What is the prevalence and management of chronic respiratory diseases such as Chronic Obstructive Pulmonary Disease (COPD) and asthma?

Prevalence and Management of Chronic Respiratory Diseases

Global Prevalence

Asthma is the most prevalent chronic respiratory disease worldwide, affecting 358 million people globally as of 2015, with twice as many cases as COPD. 1

Key Prevalence Data

Asthma:

• Global prevalence increased 13% from 1990 to 2015, reaching over 358 million persons 1
• In the United States (2010): 26 million persons total—19 million adults (≥18 years) and 7 million children (≤17 years) 1
• Prevalence is higher among children than adults 1
• Higher prevalence among multiple-race, Black, and American Indian/Alaska Native persons compared to White persons 1
• 262.4 million prevalent cases globally in 2019 2

COPD:

• 212.3 million prevalent cases globally in 2019 2
• Third leading cause of death worldwide in 2017, accounting for 7.0% of all deaths 3
• 3.9 million deaths in 2017, representing an 18% increase since 1990 3
• Fourth leading cause of death in North America 1
• In 2019, COPD was responsible for 3.3 million deaths globally 2

Combined Chronic Respiratory Diseases:

• 544.9 million people affected worldwide in 2017, a 39.8% increase from 1990 3
• Total deaths from CRDs: 4.0 million in 2019 2
• Despite absolute increases, age-standardized death rates decreased by 42.6% and DALY rates by 38.2% from 1990 to 2017 3

Geographic Variations

Highest prevalence rates occur in high-income regions for both males and females, while the lowest prevalence is found in sub-Saharan Africa and south Asia. 3

• South Asia has the highest mortality rates from CRDs despite lower absolute prevalence 3
• Low and low-middle SDI countries have the highest age-standardized death and DALY rates 2
• High SDI countries have the highest prevalence rates but lower mortality 2

Diagnosis

COPD Diagnosis

Spirometry is required to make the diagnosis of COPD; a post-bronchodilator FEV1/FVC <0.70 confirms the presence of persistent airflow limitation. 1

Clinical presentation warranting evaluation:

• Dyspnea (chronic and progressive—the most characteristic symptom) 1
• Chronic cough (often the first symptom, frequently discounted by patients) 1
• Sputum production (regular production for ≥3 months in 2 consecutive years defines chronic bronchitis) 1
• History of exposure to risk factors (smoking, occupational exposures, biomass fuel) 1
• Wheezing and chest tightness 1

Essential medical history components:

• Smoking history and occupational/environmental exposures 1
• Past medical history including asthma, childhood respiratory infections 1
• Pattern of symptom development and exacerbation history 1
• Comorbidities (heart disease, osteoporosis, malignancies) 1
• Impact on quality of life, work productivity, and psychological status 1

Physical examination has limited diagnostic value—physical signs of airflow limitation are usually not identifiable until significantly impaired lung function is present. 1

Asthma Diagnosis

Asthma diagnosis and management require updated clinical practice guidelines, with the National Heart, Lung, and Blood Institute supporting systematic evidence reviews to update the 2007 Expert Panel Report 3. 1

Risk Factors

COPD Risk Factors

Smoking is the leading risk factor for COPD-related disability globally, followed by air pollution and occupational risks. 2

Major risk factors include:

• Tobacco smoking (cigarettes, pipe, cigar, water pipe, marijuana) 1
• Passive smoke exposure (environmental tobacco smoke) 1
• Occupational exposures (organic/inorganic dusts, chemical agents, fumes) 1
• Indoor air pollution from biomass cooking and heating in poorly ventilated dwellings 1
• Ambient particulate matter and ozone pollution 2
• Asthma (may be a risk for developing chronic airflow limitation) 1
• Severe childhood respiratory infections 1
• HIV infection (accelerates smoking-related emphysema) 1
• Tuberculosis 1
• Abnormal lung growth and development during gestation, birth, and childhood 1
• Non-optimal temperature 2

Asthma Risk Factors

For asthma, high body-mass index is an additional significant risk factor beyond smoking and air pollution. 2

Management Approach

COPD Management Goals

The goals of COPD assessment are to determine the level of airflow limitation, the impact on health status, and the risk of future events (exacerbations, hospitalizations, death) to guide therapy. 1

Key management principles:

• Smoking cessation is the priority intervention for reducing risk 1
• Concomitant chronic diseases occur frequently and must be treated as they independently affect mortality and hospitalizations 1
• Treatment can significantly improve quality of life and length of life despite the progressive nature of the disease 1

Pharmacologic Management

STIOLTO RESPIMAT (tiotropium/olodaterol combination) is indicated for long-term, once-daily maintenance treatment of COPD, including chronic bronchitis and/or emphysema, but is NOT indicated for acute deteriorations or asthma. 4

Important pharmacologic considerations:

• Long-acting beta-agonists (LABAs) when used as monotherapy without inhaled corticosteroids increase the risk of serious asthma-related events including death 4
• Patients should not use additional long-acting beta2-agonists when prescribed combination therapy 4
• Acute symptoms require treatment with short-acting beta2-agonists like albuterol, not maintenance medications 4
• Combination therapy (tiotropium/olodaterol) shows superior FEV1 response over 24-hour dosing intervals compared to individual components 4

Exacerbation Management

Tiotropium 5 mcg significantly reduces COPD exacerbations compared to placebo, with a rate ratio of 0.78 and delays time to first exacerbation with a hazard ratio of 0.69. 4

• COPD exacerbations are defined as lower respiratory events lasting ≥3 days requiring antibiotics, systemic steroids, and/or hospitalization 4
• RSV vaccination is recognized as an effective preventive measure in COPD patients 1
• Patients with COPD have RSV hospitalization rates 3.2 to 13.4 times higher than those without COPD 1

Asthma Management

Poorly controlled or uncontrolled asthma is common and associated with medical expenditures nearly $4,423 greater than those without asthma, with 4.6-fold greater hospital discharges and 2-fold greater emergency department visits. 1

• Total annual costs for medically treated asthma (including medical care, absenteeism, mortality) are estimated at $82 billion 1
• Updated clinical practice guidelines are crucial for treatment, control, and prevention of exacerbations 1

Clinical Pitfalls to Avoid

Do not diagnose COPD without objective spirometric confirmation—clinical examination alone is insufficient. 1, 5

Critical errors to avoid:

• Never rely solely on physical examination to rule out pneumonia in smokers with prolonged symptoms, as signs may be normal or non-specific 5
• Do not assume failed antibiotic treatment indicates only resistance; consider alternative diagnoses including malignancy 5
• Do not use STIOLTO RESPIMAT or other maintenance medications for acute symptom relief 4
• Never prescribe LABAs as monotherapy for asthma due to increased mortality risk 4
• Do not overlook comorbidities—they independently affect outcomes and must be managed concurrently 1

Regional Disparities and Future Burden

Low and low-middle income countries face the highest death and DALY rates from CRDs, highlighting urgent need for improved preventive, diagnostic, and therapeutic measures. 2

• By 2040, COPD is expected to reach the fourth leading cause of years of life lost globally 6
• Global strategies for tobacco control, air quality enhancement, occupational hazard reduction, and clean cooking fuels are crucial for reducing CRD burden 2
• Despite declining age-standardized rates, absolute numbers continue to rise due to population growth and aging 2, 3