Table 3.
Univariable and multivariable meta-regression models for herpes simplex virus type 1 seroprevalence in Europe, with time trend assessed categorically by decade
| Outcome measure | Sample | Univariable analysis | Multivariable analysis* | |||||||
| Model 1* | Model 2† | |||||||||
| Total n | Total N | RR (95% CI) | P value | LR test p value | Adjusted R2 (%) | ARR (95% CI) | P value | ARR (95% CI) | P value | |
| Population characteristics | ||||||||||
| Age bracket | ||||||||||
| Children | 104 | 24 097 | 1.00 | – | <0.001 | 50.16 | 1.00 | – | – | – |
| Adults | 505 | 126 430 | 2.23 (2.07 to 2.4) | <0.001 | 2.11 (1.98 to 2.26) | <0.001 | – | – | ||
| Age mixed | 13 | 5985 | 1.67 (1.38 to 2.02) | <0.001 | 1.43 (1.21 to 1.69) | <0.001 | – | – | ||
| Age group (years) | ||||||||||
| <20 | 147 | 32 492 | 1.00 | – | <0.001 | 48.69 | – | – | 1.00 | – |
| 20–30 | 73 | 13 156 | 1.70 (1.54 to 1.87) | <0.001 | – | – | 1.62 (1.49 to 1.76) | <0.001 | ||
| 30–40 | 60 | 9594 | 1.91 (1.73 to 2.11) | <0.001 | – | – | 1.82 (1.67 to 1.99) | <0.001 | ||
| 40–50 | 25 | 5188 | 1.95 (1.70 to 2.24) | <0.001 | – | – | 1.93 (1.70 to 2.18) | <0.001 | ||
| >50 | 47 | 16 363 | 2.17 (1.94 to 2.42) | <0.001 | – | – | 2.29 (2.06 to 2.53) | <0.001 | ||
| Mixed | 270 | 79 719 | 1.99 (1.86 to 2.13) | <0.001 | – | – | 1.91 (1.79 to 2.04) | <0.001 | ||
| Sex | ||||||||||
| Women | 258 | 62 162 | 1.00 | – | 0.027 | 1.27 | 1.00 | – | 1.00 | – |
| Men | 194 | 49 887 | 0.91 (0.83 to 0.98) | 0.020 | 0.93 (0.87 to 0.98) | 0.006 | 0.91 (0.86 to 0.96) | 0.001 | ||
| Mixed | 170 | 44 463 | 1.01 (0.93 to 1.10) | 0.773 | 0.98 (0.92 to 1.05) | 0.633 | 0.93 (0.87 to 1.00) | 0.039 | ||
| Population type | ||||||||||
| Healthy | 516 | 135 456 | 1.00 | – | <0.001 | 3.71 | 1.00 | – | 1.00 | – |
| Clinical | 62 | 11 071 | 1.16 (1.03 to 1.30) | 0.014 | 1.05 (0.96 to 1.15) | 0.256 | 1.06 (0.97 to 1.16) | 0.179 | ||
| Other | 44 | 9985 | 1.33 (1.16 to 1.52) | <0.001 | 1.24 (1.13 to 1.36) | <0.001 | 1.22 (1.11 to 1.34) | <0.001 | ||
| European subregion/country | ||||||||||
| Northern Europe | 161 | 47 202 | 1.00 | – | <0.001 | 8.78 | 1.00 | – | 1.00 | – |
| Eastern Europe | 64 | 12 260 | 1.42 (1.26 to 1.61) | <0.001 | 1.54 (1.39 to 1.72) | <0.001 | 1.54 (1.39 to 1.72) | <0.001 | ||
| Southern Europe | 77 | 16 063 | 1.34 (1.19 to 1.51) | <0.001 | 1.37 (1.25 to 1.49) | <0.001 | 1.36 (1.25 to 1.49) | <0.001 | ||
| Western Europe | 264 | 68 556 | 1.16 (1.06 to 1.26) | 0.001 | 1.24 (1.16 to 1.32) | <0.001 | 1.20 (1.12 to 1.28) | <0.001 | ||
| Israel | 35 | 7060 | 1.17 (0.99 to 1.37) | 0.053 | 1.29 (1.16 to 1.44) | <0.001 | 1.22 (1.09 to 1.37) | 0.001 | ||
| Turkey | 17 | 3076 | 1.56 (1.26 to 1.93) | <0.001 | 1.37 (1.12 to 1.67) | 0.002 | 1.38 (1.15 to 1.72) | 0.001 | ||
| Mixed subregions | 4 | 2295 | 1.28 (0.84 to 1.95) | 0.239 | 1.14 (0.86 to 1.51) | 0.339 | 1.13 (0.85 to 1.50) | 0.386 | ||
| Country’s income | ||||||||||
| UMIC | 46 | 8893 | 1.00 | – | <0.001 | 3.68 | 1.00 | – | 1.00 | – |
| HIC‡ | 576 | 147 619 | 0.74 (0.65 to 0.84) | <0.001 | 0.92 (0.80 to 1.05) | 0.245 | 0.92 (0.81 to 1.06) | 0.274 | ||
| Study methodology characteristics | ||||||||||
| Assay type | ||||||||||
| Western blot | 52 | 6551 | 1.00 | – | 0.021 | 0.92 | 1.00 | – | 1.00 | – |
| ELISA | 518 | 137 318 | 0.84 (0.74 to 0.96) | 0.011 | 0.94 (0.86 to 1.03) | 0.258 | 1.00 (0.91 to 1.10) | 0.977 | ||
| Others | 52 | 12 643 | 0.80 (0.67 to 0.95) | 0.013 | 0.85 (0.73 to 0.98) | 0.031 | 0.89 (0.77 to 1.03) | 0.131 | ||
| Sample size§ | ||||||||||
| <100 | 46 | 1795 | 1.00 | – | 0.016 | 1.19 | 1.00 | – | 1.00 | – |
| ≥100 | 576 | 154 717 | 0.84 (0.73 to 0.96) | 0.016 | 0.91 (0.82 to 1.01) | 0.090 | 0.94 (0.84 to 1.04) | 0.240 | ||
| Sampling method | ||||||||||
| Probability based | 267 | 67 601 | 1.00 | – | 0.395 | 0.00 | – | – | – | – |
| Non- probability based | 355 | 88 911 | 1.03 (0.96 to 1.11) | 0.395 | – | – | – | – | ||
| Response rate | ||||||||||
| ≥80 | 37 | 11 985 | 1.00 | – | 0.083 | 0.42 | 1.00 | – | 1.00 | – |
| <80 | 94 | 29 203 | 0.84 (0.71 to 0.99) | 0.049 | 0.96 (0.84 to 1.10) | 0.606 | 0.90 (0.79 to 1.02) | 0.123 | ||
| Unclear | 491 | 115 324 | 0.93 (0.80 to 1.08) | 0.326 | 0.98 (0.89 to 1.09) | 0.768 | 0.96 (0.86 to 1.06) | 0.387 | ||
| Year of publication range | ||||||||||
| <2000 | 127 | 23 076 | 1.00 | – | 0.001 | 2.22 | 1.00 | – | 1.00 | – |
| 2000–2010 | 361 | 86 175 | 0.97 (0.88 to 1.06) | 0.482 | 0.89 (0.83 to 0.96) | 0.003 | 0.91 (0.84 to 0.98) | 0.010 | ||
| >2010 | 134 | 47 261 | 0.83 (0.74 to 0.93) | 0.001 | 0.85 (0.78 to 0.93) | <0.001 | 0.87 (0.80 to 0.95) | 0.002 | ||
*Variance explained by the final multivariable model 1 (adjusted R2)=63.80%.
†Variance explained by the final multivariable model 2 (adjusted R2)=63.69%.
‡High income country category includes one measure representing 12 European countries.
§Sample size denotes the sample size of the study population found in the original publication.
ARR, adjusted risk ratio; ELISA, enzyme linked immunosorbent type specific assay; HIC, high income country; HSV-1, herpes simplex virus type 1; RR, risk ratio; UMIC, upper middle income country.