Introduction
Previous studies have demonstrated the effects of information about prescribed drugs on patient adherence¹, whilst others have assessed patient satisfaction with the information provided² . Work by our group has previously sought to measure patients' desire for information^3,4. The aim of this study was to further investigate relationships between patients' need for drug information and their anxieties about their illness.

Methods
Patients were interviewed as they visited an out-patient clinic at a London teaching hospital, using a semi-structured questionnaire. This comprised both quantitative and qualitative questions, and patient demographics and characteristics. Patients' desire for drug information was assessed through a previously validated tool, the IDI scale (Intrinsic Desire for Information)^3,4, whilst anxieties about their illness were assessed through a second scale³ and further explored through semi-structured questions. Data were coded and entered into a statistical software program for analysis.

Results
One hundred patients were interviewed during the study. Factor analysis was undertaken to explore the two scales. Principal component analysis with oblique rotation was used, and the structure matrix suggested one factor within each scale.

The IDI scale was found to be reliable (coefficient alpha = 0.7), a further validation of this scale in both in- and out-patient samples. An association was found between gender and the patient's score to the IDI scale; a greater proportion of males were low scorers than females (Chi² = 4.333, p<0.05), implying that males wanted less information about their prescribed drugs than females. The anxiety of illness scale (AI) was also found to be reliable (coefficient alpha = 0.8). However, although previous work identified a negative correlation between the two scales, implying that patient with a high desire for information felt less anxious about their illness³, this was not found here. One explanation may be the different study populations, this sample were attending an out-patient clinic and exhibited a wide range of illnesses with varying severity, compared to a sample interviewed post-discharge.

Conclusions
This study has verified the use of the IDI scale as a credible tool to measure patients' desire for drug information, in both in- and out-patient populations. The AI scale needs further investigation, but is potentially valuable as a measure of the impact of illness. Together these scales can help healthcare professionals to target patients and provide more appropriate medical information to ensure adherence, whilst empowering patients.

References

1. Weinmann, J. (1987) Patients and doctors In: An outline of psychology as applied to medicine. (2^nd edition). Bristol-Wright.
2. Gibbs, S.W. and George, W.H. (1990) Communicating information to patients about medicine. Prescription information leaflets a national survey. Journal of the Royal Society of Medicine 83 292-297.
3. Duggan C., Bates I. Development and evaluation of a survey tool to explore patients' perceptions of their prescribed drugs and their need for drug information. Int J Pharm Pract 2000; 8: 42-52.
4. Astrom K., Carlsson J., Bates I., Webb D., Duggan C., Sanghani P., McRobbie D. Desire for information about drugs: a multi method study in general medical inpatients. Pharm World Sci 2000; 22(4): 159-64.