Background In children with asthma, web-based monitoring and inflammation-driven therapy may lead to improved asthma control and reduction in medications. However, the cost-effectiveness of these monitoring strategies is yet unknown.

Objective We assessed the cost-effectiveness of web-based monthly monitoring and of 4-monthly monitoring of FE_NO as compared with standard care.

Methods An economic evaluation was performed alongside a randomised controlled multicentre trial with a 1-year follow-up. Two hundred and seventy-two children with asthma, aged 4–18 years, were randomised to one of three strategies. In standard care, treatment was adapted according to Asthma Control Test (ACT) at 4-monthly visits, in the web-based strategy also according to web-ACT at 1 month intervals, and in the FE_NO-based strategy according to ACT and FE_NO at 4-monthly visits. Outcome measures were patient utilities, healthcare costs, societal costs and incremental cost per quality-adjusted life year (QALY) gained.

Results No statistically significant differences were found in QALYs and costs between the three strategies. The web-based strategy had 77% chance of being most cost-effective from a healthcare perspective at a willingness to pay a generally accepted €40 000/QALY. The FE_NO-based strategy had 83% chance of being most cost-effective at €40 000/QALY from a societal perspective.

Conclusions Economically, web-based monitoring was preferred from a healthcare perspective, while the FE_NO-based strategy was preferred from a societal perspective, although in QALYs and costs no statistically significant changes were found as compared with standard care. As clinical outcomes also favoured the web-based and FE_NO-based strategies, these strategies may be useful additions to standard care.

Trial registration number Netherlands Trial Register (NTR1995).