Patient-Reported Outcome Measures in Pruritus: A Systematic Review of Measurement Properties.

This review aims to systematically evaluate studies on the measurement properties of patient-reported outcome measures in pruritus, especially for use in clinical trials. Validation studies on instruments were identified based on a PubMed literature search. The consensus-based standards for the selection of health status measurement instruments checklist was used to evaluate the studies' methodological quality, and the consensus-based standards for the selection of health status measurement instruments criteria were used to synthesize the instruments' measurement properties. Twenty-three studies were included, which contain 37 examinations of reliability and/or validity for 23 different outcome measures. The methodological quality of reliability and validity evidence was moderate for six outcome measures; for these measures, psychometric property rating was adequate too, making them suitable for use in clinical trials. Itch severity scale, itchy quality of life, numerical rating scale-6, numerical rating scale-11, visual analog scale (horizontal), and verbal numerical rating scale-4 are currently the most appropriate patient-reported outcome measures with regard to overall reliability and validity.