Table 3.
Incidence rates (IRs, unadjusted) and incidence rate ratios (IRRs, unadjusted and adjusted) for women (N = 12,609) by male ART coverage, ART scale-up period, and year.
| Events | Person-years | Inc rate (95% CI) | Unadj. IRR (95% CI) | P-value | Adj. IRR (95% CI)d | P-value | |
|---|---|---|---|---|---|---|---|
| Model 1: By male ART coveragea | |||||||
| 0–9% | 642 | 14,653 | 4.38 (4.00–4.79) | Ref. | – | Ref. | – |
| 10–24% | 674 | 14,549 | 4.63 (4.24–5.07) | 1.06 (0.92–1.21) | 0.422 | 0.99 (0.89–1.11) | 0.891 |
| 25–34% | 847 | 17,570 | 4.82 (4.47–5.21) | 1.10 (0.98–1.24) | 0.114 | 0.87 (0.77–0.97) | 0.016 |
| 35–55% | 416 | 11,014 | 3.78 (3.38–4.23) | 0.86 (0.75–1.00) | 0.043 | 0.68 (0.59–0.78) | <0.01 |
| Model 2: By ART scale-up periodb | |||||||
| 2005–2010 | 1,316 | 29,203 | 4.51 (4.25–4.78) | Ref. | – | Ref. | – |
| 2011–2015 | 1,030 | 21,796 | 4.73 (4.42–5.05) | 1.05 (0.96–1.15) | 0.317 | 0.85 (0.77–0.93) | <0.01 |
| 2016–2017 | 234 | 6789 | 3.45 (2.95–4.02) | 0.76 (0.65–0.90) | <0.01 | 0.63 (0.55–0.74) | <0.01 |
| Model 3: By yearc | |||||||
| 2005 | 186 | 4567 | 4.08 (3.40–4.90) | 0.84 (0.65–1.08) | 0.166 | 1.11 (0.90–1.37) | 0.339 |
| 2006 | 223 | 5008 | 4.45 (3.77–5.27) | 0.91 (0.71–1.17) | 0.465 | 1.16 (0.95–1.42) | 0.157 |
| 2007 | 231 | 5078 | 4.56 (3.86–5.39) | 0.93 (0.73–1.19) | 0.585 | 1.18 (0.97–1.44) | 0.097 |
| 2008 | 231 | 5050 | 4.58 (3.89–5.40) | 0.94 (0.74–1.19) | 0.604 | 1.13 (0.92–1.38) | 0.234 |
| 2009 | 220 | 4818 | 4.58 (3.85–5.44) | 0.94 (0.73–1.20) | 0.604 | 1.14 (0.94–1.39) | 0.176 |
| 2010 | 221 | 4681 | 4.72 (3.98–5.61) | 0.97 (0.75–1.25) | 0.795 | 1.15 (0.94–1.40) | 0.169 |
| 2011 | 209 | 4566 | 4.59 (3.85–5.47) | 0.94 (0.73–1.21) | 0.624 | 0.97 (0.79–1.20) | 0.803 |
| 2012 | 214 | 4319 | 4.95 (4.14–5.92) | 1.01 (0.78–1.31) | 0.920 | 1.02 (0.83–1.25) | 0.846 |
| 2013 | 211 | 4354 | 4.85 (4.05–5.81) | 0.99 (0.76–1.30) | 0.961 | 1.00 (0.82–1.21) | 0.968 |
| 2014 | 211 | 4329 | 4.89 (4.09–5.84) | Ref. | – | Ref. | – |
| 2015 | 182 | 4225 | 4.31 (3.58–5.20) | 0.88 (0.67–1.16) | 0.368 | 0.86 (0.71–1.06) | 0.164 |
| 2016 | 141 | 3783 | 3.74 (3.04–4.61) | 0.77 (0.58–1.02) | 0.064 | 0.78 (0.63–0.97) | 0.026 |
| 2017 | 92 | 3005 | 3.06 (2.38–3.94) | 0.63 (0.46–0.86) | <0.01 | 0.65 (0.51–0.83) | <0.01 |
HIV events, person-years, unadjusted IRs, and unadjusted adjusted IRRs are averages over 300 datasets generated by imputing a single random infection date within the censoring interval. Rubin’s rules were used to calculate 95% confidence intervals
aOpposite-sex ART coverage used because of the generalized, heterosexual HIV epidemic in South Africa, with 0–9% as the reference category
bTime intervals were defined by changes in national criteria for ART eligibility, with 2005–2010 as the reference period
cTime intervals were defined by year, with 2012 as the reference year
dEstimates adjusted for age, self-reported condom use, circumcision and marital status, household assets index, cumulative time spent outside surveillance area, and opposite-sex HIV prevalence in the surrounding community (see Supplementary Table 5 for full results)