Introduction & Objectives
Rheumatoid arthritis (RA) causes damage to the synovial joints but also has systemic manifestations. Organ systems it can affect include the cardiac, pulmonary, ocular, skin and hematologic systems, increasing the risk of multiple, associated complications.
RA is associated with poor physical function, worsening quality of life, and increased morbidity and mortality, especially due to cardiovascular disease complications. Several studies have found patients with RA have a higher mortality risk than the general population. Recognizing predictors of mortality and morbidity is important from clinical, research and public health perspectives.
The Health Assessment Questionnaire (HAQ) disability index is commonly used to measure disability due to RA using the patient’s self-reported functional assessment. The HAQ has eight categories, scored on a scale of 0 (no problem) to 3 (unable to perform) per category, leading to a final score between 0 and 3, with 0 representing no self-reported functional impairment and 3 representing severe functional impairment. It is a valid and reliable tool used to monitor the impact of disease severity and activity; as well, it helps assess changes in physical function with treatment.
In this study, Fatima et al. analyzed how well the HAQ predicted future all-cause mortality in patients with early RA.
Methods
Patients with early RA (i.e., with a symptom duration of less than one year) enrolled in the Canadian Early Arthritis Cohort who initiated disease-modifying anti-rheumatic drugs and had complete HAQ data at baseline and one year were included in the study. Discrete-time proportional hazards models were used to estimate crude and multi-adjusted associations of baseline HAQ and the HAQ at one year with all-cause mortality in each year of follow-up.
Results
A total of 1,724 patients with early RA were included. Their mean age was 55 years, and 72% were women. Over 10 years, 62 deaths (2.4%) were recorded. Deceased patients had higher HAQ scores at baseline (mean ± SD 1.2 ± 0.7) and at one year (0.9 ± 0.7) than living patients (1.0 ± 0.7 and 0.5 ± 0.6, respectively; P<0.001). Disease Activity Score in 28 joints (DAS28) was higher in deceased than living patients at baseline (mean ± SD 5.4 ± 1.3 vs. 4.9 ± 1.4) and at one year (mean ± SD 3.6 ± 1.4 vs. 2.8 ± 1.4) (P<0.001).
Other correlates of mortality include: older age, male sex, lower education level, smoking, more comorbidities, higher baseline DAS and glucocorticoid use.
