Objective: To explore the factors that influence older people's decision making regarding use of topical or oral ibuprofen for their knee pain.
Design: Qualitative interview study nested within a randomised controlled trial and a patient preference study that compared advice to use oral or topical non-steroidal anti-inflammatory drugs (NSAIDs) for knee pain in older people.
Setting: 11 general practices.
Participants: 30 people aged > or =50 with knee pain.
Results: Participants' decision making was influenced by their perceptions of the associated risk of adverse effects, presence of other illness, nature of their pain, advice received, and practicality. Although participants' understanding of how the medications worked was sometimes poor their decision making about the use of NSAIDs seemed logical and appropriate. Participants' model for treatment was to use topical NSAIDs for mild, local, and transient pain and oral NSAIDs for moderate to severe, generalised, and constant pain (in the absence of other more serious illness or risk of adverse effects). Participants showed marked tolerance and normalisation of adverse effects.
Conclusion: Participants had clear ideas about the appropriate use of oral and topical NSAIDs. Taking such views into account when prescribing may improve adherence, judgment of efficacy, and the doctor-patient relationship. Tolerance and normalisation of adverse effects in these patients indicate that closer monitoring of older people who use NSAIDs might be needed.