over the course of up to 10 years of follow-up, according to an analysis of patients enrolled in the Canadian Early Arthritis Cohort (CATCH).
Higher Disease Activity Score in 28 joints (DAS28) at follow-up was also associated with higher all-cause mortality among the patients, who all took at least one conventional synthetic or biologic disease-modifying antirheumatic drug during the first year. Higher DAS28 scores in previous studies has been associated with increased disability as measured by the HAQ, Safoora Fatima, MD, of the University of Western Ontario, London, and colleagues wrote in Arthritis & Rheumatology.
“Combining our study findings with this association suggests that poorer disease control (high DAS28) within the first treatment year for RA may lead to increased disability (high HAQ scores) which in turn may contribute to higher mortality. This may indicate that RA patients who do not have a deep response in the first year to treatment have higher subsequent mortality,” the researchers wrote.
In addition to higher HAQ scores, all-cause mortality was independently associated with age, male sex, lower education, smoking, more comorbidities, higher baseline disease activity, and glucocorticoid use. “This is helpful in a clinical setting as it can guide physician-patient discussions in terms of risk factors associated with prognosis, prescribing glucocorticoids, counseling on smoking cessation, monitoring treatment responses, and focusing on patient education,” the authors wrote.
While the impact of increased disease activity and damage likely plays a role in the association between high HAQ score and increased mortality, the authors noted that “comorbidities could be causing deaths and those with comorbidities in [early RA] have less chance of remission and more functional impairment at 1 year versus those without any comorbidities, as has been shown [before] in the CATCH [early RA] cohort.”
Dr. Fatima and associates studied 1,724 patients with RA who had a symptom duration of less than 1 year at the time of enrollment in CATCH during 2007-2017. These patients had a mean age of 55 years, and 72% were women. Over the 10-year follow up period, 62 patients (2.4%) died. HAQ scores proved to be significantly higher at both baseline and 1 year for those who died, going from 1.2 to 0.9, compared with scores moving from 1.0 to 0.5 among patients who did not die. (The HAQ has eight categories that are each scored 0-3, with 0 meaning no self-reported functional impairment and 3 meaning severe functional impairment.) Similarly, DAS28 scores were significantly higher at both time points for patients who died versus those who lived, declining from 5.4 to 3.6 for deceased and from 4.9 to 2.8 for nondeceased patients in a year.
Whereas HAQ at baseline was not significantly associated with all-cause mortality in a multivariate, discrete-time survival model that adjusted for age, gender, comorbidities, disease activity, smoking, education, seropositivity, symptom duration, and glucocorticoid use, the association between HAQ at 1 year and death remained statistically significant with a hazard ratio of 1.87.
The authors noted that potential confounders may not have been adjusted for in the comparisons, such as “variable access to advanced therapies, other comorbidities not in the standardized comorbidity questionnaire, [and] severity of comorbidities.”
CATCH has been funded over many years by multiple companies including Amgen and Pfizer Canada, AbbVie, Medexus, Eli Lilly Canada, Merck Canada, Sandoz, Hoffman–La Roche, Janssen, UCB Canada, Bristol-Myers Squibb Canada, and Sanofi Genzyme. The authors had no disclosures.
SOURCE: Fatima S et al. Arthritis Rheumatol. 2020 Sep 6. doi: 10.1002/art.41513.