Erratum to: Long-term exposure to air pollution and the incidence of asthma: meta-analysis of cohort studies

Erratum to: Air Qual Atmo Health

DOI 10.1007/s11869-011-0144-5

We wish to correct the estimates for NO₂ and asthma incidence reported in the above paper. The original analysis was based on 13 studies, 2 of which reported only NO_x. We believed we had scaled these two NO_x estimates to NO₂ equivalents so that they could be included in the meta-analysis but have since discovered that this scaling was not implemented. The corrected estimates for the main meta-analysis and sensitivity analyses are given in a revised version of Table 2 presented below. Correcting for this error now gives a random effects estimate for NO₂ (10 μg/m³) and asthma incidence for the 13 studies of 1.15 (95 % CI 1.06 to 1.26) which compares with the estimate of 1.07 (95 % CI 1.02 to 1.13) previously reported. As in the original analysis there was some evidence of publication bias and correcting for this using the Trim and Fill technique reduced the revised estimate from 1.15 to 1.11. The conclusion drawn from the original analysis was that long term exposure to NO₂ is significantly associated with the incidence of asthma. This revised analysis strengthens this conclusion.

Table 2 Revised results. Cohort studies of air pollution and asthma incidence. Meta-analyses of associations between NO₂ per 10 μg/m³ and the incidence or lifetime prevalence of asthma or wheeze symptom