Reid index

Reid Index is a medical measurement used primarily in the field of pulmonology to quantify the extent of chronic bronchitis in histological lung samples. Named after the British pathologist, James Reid, who first described it in 1956, the Reid Index is a ratio that compares the thickness of the mucous gland layer to the thickness of the wall between the epithelium and the cartilage in the bronchus.

Calculation

The Reid Index is calculated by measuring the thickness of the mucous gland layer (d) and the thickness of the wall between the epithelium and the cartilage (h). The formula for the Reid Index is d/h. The normal value for the Reid Index is less than 0.4. A Reid Index of greater than 0.4 is indicative of chronic bronchitis.

Clinical Significance

The Reid Index is used in the diagnosis of chronic bronchitis. Chronic bronchitis is a type of chronic obstructive pulmonary disease (COPD) characterized by a long-term cough with mucus. The Reid Index helps to quantify the extent of the disease and can be used to monitor the progression of the disease over time.

Limitations

While the Reid Index is a useful tool in the diagnosis and monitoring of chronic bronchitis, it has its limitations. The measurement is dependent on the quality of the histological sample and the accuracy of the measurements. Additionally, the Reid Index does not take into account other factors that may contribute to the symptoms of chronic bronchitis, such as inflammation or infection.

See Also

• Chronic bronchitis
• Chronic obstructive pulmonary disease
• James Reid (pathologist)