Reid index:
Chapter: 12
A ratio that may be used to quantitate the degree of submucosal glandular hypertrophy and hyperplasia seen in patients with chronic bronchitis. The Reid index is the ratio of the thickness of the submucosal glands divided by the thickness of the bronchial wall (measured from the basement membrane to the innermost perichondrium). The Reid index normally is less than 0.4, but in chronic bronchitis the Reid index is increased, usually in proportion to the severity and duration of the disease.