Response shift in severity assessment of hand eczema with visual analogue scales.

Abstract

Hand eczema is a common and fluctuating disease. Visual analogue scales (VASs) are used to assess disease severity, both currently and when at its worst. However, such patient-reported outcomes may be at risk of being flawed owing to recall bias or response shifts. To explore whether the current state of hand eczema severity affects the recollection of the eczema when at its worst, thus resulting in a response shift. We utilized a dataset from a recent clinical trial examining nurse counselling of hand eczema patients. The patients assessed the disease severity currently (VASnow ) and when at its worst (VASworst ), both at baseline and at a 6-month follow-up. The patients who reported improvement during the course were generally more likely to downwardly adjust their assessment of VASworst than patients reporting unchanged or worsened severity (odds ratio 1.94, p = 0.017). No other determinants were found. Patients may downwardly adjust their assessment of worst-ever disease severity according to the assessment of present disease severity. Regular photographic documentation of the hand eczema along with the patient's self-monitoring of symptoms as part of the treatment course could perhaps counteract this tendency for there to be severity habituation.