Effective instructions for patients.

Information designed for patients aims to educate them. This means that the written word must be both read and understood. In whatever format patient information is presented it must influence patient behaviour and favourably affect compliance and morbidity if it is to be of value. The production of patient information should take account of the needs of the audience as well as the aims of the educators. Prototypes should be field tested to ensure that they are effective and that the material can be revised before general use. Patient information and its effect on the understanding of disease processes and management can be assessed by various standard techniques. Their effectiveness must ultimately be validated in randomised controlled trials.