How to diagnose Chronic Obstructive Airway Disease (COAD) in a 70-year-old patient with chronic cough and sputum production who is not willing to undergo a lung function test?

Clinical Diagnosis of COPD Without Spirometry

In a 70-year-old patient with chronic cough and sputum production who refuses spirometry, you can make a clinical diagnosis of chronic bronchitis (a form of COPD) based on the classic symptom definition: cough and sputum expectoration occurring on most days for at least 3 months per year for at least 2 consecutive years, after excluding other respiratory or cardiac causes. 1

Diagnostic Approach Without Lung Function Testing

Step 1: Confirm the Clinical Definition

• Document that the patient has chronic cough and sputum production occurring on most days for at least 3 months per year for at least 2 consecutive years 1
• This clinical definition alone establishes the diagnosis of chronic bronchitis when other causes are excluded 1

Step 2: Assess Risk Factors and Exposure History

• Smoking history is critical: A smoking history >40 pack-years has the highest likelihood ratio (LR 12) for identifying airflow obstruction 1
• Document exposure to cigarette, cigar, or pipe smoke, passive smoke, and occupational/environmental hazards 1
• Most patients with COPD are long-term cigarette smokers, typically over age 40 1

Step 3: Identify Key Clinical Predictors

The combination of three findings essentially confirms COPD (LR 156): 1

• Smoking history >55 pack-years
• Wheezing on auscultation during examination
• Patient self-reported wheezing

Importantly, the absence of all three of these findings practically rules out airflow obstruction (LR 0.02). 1

Step 4: Physical Examination Findings

Look for these specific signs that indicate airflow limitation: 1, 2

• Wheezing during tidal breathing (useful indicator of airflow limitation)
• Prolonged forced expiratory time >5 seconds (useful indicator)
• Diminished breath sounds
• Reduced ribcage expansion and diaphragmatic excursion
• Hyperresonance on percussion

For severe disease, look for: 1, 2

• Visible use of accessory muscles (sternomastoid)
• Pursed-lip breathing
• Central cyanosis (indicates significant hypoxemia)
• Weight loss and anorexia

Step 5: Exclude Other Causes

Rule out these alternative diagnoses: 1

• Pulmonary tuberculosis (already investigated and negative in your patient)
• Bronchiectasis (suggested by persistent large volumes of purulent sputum >30 mL/24h)
• Chronic asthma (distinguished by atopy, marked bronchodilator response if tested)
• Cardiac causes of chronic productive cough
• Lung cancer (especially if hemoptysis present)

Important Clinical Caveats

Limitations of Clinical Diagnosis

• Physical examination alone has poor sensitivity for detecting or excluding moderately severe COPD, and reproducibility of physical signs is variable 1, 2
• Physical signs are poor guides to severity of airflow limitation 1, 2
• The absence of wheezing or other physical signs does not exclude COPD 1, 2

When Clinical Diagnosis is Acceptable

While spirometry is the gold standard and required for definitive diagnosis 1, a clinical diagnosis of chronic bronchitis can be made based on symptoms alone when: 1

• The classic symptom definition is met (3 months/year for 2 consecutive years)
• Significant smoking history is present
• Other causes have been excluded
• The patient refuses or cannot perform spirometry

Severity Assessment Without Spirometry

Without lung function testing, assess severity clinically by: 1

• Breathlessness level: Mild disease has little/no breathlessness; moderate disease shows breathlessness on exertion; severe disease shows breathlessness on minimal exertion or at rest
• Frequency of respiratory infections: History of repeated infections, especially in winter 1
• Impact on daily activities: Use standardized questionnaires to assess exercise capacity 1
• Presence of complications: Peripheral edema, raised jugular venous pressure, hepatic enlargement (signs of cor pulmonale) 1

Practical Management Recommendation

Despite the patient's reluctance, continue to encourage spirometry at future visits, as it remains essential for confirming the diagnosis, assessing severity, and guiding treatment decisions. 1 However, do not delay initiating smoking cessation interventions and appropriate symptomatic treatment based on the clinical diagnosis. 1

The clinical diagnosis allows you to begin management (particularly smoking cessation, which is the most important intervention) while continuing to work toward obtaining objective spirometric confirmation. 1