Risk communication and older people - understanding of probability and risk information by medical inpatients aged 75 years and older

Objective: to determine older people's understanding of probability and risk information, and the impact of pictorial representation of risk.

Design: a researcher-administered questionnaire.

Subjects: 50 inpatients aged 75 years on elderly medicine wards at Huddersfield Royal Infirmary, Huddersfield, UK.

Results: older people understand percentage probability better than fractional probability, and a wide range of incorrect responses indicated significant over- and underestimation of probabilities. Visual data about percentages were well received and understood, and were perceived as a good idea by participants.

Conclusions: we have demonstrated a wide variation in understanding of risk and probability information by older people, with over- and underestimations of probability, along with confusion between fractional and percentage probability. Pictorial representation of probability was well understood. It could be developed as a simple, yet powerful communication tool to be used in daily clinical practice to help older people understand information on risks and benefits when making decisions about treatment choices.