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.

From: Declines in HIV incidence among men and women in a South African population-based cohort

 

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

  1. 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
  2. aOpposite-sex ART coverage used because of the generalized, heterosexual HIV epidemic in South Africa, with 0–9% as the reference category
  3. bTime intervals were defined by changes in national criteria for ART eligibility, with 2005–2010 as the reference period
  4. cTime intervals were defined by year, with 2012 as the reference year
  5. 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)
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