Association of Rheumatoid Arthritis (RA) Patient Characteristics and Perceived Treatment Satisfaction, RA Impact on Life, and Task Difficulty with Promis Measures’ Physical Functioning and Upper Extremity Scores

OBJECTIVES: This study evaluates the NIH’s Patient-Reported Outcomes Measurement Information System (PROMIS) Physical Functioning 8b (PF) and Upper Extremity 7a (UE) alongside RA patient characteristics and other PROs.

METHODS: This cross-sectional study conducted in 2022 utilized a web-based survey with participants with RA recruited from an online registry, PatientSpot (formerly ArthritisPower). Ninety-nine participants completed the survey containing demographic items, PROMIS PF, PROMIS UE, RA impact on life scale, RA treatment satisfaction scale, and Task Difficulty Scale, containing items related to Instrumental Activities of Daily Living (IADLs) and Activities of Daily Living (ADLs).

RESULTS: A final sample of 93 (93.9%) participants was utilized in analyses due to nonresponse. Most participants reported having RA ≥5 years (69.7%), being female (84.9%), white (92.5%), married (50.5%), having ≥4-year college degree (57.0%), income ≥$50,000 (56.1%), and being 45-65 years-of-age (61.3%). All 5 scales had adequate internal reliability (α≥.700). Pearson correlations between PRO scales demonstrated significant relationships between PROMIS PF, PROMIS UE, RA impact on life, and Task Difficulty scales (all r≥0.600). Two backward-reduced multiple linear regression models were developed, modeling PROMIS PF and PROMIS UE, and found strong correlations (R²=0.845; R²=0.794, respectively) with both reduced models containing 7 variables, with no evidence the that inclusion of additional variables was warranted (F=0.3071, p=0.955; F=0.4051, p=0.996, respectively). The reduced models described similar significant covariates in perceived difficulty in dinner preparation and ability to stand. However, the models diverge, with the UE model including significant predictors related to fine motor skills in one’s ability to open pill bottles and driving-related IADLs, and the PF model containing more general significant covariates such as age and RA’s impact on life.

CONCLUSIONS: Several novel items, particularly those from the Task Difficulty scale, present opportunities for developing more streamlined PRO IADL/ADL-oriented measurement to facilitate task-related clinical assessments and identify patients’ PF and UE RA-related limitations.