This is a retrospective observational study utilising anonymised individual patient clinical and prescribing information routinely collected by UK General Practitioners (GPs). This information will be observed for two years, one year pre and one year post- "Index Prescription Date" (IPD). The IPD is the date when a patient was first switched to any option of the step-3 asthma treatment regimen. The one year before the IPD is the baseline period and will be reviewed for risk factors and confounding factors. The one year after the IPD is the outcome period and will be observed to see the outcomes of the new treatment.

Inclusion Criteria:

1. Patients with a physician diagnosis of asthma who have stepped-up to any option of step-3 asthma treatment (trial therapy), and;
2. Patients with the trial therapy who have data in their records for at least one year for the baseline period and at least one year for the outcome period.

Exclusion Criteria:

1. Patients who were not prescribed with any option of step-3 treatment (the trial therapy) during the study period.
2. Patients treated with the trial therapy, but do not have data in their records for at least one year for the baseline period and at least one year for the outcome period.
3. Patients treated with long-acting anticholinergic drugs, either alone or in combination with other therapy.
4. Patients with a physician diagnosis of COPD with or without asthma.
5. Patients who have resolved from asthma; i.e. patients who were previously diagnosed as having asthma, have now been undiagnosed.

1. Patients with a physician diagnosis of asthma who have stepped-up to any option of step-3 asthma treatment (trial therapy), and;
2. Patients with the trial therapy who have data in their records for at least one year for the baseline period and at least one year for the outcome period.