Study Group | Nc | Stool Test | Colonoscopy | Any Screening Testb | |||
---|---|---|---|---|---|---|---|
% Screened | pd | % Screened | pd | % Screened | pd | ||
Control | 2,643 | 0.56 | — | 3.32 | — | 3.91 | — |
Card intervention | 7,213 | 4.11 | 0.000 | 4.62 | 0.005 | 8.64 | 0.000 |
Kit intervention | 407 | 6.92 | 0.000 | 0.20 | 0.000 | 7.13 | 0.003 |
a. We standardized the age-sex distributions of each study group to that of the July 1, 2008, estimated U.S. resident population (U.S. Census Bureau, 2009).
b. Includes stool test, colonoscopy, flexible sigmoidoscopy, or barium enema x ray. People with screens by multiple modalities are counted only once.
c. The number of age-standardized patients in each study group is lower than the total number of patients in each group due to missing age and sex data. There were 19 control patients with missing age data, 2 card-intervention patients with missing age data and 280 with missing sex data, and 63 kit-intervention patients with missing sex data.
d. We used a two-sample test of proportions to compare the control and card-intervention, and control and kit-intervention groups, respectively.