The importance of monitoring asthma and adjusting treatment according to control is a fundamental part of asthma management and many studies have demonstrated the benefits of achieving good control. Numerous tools can be used, including spirometry, inflammometry, airway hyper-responsiveness and validated questionnaires of asthma control and asthma-related quality of life. In practice, the clinician uses a combination of some (or none!) of these. However, the evidence of the utility of most of these is lacking, particularly in children. Studies that have been carried out are hampered by a number of constraints: first, there is no gold standard for asthma control. The Global Initiative for Asthma (GINA) definition of controlled, partially controlled or uncontrolled is often used.1 This is a composite measure, including symptoms, exacerbations and lung function, which was developed for adults and has not been validated in children. It is not universally used to assess the usefulness of monitoring strategies and a variety of end points, including exacerbations, symptom-free days (SFD), inhaled corticosteroid (ICS) dose and FEV₁, have been reported. Second, studies tend to evaluate each measure in isolation: lung function or measurement of exhaled nitric oxide (FeNO) versus standard care and so on and there is limited evidence as to how the various components of control should be integrated. Third, the term ‘standard care’ is also open to much interpretation. The BATMAN …