Quarter | % change (95% CI) | p Value |
1 | −0.4 (−1.2 to 0.3) | 0.26 |
2 | −0.2 (−0.9 to 0.6) | 0.66 |
3 | 0.1 (−0.6 to 0.9) | 0.74 |
4 | 0.0 (−0.7 to 0.8) | 0.95 |
*Using fixed effects Poisson regression to model the number of mammograms. Models included fixed effects for each physician and indicators for study month as well as four indicator variables reflecting presence or absence of a colonoscopy adverse event in each of the four quarters before the month of interest. Models also include the number of patients assigned to the physician in that month, which serves as an offset variable allowing an interpretation of the dependent variable (number of mammograms) as a rate (number of mammograms per number of assigned patients).