When joint-yrs of use were fitted as a continuous variable, thus providing greater statistical power than the assessment bytertile of use, a significant increasing risk of 8% with each joint-yr of use was found (RR51.08, 95% CI 1.02–1.15; table 3). Thisestimate was unaltered when the analysis was restricted tonon-Maori subjects. The difference in AIC between the modelfitting joint-yrs of use as a continuous variable and that fittingtertiles of use was 2.23, indicating no clear discernment
between a threshold and continuous effect of cannabis useand risk of lung cancer.