Page 29 - ADULT-ONSET ASTHMA PREDICTORS OF CLINICAL COURSE AND SEVERITY

nonallergic phenotypes and these clusters were more prone to show a phenotype shi with regard to worsening asthma outcomes as compared to allergic clusters 67.
PREDICTORS OF UNCONTROLLED ASTHMA
The strongest predictors of uncontrolled asthma are smoking and uncontrolled asthma at baseline. A higher risk of developing uncontrolled asthma was observed in a 10-year follow- up of allergic rhini s pa ents with new-onset asthma who smoked. An increasing number of pack years gave an increased risk of uncontrolled asthma, with OR 13.4 (95% CI 4.6-39.2) for pa ents who had smoked > 10 pack years 60. Another important predictor of future asthma control is the current status of asthma control. In an 8-year follow-up study of 214 pa ents the distribu on of asthma control at baseline was signi cantly associated with asthma control at follow-up. The authors reported for par al asthma control at baseline a rela ve risk ra o (RRR) 2.7 and for no asthma control at baseline a RRR 7.7 for uncontrolled asthma at follow- up. Furthermore, women had a higher risk of uncontrolled asthma as compared to men (RRR 4.3). Chronic cough and phlegm produc on gave a RRR 3 for having uncontrolled asthma during follow-up 68. Several studies in general asthma popula ons reported similar predictors of poor future asthma control, such as signs of current uncontrolled asthma69-71 and smoking 70, 71, but also higher BMI 72.
PREDICTING ASTHMA EXACERBATIONS
Predictors of asthma exacerba ons have been evaluated in both cross-sec onal and follow- up studies, they include markers of in amma on, environmental triggers and asthma control status. In a 1 year follow-up study with strict recording of exacerba ons, Kupczyk et al. evaluated mul variate predictors of 2 or more exacerba ons and found frac on of exhaled nitric oxide >45 ppb (OR 4.3, 95%CI 1.0-18.3) and smoking (OR 2.9, 95% CI 1.1-7.4) as independent predictors. For 3 or more exacerba ons only smoking was a signi cant predictor with an OR 3.6 (95% CI 1.1-12) 73. Recently, we showed in a cohort of never smoking and (ex) smoking adult-onset asthma pa ents, di erent predictors of frequent exacerba ons in these two groups. In never smokers higher blood eosinophil counts were associated with frequent exacerba ons, whereas in (ex)smokers higher blood neutrophil counts and a higher dose inhaled cor costeroids were associated 74. This in line with several other studies in general asthma popula ons that found an associa on between blood or sputum eosinophils and exacerba ons in non-smokers 75-77. Whereas in pa ents with severe eosinophilic late-onset asthma apart from FeNO >50 ppb, also air trapping and sinus disease were predictors of frequent exacerba ons 78. Andersen et al. evaluated the e ect of long-term exposure to air pollu on on the risk of asthma hospitalisa on in pa ents 50 years or older in a popula on cohort study. The risk of hospital admission for asthma exacerba ons was posi vely associated with exposure to increasing concentra on of NO2 at their residences. Results were corrected for age, smoking status, tobacco exposure, occupa onal exposure, obesity and educa onal
THE PROGNOSIS OF ADULT-ONSET ASTHMA
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