Inclusion and exclusion criteria
| Inclusion criteria |
| Studies using any type of epidemiological design addressing the association between the prevalence rates of asthma and/or allergies and SEP |
| Exclusion criteria |
| Population |
| Mixed sample of children and adults if results were not presented separately |
| Objectives |
| Assessed biological aetiology of asthma or allergies (genomics, proteomics, transcriptomics or metabolomics) |
| Assessed severity, treatment or access to services of asthma or allergies |
| Type of articles |
| Experimental studies |
| Genetic analysis |
SEP: socioeconomic position.