Table 3. Estimates and Risk Differences in 90-Day Mortality by Surgeon and Hospital Volume for Each Emulated Target Triala.
| Variable | Surgeon volume 2/yb | Surgeon volume 5/y | Surgeon volume 18/y | Surgeon volume 25/y |
|---|---|---|---|---|
| Hospital: natural value | ||||
| Trial 1 | ||||
| Estimate, % (95% CI) | 7.9 (6.4 to 9.4) | 7.5 (5.9 to 9.5) | 6.6 (4.4 to 10.2) | 5.2 (2.7 to 10.9) |
| Risk difference (95% CI), percentage points | Reference | −0.3 (−2.1 to 1.9) | −1.2 (−4.5 to 3.0) | −2.6 (−5.7 to 3.2) |
| Hospital: 2/y | ||||
| Trial 2 | ||||
| Estimate, % (95% CI) | 11.0 (9.1 to 12.9) | 10.5 (7.5 to 14.4) | 9.3 (5.5 to 14.6) | 7.4 (3.7 to 14.7) |
| Risk difference (95% CI), percentage points | Reference | −0.4 (−2.6 to 2.5) | −1.7 (−5.7 to 3.4) | −3.6 (−7.6 to 3.5) |
| Trial 3 | ||||
| Estimate, % (95% CI) | 10.5 (8.9 to 12.4) | 10.2 (7.9 to 13.2) | 10.0 (7.6 to 13.3) | 9.7 (7.5 to 12.8) |
| Risk difference (95% CI), percentage points | Reference | −0.3 (−1.9 to 1.7) | −0.6 (−2.5 to 2.2) | −0.8 (−2.7 to 1.9) |
| Trial 4 | ||||
| Estimate, % (95% CI) | 10.0 (8.0 to 12.3) | 9.5 (7.2 to 12.9) | 9.1 (6.7 to 12.4) | 8.9 (6.6 to 12.2) |
| Risk difference (95% CI), percentage points | Reference | −0.5 (−1.9 to 1.6) | −0.8 (−2.5 to 1.3) | −1.1 (−2.7 to 1.1) |
| Hospital: 12/y | ||||
| Trial 2 | ||||
| Estimate, % (95% CI) | 6.8 (4.8 to 9.0) | 6.5 (5.1 to 8.3) | 5.7 (3.4 to 8.9) | 4.5 (2.1 to 9.3) |
| Risk difference (95% CI), percentage points | Reference | −0.3 (−2.1 to 1.4) | −1.1 (−4.0 to 2.2) | −2.3 (−5.1 to 2.2) |
| Trial 3 | ||||
| Estimate, % (95% CI) | 7.8 (6.3 to 9.3) | 7.5 (6.3 to 8.9) | 7.4 (6.1 to 8.8) | 7.2 (6.0 to 8.7) |
| Risk difference (95% CI), percentage points | Reference | −0.2 (−1.5 to 1.0) | −0.4 (−1.9 to 1.2) | −0.5 (−2.0 to 1.1) |
| Trial 4 | ||||
| Estimate, % (95% CI) | 7.9 (6.5 to 9.6) | 7.5 (6.3 to 9.0) | 7.3 (6.0 to 8.7) | 7.1 (5.9 to 8.6) |
| Risk difference (95% CI), percentage points | Reference | −0.4 (−1.6 to 1.0) | −0.6 (−2.1 to 0.8) | −0.8 (−2.3 to 0.7) |
| Hospital: 43/y | ||||
| Trial 2 | ||||
| Estimate, % (95% CI) | 6.8 (3.2 to 10.4) | 6.5 (3.1 to 10.4) | 5.7 (3.1 to 8.3) | 4.5 (2.2 to 7.2) |
| Risk difference (95% CI), percentage points | Reference | −0.3 (−1.9 to 1.5) | −1.1 (−4.7 to 1.6) | −2.3 (−6.0 to 1.4) |
| Trial 3 | ||||
| Estimate, % (95% CI) | 7.8 (6.4 to 9.4) | 7.6 (6.2 to 9.2) | 7.4 (6.3 to 8.7) | 7.2 (6.2 to 8.5) |
| Risk difference (95% CI), percentage points | Reference | −0.2 (−1.5 to 1.0) | −0.4 (−2.0 to 1.1) | −0.6 (−2.2 to 1.0) |
| Trial 4 | ||||
| Estimate, % (95% CI) | 8.0 (6.6 to 9.7) | 7.6 (6.4 to 9.3) | 7.4 (6.4 to 8.6) | 7.2 (6.3 to 8.4) |
| Risk difference (95% CI), percentage points | Reference | −0.4 (−1.6 to 1.0) | −0.6 (−2.4 to 0.8) | −0.8 (−2.5 to 0.7) |
a
Surgeon and hospital volumes indicate the number of operations performed per year.
b
The reference value is lowest-volume surgeon within each hospital volume category.