Beliefs about medication predict the misattribution of a common symptom as a medication side effect — Evidence from an analogue online study.

Objective
Some perceived medication side effects may be ‘normal’ symptoms that patients misattribute to the medication. Using an analogue approach, we tested if medication beliefs predict whether participants misattribute a headache as a side effect and subsequently intend to stop medication.

Methods
We recruited 690 participants, 223 reporting a past asthma diagnosis. They received information about asthma and Molair, a fictitious asthma treatment modeled on a licensed treatment (montelukast). We varied the description of efficacy and side effects (which did not include headache). Pre-exposure to this information, participants completed the Beliefs about Medicine Questionnaire (BMQ)-General and the Perceived Sensitivity to Medicines Scale (PSM), post-exposure they completed the BMQ-Specific. Participants were asked to imagine they experienced a headache while taking Molair. Finally, they rated whether the headache was a side effect (misattribution) and if they would stop taking Molair (behavioral intention).

Results
Nearly a quarter (170) of participants misattributed the headache to Molair and 69 (10%) subsequently intended to stop Molair. Both outcomes were predicted by general and specific medication beliefs. Odds of misattribution (m) and behavioral intention (i) increased with higher General Harm (ORm = 1.90, ORi = 2.72), General Overuse (ORm = 1.74, ORi = 1.56) and Molair Concern beliefs (ORm = 1.52, ORi = 1.78, all p < .01), but decreased with General Benefit (ORm = 0.72, ORi = 0.53) and Molair Necessity beliefs (ORm = 0.72, ORi = 0.70, all p < .05).

Conclusion
Symptom misattribution and subsequent intentions to stop Molair were predicted by pre-exposure beliefs about medicines in general and post-exposure beliefs about Molair. Patients with negative medication beliefs may be prone to misattribute symptoms and subsequently stop medication.