The Risk Score for asthma Exacerbation (RSE) calculator evaluates an individual's risk of experiencing asthma exacerbation within six months by using their responses to five specific health-related criteria. Each criterion is assigned a score based on predefined risk factors, and these scores are summed to compute a total risk score. This total score is then interpreted to estimate the risk of future exacerbations.

The criteria evaluated are:

1. Body Mass Index (BMI)
2. Asthma Control Questionnaire-5 Score (ACQ-5)
3. Postbronchodilator FEV1 Percentage of Predicted Normal (% PN)
4. Reliever Use per Day
5. Global Initiative for Asthma Treatment Step

The scoring system assigns specific values to each category within these criteria:

- BMI:
  - >= 30: 14 points
  - < 30: 0 points

- Asthma Control Questionnaire-5 Score:
  - < 1.5: 0 points
  - 1.5-2.5: 7 points
  - >= 2.5: 13 points

- Postbronchodilator FEV1 % PN:
  - >= 90%: 0 points
  - 80-90%: 13 points
  - < 80%: 20 points

- Reliever Use per Day:
  - < 2: 0 points
  - 2-4: 11 points
  - >= 4: 26 points

- Global Initiative for Asthma Treatment Step:
  - Step 3: 0 points
  - Step 4: 27 points

To compute the risk score, the user-provided input for each criterion is translated into its corresponding score using the above definitions. All the individual scores are then summed to produce a total risk score ranging from 0 to 100.

The interpretation of the total score is as follows:

- Score 0-10: Risk of exacerbation in 6 months is 5%
- Score 11-20: Risk of exacerbation in 6 months is 5-7%
- Score 21-30: Risk of exacerbation in 6 months is 7-10%
- Score 31-40: Risk of exacerbation in 6 months is 10-12%
- Score 41-50: Risk of exacerbation in 6 months is 12-15%
- Score 51-60: Risk of exacerbation in 6 months is 15-18%
- Score 61-70: Risk of exacerbation in 6 months is 18-24%
- Score 71-80: Risk of exacerbation in 6 months is 24-30%
- Score 81-90: Risk of exacerbation in 6 months is 30-37%
- Score 91-100: Risk of exacerbation in 6 months is 37-45%

The Risk Score for Asthma Exacerbation (RSE) is a clinical calculator used to predict the risk of severe asthma exacerbations in patients diagnosed with asthma. This scoring system is particularly useful in identifying patients who are at a higher risk of experiencing severe asthma attacks, thereby aiding clinicians in tailoring treatment plans and preventive measures to reduce the risk of exacerbations. The RSE includes factors such as patient's age, history of previous severe exacerbations, current use of oral corticosteroids, and hospitalization or emergency department visits due to asthma in the past year. It is not applicable to patients without a confirmed diagnosis of asthma.