In addition to providing a more accurate diagnosis, exhaled nitric oxide (NO) measurements can be used to assess the effectiveness of anti-inflammatory treatment and therefore the possibility for guiding the selection of therapy and improving dosage. While symptoms are a poor indicator of underlying inflammation, exhaled NO measurements are highly sensitive, and can be used to optimise treatment, and to predict and avoid relapses. The GOAL study (Gaining Optimal Asthma Control) indicated that total control of asthma led to better clinical outcomes and improved cost-effectiveness [Briggs 2006].

This suggests that improved control with regular exhaled NO monitoring will improve outcome and cost-effectiveness. This was confirmed by Smith et al who found that regular monitoring of NO levels in asthma patients led to the need for a reduction in steroid doses – up to a half in some cases – without loss of asthma control [Smith 2005].

In another study, it was found that regular exhaled NO measurements led to improved treatment of the patient. Although there is an extra cost involved in measuring NO, the authors concluded that these would be more than offset by cost savings due to reduced consumption of drugs, and to less frequent exacerbations. (Berg 2008) 

More detail on cost-effectiveness and reimbursement matters can be found in the Reimbursement section.