Desire for information about drugs: relationships with patients' characteristics and adverse effects

Adverse effects of drugs are known to cause problems both in hospital and general practice settings, contributing to longer stays in a hospital, and increased costs of hospitalisation. By developing both a greater understanding of adverse drug reactions and effects and developing ways to reduce them will assist pharmacists in managing medicines more effectively. The aim of this study was to explore the relationships between patient characteristics, information requirements and perceptions about adverse drug effects to assist pharmacists in identifying patients most at risk of ADRs.

The study took place on medical wards at a London teaching hospital during an eight week period in Autumn 2000. Patients were recruited using convenience sampling during the recruitment period. Once eligible patients consented to take part, standardised interviews were conducted at their bedside. The interviews included the use of the previously validated scale which measures the extent of information desired (EID), patient characteristics including age, gender, socio-economic status etc and the presence of an adverse drug effect was assessed using the Naranjo algorithm. Patients were also asked semi-structured questions to explore past and present experiences of adverse drug effects.

82 patients were recruited, 80 were eligible for adverse effects of drugs assessment. Fifteen percent (12/80) of patients were assessed as having "definite" and "probable" adverse drug effects, based on the Naranjo algorithm. The previously validated EID scale was found to be both valid and reliable in this patient sample. There was an association between high scores on the EID scale and the presence of an adverse drug effect (chi-squared = 4.97, p = 0.02).

The results show an association between the occurrence of an adverse drug effect on admission (identified by the Naranjo scale), the experience of an adverse drug effect in the past and a patient's desire for information. The EID-scale could be developed into a useful tool for assessing and addressing patients' drug information needs for pharmacists to use when assessing adverse drug effects in everyday practice.