SIDE-EFFECTS OF SIDE-EFFECT INFORMATION IN DRUG INFORMATION LEAFLETS

This study examines the way side effects information is presented in p atient information leaflets about drugs. In a field experiment, we tes ted the effects of two attempts to improve a side effects paragraph in a leaflet about a nonsteroid anti-inflammatory drug. First, a short i ntroductory passage on the nature of side effects was added. Second an d more importantly, we changed the frequency descriptors (FDs) for the side effects. A preliminary study had shown that the frequencies asso ciated with common Dutch FDs are much higher than the writers of patie nt information leaflets and package inserts mean to convey. In our exp eriment we replaced the original FDs by lower-assessed FDs. For instan ce, soms (sometimes) was replaced by zelden (seldomly). Replacing FDs led to lower recall for the side effects mentioned in the leaflet. It also decreased the number of side effects experienced. Contrary to our expectations, lower FDs did not significantly increase the confidence in the safety and effectiveness of the drug, nor did they increase th erapy compliance; incompliance was extremely rare in our sample of pat ients. Adding an introductory passage on the nature of side effects lo wered FD interpretations. I did not significantly affect any of the ot her dependent variables.