is presented in a thin layer on a glass slide. These slides can then either be screened by skilled staff or subjected to partially automated imaging. The process is being widely used in the United States, many European countries, and elsewhere.

In this week's BMJ two studies compare the accuracy of liquid based cytology with conventional cytology.2 3 The randomised trial by Ronco and colleagues found no significant difference in sensitivity for cervical intraepithelial neoplasia of grade 2 or more with liquid based cytology using ThinPrep (Cytyc, Boxborough, MA, USA) compared with conventional cytology.2 However, more positive …