THE ASSOCIATION BETWEEN ORAL LEUKOPLAKIA AND USE OF TOBACCO, ALCOHOL AND KHAT BASED ON RELATIVE RISKS ASSESSMENT IN KENYA

A case-control study was conducted to determine the significance of to bacco, alcohol and khat (Catha edulis) chewing habits in the developme nt of oral leukoplakia among Kenyans aged 15 yr and over. In a house-t o-house survey, 85 cases and 141 controls matched for sex, age and clu ster origin was identified and compared for these risk factors. Smokin g unprocessed tobacco (Kiraiku) with a relative risk (RR) of 10.0 (95% confidence interval (CI)=2.9-38.4) and smoking cigarettes (RR=8.4; 95 % CI=4.1-17.4) were the most significant factors. While the RR associa ted with smoking cigarettes alone was 4.5 (95% CI=1.9-10.8), smoking o f both products (RR=15.2) suggested probable synergy or additive effec ts. Oral leukoplakia in 18 cases could not be attributed to smoking to bacco. Commercial beer, wines and spirits were relatively weak, but st atistically significant, risk factors. Traditional beer, khat and chil ies were not significantly associated with oral leukoplakia.