Outcome measures | Sample size | Univariable analysis | Multivariable analysis* | |||||||||
Total n | Total N | RR (95% CI) | p value | LR test P value | Adjusted R2 (%) | Model 1† | Model 2 ‡ | |||||
ARR (95% CI) | P value | ARR (95% CI) | P value | |||||||||
Population characteristics | Population type | General populations | 236 | 56 457 | 1.00 | – | <0.001 | 45.98 | 1.00 | – | 1.00 | – |
Intermediate-risk populations | 24 | 6775 | 1.52 (1.16 to 2.00) | 0.002 | 1.55 (1.22 to 1.96) | <0.001 | 1.54 (1.22 to 1.96) | <0.001 | ||||
High-risk populations | 93 | 25 344 | 3.09 (2.64 to 3.61) | <0.001 | 3.09 (2.67 to 3.57) | <0.001 | 3.08 (2.66 to 3.57) | <0.001 | ||||
STI clinic attendees and symptomatic populations | 6 | 432 | 2.49 (1.47 to 4.22) | 0.001 | 2.40 (1.48 to 3.90) | <0.001 | 2.35 (1.45 to 3.81) | 0.001 | ||||
HIV-positive individuals and individuals in HIV discordant couples | 19 | 2840 | 3.21 (2.38 to 4.32) | <0.001 | 3.06 (2.37 to 3.95) | <0.001 | 3.02 (2.34 to 3.89) | <0.001 | ||||
Other populations§ | 24 | 3497 | 2.42 (1.85 to 3.16) | <0.001 | 1.56 (1.24 to 1.97) | <0.001 | 1.53 (1.21 to 1.94) | <0.001 | ||||
Age group | <20 years | 35 | 6538 | 1.00 | – | <0.001 | 10.26 | 1.00 | – | 1.00 | – | |
20–30 years | 47 | 7751 | 2.05 (1.40 to 3.00) | <0.001 | 1.63 (1.27 to 2.09) | <0.001 | 1.62 (1.26 to 2.09) | <0.001 | ||||
30–40 years | 22 | 2933 | 2.58 (1.64 to 4.04) | <0.001 | 2.24 (1.68 to 2.99) | <0.001 | 2.22 (1.66 to 2.97) | <0.001 | ||||
>40 years | 39 | 5940 | 2.84 (1.92 to 4.18) | <0.001 | 3.22 (2.50 to 4.14) | <0.001 | 3.08 (2.40 to 3.96) | <0.001 | ||||
Mixed ages | 259 | 72 183 | 2.49 (1.82 to 3.41) | <0.001 | 1.79 (1.44 to 2.21) | <0.001 | 1.71 (1.39 to 2.11) | <0.001 | ||||
Sex | Women | 234 | 38 816 | 1.00 | – | 0.001 | 4.82 | 1.00 | – | 1.00 | – | |
Men | 144 | 39 525 | 0.67 (0.56 to 0.80) | <0.001 | 0.68 (0.60 to 0.76) | <0.001 | 0.69 (0.61 to 0.77) | <0.001 | ||||
Mixed sexes | 24 | 17 004 | 0.81 (0.57 to 1.16) | 0.267 | 0.59 (0.46 to 0.77) | <0.001 | 0.62 (0.48 to 0.80) | <0.001 | ||||
Countries | Brazil | 106 | 25 766 | 1.00 | – | <0.001‡ | 12.58 | – | – | – | – | |
Colombia | 19 | 2247 | 1.36 (0.91 to 2.01) | 0.125 | – | – | – | – | ||||
Costa Rica | 13 | 2364 | 1.46 (0.92 to 2.30) | 0.102 | – | – | – | – | ||||
Mexico | 76 | 23 437 | 0.71 (0.56 to 0.91) | 0.008 | – | – | – | – | ||||
Panama | 15 | 3334 | 1.81 (1.18 to 2.78) | 0.006 | – | – | – | – | ||||
Peru | 131 | 24 976 | 0.92 (0.74 to 1.14) | 0.476 | – | – | – | – | ||||
Other¶ | 42 | 13 221 | 1.84 (1.39 to 2.45) | <0.001 | – | – | – | – | ||||
Subregions | Central America | 124 | 38 103 | 1.00 | – | 0.065 | 0.82 | 1.00 | – | 1.00 | – | |
South America | 264 | 54 798 | 0.95 (0.79 to 1.14) | 0.606 | 1.13 (1.00 to 1.27) | 0.047 | 1.12 (0.99 to 1.27) | 0.053 | ||||
Caribbean | 14 | 2444 | 1.62 (1.02 to 2.58) | 0.040 | 1.17 (0.87 to 1.57) | 0.281 | 1.17 (0.87 to 1.56) | 0.287 | ||||
Country’s income | LIC and LMIC | 29 | 9846 | 1.00 | – | <0.001‡ | 9.07 | – | – | – | – | |
UMIC | 354 | 81 539 | 0.45 (0.33 to 0.62) | <0.001 | – | – | – | – | ||||
HIC | 19 | 3960 | 0.86 (0.54 to 1.36) | 0.528 | – | – | – | – | ||||
Study methodology characteristics | Assay type | Western blot | 94 | 11 898 | 1.00 | – | 0.432 | 0.00 | – | – | – | – |
ELISA | 304 | 82 744 | 0.89 (0.73 to 1.09) | 0.280 | – | – | – | – | ||||
Monoclonal antibody | 4 | 703 | 1.24 (0.53 to 2.87) | 0.614 | – | – | – | – | ||||
Sample size** | <200 | 81 | 7542 | 1.00 | – | <0.001 | 7.27 | 1.00 | – | 1.00 | – | |
>200 | 321 | 87 803 | 0.58 (0.47 to 0.71) | <0.001 | 0.75 (0.64 to 0.87) | <0.001 | 0.74 (0.64 to 0.87) | <0.001 | ||||
Sampling method | Probability-based | 151 | 47 471 | 1.00 | – | <0.001 | 18.05 | 1.00 | – | 1.00 | – | |
Non-probability-based | 251 | 47 874 | 2.08 (1.76 to 2.44) | <0.001 | 1.16 (1.00 to 1.35) | 0.037 | 1.17 (1.01 to 1.35) | 0.033 | ||||
Response rate | ≥80% | 194 | 48 220 | 1.00 | – | 0.002 | 5.52 | 1.00 | – | 1.00 | – | |
<80% | 32 | 6062 | 0.59 (0.42 to 0.82) | 0.002 | 0.79 (0.63 to 0.99) | 0.044 | 0.77 (0.62 to 0.96) | 0.025 | ||||
Unclear | 176 | 41 063 | 1.25 (1.05 to 1.49) | 0.010 | 1.07 (0.94 to 1.22) | 0.262 | 1.09 (0.96 to 1.24) | 0.169 | ||||
Temporal variables | Year of publication category | <2000 | 49 | 7244 | 1.00 | – | <0.001 | 4.39 | 1.00 | – | – | – |
2000–2010 | 206 | 51 983 | 0.61 (0.47 to 0.79) | <0.001 | 0.88 (0.75 to 1.05) | 0.166 | – | – | ||||
>2010 | 147 | 31 118 | 0.56 (0.42 to 0.73) | <0.001 | 0.74 (0.61 to 0.89) | 0.002 | – | – | ||||
Year of publication | 402 | 95 345 | 0.97 (0.96 to 0.98) | <0.001 | <0.001 | 2.98 | – | – | 0.98 (0.97 to 0.99) | 0.002 |
The analysis using year of data collection as the temporal variable is found in online supplemental table S6.
*Countries and country’s income were not included in the multivariable models due to collinearity with the variable subregions.
†Variance explained by multivariable model 1 (adjusted R2)=68.85%.
‡Variance explained by multivariable model 2 (adjusted R2)=68.99%.
§Other populations include populations with an undetermined risk of acquiring HSV-2 infection such as patients with cervical cancer or their spouses.
¶Other countries include Argentina, Barbados, Bolivia, Chile, Dominican Republic, El Salvador, Guatemala, Haiti, Honduras, Jamaica and Nicaragua.
**Sample size denotes the sample size of each study population found in the original publication.
ARR, adjusted risk ratio; HIC, high-income country; HSV-2, herpes simplex virus type 2; LIC, low-income country; LMIC, lower-income to middle-income country; LR, likelihood ratio; RR, risk ratio; UMIC, upper-income to middle-income country.