A randomized questionnaire-based study on the impact of providing numerical information on colorectal cancer screening.

Objectives: To establish whether the provision of numerical data using pictograms and framed as event rates affects subjects' attitudes to colorectal cancer (CRC) screening.

Design: Randomized questionnaire and telephone study comparing a control group given standard NHS CRC information leaflets with an intervention group given the same leaflet but enhanced with additional numerical and pictorial information.

Setting: District General hospital and two general practices in North East England.