Cost analysis of FeNO for asthma diagnosis in primary care in Germany.

Background: Measurement of the biomarker FeNO (fractionated exhaled nitric oxide) provides information on the degree of lung inflammation and can be used to support asthma diagnosis. The latest UK NICE asthma guideline (2017) recommends a diagnostic algorithm including FeNO, based on a cost-effectiveness analysis. In Germany FeNO testing is not yet reimbursed by the statutory health insurance (SHI) but endorsed in the national asthma guideline. Methods: To evaluate FeNO in primary care from SHI perspective, two diagnostic approaches were compared by modelling diagnostic accuracy and expected costs. The strategy according to the German guideline and the NICE diagnostic algorithm were transferred into decision trees. The probabilities used in the NICE cost-effectiveness analysis were inserted and supplemented by expert opinions on the underlying assumptions for Germany. Results: A base case was assumed for calculation of costs, in which 80% of the patients consult a general practitioner initially and 20% refer to a specialist. Further the case assumed a more frequent use of bronchial provocation instead of peak flow variability and a reimbursement of FeNO at 21.17 Euro per test. The resulting total sensitivity according to the German guideline is 78%, the total specificity 54% (PPV 53%, NPV 78%) and results in expected costs of 117.27 Euro. The UK NICE diagnosis algorithm transferred to Germany shows an overall sensitivity of 87%, specificity of 78% (PPV 73%, NPV 89%) and expected costs of 107.15 Euro. Conclusion: For the diagnosis of asthma, the strategy of the UK NICE guideline transferred to Germany is superior in terms of diagnostic accuracy and expected costs, up to a maximum price of 30 Euro per FeNO test.