Framing effects on expectations, decisions, and side effects experienced: the case of influenza immunization

To examine the effects of using positive or negative frames to describe influenza vaccine benefits and side effects on patients' expectations, decisions, decisional conflict, and reported side effects.

292 previously unimmunized patients with chronic respiratory or cardiac disease were randomly assigned to receive benefit/risk information that was framed: (1) positively as the percentage who remain free of influenza and have no vaccine side effects, or (2) negatively as the percentage who acquire influenza and have vaccine side effects. Questionnaires elicited expectations, decisions, and decisional conflict. Vaccines were telephoned 3 days later for a self-report of local and systemic side effects and work absenteeism.

Both groups had similar immunization rates and decisional conflict scores. The positive frame group had lower and more realistic expectations of vaccine side effects, fewer systemic side effects, and less work absenteeism (p < 0.05).

In contrast to previous studies of health care workers, framing did not influence patients' decisions, possibly due to the patients' awareness of their higher risk of influenza complications and greater desire to follow recommendations. The common practice of using negative frames when describing probabilities of side effects may need to be reexamined, considering its deleterious influence on self-reported side effects and work absenteeism.