Differences in Patient and Physician Assessment of a Dynamic Patient Reported Outcome Tool for Chronic Pruritus

BACKGROUND: Chronic pruritus is a subjective symptom, mainly measured through patient reported outcomes. Our aim is to assess two different methods regarding the change of symptoms: a visual dynamic pruritus score (vDPS) documented by patients, and a numerical value (nDPS) documented by physicians.

METHODS: Inferential statistics and reliability analyses have been performed on data collected in 2013.

RESULTS: Data of 701 patients were analysed (45.6% males, 54.4% females, mean age 60 ± 16 years). The nDPS showed less extreme and generally lower values than the vDPS. There was a slight concordance between both methods; the highest concordance was seen for no/weak change and very good reduction.

CONCLUSION: The difference between patient and physician assessed same score points to an important bias in pruritus assessment which has to be taken into account especially in clinical trials. Though further studies are needed, the patient-based assessment seems to be less biased by a social desirability effect.