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. Author manuscript; available in PMC: 2010 Mar 3.
Published in final edited form as: Lancet. 2008 Sep 20;372(9643):1058–1064. doi: 10.1016/S0140-6736(08)61447-6

Figure 2.

Figure 2

FEV1/FVC ratio and asthma at age 22 years by age at first asthma diagnosis. FEV1/FVC ratio was adjusted for sex in a linear regression and the standardized residuals from the regression (z-scores) were saved and used as the outcome measure for this figure (a z-score of 1 represents one standard deviation from the group mean of zero). Age at first diagnosis was divided into three groups based on the questionnaire when the diagnosis was first reported: 2-6yrs, 8-11yrs and 13-16yrs. Newly Dx is first diagnosis of asthma and current symptoms at age 22 years, inactive is first diagnosis of asthma between 2 and 16 years with no symptoms at age 22 years, chronic is first diagnosis between 2 and 16 years with active symptoms at age 22 years, the none group never received a diagnosis of asthma during the study period. Age at diagnosis was significantly and linearly related to the FEV1/FVC ratio, p=0.009, among inactive and chronic asthmatics at age 22 years, after adjusting for asthma status and sex.