Univariate analysis | Multivariate Model 1 | Multivariate Model 2 | |||||
---|---|---|---|---|---|---|---|
Incidence rate (%) | ORunadj | (95% CI) ORadj | ORunadj | (95% CI) ORadj | ORunadj | (95% CI) ORadj | |
Gender | |||||||
Male (ref.) | 1.04 | 1.00 | 1.00 | 1.00 | |||
Female | 1.51 | 1.45 | (0.94 to 2.26) | 1.73* | (1.02 to 2.95) | 1.54 | (0.89 to 2.67) |
Age (years) | |||||||
0–4 | 1.98 | 2.79 | (0.94 to8.27) | NA | NA | ||
5–14 | 1.31 | 1.84 | (0.83 to 4.08) | NA | NA | ||
15–24 | 2.43 | 3.43* | (1.85 to 6.37) | NA | NA | ||
25–44 | 1.35 | 1.89 | (1.05 to 3.40) | NA | NA | ||
≥45 (ref.) | 0.72 | 1.00 | NA | NA | |||
Marital status | |||||||
Married/cohabiting (ref.) | 0.85 | 1.00 | 1.00 | 1.00 | |||
Single/divorced/widowed | 1.74 | 2.06* | (1.31 to 3.24) | 1.86* | (1.10 to 3.14) | 1.80* | (1.04 to 3.10) |
Education | |||||||
Primary or below (ref.) | 0.62 | 1.00 | NA | NA | |||
Secondary | 1.41 | 2.31 | (1.13 to 4.73) | NA | NA | ||
Postsecondary† | 1.63 | 2.67 | (1.25 to 5.69) | NA | NA | ||
Occupational status | |||||||
White-collar job‡ (ref.) | 1.70 | 1.00 | NA | NA | |||
Blue-collar job§ | 0.42 | 0.25 | (0.06 to 1.02) | NA | NA | ||
Housewives | 0.94 | 0.55 | (0.26 to 1.17) | NA | NA | ||
Retired | 0.32 | 0.19* | (0.06 to 0.61) | NA | NA | ||
Students | 1.70 | 1.00 | (0.61 to 1.65) | NA | NA | ||
Others | 1.25 | 0.73 | (0.26 to 2.06) | NA | NA | ||
Monthly household income (HK$¶) | |||||||
<10 000 (ref.) | 0.32 | 1.00 | 1.00 | 1.00 | |||
10 000–19 999 | 1.32 | 4.20 | (1.24 to 14.2) | 10.9* | (1.44 to 83.0) | 6.85** | (0.89 to 52.7) |
20 000–29 999 | 1.15 | 3.64 | (1.02 to 12.9) | 9.21* | (1.17 to 72.4) | 6.08** | (0.76 to 48.7) |
≥30 000 | 1.93 | 6.18* | (1.89 to 20.2) | 14.7** | (2.00 to 108.3) | 7.60* | (1.01 to 57.1) |
Size of living area (ft2‡‡) | |||||||
≤400 (ref.) | 0.78 | 1.00 | NA | NA | |||
401–600 | 0.72 | 0.92 | (0.43 to 1.96) | NA | NA | ||
601–700 | 1.74 | 2.25 | (1.08 to 4.69) | NA | NA | ||
>700 | 1.88 | 2.42* | (1.25 to 4.69) | NA | NA | ||
Living density (ft2/person‡‡) | |||||||
<120 (ref.) | 0.59 | 1.00 | 1.00 | 1.00 | |||
120–159 | 1.00 | 1.70 | (0.72 to 3.98) | 1.31 | (0.51 to 3.37) | 1.05 | (0.39 to 2.77) |
160–249 | 1.44 | 2.45 | (1.16 to 5.20) | 1.89 | (0.82 to 4.34) | 1.19 | (0.50 to 2.86) |
≥250 | 1.65 | 2.81 | (1.27 to 6.23) | 2.87* | (1.21 to 6.82) | 1.45 | (0.58 to 3.61) |
Pet ownership | |||||||
No (ref.) | 0.19 | 1.00 | – | 1.00 | |||
Yes | 8.56 | 48.3* | (25.5 to 91.4) | – | 52.0*** | (22.1 to 122.4) |
*Significant difference level at p=0.05 reached in the univariate analysis. **Significant difference level at p=0.01. ***Significant difference level at p=0.001. Bonferroni correction was applied to correct multiple testing. A significance level of a=0.00417 (0.05/12) was therefore adopted.
†Post-secondary education included non-degree and degree courses.
‡White-collar job: including manager and administrators, professionals, associate professionals, clerical support workers and service and sales workers.
§Blue-collar job: including craft and related workers, plant and machine operators, elementary occupations and skilled agricultural and fishery workers.
¶Annual exchange rate in 2009: HK$1=US$0.129 (US$1= HK$7.75); HK$10 000=US$1290; HK$20 000=US$2580; HK$30 000=US$3870.
‡‡1 ft2=0.093 m2 (1 m2=10.76 ft2).
NA, the variables were selected but excluded from the Model 1 according to the variable selection method with p<0.10 as the entry and removal criteria; ref., reference group; –, pet ownership was not put in the Model 1.