This study has been conceived in the context of Health Outcomes Research where the outcomes of health interventions in routine clinical practice constitute the main objective of the research process. In the case of asthma in Spain, the investigators do not clearly know the use of resources generated by the patient with asthma, its impact on the effectiveness of the current approach of asthmatic patients and the overall efficiency of health interventions on asthmatic patients. This observational, retrospective and multicenter study aims to estimate the use of health care resources in managing patients with asthma and to determine the management of the disease in the usual clinical practice in Valencia Autonomous Region. The data will be obtained at primary care level from the Electronic Health Record SIA+GAIA data base and at hospital level from allergologists and pneumologists clinical records. The investigators plan to introduce 289 ambulatory patients followed-up in Primary or Specialized Care Services, older than 15 years of age, diagnosed of asthma at least one year before the beginning of the study. The inclusion period will be of 3 months and the retrospective data of 12 previous months of follow-up will be collected.