Possible limitations of case–control studies should be considered when interpreting our results. Recall bias may be a problem in studies that query people about past events, although the effects of recall bias may have been diminished by requesting that participants report detailed alcohol consumption in multiple ways and over multiple time periods. Interviewers were highly trained and monitored to avoid interviewer bias and data were collected using a standardized questionnaire that included recent and past exposures. Because our results showed consistent trends between pancreatic cancer and dose and duration of alcohol exposure and, as noted earlier, underreporting would have diminished the risk estimates toward the null, recall bias may have had limited influence. Although rapid case ascertainment methods were used, similar to other population-based studies of pancreatic cancer, a large number of patients had died prior to initial contact due to the aggressive nature of the disease. The potential effect of these non-interviewed patients on risk estimates is unknown, as alcohol consumption data were not available for non-interviewed cases who died shortly after diagnosis. Our prior comparison of demographic data
