Table 1. Surgeon volume and patient demographic characteristics, follow-up duration and survival.
| Surgeon volumea (N) | High (6) (⩾50) | Medium (4) (11–49) | Low (15) (⩽10) | Total (25) | Test, P-value |
|---|---|---|---|---|---|
| Age at diagnosis (years) | Spearman's rank | ||||
| N (%) | 2092 | 536 | 76 | 2704 | correlation |
| Mean (s.d.) | 58.6 (5.6) | 58.7 (5.7) | 58.5 (4.9) | 58.5 (5.6) | P=0.48 |
| Range | 41.3–81.0 | 49.2–84.9 | 41.4–72.9 | 41.3–84.9 | |
| Townsend deprivation score | ANOVA | ||||
| 1st quartile (most affluent) | 482 (23) | 167 (31) | 27 (36) | 676 (25) | P=0.001 |
| 2nd quartile | 553 (26) | 106 (20) | 11 (14) | 670 (25) | |
| 3rd quartile | 511 (24) | 142 (26) | 21 (28) | 674 (25) | |
| 4th quartile | 539 (26) | 118 (22) | 17 (22) | 674 (25) | |
| Missingb | 7 (0.3) | 3 (0.6) | 0 | 10 (0.4) | |
| Follow-up (years) | Spearman's rank | ||||
| N (%) | 2086 | 534 | 75 | 2696 | correlation |
| Median (IQR) | 3.0 (1.9–4.2) | 3.0 (1.5–4.2) | 3.1 (2.0–4.9) | 3.0 (1.8–4.2) | P<0.001 |
| Missingb | 6 (0.29) | 2 (0.37) | 1 (1.3) | 9 (0.33) | |
| Recurrence | Wilcoxin's rank sum | ||||
| N (%) | 87 (4.2) | 26 (4.9) | 5 (6.9) | 118 (4.4) | P=0.69 |
| All-cause mortality | Wilcoxin's rank sum | ||||
| N (%) | 146 (7.1) | 46 (8.6) | 11 (4.5) | 203 (7.5) | P=0.76 |
| Breast cancer mortality | Wilcoxin's rank sum | ||||
| N (%) | 86 (4.1) | 28 (5.2) | 6 (7.9) | 120 (4.4) | P=0.9996 |
ANOVA=analysis of variance; IQR=interquartile range.
All tumours N (%): 2704 (100), one patient with missing surgeon ID.
a
Surgeon volume analysed as a continuous variable.
b
Missing values not used in analyses.