Table 6

Multivariate baseline predictors of mortality due to pneumonia and mortality due to other respiratory diseases in rheumatoid arthritis patients

Step and variable

Hazard ratio (95% CI)

P

Mortality due to pneumonia

1. Age

1.08/yr (1.05, 1.17)

< 0.0001

2. MMP-8 (ng/ml)

1.012 (1.010, 1.025)

0.0002

3. Nodular disease

2.36 (1.01, 5.53)

0.01

4. Rheumatoid factor

2.66 (1.03, 6.82)

0.05

Mortality due to other respiratory diseases*

1. Age

1.09/yr (1.03, 1.16)

0.006

2. Nodular disease

4.45 (1.55, 12.81)

0.006

3. MMP-8 (ng/ml)

1.016 (1.004, 1.03)

0.004

Stepwise Cox proportional hazards regression. Baseline variables included in the analyses were age, sex, disease duration, metalloproteinase (MMP)-8 (ng/ml), rheumatoid factor (+/-), nodular disease (+/-), C-reactive protein (mg/dl), erythrocyte sedimentation rate (mm/h), Health Assessment Questionnaire (score 0 to 3), Larsen score, taking drugs for cardiovascular disease (CVD) (+/-) and smoking at entry (+/-). Only significant variables retained in the stepwise analysis are shown. *Includes pulmonary fibrosis (n = 3), chronic obstructive pulmonary disease (n = 4), bronchitis (n = 2), bronchiectasis (n = 3) and asthma (n = 1).

Mattey et al. Arthritis Research & Therapy 2012 14:R204   doi:10.1186/ar4042