Risk Factors

Age The prevalence of chronic sinusitis varies with age. According to estimates from the National Center for Health Statistics, it occurs in 6 percent of people under age 18, 16.4 percent of those between ages 18 and 44, 18.5 percent of those age 45–64, and 15.4 percent of those over age 65 (NCHS, 1986). A similar age pattern was reported in Tucson (Lebowitz et al., 1975).

Allergy Allergic rhinitis is considered a common risk factor for both acute and chronic sinusitis (Slavin, 1989), but the proportion of chronic sinusitis for which it is the dominant factor is unknown. The NHANES data, analyzed by Gergen and Turkeltaub (1992), did not show a relationship between reported sinusitis and skin test reactivity.

Nonallergic factors that predispose an individual to sinusitis are upper respiratory infection, overuse of topical decongestants, hypertrophied adenoids, deviated nasal septum, nasal polys, nasal tumors, foreign bodies, cigarette smoke, swimming and diving, barotrauma, and dental extractions. Immunodeficiency syndromes, cystic fibrosis, bronchiectasis, and the immotile cilia syndrome can also be associated with chronic sinusitis.

CHRONIC BRONCHITIS

Chronic bronchitis is commonly defined by clinicians as a chronic productive cough, without a medically discernible cause, that is present more than half the time for 2 years (Snider, 1988). Epidemiologists define chronic bronchitis more precisely as a cough productive of phlegm for a total of 3 months per year for at least 2 years in a patient in whom other causes of chronic cough have been excluded (e.g., infection with Mycobacterium tuberculosis, carcinoma of the lung, chronic congestive heart failure; Snider, 1988). The major risk factor for chronic bronchitis is cigarette smoking. The prevalence of chronic bronchitis among nonsmokers rises from age 15 to 60, increasing from 7 to 18 percent; prevalence among smokers rises from 40 to 82 percent (Snider, 1988).

Figure 2-10 illustrates the overlap between asthma, chronic bronchitis, and emphysema (Snider, 1988). Asthma, by definition, is characterized by reversible airflow obstruction, although a few patients may develop unremitting airflow obstruction. Patients with chronic bronchitis may have partially reversible airflow obstruction (Snider, 1988). The term chronic obstructive pulmonary disease (COPD) is often used by doctors when adult patients have evidence of one or more of three diseases: chronic bronchitis, emphysema, and asthma.

The nonproportional Venn diagram in Figure 2-10 shows subsets of patients with chronic bronchitis, emphysema, and asthma in three overlapping



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