The influence of fear of symptoms and perceived control on asthma symptom perception

Abstract

Objective: Self-reported asthma symptoms correlate only modestly with measures of underlying pathophysiological mechanisms. In this study, we investigated the role of fear of symptoms and perceived control on respiratory symptom perception in patients with asthma.

Methods: Patients with intermittent to moderate persistent asthma (N=32) were administered 4 subsequent rebreathing challenges (one using 100% O(2) and three using 5% CO(2) and 95% O(2)). We manipulated perceived control by providing information on the availability/unavailability of rescue medication during the challenges (perceived control/no control condition). Perceived symptoms and lung function were assessed after each rebreathing challenge.

Results: Persons with low fear of symptoms reported respiratory symptoms to be less unpleasant during the perceived control condition compared to the no control condition. The reverse was found for persons with high fear of symptoms. The interaction between fear of symptoms and the control manipulations was mediated by threat perception.

Conclusion: Messages intended to increase perceived control over symptoms may actually increase threat in persons with high fear of symptoms and eventually increase unpleasantness of respiratory sensations. This finding underlines the importance of affective processes in the perception of asthma symptoms and shows that instructions to patients should take pre-existing fear levels into account.