Volume 22, Number 6—June 2016
Research
Heterogeneous and Dynamic Prevalence of Asymptomatic Influenza Virus Infections
Table 1
Heterogeneity within asymptomatic and subclinical influenza infection cases, by virus type/subtype, as determined through a systematic review and meta-analysis of 55 studies
Type/subtype |
Prevalence (95% CI) |
Cochran’s Q |
p value (Cochran’s Q) |
I2,* % |
---|---|---|---|---|
Asymptomatic | ||||
All types of influenza | 19.1 (5.2–35.5) | 752.40 | <0.001 | 97 |
Influenza A | 21.0 (4.2–41.0) | 692.94 | <0.001 | 98 |
Influenza A(H1N1) |
22.7 (7.7–39.8) |
561.14 |
<0.001 |
97 |
Subclinical | ||||
All types of influenza | 43.4 (25.4–61.8) | 1768.24 | <0.001 | 97 |
Influenza A | 42.8 (22.3–63.9) | 1689.78 | <0.001 | 98 |
Influenza A(H1N1) | 39.8 (16.4–64.5) | 1388.54 | <0.001 | 98 |
*The I² statistic describes the percentage of variation across studies that is attributable to heterogeneity rather than chance.