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 measureSampleUnivariable analysisMultivariable analysis*
Model 1*Model 2†
Total nTotal NRR (95% CI)P valueLR test p valueAdjusted R2 (%)ARR (95% CI)P valueARR (95% CI)P value
Population characteristics
Age bracket
 Children10424 0971.00–<0.00150.161.00–––
 Adults505126 4302.23 (2.07 to 2.4)<0.0012.11 (1.98 to 2.26)<0.001––
 Age mixed1359851.67 (1.38 to 2.02)<0.0011.43 (1.21 to 1.69)<0.001––
Age group (years)
 <2014732 4921.00–<0.00148.69––1.00–
 20–307313 1561.70 (1.54 to 1.87)<0.001––1.62 (1.49 to 1.76)<0.001
 30–406095941.91 (1.73 to 2.11)<0.001––1.82 (1.67 to 1.99)<0.001
 40–502551881.95 (1.70 to 2.24)<0.001––1.93 (1.70 to 2.18)<0.001
 >504716 3632.17 (1.94 to 2.42)<0.001––2.29 (2.06 to 2.53)<0.001
 Mixed27079 7191.99 (1.86 to 2.13)<0.001––1.91 (1.79 to 2.04)<0.001
Sex
 Women25862 1621.00–0.0271.271.00–1.00–
 Men19449 8870.91 (0.83 to 0.98)0.0200.93 (0.87 to 0.98)0.0060.91 (0.86 to 0.96)0.001
 Mixed17044 4631.01 (0.93 to 1.10)0.7730.98 (0.92 to 1.05)0.6330.93 (0.87 to 1.00)0.039
Population type
 Healthy516135 4561.00–<0.0013.711.00–1.00–
 Clinical6211 0711.16 (1.03 to 1.30)0.0141.05 (0.96 to 1.15)0.2561.06 (0.97 to 1.16)0.179
 Other4499851.33 (1.16 to 1.52)<0.0011.24 (1.13 to 1.36)<0.0011.22 (1.11 to 1.34)<0.001
European subregion/country
 Northern Europe16147 2021.00–<0.0018.781.00–1.00–
 Eastern Europe6412 2601.42 (1.26 to 1.61)<0.0011.54 (1.39 to 1.72)<0.0011.54 (1.39 to 1.72)<0.001
 Southern Europe7716 0631.34 (1.19 to 1.51)<0.0011.37 (1.25 to 1.49)<0.0011.36 (1.25 to 1.49)<0.001
 Western Europe26468 5561.16 (1.06 to 1.26)0.0011.24 (1.16 to 1.32)<0.0011.20 (1.12 to 1.28)<0.001
 Israel3570601.17 (0.99 to 1.37)0.0531.29 (1.16 to 1.44)<0.0011.22 (1.09 to 1.37)0.001
 Turkey1730761.56 (1.26 to 1.93)<0.0011.37 (1.12 to 1.67)0.0021.38 (1.15 to 1.72)0.001
 Mixed subregions422951.28 (0.84 to 1.95)0.2391.14 (0.86 to 1.51)0.3391.13 (0.85 to 1.50)0.386
Country’s income
 UMIC4688931.00–<0.0013.681.00–1.00–
 HIC‡576147 6190.74 (0.65 to 0.84)<0.0010.92 (0.80 to 1.05)0.2450.92 (0.81 to 1.06)0.274
Study methodology characteristics
Assay type
 Western blot5265511.00–0.0210.921.00–1.00–
 ELISA518137 3180.84 (0.74 to 0.96)0.0110.94 (0.86 to 1.03)0.2581.00 (0.91 to 1.10)0.977
 Others5212 6430.80 (0.67 to 0.95)0.0130.85 (0.73 to 0.98)0.0310.89 (0.77 to 1.03)0.131
Sample size§
 <1004617951.00–0.0161.191.00–1.00–
 ≥100576154 7170.84 (0.73 to 0.96)0.0160.91 (0.82 to 1.01)0.0900.94 (0.84 to 1.04)0.240
Sampling method
 Probability based26767 6011.00–0.3950.00––––
 Non- probability based35588 9111.03 (0.96 to 1.11)0.395––––
Response rate
 ≥803711 9851.00–0.0830.421.00–1.00–
 <809429 2030.84 (0.71 to 0.99)0.0490.96 (0.84 to 1.10)0.6060.90 (0.79 to 1.02)0.123
 Unclear491115 3240.93 (0.80 to 1.08)0.3260.98 (0.89 to 1.09)0.7680.96 (0.86 to 1.06)0.387
Year of publication range
 <200012723 0761.00–0.0012.221.00–1.00–
 2000–201036186 1750.97 (0.88 to 1.06)0.4820.89 (0.83 to 0.96)0.0030.91 (0.84 to 0.98)0.010
 >201013447 2610.83 (0.74 to 0.93)0.0010.85 (0.78 to 0.93)<0.0010.87 (0.80 to 0.95)0.002

  • *Variance explained by the final multivariable model 1 (adjusted R 2 )=63.80%.

  • †Variance explained by the final multivariable model 2 (adjusted R 2 )=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.