How do you grade asthma severity in a patient who meets criteria for both mild and moderate asthma?

Grading Asthma Severity When Criteria for Both Mild and Moderate Asthma Are Present

When a patient meets criteria for both mild and moderate asthma, they should be classified according to their most severe category of impairment or risk, which means they should be graded as having moderate asthma. 1

Understanding Asthma Classification Principles

Asthma severity classification is based on two key domains:

1. Impairment domain: Assesses current symptom frequency, nighttime awakenings, rescue medication use, activity limitations, and lung function
2. Risk domain: Evaluates likelihood of exacerbations, decline in lung function, and medication side effects

When evaluating patients with mixed presentations, follow these principles:

• Assign severity to the most severe category in which any feature occurs 2, 1
• Focus on the highest-impact features that affect morbidity, mortality, and quality of life
• Consider both current impairment and future risk factors

Algorithm for Classification When Criteria Overlap

1. Identify all relevant parameters:

   • Symptom frequency
   • Nighttime awakenings
   • Short-acting β2-agonist use
   • Activity limitations
   • Lung function (FEV1, FEV1/FVC)
   • Exacerbation history

2. Apply the "most severe feature" rule:

   • If ANY parameter falls into the moderate category, classify as moderate asthma
   • Example: A patient with symptoms ≤2 days/week (mild) but nighttime awakenings 3-4 times/month (moderate) should be classified as moderate asthma 1

3. Prioritize risk domain over impairment when they differ:

   • If a patient has ≥2 exacerbations requiring oral corticosteroids in the past year, they should be classified as having at least moderate persistent asthma regardless of current symptom control 1

Specific Classification Criteria

According to the National Asthma Education and Prevention Program guidelines 1:

Component	Mild Persistent	Moderate Persistent
Symptoms	>2 days/week but not daily	Daily
Nighttime awakenings	3-4 times/month	>1 time/week but not nightly
SABA use	>2 days/week but not daily	Daily
Activity limitation	Minor limitation	Some limitation
Lung function	FEV1 >80% predicted	FEV1 >60% but <80% predicted
	FEV1/FVC normal	FEV1/FVC reduced 5%
Exacerbations	0-1/year requiring oral steroids	≥2/year requiring oral steroids

Common Pitfalls to Avoid

1. Underclassification error: Focusing only on the most prominent symptoms while ignoring other parameters that indicate higher severity

   • Solution: Systematically evaluate all parameters

2. Overreliance on lung function: Some patients may have normal spirometry but significant symptoms or exacerbation risk

   • Solution: Consider both impairment and risk domains equally

3. Failure to consider exacerbation history: Past exacerbations are strong predictors of future risk

   • Solution: Always include exacerbation history in your assessment

4. Inconsistent classification over time: Changing classification without clear criteria

   • Solution: Use consistent parameters for ongoing assessment

Clinical Application Example

A 35-year-old patient presents with:

• Symptoms 2 days/week (mild)
• Nighttime awakenings 3 times/month (moderate)
• SABA use 2 days/week (mild)
• FEV1 85% predicted (mild)
• 1 exacerbation requiring oral steroids in past year (mild)

Classification: Moderate persistent asthma (based on nighttime awakenings falling in moderate category)

By consistently applying this approach, you ensure appropriate treatment intensity that addresses both current symptoms and future risk, ultimately improving patient outcomes related to morbidity, mortality, and quality of life.