Multivariate analysis of the risk of mortality in the study patients.

<p>Multivariate analysis of the risk of mortality in the study patients.</p

Etiology of pneumonia in the RA and non-RA patients.

<p>Etiology of pneumonia in the RA and non-RA patients.</p

Characteristics of the patients with and without RA.

<p>Characteristics of the patients with and without RA.</p

Etiology of pneumonia in RA.

<p>Etiology of pneumonia in RA.</p