Patients with RA have a significantly higher risk of developing COPD than that of the control population. Further, age-related risk analysis indicated much higher adjusted HR in younger patients although COPD incidence increased with age. It can be hypothesized that in addition to cigarette smoke, RA may be a determining factor for COPD incidence and/or facilitates shortening of the time course for developing COPD. However, further investigation is needed to corroborate this hypothesis.

TB was much more prevalent in RA patients than in control subjects. Prospective cohort studies are required to establish a causal relationship between previous TB and RA.

TB patients are at elevated risk of developing cataract. Although the incidence decreased with time, the aHR remains statistically significant through the follow-up years.