Sexual behaviour in a rural high HIV prevalence South African community:
time trends in the antiretroviral treatment era
McGrath N, Eaton JW, Bärnighausen TW, Tanser F, Newell M-L
Supplementary Information
Figure S1: Distribution of number of surveys for which eligible and the number in which
participated
Number of respondents
5000 10000
20000
0
0
Number of respondents
5000 10000
20000
Women
0
1 2 3 4 5 6 7
Surveys for which eligible
0
1 2 3 4 5 6 7
Surveys for which eligible
Number of respondents
5000 10000
20000
0
0
Number of respondents
5000 10000
20000
Men
0 1 2 3 4 5 6 7
Surveys participated sexual behaviour
0 1 2 3 4 5 6 7
Surveys participated sexual behaviour
Table S1: Number of surveys in which participated by number for which eligible
Women -- all respondents
Sexual behaviour surveys participated
Surveys
eligible
1
2
3
4
5
6
7
Total
0
5198
2698
1349
850
562
286
437
11380
1
1222
1736
1406
1119
814
548
676
7521
2
3
4
5
6
7
414
809
1026
857
743
913
4762
167
410
585
596
1003
2761
102
277
410
918
1707
54
163
603
820
29
277
306
61
61
Total
6420
4848
3731
3507
3149
2775
4888
Survey
completion %
19%
26%
31%
34%
36%
39%
42%
36%
Total
6368
4555
3426
3330
2573
2096
3406
Survey
completion %
14%
21%
23%
27%
26%
29%
28%
26%
Men -- all respondents
Sexual behaviour surveys participated
Surveys
eligible
1
2
3
4
5
6
7
0
5465
2912
1657
1107
737
436
711
13025
1
903
1395
1228
1182
787
549
745
6789
2
3
4
5
6
7
248
461
749
651
527
738
3374
80
244
311
351
606
1592
48
79
175
363
665
8
50
175
233
8
57
65
11
11
Table S2: Association between sexual behaviour survey completion and demographic characteristics, all survey rounds
Women
Eligible
107948
Partic.
38519
Perc.
35.7%
Adj OR*
Men
Eligible
88359
Partic.
22605
Perc.
OR
Adj OR*
25.6% 0.62 (0.61, 0.63) 0.72 (0.71, 0.73)
Rural
Peri-urban
Urban
Non-res
58305
30980
9040
9623
23619
10664
1645
2591
40.5%
1
1
34.4% 0.77 (0.75, 0.79) 0.80 (0.78, 0.83)
18.2% 0.33 (0.31, 0.35) 0.40 (0.38, 0.43)
26.9% 0.54 (0.52, 0.57) 0.58 (0.56, 0.61)
44778
26606
6882
10093
12386
7034
894
2291
27.7%
1
1
26.4% 0.94 (0.91, 0.97) 1.04 (1.01, 1.08)
13.0% 0.39 (0.36, 0.42) 0.54 (0.50, 0.58)
22.7% 0.77 (0.73, 0.81) 0.95 (0.90, 1.00)
Age 17-19
Age 20-24
Age 25-29
Age 30-34
Age 35-39
Age 40-44
Age 45-49
Age 50-54
18322
24457
17263
13711
12092
11207
10896
8281
9223
5696
4456
3937
3571
3355
45.2%
37.7%
33.0%
32.5%
32.6%
31.9%
30.8%
1.47 (1.41, 1.54)
1.17 (1.12, 1.22)
1
0.96 (0.91, 1.01)
0.93 (0.88, 0.98)
0.83 (0.79, 0.88)
0.77 (0.72, 0.81)
18392
21751
13231
9704
7891
6639
5840
4911
7347
6122
2872
1960
1447
1099
970
788
39.9%
28.1%
21.7%
20.2%
18.3%
16.6%
16.6%
16.0%
6948
2441
35.1% 0.81 (0.77, 0.85) 0.95 (0.90, 1.01)
5692
1101
19.3% 0.53 (0.49, 0.57) 0.87 (0.80, 0.94)
12017
12668
36722
28039
11554
4579
5245
14714
8738
2802
9970
11376
30466
21026
9829
2495
3273
9496
4542
1698
25.0%
28.8%
31.2%
21.6%
17.3%
Total
No education
Some
primary
Primary
Compulsory
Matric
Higher
38.1%
41.4%
40.1%
31.2%
24.3%
OR
1.67 (1.60, 1.75)
1.23 (1.18, 1.28)
1
0.98 (0.93, 1.03)
0.98 (0.93, 1.03)
0.95 (0.90, 1.00)
0.90 (0.86, 0.95)
0.92 (0.88, 0.96)
1.06 (1.01, 1.10)
1
0.68 (0.66, 0.70)
0.48 (0.46, 0.50)
1.06 (1.01, 1.11)
1.09 (1.04, 1.14)
1
0.78 (0.75, 0.81)
0.69 (0.66, 0.73)
*Odds-ratio linearly adjusted for residence location, age group, education level, and survey round
2.40 (2.28, 2.52)
1.41 (1.34, 1.49)
1
0.91 (0.86, 0.97)
0.81 (0.75, 0.87)
0.72 (0.66, 0.77)
0.72 (0.66, 0.78)
0.69 (0.63, 0.75)
0.74 (0.70, 0.78)
0.89 (0.85, 0.94)
1
0.61 (0.58, 0.63)
0.46 (0.44, 0.49)
2.19 (2.08, 2.31)
1.36 (1.29, 1.43)
1
0.91 (0.86, 0.98)
0.80 (0.75, 0.86)
0.69 (0.63, 0.74)
0.69 (0.63, 0.75)
0.65 (0.60, 0.72)
0.92 (0.87, 0.97)
0.93 (0.89, 0.98)
1
0.75 (0.72, 0.78)
0.75 (0.71, 0.80)
Figure S2: Survey participation by age group over time. Solid lines show the proportion of
eligible participants who participate in any portion of the surveillance (HIV, general health,
or sexual behaviour), and dashed lines indicate the proportion of all eligible respondents
who have complete data in the sexual behaviour survey. For men, participation was about
10% to 15% higher amongst 17–24 year-olds than 25–34 or 35–54 year-olds. There was no
difference in survey participation amongst the older two age groups, but 35–54 year-olds
were less likely to have complete sexual behaviour data than were men 25–34 years. The
differential in participation between age groups was smaller for women than for men, although the gradient in the proportion with complete sexual behaviour data was similar.
Table S3: Predictors of sexual behaviour survey participation, adjusting for demographic
characteristics and previous sexual behaviour reports
N
Adj OR*
95% CI
First time eligible for participation in current round
196307
0.94
(0.91, 0.97)
Was eligible for participation in previous round
Completed sexual behaviour survey in previous round,
conditional on being eligible
Participated in HIV testing in previous round, conditional on
being eligible
Tested positive for HIV in previous round, conditional on
participating in previous HIV testing round
Multiple sexual partnerships at previous round, conditional
on participating in previous sexual behaviour survey round
Concurrent sexual partnerships at previous round,
conditional on participating in previous sexual behaviour
survey round
Had casual partner at previous round, conditional on
participating in previous sexual behaviour survey round
Condom at last sex with regular partner at previous round,
conditional on participating in previous round and having a
regular partner
196307
1.06
(1.03, 1.09)
131273
1.93
(1.88, 1.98)
131273
1.99
(1.93, 2.04)
36332
0.86
(0.82, 0.91)
48698
0.94
(0.86, 1.03)
44735
0.95
(0.83, 1.08)
48561
0.97
(0.89, 1.05)
33500
0.97
(0.92, 1.02)
*Adjusted odds ratio, adjusting for sex * age group, resident location, education level, and survey round