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Published on: March 1, 2024
Minimal clinically important difference (MCID) for work productivity and activity impairment (WPAI) questionnaire in
Background:
The clinical meaningfulness of improvements in the Work Productivity and Activity Impairment Questionnaire for Psoriasis (WPAI-PsO) reported by patients with psoriasis in response to treatment is unknown due to the lack of any publications that report minimal clinically importance differences (MCID) for WPAI-PsO outcomes.
Objective:
To determine the MCIDs for the work productivity loss and activity impairment domains of the Work Productivity and Activity Impairment Questionnaire for Psoriasis (WPAI-PsO) using results from three Phase 3 trials of ixekizumab.
Methods:
MCIDs for WPAI-PsO domains were derived using treatment agnostic data from patients participating in UNCOVER-1/-2/-3. The analysis included patients randomized to placebo and two ixekizumab treatment groups (ixekizumab either every 2 weeks or 4 weeks) from the trials. WPAI-PsO was administered at baseline and Week 12 for UNCOVER-1/-2/-3 and at Weeks 24, 36, 52 and 60 in UNCOVER-1/-2. MCIDs for the WPAI-PsO domains through Week 12 were derived using an anchor-based method supplemented with the distribution-based method. Anchors included 75%/90%/100% improvement in Psoriasis Area and Severity Index, Static Physicians Global Assessment (sPGA[0] and sPGA[0,1]) and Dermatology Life Quality Index MCID). MCIDs were triangulated using receiver operating characteristics (ROC) and distribution-based methods.
Results:
The analyses included 3126 patients (Placebo: 792, Ixekizumab: 2334). All anchors were shown to be valid. Significant differences in the domains of WPAI-PsO were observed between patients achieving clinically meaningful improvement in the validated anchors (all P-values < 0.001). ROC analyses suggested a 20% improvement in the work productivity loss or activity impairment components best represented the benefit of meeting a clinical meaningful improvement in the validated anchors. The distribution-based method supported the results of the anchor-based method.
Conclusion:
The MCIDs for both the work productivity loss and the activity impairment domains of WPAI-PsO were estimated to be 20% in patients with PsO.
Insights
Minimal clinically important differences (MCID) for the Work Productivity and Activity Impairment Questionnaire for Psoriasis (WPAI-PsO) were established. A 20% improvement in work productivity loss and activity impairment indicates a meaningful change for psoriasis patients.
Area of Science:
- Dermatology
- Clinical Trials
- Health Outcomes Research
Background:
- The clinical meaningfulness of psoriasis treatment improvements measured by the Work Productivity and Activity Impairment Questionnaire for Psoriasis (WPAI-PsO) remains unclear.
- No prior publications have established minimal clinically important differences (MCIDs) for WPAI-PsO outcomes.
Purpose of the Study:
- To determine the MCIDs for work productivity loss and activity impairment domains of the WPAI-PsO.
- Utilize data from three Phase 3 ixekizumab trials (UNCOVER-1, -2, -3) to establish these MCIDs.
Main Methods:
- Derived MCIDs using treatment-agnostic data from 3126 patients in UNCOVER trials.
- Employed an anchor-based method, supplemented by distribution-based methods, using validated anchors like PASI, sPGA, and DLQI.
- Utilized receiver operating characteristic (ROC) analysis to triangulate MCID values.
Main Results:
- All anchors used were validated, showing significant differences in WPAI-PsO domains for patients achieving meaningful improvement (P < 0.001).
- ROC analyses indicated that a 20% improvement in WPAI-PsO work productivity loss or activity impairment best reflects clinically meaningful benefit.
- Distribution-based methods corroborated the anchor-based findings.
Conclusions:
- The MCID for both work productivity loss and activity impairment domains of the WPAI-PsO was estimated at 20% for patients with psoriasis.
- This finding provides a benchmark for assessing treatment meaningfulness in psoriasis clinical trials.
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