Change in quarterly number of colonoscopies among physicians’ patients following an adverse colonoscopy event among a physician’s patient
| % change (95% CI)* | p Value* | |
| Primary model | ||
| Quarter 1 | −0.7 (−2.0 to 0.7) | 0.34 |
| Quarter 2 | −2.1 (−3.4 to −0.8) | 0.002 |
| Quarter 3 | −0.9 (−2.3 to 0.4) | 0.18 |
| Quarter 4 | 0.0 (−1.4 to 1.4) | 1.00 |
| Model stratified by patient age (above/below 75 years)† | ||
| Patients 65–75 years | ||
| Quarter 1 | −0.1 (−2.5 to 2.3) | 0.91 |
| Quarter 2 | −4.3 (−6.6 to −2.0) | <0.001 |
| Quarter 3 | −1.1 (−3.6 to 1.4) | 0.39 |
| Quarter 4 | −1.6 (−4.0 to 0.9) | 0.21 |
| Patients>75 years | ||
| Quarter 1 | −3.4 (−6.0 to −0.7) | 0.01 |
| Quarter 2 | −2.7 (−5.3 to −0.1) | 0.04 |
| Quarter 3 | −3.5 (−6.1 to −0.7) | 0.01 |
| Quarter 4 | −1.1 (−3.8 to 1.7) | 0.43 |
| Model stratified by physician experience (age above/below median)‡ | ||
| Physicians<50.2 years | ||
| Quarter 1 | −1.2 (−3.3 to 0.9) | 0.25 |
| Quarter 2 | −5.1 (−7.3 to −3.0) | <0.001 |
| Quarter 3 | −2.4 (−4.4 to −0.4) | 0.02 |
| Quarter 4 | −0.2 (−2.4 to 2.0) | 0.85 |
| Physicians≥50.2 years | ||
| Quarter 1 | −0.6 (−2.4 to 1.1) | 0.48 |
| Quarter 2 | −0.1 (−1.9 to 1.7) | 0.93 |
| Quarter 3 | 0.1 (−1.8 to 2.0) | 0.93 |
| Quarter 4 | −0.1 (−2.0 to 1.8) | 0.91 |
| Model including physicians’ patients and patients of other physicians in their practice (among 5513 practices with two or more physicians) | ||
| Physician | ||
| Quarter 1 | −0.8 (−2.5 to 0.8) | 0.31 |
| Quarter 2 | −2.6 (−4.1 to −1.1) | 0.001 |
| Quarter 3 | −1.0 (−2.6 to 0.7) | 0.25 |
| Quarter 4 | 0.8 (−0.9 to 2.4) | 0.37 |
| Physicians’ practice peers | ||
| Quarter 1 | 0.3 (−0.4 to 1.0) | 0.39 |
| Quarter 2 | 0.5 (−0.2 to 1.2) | 0.16 |
| Quarter 3 | 0.0 (−0.7 to 0.7) | 0.95 |
| Quarter 4 | 0.6 (0.0 to 1.3) | 0.07 |
Bolded values reflect statistical significance at two-sided p<0.05.
*Using fixed effects Poisson regression to model the number of colonoscopies. 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 colonoscopies) as a rate (number of colonoscopies per number of assigned patients).
†p for interaction=0.15.
‡p for interaction=0.007.