Risk factors for incident syphilis infections*
| Univariate analysis‡ | ||||||
|---|---|---|---|---|---|---|
| No† | Obs | Py | Rate | RR | p Value | |
| *Included in analysis are those people with at least two syphilis tests during the study period, and who are considered to have been uninfected with syphilis during the study period. | ||||||
| †No = the number of people (sums to 935 for all variables except “gonorrhoea” and “syphilis” for which subjects can contribute to more that one level); Obs = number of incident infections; Py = person years of follow up; rate = incident rate per 100 person years. | ||||||
| ‡In univariate analysis each variable is fitted separately. p Values in parentheses are overall test for heterogeneity. | ||||||
| §Prevalent infection is at first test during study period. Incident infections are up to 7 days before date of relevant incident chlamydia infection during study period. Levels are hierarchical: “no test,” “no,” “prevalent,” “incident” (a person contributes only to relevant levels). | ||||||
| Sex | ||||||
| Male | 422 | 7 | 626.9 | 1.12 | 1.0 | |
| Female | 513 | 10 | 852.0 | 1.17 | 1.05 | 0.919 |
| Age (years) at first incident chlamydia | ||||||
| 25+ | 406 | 3 | 618.1 | 0.49 | 1.0 | |
| 20–24 | 222 | 6 | 350.2 | 1.71 | 3.53 | 0.074 |
| 15–19 | 192 | 6 | 316.9 | 1.89 | 3.90 | 0.054 |
| 12–14 | 115 | 2 | 193.6 | 1.03 | 2.13 | 0.408 (0.230) |
| Time | ||||||
| <June 1997 | 905 | 12 | 799.4 | 1.50 | 1.0 | |
| ≥June 1997 | 830 | 5 | 679.4 | 0.74 | 0.49 | 0.180 |
| Resident status | ||||||
| Permanent | 864 | 16 | 1385.0 | 1.16 | 1.0 | |
| Removed | 71 | 1 | 93.9 | 1.07 | 0.92 | 0.937 |
| Marital status | ||||||
| Never married | 278 | 6 | 456.2 | 1.32 | 1.0 | |
| 1+ wives | 558 | 10 | 876.3 | 1.14 | 0.87 | 0.783 |
| Widow/past | 67 | 1 | 104.4 | 0.96 | 0.73 | 0.769 (0.989) |
| Not known | 32 | 0 | 41.9 | 0 | — | |
| Alcohol | ||||||
| No abuse | 564 | 12 | 923.7 | 1.30 | 1.0 | |
| Abuse | 323 | 4 | 488.9 | 0.82 | 0.63 | 0.423 |
| Not known | 48 | 1 | 66.3 | 1.51 | 1.16 | 0.886 (0.702) |
| Petrol sniffing | ||||||
| Never | 746 | 12 | 1173.0 | 1.02 | 1.0 | |
| Male ever occasional | 32 | 1 | 48.7 | 2.05 | 2.01 | 0.503 |
| Male ever regular | 103 | 2 | 164.2 | 1.22 | 1.19 | 0.819 |
| Female ever occasional | 27 | 2 | 45.8 | 4.37 | 4.27 | 0.057 (0.428) |
| Female ever regular | 27 | 0 | 47.1 | 0 | — | |
| Gonorrhoea§ in study period | ||||||
| No | 748 | 9 | 1015.8 | 0.89 | 1.0 | |
| Prevalent | 135 | 3 | 168.5 | 1.78 | 2.01 | 0.295 |
| Incident | 222 | 5 | 220.3 | 2.27 | 2.56 | 0.092 (0.367) |
| No test | 139 | 0 | 74.2 | 0 | — | |
| Chlamydia§ in study period | ||||||
| No | 793 | 13 | 1117.6 | 1.16 | 1.0 | |
| Prevalent | 94 | 1 | 122.8 | 0.81 | 0.70 | 0.731 |
| Incident | 180 | 3 | 175.2 | 1.71 | 1.47 | 0.546 (0.910) |
| No test | 100 | 0 | 63.3 | 0 | — | |
| Syphilis in 91–95 | ||||||
| No | 656 | 13 | 1048.5 | 1.24 | 1.0 | |
| Prevalent infection | 104 | 1 | 160.7 | 0.62 | 0.50 | 0.507 |
| Incident infection | 91 | 3 | 149.3 | 2.01 | 1.62 | 0.451 (0.767) |
| No test | 84 | 0 | 120.4 | 0 | — | |