Classifying Chronic Lower Respiratory Disease Events in Epidemiologic Cohort Studies

Area of Science:

• Respiratory Medicine
• Epidemiology
• Clinical Research Methodology

Background:

• Chronic lower respiratory diseases (CLRDs), including chronic obstructive pulmonary disease and asthma, affect 1 in 12 adults.
• Acute exacerbations of CLRDs are significant causes of illness and death.
• Accurate classification of CLRD cases and exacerbations is crucial for prevention research.

Purpose of the Study:

• To evaluate a protocol for identifying CLRD cases and exacerbations leading to emergency department (ED) visits or hospitalizations.
• To assess the feasibility, reproducibility, and performance of this protocol in general adult populations.

Main Methods:

• A protocol was developed for classifying CLRD cases and severe exacerbations through medical record review.
• Data were collected prospectively from the Hispanic Community Health Study/Study of Latinos and retrospectively from the Multi-Ethnic Study of Atherosclerosis.
• Exacerbations were categorized as "probable," "highly probable," or "definite" based on diagnostic criteria and treatment.

Main Results:

• The protocol demonstrated high agreement between independent reviewers (2-8% disagreement).
• Eighty-nine percent of records were confirmed as probable CLRD cases.
• A primary discharge diagnosis of CLRD was specific but insensitive for identifying exacerbations.

Conclusions:

• Protocol-based classification of medical records can effectively identify CLRD cases and severe exacerbations in population-based studies.
• This method can supplement and validate existing identification strategies for CLRD research.
• The findings support the use of this protocol in epidemiological studies and clinical trials.