Table 5.
Unadjusted Associations Between Covariates and Time-Varying Method Users (vs. Dual Method Users) Among Sexually Active HIV-Discordant Couples Who Are Not Currently Pregnant
| Method using intervals | Dual method using intervals | |||||||
|---|---|---|---|---|---|---|---|---|
| N intervals | % | N intervals | % | HR | 95% CI | p-Value (two-tail) | ||
| Couple serostatus | ||||||||
| M+F− | 1,854 | 50% | 3,343 | 55% | 1.06 | 0.94 | 1.18 | 0.343 |
| M−F+ | 1,869 | 50% | 2,753 | 45% | Ref. | |||
| Man's age in years (mean, SD) (HR per 5-year increase) | 33.92 | 7.52 | 35.30 | 7.48 | 0.95 | 0.91 | 0.99 | 0.010 |
| Woman's age in years (mean, SD) (HR per 5-year increase) | 27.22 | 6.03 | 28.48 | 6.27 | 0.95 | 0.90 | 0.99 | 0.013 |
| Household income in USD (median, IQR) (HR per 20 USD increase) | 49.56 | 64.03 | 55.00 | 71.40 | 0.99 | 0.98 | 1.01 | 0.467 |
| Years cohabiting (mean, SD) (HR per 5-year increase) | 6.85 | 5.38 | 7.65 | 5.81 | 0.97 | 0.92 | 1.02 | 0.219 |
| Woman reads Nyanja | ||||||||
| Yes, easily | 879 | 24% | 1,407 | 24% | Ref. | |||
| With difficulty/not at all | 2,709 | 76% | 4,475 | 76% | 0.97 | 0.84 | 1.12 | 0.669 |
| Man reads Nyanja | ||||||||
| Yes, easily | 1,381 | 45% | 2,073 | 45% | ||||
| With difficulty/not at all | 1,688 | 55% | 2,497 | 55% | 0.98 | 0.86 | 1.11 | 0.721 |
| Man's religion (2002–2012) | ||||||||
| Catholic | 444 | 26% | 900 | 29% | 0.87 | 0.68 | 1.10 | 0.247 |
| Other Christian | 893 | 53% | 1,585 | 51% | 0.99 | 0.80 | 1.21 | 0.923 |
| Other/none | 349 | 21% | 615 | 20% | Ref. | |||
| Woman's religion (2002–2012) | ||||||||
| Catholic | 449 | 20% | 1,032 | 23% | 0.88 | 0.70 | 1.11 | 0.273 |
| Other Christian | 1,393 | 64% | 2,686 | 61% | 1.02 | 0.83 | 1.25 | 0.847 |
| Other/none | 349 | 16% | 682 | 16% | Ref. | |||
| Baseline contraceptive method used | ||||||||
| None/condoms alone | 2,455 | 66% | 4,253 | 70% | Ref. | |||
| OCP | 614 | 17% | 916 | 15% | 1.11 | 0.94 | 1.32 | 0.205 |
| Injectable | 433 | 12% | 615 | 10% | 1.25 | 1.05 | 1.50 | 0.015 |
| Implant | 95 | 3% | 115 | 2% | 1.44 | 1.02 | 2.03 | <0.001 |
| IUD | 87 | 2% | 124 | 2% | 1.14 | 0.72 | 1.79 | 0.574 |
| Sterilization | 19 | 1% | 40 | 1% | 0.93 | 0.37 | 2.33 | 0.883 |
| Time-varying contraceptive method use | ||||||||
| OCP | 1,491 | 40% | 2,023 | 34% | Ref. | |||
| Injectable | 1,446 | 39% | 2,107 | 35% | 1.04 | 0.93 | 1.16 | 0.501 |
| Implant | 449 | 12% | 1,220 | 20% | 0.81 | 0.66 | 1.00 | 0.055 |
| IUD | 231 | 6% | 392 | 7% | 1.09 | 0.82 | 1.45 | 0.558 |
| Sterilization | 87 | 2% | 259 | 4% | 0.65 | 0.44 | 0.98 | 0.040 |
| Number of previous pregnancies (mean, SD) (HR per pregnancy increase) | 3.68 | 2.09 | 3.77 | 2.22 | 1.00 | 0.97 | 1.02 | 0.823 |
| HIV stage of HIV+ partner | ||||||||
| Stage I | 1,333 | 36% | 2,164 | 35% | Ref. | |||
| Stage II | 1,306 | 35% | 2,120 | 35% | 0.91 | 0.79 | 1.05 | 0.196 |
| Stage III | 876 | 24% | 1,428 | 23% | 0.92 | 0.79 | 1.07 | 0.263 |
| Stage IV | 208 | 6% | 384 | 6% | 0.90 | 0.72 | 1.12 | 0.340 |
| Log viral load of HIV+ partner (mean, SD) (HR per log viral load increase) | 4.49 | 0.93 | 4.39 | 93% | 1.03 | 0.94 | 1.13 | 0.489 |
| Circumcision status (male partner) | ||||||||
| Yes | 543 | 15% | 773 | 13% | Ref. | |||
| No | 3,170 | 85% | 5,296 | 87% | 0.88 | 0.75 | 1.04 | 0.140 |
| Man lifetime sex partners (mean, SD) (HR per partner increase) | 11.41 | 14.94 | 11.66 | 18.44 | 1.00 | 1.00 | 1.00 | 0.615 |
| Woman lifetime sex partners (mean, SD) (HR per partner increase) | 3.03 | 2.58 | 2.97 | 5.44 | 1.00 | 0.99 | 1.01 | 0.945 |
| Postpartum status (time-varying) | ||||||||
| Not pregnant/not postpartum | 4,504 | 98% | 4,059 | 98% | Ref. | |||
| Postpartum (up to 6 months) | 70 | 2% | 63 | 2% | 1.14 | 0.90 | 1.43 | 0.286 |
| Fertility intentions of man (2002–2011) | ||||||||
| Yes, next year | 164 | 10% | 237 | 8% | 1.19 | 0.93 | 1.52 | 0.171 |
| Yes, but not next year | 697 | 41% | 1,113 | 36% | 1.17 | 0.97 | 1.41 | 0.108 |
| Don't know/no | 825 | 49% | 1,750 | 56% | Ref. | |||
| Fertility intentions of woman (2002–2011) | ||||||||
| Yes, next year | 178 | 10% | 349 | 10% | 0.97 | 0.74 | 1.29 | 0.854 |
| Yes, but not next year | 545 | 30% | 757 | 22% | 1.25 | 1.04 | 1.49 | 0.015 |
| Don't know/no | 1,105 | 60% | 2,291 | 67% | Ref. | |||
| Circumcision × serostatus | ||||||||
| M+F− | ||||||||
| Yes | 253 | 7% | 306 | 5% | 1.55 | 1.19 | 2.01 | 0.001 |
| No | 1,594 | 43% | 3,028 | 50% | 0.99 | 0.87 | 1.11 | 0.815 |
| M−F+ | ||||||||
| Yes | 290 | 8% | 467 | 8% | 0.91 | 0.76 | 1.08 | 0.289 |
| No | 1,576 | 42% | 2,268 | 37% | Ref. | |||