Geographical Differences of Risk of Asthma and Allergic Rhinitis according to Urban/Rural Area: a Systematic Review and Meta-analysis of Cohort Studies

AbstractSeveral studies have demonstrated an association between the risk asthma/allergic rhinitis and the environment. However, to date, no systematic review or meta-analysis has investigated these factors. We conducted a systematic review and meta-analysis to assess the association between urban/rural living and the risk of asthma and allergic rhinitis. We searched the Embase and Medline databases for relevant articles and included only cohort studies to observe the effects of time-lapse geographical differences. Papers containing information on rural/urban residence and respiratory allergic diseases were eligible for inclusion. We calculated the relative risk (RR) and 95% confidence interval (CI) using a 2 × 2 contingency table and used random effects to pool data. Our database search yielded 8388 records, of which 14 studies involving 50,100,913 participants were finally included. The risk of asthma was higher in urban areas compared to rural areas (RR, 1.27; 95% CI, 1.12–1.44,p< 0.001), but not for the risk of allergic rhinitis (RR, 1.17; 95% CI, 0.87 –1.59,p = 0.30). The risk of asthma in urban areas compared to rural areas was higher in the 0 –6 years and 0–18 years age groups, with RRs of 1.21 (95% CI, 1.01–1.46,p = 0.04) and 1.35 (95% CI, 1.12 –1.63,p = 0.002), respectively. However, there was no significant difference in the risk of asthma between urban and rural areas for children aged 0 –2 years, with a RR of 3.10 (95% CI, 0.44–21.56,p = 0.25)....
Source: Journal of Urban Health - Category: Health Management Source Type: research