On the 1996 questionnaire in both cohorts, participants were asked to to identify their blood type, be it A, B, AB or O and their Rh factor.

Rh factor? Rhesus (Rh) factor is an inherited trait that refers to a specific protein found on the surface of red blood cells. If your blood has the protein, you're Rh positive

The blood type given was validated through laboratory confirmation given by serological tests. Out of 98 subjects, 96 had self-reported and serologically tested for Rh factor.

SR blood type and ST results matched in 91% of participants while SR Rh type and ST results matched in 98% of participants.

It is evident that the difference between the theoretical and true data was not significant, referring to minimal percent error.

Aside from the validation, other risk factors were taken into consideration. In this study, there are referred to as covariates. A covariate is a variable that may affect the outcome of a clinical trial, either because it has a direct causal relationship to the outcome. These are as follows.

Body Mass Index (weekly physical activity was derived) Smoking status (current, past or never)Family history of pancreatic cancer and diabetes mellitus