In this series, serositis and cutaneous vasculitis were predominant extra-articular manifestations of RA; and mortality was greater in the ExRA than in the non-ExRA subgroup, perhaps due to a high frequency of associated heart disease.

RA was predicted by an early age at menopause. This implicates an influence of hormonal changes during the fertile period on the development of RA in postmenopausal women.

In this study, long-term breast feeding, but not OC use, was associated with a significant reduction in the risk of RA.

Pulmonary dysfunction did not predict RA, but smoking and low socio-economic status were independent risk factors for RA. Other effects of smoking may be important for RA susceptibility.