Table 1.
Characteristics of the studies (RCTs) included in the meta-analysis
| First author (year) | Study type | Countries | Average follow-up period | Patient characteristics | Number of cases/number of patients | Number of cases/number of patients | |||
|---|---|---|---|---|---|---|---|---|---|
| Age (years) | Number of sexual partners | ||||||||
| Mean | Range | ||||||||
| Vaccinated groupa | Placebo groupb | Vaccinated group | Placebo group | ||||||
| Garland (2007) [20] | RCT | 16 countries from Asia Pacific, Europe, North- Central- and South America | 3 years | 20.2 ± 1.8 | 20.3 ± 1.8 | 16–24 | < 4 | 0/2261 | 48/2279 |
| Dillner (2010) [21] | RCT | 24 countries from North America, Latin America, Europe, Asia Pacific | 42 months | 20 | 16–26 | < 4 | 2/6718 | 186/6647 | |
| Majewski (2009) [22] | RCT | Austria, Czech Republic, Denmark, England, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Norway, Poland, Portugal, Russian Federation, Spain, and Sweden. | 36 months | 19.7 | 16–24 | ≤4 | 1/4059 | 90/4057 | |
|
Villa (2006) [23] |
RCT | Brazil, Nordic countries, Finland, Sweden, Norway | 60 months | 20.2 | 20.0 | 16–23 | ≤4 | 0/214 | 20/209 |
| Munoz (2010) [24] | RCT | Australia, Austria, Brazil, Canada, Colombia, Czech Republic, Denmark, Finland, Germany, Hong Kong, Iceland, Italy, Mexico, New Zealand, Norway, Peru, Poland, Puerto Rico, Russia, Singapore, Sweden, Thailand, the United Kingdom, United States | 3,6 years | ? | ? | 15–26 | < 4 except Finnish women | 4/4689 | 138/4735 |
| Perez (2008) [25] | RCT | Brazil, Mexico, Colombia, Costa Rica, Guatemala, Peru | ? | 19.8 ± 3.0 | 20.3 ± 2.2 | 9–24 | ≤4 | 0/2075 | 9/1976 |
| Yoshikawa (2013) [26] | RCT | Japan | 23 months | 22.7 ± 2.1 | 22.9 ± 2.1 | 18–26 | ≤4 | 2/400 | 7/376 |
| Mikamo (2019) [16] | RCT | Japan | 36 months | 22.6 ± 2.1 | 22.6 ± 2.0 | 18–27 | 17–26 | 0/561 | 1/562 |
RCT: randomised controlled trial
a: vaccine = quadrivalent HPV vaccine (HPV types 6, 11, 16, 18)
b: placebo = aluminium hydroxyphosphate sulphate adjuvant