THU0611-HPR MEASUREMENT OF MINIMAL DISEASE ACTIVITY IN PSORIATIC ARTHRITIS USING PROMIS-PHYSICAL FUNCTION OR THE HEALTH ASSESSMENT QUESTIONNAIRE-DISABILITY INDEX
Authors: E. Chew, J. Perin, T. Grader-Beck, A. M. Orbai
Journal: Annals of the Rheumatic Diseases (2020)

Background: Minimal disease activity (MDA) is a treat-to-target strategy (T2T) objective in psoriatic arthritis (PsA). MDA criteria, include physical function, traditionally assessed via the Health-Assessment Questionnaire Disability Index (HAQ-DI). It is of interest to assess the performance of more current physical function instruments such as the Patient-Reported Outcomes Measurement Information System-Physical Function Profile (PROMIS-PF). Objectives: To assess the interchangeability of the HAQ-DI with the PROMIS-PF in the calculation of MDA in PsA. Methods: Longitudinal PsA data were collected including HAQ-DI and PROMIS-PF in a PsA cohort. MDA definitions were built substituting the HAQ-DI criterion with the PROMIS-PF short form 4a (PROMIS-PF4a) or with the PROMIS-PF computer adaptive test (PROMIS-PF Bank). We assessed agreement/accuracy between HAQ-DI based and PROMIS-PF based MDA definitions at each visit and longitudinally through the kappa statistic/ROC curve analysis. Results: One hundred participants contributed 352 observations with up to five visits. Mean (SD) age was 52 (12) years, 60% were female, and 43% were in MDA at baseline. Kappa statistic for PROMIS-PF based MDA reflected almost perfect agreement with HAQ-DI MDA: kappa=0.94 (95% CI 0.90-0.97) for MDA PROMIS-PF Bank, and kappa=0.90 (95% CI 0.80-0.95) for MDA PROMIS-PF4a. Higher longitudinal agreement was seen between MDA HAQ-DI and MDA PROMIS-PF Bank versus MDA PROMIS-PF4a between consecutive visits: kappa ranged between 0.81-0.94 versus 0.72-0.84, respectively (Table 1). Area under ROC curve for predicting MDA HAQ-DI was 0.97 for MDA PROMIS-PF Bank and 0.95 for MDA PROMIS-PF4a (Figure 1). Table 1. Agreement between HAQ-DI based MDA and PROMIS-PF based MDA definitions at each visit and longitudinally Agreement Visit 1 Visit 2 Visit 3 Visit 4 MDA HAQ-DI and MDA PROMIS-PF4a Kappa 95% CI N 0.91 (0.80-0.98) 86 0.93 (0.82-1.00) 81 0.92 (0.80-1.00) 72 0.83 (0.66-0.96) 58 MDA HAQ-DI and MDA PROMIS-PF4a Kappa 95% CI N 0.91 (0.81-0.98) 86 0.98 (0.90-1.00) 82 0.94 (0.84-1.00) 73 0.93 (0.82-1.00) 58 Longitudinal agreement Visit 1 to visit 2 Visit 2 to visit 3 Visit 3 to visit 4 N/A MDA HAQ-DI state change with MDA PROMIS-PF4a state change Kappa 95% CI N 0.75 (0.47-0.95) 71 0.84 (0.58-1.00) 67 0.72 (0.37-0.94) 51 N/A MDA HAQ-DI state change with MDA PROMIS-PF Bank state change Kappa 95% CI N 0.81 (0.49-1.00) 72 0.94 (0.75-1.00) 68 0.84 (0.48-1.00) 52 N/A *Bias corrected 95% CI were calculated using bootstrapping with 2000 repetitions of individual patients. ^MDA state changes are defined as transitions in the respective MDA state between designated consecutive visits. Abbreviations: CI confidence interval; N number of observations; HAQ-DI Heath Assessment Questionnaire-Disability Index; PROMIS-PF4a Patient Reported Outcomes Measurement Information System Physical Function form 4a; PROMIS-PF Bank Patient Reported Outcomes Measurement Information System Physical Function Bank administered as a computer adaptive test; MDA HAQ-DI Minimal disease activity includes the HAQ-DI ≤0.5 criterion; MDA PROMIS-PF4a includes the PROMIS-PF4a ≥41.3 criterion; MDA PROMIS-PF Bank includes the PROMIS-PF CAT ≥41.3 criterion. Figure 1. Areas under receiver operative characteristic curve to predict HAQ-DI based MDA using MDA PROMIS-PF4a or MDA PROMIS-PF Bank at each visit and overall using all observations (from left to right: visit 1, 2, 3, 4, and overall across visits) Conclusion: Excellent agreement was seen between HAQ-DI and PROMIS-based MDA definitions statically and longitudinally. The PROMIS-PF Bank and PROMIS-PF4a are accurate replacements for the HAQ-DI in calculating MDA state in PsA. References: [1]Schalet BD, et al. J Gen Intern Med 2015 Disclosure of Interests: Erin Chew: None declared, Jamie Perin: None declared, Thomas Grader-Beck Grant/research support from: Abbvie, Celgene, Consultant of: Novartis, Lilly, Ana-Maria Orbai Grant/research support from: Abbvie, Eli Lilly and Company, Celgene, Novartis, Janssen, Horizon, Consultant of: Eli Lilly; Janssen; Novartis; Pfizer; UCB. Ana-Maria Orbai was a private consultant or advisor for Sun Pharmaceutical Industries, Inc, not in her capacity as a Johns Hopkins faculty member and was not compensated for this service.