Table 1.
Baseline characteristics of index patients and their household contacts
| Characteristics | Index patient (n = 185) | Secondary cases (n = 466) | Non‐cases (n = 382) | P value † |
|---|---|---|---|---|
| Median age, IQR | 36 (26–42) | 12 (6–33) | 18 (8–35) | <0.001 |
| Age group (years), n (%) | 0.002 | |||
| <12 | 36 (19.5) | 241 (51.7) | 145 (38.0) | |
| 13–17 | 3 (1.6) | 35 (7.5) | 42 (11.0) | |
| 18–30 | 26 (14.0) | 61 (13.1) | 64 (16.7) | |
| 31–50 | 105 (56.8) | 100 (21.5) | 102 (26.7) | |
| >50 | 15 (8.1) | 29 (6.2) | 29 (7.6) | |
| Gender, n (%) | 0.002 | |||
| Male | 125 (67.6) | 185 (39.7) | 193 (50.5) | |
| Female | 60 (32.4) | 281 (60.3) | 189 (49.5) | |
| Race, n (%) | — ‡ | |||
| Malay | 166 (89.7) | 421 (90.3) | 324 (84.8) | |
| Chinese | 4 (2.2) | 7 (1.5) | 8 (2.1) | |
| Indian | 14 (7.6) | 36 (7.7) | 43 (11.3) | |
| Others | 1 (0.5) | 2 (0.4) | 7 (1.8) |
†
P value indicated differences between secondary cases and non‐cases.
‡
Conditions for Pearson's χ 2 test not met due to two cells (25%) had expected counts <5.
IQR, interquartile range.