Table 1

Characteristics of patients with and without ankylosing spondylitis (AS) who were hospitalised for pneumonia from 1997 to 2016 in Denmark

AS
N (%)
Non-AS
N (%)
N842 (0.2)386.954 (99.8)
Age, median (IQR)65 (52–74)71 (57–81)
 16–29 years22 (2.6)15.965 (4.1)
 30–44 years102 (12.1)35.690 (9.2)
 45–59 years195 (23.2)58.375 (15.1)
 60–74 years316 (37.5)111.667 (28.9)
 75 years and above207 (24.6)165.247 (42.7)
Sex
 Female218 (25.9)190.532 (49.2)
 Male624 (74.1)196.422 (50.8)
Pneumonia 1997–2006274 (0.2)161.597 (99.8)
Pneumonia 2006–2017568 (0.3)224.500 (99.7)
Comorbidity within 10 years before pneumonia
 Congestive heart failure97 (11.5)30.946 (8.0)
 Peripheral vascular disease66 (7.8)26.598 (6.9)
 Previous myocardial infarction48 (5.7)20.386 (5.3)
 Chronic pulmonary disease152 (18.1)60.981 (15.8)
 Cerebrovascular disease91 (10.8)48.986 (12.7)
 Hemiplegia19 (2.7)1.917 (0.5)
 Dementia7 (0.8)13.304 (3.4)
 Connective tissue disease79 (9.4)9.834 (2.5)
 Peptic ulcer disease54 (6.4)17.479 (4.5)
 Diabetes type I and II77 (9.1)30.399 (7.8)
 Diabetes with end organ damage46 (5.5)17.004 (4.4)
 Moderate to severe renal disease45 (5.3)13.961 (3.6)
 Any tumour98 (11.6)52.629 (13.6)
 Leukaemia5 (0.6)3.484 (0.9)
 Lymphoma13 (1.5)6.205 (1.6)
 Metastatic solid tumour18 (2.1)9.365 (2.4)
 Mild liver disease16 (1.9)5.636 (1.5)
 Moderate-to-severe liver disease2 (0.2)1.72 (0.45)
 AIDS0545 (0.1)
Comorbidity index (level of Charlson Index Score)
 Low (0)350 (41.6)180.629 (46.8)
 Medium (1–2)316 (37.5)137.850 (35.7)
 High (≥3)176 (20.1)67.934 (17.6)
Duration of hospital stay in days, median (IQR)6 (3–11.5)7 (4–12)