Baseline Score on the Validated Psoriasis Symptoms and Signs Diary
A study published in JAMA Dermatology found that Psoriasis Symptoms and Signs Diary (PSSD) score improvements of 15, 25, and 30 points correspond to increasingly significant improvements in the symptoms and signs of psoriasis.
Researchers aimed to establish meaningful within-patient score change thresholds on the PSSD by anchoring these changes to patient-reported assessments, specifically the Patient Global Impression of Change (PGI-C) and the Patient Global Impression of Severity (PGI-S).
Data was drawn from the POETYK PSO-1 trial, which was a multicenter, randomized, double-blind, placebo-controlled study involving 666 adults with moderate to severe plaque psoriasis. Participants were randomized to receive either deucravacitinib, a selective TYK2 inhibitor; placebo; or apremilast, a commonly used psoriasis treatment. The PSSD was completed daily by participants, and score changes from baseline to week 16 were analyzed to determine meaningful change thresholds.
The study identified 3 key thresholds for meaningful PSSD score improvements:
- A 15-point improvement from baseline was associated with meaningful change based on the PGI-C.
- A 25-point improvement was supported by both the PGI-C and PGI-S.
- A 30-point improvement was indicative of greater symptom relief and disease burden reduction.
The findings suggest that PSSD score improvements of 15, 25, and 30 points correspond to increasingly significant improvements in the symptoms and signs of psoriasis. These thresholds provide a standardized way to interpret patient-reported outcomes in clinical trials and help gauge the effectiveness of psoriasis treatments from the patient's perspective.
Reference
Papp KA, Gordon K, Strober B, et al. Meaningful change thresholds for the Psoriasis Symptoms and Signs Diary: a secondary analysis of a randomized clinical trial. JAMA Dermatol. 2024;160(2):204-209. doi:10.1001/jamadermatol.2023.5058
