Table 1 Selected design characteristics of studies included in an analysis of the relation between asthma and IPD
Study | Study design | Country | Sample size | Population age | IPD definition |
|---|---|---|---|---|---|
Talbot TR et al. (2005) | Case–control | USA | 6985 | 2–49 years | Isolation of S. pneumoniae from a normally sterile site |
James P. Watt et al. (2007) | Case–control | USA | 471 |  > 18 years | Isolation of S. pneumoniae from a normally sterile site |
Hjuler T et al. (2008) | Case–control | Denmark | 17,028 | 0–17 years | Isolation of S. pneumoniae from a normally sterile site |
Juhn YJ et al. (2008) | Case–control | USA | 522 | 2–64 years | Isolation of S. pneumoniae from a normally sterile site or pneumococcal pneumonia requiring all three criteria |
K. H. Yoo et al. (2009) | Case–control | USA | 438 | All ages | Isolation of S. pneumoniae from normally sterile body fluids |
Klemets P et al. (2010) | Case–control | Finland | 14,067 | 18–49 years | S. pneumoniae was isolated from blood and/or CSF |
Pilishvili T et al. (2010) | Case–control | USA | 3294 | 3–59 months | Isolation of Pneumococcus from a normally sterile site or a surveillance area resident |
Inghammar M et al. (2013) | Case–control | Sweden | 44,438 |  > 18 years | Isolation of S. pneumoniae from normally sterile body fluids |