Secular changes in NSAID use and invasive colorectal cancer incidence: an ecological study.

In this exploratory ecological project, we sought to describe trends in NSAID use over time and trends in CRC incidence over time in order to inform the plausibility of the hypothesis that secular decreases in CRC incidence observed over the last 20 years are causally related to secular increases in NSAID use by the population. We hypothesized that an increase in NSAID use by the population would need to precede any fall in CRC incidence by six to ten years to be consistent with an NSAID mediated risk reduction as this was the induction period Chan et al found in their cohort studies of NSAID and/or aspirin use and subsequent CRC diagnoses. PMC ID: PMC2629139 (July 2008)