| Age, mean (years) ± SD | 74.4 ± 14.3 | 68.2 ± 15.4 | | < 0.001 | | |
| Age group |
| < 65 years | 16 (22.9) | 154 (36.2) | Ref | Ref | Ref | Ref |
| 65-74 years | 18 (25.7) | 107 (25.1) | 1.62 (0.79–3.32) | 0.188 | 1.70 (0.69–4.15) | 0.246 |
| 75-84 years | 16 (22.9) | 115 (27.0) | 1.34 (0.64–2.79) | 0.435 | 1.99 (0.80–4.94) | 0.138 |
| ≥ 85 years | 20 (28.6) | 50 (11.7) | 3.85 (1.85–8.00) | < 0.001 | 10.78 (4.10–28.37) | < 0.001 |
| Gender = male | 45 (64.3) | 280 (65.7) | 0.94 (0.55–1.59) | 0.814 | 1.05 (0.55–1.98) | 0.892 |
| Ethnicity |
| Chinese | 51 (72.9) | 308 (72.3) | Ref | Ref | | |
| Malay | 9 (12.9) | 52 (12.2) | 1.05 (0.49–2.25) | 0.910 | | |
| Indian | 7 (10.0) | 32 (7.5) | 1.32 (0.55–3.15) | 0.530 | | |
| Others | 3 (4.3) | 34 (8.0) | 0.53 (0.16–1.80) | 0.311 | | |
| Vaccination status (received ≥ 14 days prior to admission) |
| Any pneumococcal vaccination | 7 (10.0) | 73 (17.1) | 0.54 (0.24–1.22) | 0.138 | | |
| Influenza vaccination in past 1 yr | 8 (11.4) | 67 (15.7) | 0.69 (0.32–1.51) | 0.354 | | |
| Co-morbidities |
| Charlson’s score, median (IQR) | 1 (0–4) | 2 (1–4) | | < 0.001 | | |
| Charlson’s score > 3 | 30 (42.7) | 107 (25.1) | 2.24 (1.33–3.77) | 0.002 | 1.93 (1.02–3.64) | 0.042 |
| Myocardial infarction / Congestive heart failure | 30 (42.9) | 113 (26.5) | 2.08 (1.24–3.49) | 0.006 | | |
| Cerebrovascular disease | 17 (24.3) | 49 (11.5) | 2.47 (1.33–4.60) | 0.004 | | |
| Dementia | 16 (22.9) | 38 (8.9) | 3.03 (1.58–5.79) | 0.001 | | |
| Chronic pulmonary disease | 16 (22.9) | 133 (31.2) | 0.65 (0.36–1.18) | 0.160 | | |
| Liver disease | 3 (4.3) | 24 (5.6) | 0.75 (0.22–2.56) | 0.997 | | |
| Diabetes mellitus | 24 (34.3) | 123 (28.9) | 1.29 (0.75–2.20) | 0.409 | | |
| Renal disease | 16 (22.9) | 77 (18.1) | 1.34 (0.73–2.47) | 0.343 | | |
| Any malignancy | 12 (17.1) | 41 (9.6) | 1.94 (0.97–3.91) | 0.063 | | |
| Invasive pneumococcal disease | 24 (34.3) | 68 (16.0) | 2.75 (1.57–4.80) | < 0.001 | 3.19 (1.55–6.59) | 0.002 |
| Outcomes |
| ICU admission | 31 (44.3) | 23 (5.4) | 13.93 (7.40–26.19) | < 0.001 | 23.22 (11.07–48.70) | < 0.001 |
| Length of stay (days), median (IQR) | 7 (4–21) | 8 (6–15) | | 0.081 | | |
| Length of stay > 7 days | 33 (47.1) | 242 (56.8) | 1.08 (0.90–1.29) | 0.414 | | |
