Previous qualitative work has identified communication problems between doctors and patients in general practice consultations, particularly in relation to prescribing. This study aimed to develop quantitative measures to extend the research and provide instruments for both researchers and practitioners to use in monitoring communication and prescribing. Questionnaires were developed from existing instruments. When used with patients and doctors in a variety of general practices, the instruments appeared to be acceptable and had high response rates. While many consultations were satisfactory in terms of patients' expectations and their experiences with medicines, only 38% did not have any poor outcome. The results using quantitative instruments were similar to but less striking compared to our previous qualitative work. The research was developmental and findings suggest that unnecessary prescribing and problems in communication are more likely to lead to poor outcomes in terms of non-adherence and patients having barriers to using their medication. (C) 2003 Elsevier Science Ireland Ltd. All rights reserved.