Impact of patient information leaflets on pain medication intake behavior: a pilot study

Patient information leaflets on pain medication primarily list side effects while positive effects and action mechanisms remain underrepresented. Nocebo research has shown that negative instructions can lower analgesic effects.

Research on information leaflets and their influence on mood, memory of side effects, and intake behavior of healthy participants is needed.

To determine the ratio of positive to negative phrases, 18 information leaflets of common, over-the-market analgesics were examined of which 1 was selected. In a randomized, controlled study design, 18 healthy participants read this leaflet while 18 control group participants read a matched, neutral leaflet of an electrical device. Collected data concerned the recall of positive and negative contents, mood, anxiety, and the willingness to buy and take the drug.

All examined leaflets listed significantly more side effects than positive effects (t₁₇ = 5.82, P < 0.01). After reading the analgesic leaflet, participants showed a trend towards more negative mood (F_1,34 = 3.78, P = 0.06, η_p² = 0.1), a lower intention to buy [χ² (1, n = 36) = 12.5, P < 0.01], a higher unwillingness to take the medication [χ² (1, n = 36) = 7.2, P < 0.01], and even a greater recall for side effects than positive effects (t₁₇ = 7.47, P < 0.01).

Reading the patient information leaflets can increase fear and lower the intention to buy and the willingness to take a pain medication.