Table 2. Seroprevalence (%) and odds ratios for presence of CHIKV-neutralizing antibodies according to socio-demographic characteristics of respondents from National Health Survey, Singapore, 2010.
| Socio-demographics | % sero-positive | Univariable analysis | Multivariable analysis* | |||||
|---|---|---|---|---|---|---|---|---|
| cOR | (95% CI) | p-value | aOR | (95% CI) | p-value | |||
| Age group (years) | <0.0005 | <0.0005 | ||||||
| 18–29 | 0.5 | 1.00 | Referent | 1.00 | Referent | |||
| 30–39 | 3.1 | 7.31 | (2.13–25.08) | 0.002 | 6.58 | (1.90–22.80) | 0.003 | |
| 40–49 | 0.8 | 1.93 | (0.48–7.83) | 0.359 | 1.89 | (0.46–7.73) | 0.374 | |
| 50–59 | 1.0 | 2.34 | (0.59–9.25) | 0.226 | 2.51 | (0.63–10.02) | 0.193 | |
| 60–69 | 0.6 | 1.53 | (0.27–8.72) | 0.633 | 1.68 | (0.29–9.68) | 0.561 | |
| 70–79 | 11.5 | 28.23 | (8.18–97.47) | <0.0005 | 34.28 | (9.74–120.73) | <0.0005 | |
| Gender | 0.011 | 0.008 | ||||||
| Male | 2.5 | 1.96 | (1.17–3.29) | 0.011 | 2.07 | (1.21–3.56) | 0.008 | |
| Female | 1.3 | 1.00 | Referent | 1.00 | Referent | |||
| Residency | 0.039 | |||||||
| Singapore citizen | 1.7 | 1.00 | Referent | |||||
| Permanent resident | 3.1 | 1.89 | (1.03–3.47) | 0.039 | ||||
| Ethnic Group | <0.0005 | 0.001 | ||||||
| Chinese | 1.6 | 1.00 | Referent | 1.00 | Referent | |||
| Malay | 0.7 | 0.39 | (0.11–1.35) | 0.136 | 0.36 | (0.10–1.28) | 0.114 | |
| Indian | 3.5 | 2.10 | (1.05–4.18) | 0.035 | 2.14 | (1.03–4.43) | 0.041 | |
| Others | 6.4 | 4.11 | (1.87–9.00) | <0.0005 | 4.02 | (1.70–9.51) | 0.002 | |
| Main work status over last 12 months | <0.0005 | |||||||
| Working | 1.4 | 1.00 | Referent | |||||
| Student / National serviceman | 0.5 | 0.18 | (0.01–2.48) | 0.200 | ||||
| Homemaker | 2.5 | 1.71 | (0.88–3.30) | 0.113 | ||||
| Retired | 6.9 | 5.19 | (2.80–9.64) | <0.0005 | ||||
| Unemployed / Unknown | 0.0 | 0.13 | (0.001–13.88) | 0.391 | ||||
| Type of residential premises | 0.558 | |||||||
| Landed residential property and others | 2.5 | 1.00 | Referent | |||||
| Public housing apartment | 1.9 | 0.86 | (0.30–2.53) | 0.788 | ||||
| Private flat and condominium | 0.9 | 0.36 | (0.07–1.76) | 0.207 | ||||
| Others | 0.0 | 0.00 | - | 0.998 | ||||
| Floor level of residential premises | 0.011 | 0.006 | ||||||
| Landed residential property | 2.2 | 1.52 | (0.47–4.92) | 0.488 | 1.49 | (0.44–5.09) | 0.521 | |
| Public and private apartment | ||||||||
| Ground | 5.8 | 4.99 | (1.89–13.15) | 0.001 | 6.55 | (2.30–18.72) | <0.0005 | |
| 2nd to 9th floor | 1.8 | 1.38 | (0.73–2.63) | 0.321 | 1.72 | (0.88–3.34) | 0.113 | |
| 10th floor or higher | 1.4 | 1.00 | Referent | 1.00 | Referent | |||
cOR, crude odds ratio; aOR: adjusted odds ratio; CI, confidence interval.
* Adjusted for age group, gender, ethnic group and floor level of residential premises.