Mortality risk associated with rheumatoid arthritis in a prospective cohort of older women: results from the Iowa Women's Health Study.
OBJECTIVE
To determine whether rheumatoid arthritis (RA) is associated with excess mortality among older women.


METHODS
RA associated mortality was examined in a prospective cohort study that was started in 1986, and included 31 336 women aged 55-69 years without a history of RA at baseline. Up to 1997, 158 cases of RA were identified and validated against medical records. The relative risk (RR) and 95% confidence interval (CI) were calculated as measures of association between RA onset and subsequent mortality (overall and cause-specific) using Cox proportional hazards regression.


RESULTS
Compared with non-cases, women developing RA during follow up had a significantly increased mortality risk (RR=1.52; 95% CI 1.05 to 2.20). Mortality was higher among rheumatoid factor (RF) positive cases (RR=1.90; 95% CI 1.24 to 2.92) than among RF negative cases (RR=1.00; 95% CI 0.45 to 1.99). There were trends towards increased proportions of RA related deaths from infection (RR=3.61; 95% CI 0.89-14.69) and circulatory disease (RR=1.46; 95% CI 0.76 to 2.81) but not malignancy (RR=0.97; 95% CI 0.46 to 2.04).


CONCLUSIONS
RA was associated with significantly increased mortality in a cohort of older women, and the association appeared to be restricted to those with RF positive disease.
Mikuls
T R
TR
Division of Clinical Immunology and Rheumatology, Department of Medicine, University of Alabama at Birmingham, 35294, USA. ted.mikuls@ccc.uab.edu
Saag
K G
KG
Criswell
L A
LA
Merlino
L A
LA
Kaslow
R A
RA
Shelton
B J
BJ
Cerhan
J R
JR
D000368:Aged; D001172:Arthritis, Rheumatoid / Q000401:mortality*; D005260:Female; D005500:Follow-Up Studies; D006306:Health Surveys; D006801:Humans; D007484:Iowa / Q000453:epidemiology; D008875:Middle Aged; D016016:Proportional Hazards Models; D011446:Prospective Studies; D018570:Risk Assessment; D015996:Survival Rate