Perceptual sensitivity to sensory and affective aspects of dyspnea: Test-retest reliability and effects of fear of suffocation.

Perceptual sensitivity for dyspnea (i.e. breathlessness) is often quantified using the slope of magnitude estimations plotted against the physical stimulus intensities of respiratory loads. This study investigated whether this slope and its stability varies as a function of (1) affective versus sensory aspects of dyspnea, and (2) interindividual differences in Fear of Suffocation. Eighty-three healthy women performed a load magnitude estimation task twice one week apart. Resistive loads of increasing magnitude (0-2.4-5-7.4-12.4-20 cmH20/l/s) were repeatedly presented for a single flow-targeted inspiration. One group rated the intensity of loads, another their unpleasantness. Neither slopes nor intercepts differed between sensory versus affective aspects of dyspnea. Intercepts were lower in the second compared to the first session. Fear of Suffocation was associated with flatter slopes. Test-retest reliabilities were low to moderate suggesting that perceptual sensitivity to dyspnea is less stable than commonly assumed.