Background: There is no agreed definition of 'difficult asthma' or what investigations should be available to investigate these patients. Patients with difficult asthma remain symptomatic on high levels of treatment and are high users of medical resources.
Aim: To develop a set of quality indicators for the definition and investigation of difficult asthma.
Method: Modified RAND Appropriateness Method was used. An expert panel composed of nine hospital asthma specialists who run 'difficult' asthma clinics and were identified from a short list of key workers in the field. Indicators were rated as necessary to define and investigate difficult asthma.
Results: Difficult asthma was defined as 'symptoms persisting beyond therapy consistent with step 4 of the British Thoracic Society (BTS) guidelines' (high dose inhaled corticosteroids and long acting beta(2)-agonists). Eighty-three indicators were identified (40 relating to definition and 43 relating to investigations). Of these 32 (39%) were rated as necessary: 7 out of 40 (18%) for defining difficult asthma and 23 out of 43 (53%) for investigations. Indicators of high medical resource usage were characteristic of the 'difficult' nature of the management of patient with difficult asthma. A framework for the investigation of these patients was created.
Conclusion: The listed performance indicators identify a range of requirements that are necessary to define difficult asthma. Targeting of real needs in this group of patients will lead to better patient care and reduction of 'waste' in provision of healthcare.