The Patient-Reported Outcomes Measurement Information System (PROMIS) Itch Questionnaire (PIQ) short forms show good content and construct viability for assessment of chronic itch in adults with atopic dermatitis (AD), according to study results published in Journal of the American Academy of Dermatology.
Deficiencies have been noted with existing scales that assess itch-related quality of life. The newly developed PIQ assesses patient-reported outcomes across 4 item banks: 1) itch interference; 2) mood and sleep; 3) clothing and physical activity; and 4) scratching behavior. Researchers aimed to test the validity of PIQ short forms in assessing the quality of life in patients with AD.
A total of 12 adults (50% women, 92% white) were interviewed to assess the content validity of the PIQ. Questions were divided such that each item bank was reviewed by 3 individuals. For almost all items, participants reported that the questions were clear and they felt confident when answering. Three items were revised for improved clarity.
The validity and feasibility of the PIQ was assessed in 239 adults (62.3% women, 57.9% white) with AD in a prospective, dermatology practice-based study. Patients completed self-administered questionnaires, including the PIQ short forms and existing itch-assessment measures. An 8-item short form for item banks 1-3 and a 5-item short form for bank 4 were administered. Clinically reported outcomes included the Eczema Area and Severity Index (EASI) and the objective component of the Scoring AD, as determined by full body skin examination by a dermatologist.
All item banks showed correlations with each other (P <.001 for all), with item banks 1 and 2 exhibiting the strongest correlation. All item banks had moderate correlations with all assessments of itch severity, moderate to strong correlations with AD symptoms, and weak-to-moderate correlations with clinically reported outcomes (P <.0001 for all items). Itch severity and frequency were most strongly correlated with scores from item bank 1 and showed the lowest correlation with item bank 4. Clinically reported outcomes showed similar correlations across all item banks.
The PIQ short forms were also able to distinguish between the severity of itch and symptoms. Stepwise and significant increase in scores for all item banks were observed at all levels of patient-reported severity (P <.0001 for all). However, there was no major difference in item bank 1 scores in individuals with almost clear or mild self-reported AD severity, and no item banks were able to discriminate between the two highest or lowest levels of AD and itch severity. Floor effects were observed for all item banks, but no ceiling effects were observed.
The mean completion time for all item banks was 1.8 minutes, with a median completion time of 2 minutes. There was no significant difference in completion time across age groups, sex, race or ethnicity, level of education, or severity of AD symptoms.
“PIQ [short forms] have good content, construct, discriminant and cross-cultural validity, internal consistency, and feasibility to assess AD in clinical practice, particularly moderate-severe AD,” the authors noted. However, the single-center design of the study may limit generalizability of results, and test-retest reliability remains to be addressed.
“These instruments may be incorporated into the assessment of patients with AD and chronic itch,” the researchers concluded. “They provide important information about the burden of itch that can guide therapeutic decision-making.”
Disclosure: This study was partially funded by Galderma.
Silverberg JI, Lai JS, Vakharia PP, et al. Measurement properties of the Patient-Reported Outcomes Measurement Information System Itch Questionnaire® (PIQ) Item Banks in adults with atopic dermatitis [published online December 5, 2020]. J Am Acad Dermatol. doi:10.1016/j.jaad.2019.11.057