Table 3 Radiological, and analytical findings on admission in patients ≥ 80 years hospitalized with COVID-19 during the first and successive waves

Chest X-ray findings

 < 0.001

 Normal

1091 (18.7)

768 (17.3)

323 (23.1)

 Unilateral infiltrates

1168 (20.0)

867 (19.5)

301 (21.5)

 Bilateral infiltrates

3584 (61.3)

2807 (63.2)

777 (55.5)

Laboratory findings

Arterial blood gases

 PO₂/FiO₂ ratio

277 (222–327)

273 (214–323)

289 (242–333)

 < 0.001

Blood count & biochemistry

 Lymphocytes (× 10³/μL)

0.88 (0.06–1.23)

0.88 (0.60–1.23)

0.87 (0.6–1.23)

0.532

 Lactate dehydrogenase (U/L)

322 (246–448)

330 (251–463)

302 (233–412)

 < 0.001

 C-reactive protein (mg/L)

71.0 (24.0–138)

71.6 (23.5–143)

69.8 (27.8–128)

0.330

 D-dimer (ng/mL)

1.01 (0.55–2.02)

1.02 (0.54–2.02)

1.00 (0.55–2.01)

0.558

 Serum ferritin (μg/L)

445 (212–953)

484 (230–1013)

396 (189–856)

 < 0.001

 Fibrinogen (mg/L)

598 (500–700)

607 (500–706)

564 (461–700)

 < 0.001