Factors associated with impaired physical function in elderly rheumatoid arthritis patients who had achieved low disease activity.

Abstract

We aimed to investigate factors associated with impaired physical function [defined as Health Assessment Questionnaire Disability Index (HAQ-DI) >0.5] of old-old (aged 75-84 years) patients with rheumatoid arthritis. Data from 15,185 rheumatoid arthritis patients in the National Database of Rheumatic Disease in Japan were extracted from 2017 to 2018. We enrolled 3708 patients aged 55-84 years in Simplified Disease Activity Index (SDAI) ≤11 and Steinbrocker Stage I/II. Factors associated with HAQ-DI >0.5 were analysed by multivariable logistic regression. About half of the old-old patients received methotrexate, which was lower than middle-aged (55-64 years) and young-old patients (65-74 years). The proportion of glucocorticoids in the old-old patients was highest among the three groups, and biological disease-modifying antirheumatic drugs were similarly used. The prevalence of HAQ-DI >0.5 was significantly higher in old-old patients with low disease activity than in those with remission. The same was true in the middle-aged and young-old patients. Multivariable analysis showed age, higher SDAI, glucocorticoid use, and methotrexate nonuse were significantly associated with HAQ-DI >0.5 in the old-old patients. Achieving SDAI remission was an ideal goal for old-old patients in terms of physical function. Glucocorticoids and a low proportion of methotrexate use may influence the physical function of old-old patients.