Risk factor analysis among men referred for possible acquired immune deficiency syndrome.

Responses to a lifestyle questionnaire among 13 patients with Kaposi's sarcoma and 18 with an opportunistic infection were compared with those of 29 symptom-free referred individuals. Odds ratios (OR) with 95% confidence limits were calculated as an estimate of risk. Significantly elevated odds ratios (P less than 0.05) were found for cigarette smoking (OR = 3.4), marijuana use (OR = 3.7), nitrite use (OR = 5.5), frequenting bathhouses (OR = 7.6), prior syphilis (OR = 3.4), and fist-rectal sexual practices (OR = 3.5). A response gradient for the risk estimates was found for marijuana use (OR = 2.7 for occasional, OR = 4.3 for frequent use); nitrites (OR = 4.0 for occasional; OR = 6.3 for frequent use); and prior syphilis (OR = 2.9 for one to two previous infections and 9.0 for three or more). We believe the evidence is now sufficient to recommend preventive practices which may reduce the male homosexual's risk for developing acquired immune deficiency syndrome, Kaposi's sarcoma, and/or opportunistic infections. These include cessation of cigarette smoking, marijuana use, and nitrite inhalation; reduction in number of anonymous sexual partners to decrease risk of sexually transmitted diseases; and avoidance of fisting.