Anxiety sensitivity and intolerance of uncertainty: Evidence of incremental specificity in relation to health anxiety

• Targeted relations between two individual difference variables and health anxiety.
• The two variables were anxiety sensitivity (AS) and intolerance of uncertainty (IU).
• AS and IU both showed incremental specificity in relation to health anxiety.
• Physical dimension of AS was only AS dimension to show incremental specificity.
• Inhibitory dimension of IU was only IU dimension to show incremental specificity.

Anxiety sensitivity (AS) reflects the fear of arousal-related sensations and intolerance of uncertainty (IU) represents the dispositional fear of the unknown. Within cognitive–behavioral models, AS and IU are individual difference variables considered central to the phenomenology of health anxiety. However, prior studies have cast doubt on whether both variables incrementally contribute to our understanding of health anxiety. Addressing limitations of these prior studies, the present study examined the incremental specificity of AS and IU as these two variables relate to health anxiety in a large medically healthy sample of community adults (N = 474). Both AS and IU incrementally contributed to the concurrent prediction of health anxiety beyond both negative affect and one another. However, within these analyses, the physical dimension of AS and the inhibitory dimension of IU were the only AS and IU dimensions to evidence incremental specificity in relation to health anxiety.