Table SIIa:Lifetime prevalence of AI: subgroup analysis all young peope, both sexually active and inactive

Sub-group analysis / Univariate analysis
Sub-group / N / Range % / Summary estimate (CI) / I2a
(%) / p-valueb / R2 / p-valuec
Interview method / 0.0 / .007
FTFI / 11 / 0.0-26.7 / 13.5 (8.7-18.8) / 99.4 / <.0001 / .616
SAQ / 52 / 0.7-38.9 / 13.9 (11.4-16.5) / 99.5 / <.0001 / -
ACASI / 9 / 0.9-27.0 / 13.8 (8.7-18.8) / 99.6 / <.0001 / .000
Survey year / 0.1d / .752
<2004 / 47 / 0.0-35.7 / 14.2 (1.8-16.5) / 99.7 / <.0001
≥2004 / 27 / 0.7-38.9 / 12.9 (9.1-16.7) / 99.7 / <.0001
Continent / 0.0 / .013
Africa / 9 / 1.3-14.1 / 5.8 (3.1-8.5) / 99.0 / <.0001 / .106
Asia / 5 / 0.8-7.7 / 2.9 (0.6-5.2) / 88.7 / <.0001 / .151
Europe / 9 / 6.9-38.9 / 19.4 (13.2-25.7) / 98.7 / <.0001 / .705
L. America / 4 / 7.8-16.3 / 7.3 (1.1-13.5) / 96.8 / <.0001 / .576
N. America / 46 / 14.3-39.1 / 15.6 (13.3-17.9) / 99.5 / <.0001 / -
Mean age / 23.0d / .001
<18 / 26 / 0.0-14.1 / 8.2 (5.6-10.8)) / 99.7 / <.0001
18-24 / 13 / 4.6-38.9 / 16.7 (14.0-18.9)) / 99.4 / <.0001

ACASI – audio computer-assisted self-interview, AI – anal intercourse, FTFI – face-to-face interview, SAQ – self-administered questionnaire, VI – vaginal intercourse

a I2 is calculated as described in Higgins et al.[23] I2 lies between 0 and 100%; 0% indicates no observed heterogeneity and larger values show increasing heterogeneity.b P-value to test significance of heterogeneity (I2).c P-value in bold test significance of R2 value. P-values not in bold test difference between categorical variables which were compared in turn to the variable with the largest sample size.

Table SIIb:Lifetime prevalence of VI: subgroup analysis all young people

Sub-group analysis / Univariate analysis
Sub-group / N / Range % / Summary estimate (CI) / I2a
(%) / p-valueb / R2 / p-valuec
Interview method / 2.0 / .131
FTFI / 8 / 6.3-100.0 / 76.2 (41.1-100.0) / -99.4 / <.0001 / .616
SAQ / 52 / 0.0-100.0 / 64.6 (57.2-72.1) / 98.2 / <.0001 / -
ACASI / 10 / 13.0-88.5 / 44.2 (33.7-54.6) / 99.9 / <.0001 / .000
Survey year / 0.5d / .250
<2004 / 44 / 0.0-100.0 / 67.8 (59.8-75.8) / 99.7 / <.0001
≥2004 / 26 / 2.8-100.0 / 57.5 (45.7-69.4) / 99.7 / <.0001
Continent / 2.0 / .130
Africa / 7 / 17.4-100.0 / 49.3 (27.2-71.3) / 99.0 / <.0001 / .106
Asia / 5 / 42.8 -92.1 / 44.4 (0.0-97.4) / 88.7 / <.0001 / .151
Europe / 10 / 7.3-37.3 / 79.0 (70.1-87.8) / 98.7 / <.0001 / .705
L. America / 4 / 3.8-59.5 / 34.4 (1.6-67.2) / 96.8 / <.0001 / .576
N. America / 44 / 0.0-100.0 / 67.1 (58.9-75.3) / 99.5 / <.0001 / -
Mean age / 43.0d / .001
<18 / 24 / 0.0-100.0 / 43.2 (31.8-54.7) / 99.7 / <.0001
18-24 / 43 / 2.8-100.0 / 74.1 (67.1-81.1) / 99.4 / <.0001

ACASI – audio computer-assisted self-interview, AI – anal intercourse, FTFI – face-to-face interview, SAQ – self-administered questionnaire, VI – vaginal intercourse

a I2 is calculated as described in Higgins et al.[23] I2 lies between 0 and 100%; 0% indicates no observed heterogeneity and larger values show increasing heterogeneity. b P-value to test significance of heterogeneity (I2).c P-value in bold test significance of R2 value. P-values not in bold test difference between categorical variables which were compared in turn to the variable with the largest sample size.