This is an inception cohort study that analyses data from an administrative medical records database. The two inception cohorts are: 1) patients initiated on intranasal FP and 2) patients initiated on another INS (not FP). The candidates for the inception cohorts did not use any intranasal steroid in the year prior to initiation.

Inclusion Criteria:

• Patient records dated between January 1990 - January 2002 were used to develop the overall study cohort. The cohort was composed of the following patients:

  1. All patients with at least one prescription for Flixonase
  2. A random sample of patients having at least one prescription for an INS other than Flixonase

Exclusion Criteria:

Patient-level exclusion

• Patients with less than 180 days of continuous eligibility before index date
• Patients who are under four years of age at index date
• Patients who are older than 85 years of age at index date

Episode-level exclusion

-When patient history was divided into Flixonase or other INS use episodes, patients with less than 120 days of eligibility after the last prescription in the episode Patients with an event of interest 180 days prior to patients' entry into the cohort or anytime prior to an episode index date were automatically excluded from the analysis of that event. This exclusion criterion was applied to rule out prevalent conditions.

The General Practice Research Database (GPRD). Patient records dated between January 1990 - January 2002 were used to develop the overall study cohort.