Table 1.

Inclusion and exclusion criteria

Inclusion criteria 1.Peer-reviewed quantitative studies reporting individual-level microbiology from upper respiratory tract samples 2.Participants presenting to a healthcare service or research team with a respiratory tract infection 3.Studies reporting raw data cross-tabulating one or more prognostic outcomes (e.g. illness duration, hospitalization) against respiratory tract infection-related upper respiratory tract microbes

Exclusion criteria 1.Microbiology results from lung, blood, urine or faecal samples 2.Microbiology presented as pooled data (as opposed to by individual microbe) 3.Study participants recruited from a population with a high prevalence of pre-existing disease or immune incompetence in whom microbe sampling/detection may differ from wider population 4.Studies of nosocomial infections 5.Full text not available in English 6.Recruitment in a non-OECD member [20] country