Incidence and Risk Factors for Infections Requiring Hospitalization, Including Pneumocystis Pneumonia, in Japanese Patients with Rheumatoid Arthritis

Table 2

Significant risk factors and the odds ratios for each infection.

Total (, 3.7/100 PY)	OR (95% CI)	value
Age 70 and older	1.5 (1.2–2.0)	0.002
Male	1.6 (1.1–2.2)	0.004
Class III or IV	2.2 (1.7–3.0)	<0.0001
Underlying lung disease	3.1 (2.3–4.2)	<0.0001
DAS28-ESR ≥ 3.8	1.7 (1.3–2.3)	0.0001
Corticosteroids	3.0 (2.1–4.4)	<0.0001  mg/day
Biologics	1.4 (1.0–2.0)	0.033
Methotrexate	0.7 (0.6–1.0)	0.034
Respiratory tract (, 1.7/100 PY)	OR (95% CI)	value
Age 70 and older	1.5 (1.0–2.1)	0.031
Male	2.5 (1.7–3.6)	<0.0001
Class III or IV	2.6 (1.8–3.7)	<0.0001
Underlying lung disease	5.1 (3.5–7.4)	<0.0001
Corticosteroids	2.5 (1.6–4.0)	0.0001  mg/day
Methotrexate	0.7 (0.5–1.0)	0.049
Urinary tract (, 0.5/100 PY)	OR (95% CI)	value
Female	3.9 (1.2–23.9)	0.062
Class III or IV	7.6 (4.0–15.0)	<0.0001
eGFR < 60 ml/min/1.73 m^2	2.2 (1.2–4.1)	0.013
Corticosteroids	3.8 (1.6–11.2)	0.006  mg/day
Methotrexate	0.5 (0.3–0.9)	0.028
Gastrointestinal tract (, 0.4/100 PY)	OR (95% CI)	value
Age 70 and older	4.0 (2.0–9.2)	0.0004
Class III or IV	3.4 (1.7–6.8)	0.0004
Corticosteroids	4.5 (1.7–15.4)	0.005  mg/day
Skin and soft tissue (, 0.3/100 PY)	OR (95% CI)	value
Class III or IV	4.1 (1.9–8.8)	0.0002
Corticosteroids	3.0 (1.2–9.0)	0.033  mg/day
Methotrexate	0.4 (0.2–0.9)	0.025
Herpes zoster (, 0.2/100 PY)	OR (95% CI)	value
Corticosteroids	5.3 (1.8–22.8)	0.007  mg/day
PCP (, 0.2/100 PY)	OR (95% CI)	value
Age 70 and older	3.5 (1.2–10.8)	0.025
Male	6.6 (2.4–19.0)	0.0003
Underlying lung disease	3.0 (1.0–8.6)	0.038
Corticosteroids	4.8 (1.3–31.0)	0.039  mg/day
Biologics	5.4 (1.7–15.7)	0.002
Methotrexate	5.7 (1.8–25.9)	0.008

PY, patient-years; OR, odds ratio; CI, confidence interval; Class, global functional status; PCP, Pneumocystis pneumonia. dose of corticosteroids (prednisolone equivalents).