Influence of the practice setting on diagnostic prediction rules using FENO measurement in combination with clinical signs and symptoms of asthma.
Bottom Line: Increasing age and recurrent respiratory tract infections were negatively associated.The area under the curve (AUC) of FENO (AUC=0.650; 95% CI 0.599 to 0.701) increased significantly (p<0.0001) when combined with CSS (AUC=0.753; 95% CI 0.707 to 0.798).Ruling out with FENO <16 ppb in patients <43 years was only possible without allergic symptoms when recurrent respiratory tract infections were present.
Affiliation: Institute of General Practice, University Hospital Klinikum rechts der Isar, Technische Universität München, Munich, Germany.Show MeSH
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Mentions: Further subgroup models were defined dependent on the treatment of FENO measures as either exact numerical or dichotomised at cut-offs 10, 16, 40, 50, 60, 70 or 80 ppb. The resulting covariate effects estimated from the data are given in table 3 as βi, i=0, 1, …, k, where k is the number of covariates in the respective model. This allowed the predicted probability of asthma for individual patients to be calculated. Figure 2 illustrates that the diagnostic accuracy of FENO increases remarkably when the results are combined with CSS. The AUC differences were significant in general practice (p=0.001), pneumologists’ practice (p=0.0002) and in the combined sample (p<0.0001). Beyond that, the AUCs of the general practice sample were higher than in the pneumologists’ practice sample. Box 1 gives examples of using estimate covariate effects and equations from table 3 in order to calculate posterior predicted probabilities of asthma dependent on selected combinations of symptoms and FENO measurements. In principle, diagnostic trees with all possible posterior predicted probabilities of asthma can be derived from table 3. The results can be computed with the calculator that is added as a supplement.Box 1Derivation of probability test for asthma
Affiliation: Institute of General Practice, University Hospital Klinikum rechts der Isar, Technische Universität München, Munich, Germany.