Anti-MAdCAM-1 Antibody (PF-00547659) for Active Refractory Crohn's Disease: Results of the OPERA Study

letter and to no invitation.Methods: Two multi-arm randomized controlled trials, one in males and one in females, were conducted.Screen-eligible males were randomly assigned to 1 of 4 groups: male-specific letter, unisex letter, standard CCC letter, and no invitation.Screen-eligible females were randomly assigned to 1 of 3 groups: unisex letter, standard CCC letter, and no invitation.Letters were sent in February 2014 and participants were followed for 5 months.The primary outcome was completion of a fecal occult blood test (FOBT) and the secondary outcome was uptake of any colorectal test (FOBT, flexible sigmoidoscopy, or colonoscopy) during follow-up.Multivariate regression models were created to examine the effect of letter type on screening participation in each of the trials.Results: 39,493 males and 35,824 females were included in the 2 trials.Among males, 6.5%, 6.1%, 5.4% and 1% of participants completed a FOBT in the male-specific, unisex, standard CCC letter and no invitation groups, respectively.Among females, 7.4%, 7.1% and 1.1% of participants completed a FOBT in the unisex, standard CCC letter and no invitation groups, respectively.In both trials, any mailed invitation was significantly more effective than no invitation (p<0.0001).In males, the male-specific letter was significantly more effective than the standard CCC letter for completion of a FOBT during follow-up (O.R.: 1.2, 95% C.I.: 1.1-1.4,p=0.002).In both trials, unisex letter was not significantly more effective than the standard letter for completion of a FOBT during follow-up (males: O.R.: 1.1, 95% C.I.: 1.0-1.3,p=0.05; females: O.R.: 1.0, 95% C.I.: 0.9-1.2,p=0.3).Results were similar for the uptake of any colorectal test.Conclusion: Tailored invitations developed using rigorous qualitative methods improved CRC screening participation.These findings provide quantitative evidence that high quality tailored invitations can be more effective than non-tailored invitations.Screening programs should consider using rigorous qualitative methods when developing correspondence.