Table 3.
Risk ratio (RR) of predictors of HIV-positive status according to GEE analysis
|
Independent variables |
Complete dataset |
Imputed dataset |
||||
|---|---|---|---|---|---|---|
| RR | CI 95%- | CI 95%+ | RR | CI 95%- | CI 95%+ | |
| Calendar year |
0.76 |
0.70 |
0.82 |
0.78 |
0.72 |
0.83 |
| Year of birth |
0.96 |
0.94 |
0.98 |
0.96 |
0.94 |
0.97 |
| Year of birtha |
0.95 |
0.93 |
0.97 |
0.96 |
0.94 |
0.98 |
| Year of birthb |
1.02 |
1.01 |
1.03 |
1.01 |
1.00 |
1.02 |
| Age |
1.04 |
1.03 |
1.06 |
1.04 |
1.02 |
1.05 |
| Agec |
0.95 |
0.94 |
0.96 |
0.96 |
0.95 |
0.97 |
| Aged |
1.01 |
1.01 |
1.02 |
1.01 |
1.01 |
1.02 |
| Female, non-Swiss, non-injector |
0.17 |
0.07 |
0.45 |
0.24 |
0.08 |
0.69 |
| Female, non-Swiss, ever injector |
1.64 |
1.21 |
2.24 |
1.58 |
1.18 |
2.12 |
| Female, Swiss, non-injector |
0.26 |
0.18 |
0.38 |
0.25 |
0.17 |
0.38 |
| Female, Swiss, ever injector |
1.20 |
1.05 |
1.38 |
1.18 |
1.04 |
1.34 |
| Male, non-Swiss, non-injector |
0.22 |
0.12 |
0.39 |
0.24 |
0.14 |
0.40 |
| Male, non-Swiss, ever injector |
0.93 |
0.75 |
1.15 |
0.92 |
0.74 |
1.13 |
| Male, Swiss, non-injector | 0.21 | 0.16 | 0.28 | 0.21 | 0.16 | 0.28 |
The time variables were rescaled to fit the GEE model as follows: calendar year = logarithm of year - 1990, year of birth = year - 1960, age = age - 30. aYear of birth = Year of birth × Year of birth / 10. bYear of birth = Year of birth × Year of birth × Year of birth / 100. cAge = Age × Age / 10, dAge = Age × Age × Age / 100. The group ‘Male, Swiss, ever injector’ was reference category and is therefore omitted from the independent variable list.